Target OpenGL 3.3 core profile (#1412)

Co-authored-by: MustafarYasmin <[email protected]>

README.MD

@@ -12,6 +12,14 @@
    * Complementary + Euphoria Patches is the primary compatibility target
    * Sildurs, Seus, and any other shaders might work
 
+## Core Profile
+Targets GL 3.3+ core profile
+* FFP emulation via generated GLSL shaders
+* Display list emulation
+* Software matrix stacks and state management through GLSM
+* GL_QUADS → GL_TRIANGLES conversion
+* Automatic transformation of mod shaders that use compat-only GLSL builtins (`gl_ModelViewMatrix`, `texture2D`, etc.)
+
 
 # Required Dependencies
 * [UniMixins](https://github.com/LegacyModdingMC/UniMixins/releases) >= 0.1.23
@@ -56,9 +64,9 @@
   * The [Iris](https://github.com/IrisShaders/Iris) Team: coderbot, IMS212, Justsnoopy30, FoundationGames
   * Asek3 for the Iris Forge port [Oculus](https://github.com/Asek3/Oculus/tree/839ce8eca8cf0c4f6b7a1322b906e5c99125ca69)
   * Backported code under the LGPL
-* Sodium
+* Sodium / Celeritas
   * JellySquid & the CaffeineMC team, for making Sodium in the first place
-  * Embeddedt for [Embeddium](https://github.com/embeddedt/embeddium/tree/dc59ca357c25beefd6288f0d1d40b4cd8e670ab8) under the [LGPL 3.0](https://github.com/embeddedt/embeddium/blob/16.x/forge/LICENSE)
+  * Embeddedt for Celeritas used under the LGPL 3.0
 * Reese's Sodium Options
   * FlashyReese for [Reese's Sodium Options](https://github.com/FlashyReese/reeses-sodium-options/tree/aa4ea67047cf53e54976e93c6bb1ab5ba16b142b) under the [MIT license](https://github.com/FlashyReese/reeses-sodium-options/blob/aa4ea67047cf53e54976e93c6bb1ab5ba16b142b/LICENSE.txt)
 * Neodymium
@@ -85,3 +93,8 @@
   * FalsePattern for [FalseTweaks](https://github.com/falsepattern/falsetweaks) - Item Rendering Optimizations taken from FalseTweaks under the LGPL 3.0 license
 * Beddium
   * Venn and Falsepattern for [Beddium](https://github.com/vfx-dev/Beddium) - MinimapRenderer, SafeChunkTracker, and some debug commands adapted under the LGPL 3.0 License
+* [Mesa](https://gitlab.freedesktop.org/mesa/mesa) — Code ported and/or inspired from Mesa - under the MIT licensed
+  * Display list ID allocator ported from [util_idalloc](https://gitlab.freedesktop.org/mesa/mesa/-/blob/main/src/util/u_idalloc.c) (Copyright 2017 Valve Corporation)
+  * FFP vertex shader generation inspired by ffvertex_prog.c (Copyright 2007 VMware, Inc.)
+  * FFP fragment shader generation inspired by ff_fragment_shader.c (Copyright 2007, 2009 VMware, Inc. / 2010-2011 Intel Corporation)
+  * Fog parameter optimization inspired by st_nir_lower_fog.c (Copyright 2023 Google LLC) and prog_statevars.c (Copyright 1999-2007 Brian Paul)

build.gradle.kts

@@ -1,3 +1,5 @@
+import xyz.wagyourtail.jvmdg.gradle.task.files.DowngradeFiles
+
 plugins {
     id("com.gtnewhorizons.gtnhconvention")
 }
@@ -45,6 +47,18 @@ tasks.register<Copy>("copyDependencies") {
 
 val embedOnly: Configuration by configurations
 
+// Downgrade embedOnly jars for the tests
+val downgradeEmbedOnlyForTest by tasks.registering(DowngradeFiles::class) {
+    inputCollection = embedOnly
+}
+
+tasks.test {
+    dependsOn(downgradeEmbedOnlyForTest)
+    classpath = classpath
+        .minus(embedOnly)
+        .plus(files(downgradeEmbedOnlyForTest.map { it.outputCollection }))
+}
+
 tasks.shadowJar {
     from(embedOnly.map(::zipTree))
     relocate("com.mitchej123", "com.mitchej123")

dependencies.gradle

@@ -53,6 +53,7 @@ configurations {
     embedOnly.canBeResolved = true
     compileClasspath.extendsFrom(embedOnly)
     testCompileClasspath.extendsFrom(embedOnly)
+    testRuntimeClasspath.extendsFrom(embedOnly)
 }
 
 
@@ -71,7 +72,7 @@ dependencies {
 
     // Iris Shaders
     compileOnly('org.jetbrains:annotations:26.0.2')
-    api("com.github.GTNewHorizons:GTNHLib:0.9.10:dev")
+    api("com.github.GTNewHorizons:GTNHLib:0.9.33:dev")
 
     shadowImplementation("org.anarres:jcpp:1.4.14") // Apache 2.0
     shadowImplementation("org.taumc:glsl-transformation-lib:0.2.0-26.g5ee7d96-GTNH") {
@@ -117,9 +118,8 @@ dependencies {
     compileOnly(rfg.deobf("curse.maven:security-craft-64760:2818228"))
     compileOnly(rfg.deobf("curse.maven:et-futurum-requiem-441392:5873837"))
 
-//    runtimeOnlyNonPublishable("com.github.GTNewHorizons:CoreTweaks:0.3.3.6-GTNH")
-    // For testing alternative splash screens, can be sourced from https://github.com/MalTeeez/ModernSplash/releases
-    //runtimeOnly(rfg.deobf(files("dependencies/modernsplash-1.7.10-1.2.2-dev.jar")))
+    // For testing alternative splash screens — https://github.com/MalTeeez/ModernSplash/releases
+    // devOnlyNonPublishable("com.github.MalTeeez:modernsplash:1.7.10-1.2.4:dev")
 
     // Hodgepodge
     transformedMod("net.industrial-craft:industrialcraft-2:2.2.828-experimental:dev")

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.2.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.3.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

repositories.gradle

@@ -22,5 +22,18 @@ repositories {
             includeGroup 'org.taumc'
         }
     }
+    ivy {
+        name = 'modernsplash-github'
+        url = 'https://github.com/MalTeeez/ModernSplash/releases/download/'
+        patternLayout {
+            artifact '[revision]/[module]-[revision](-[classifier]).[ext]'
+        }
+        content {
+            includeModule 'com.github.MalTeeez', 'modernsplash'
+        }
+        metadataSources {
+            artifact()
+        }
+    }
     mavenLocal()
 }

settings.gradle.kts

@@ -16,5 +16,5 @@ pluginManagement {
 }
 
 plugins {
-    id("com.gtnewhorizons.gtnhsettingsconvention") version("2.0.19")
+    id("com.gtnewhorizons.gtnhsettingsconvention") version("2.0.20")
 }

src/main/java/com/gtnewhorizons/angelica/client/font/BatchingFontRenderer.java

@@ -1,6 +1,7 @@
 package com.gtnewhorizons.angelica.client.font;
 
 import com.google.common.collect.ImmutableSet;
+import com.gtnewhorizon.gtnhlib.bytebuf.MemoryStack;
 import com.gtnewhorizon.gtnhlib.util.font.GlyphReplacements;
 import com.gtnewhorizons.angelica.config.FontConfig;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
@@ -12,8 +13,9 @@ import net.minecraft.client.gui.FontRenderer;
 import net.minecraft.util.MathHelper;
 import net.minecraft.util.ResourceLocation;
 import org.apache.commons.io.IOUtils;
+import org.joml.Matrix4f;
 import org.lwjgl.opengl.GL11;
-import org.lwjgl.opengl.GL13;
+import org.lwjgl.opengl.GL15;
 import org.lwjgl.opengl.GL20;
 
 import java.io.IOException;
@@ -24,7 +26,13 @@ import java.nio.charset.StandardCharsets;
 import java.util.Comparator;
 import java.util.Objects;
 
-import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.*;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryStack.stackPush;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAddress;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAlloc;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAllocFloat;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAllocInt;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memByteBuffer;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memRealloc;
 
 /**
  * A batching replacement for {@code FontRenderer}
@@ -49,8 +57,11 @@ public class BatchingFontRenderer {
 
     private final int AAMode;
     private final int AAStrength;
-    private final int texBoundAttrLocation;
+    private final int mvpMatrixLocation;
     private final int fontShaderId;
+    private static int fontVAO = 0;
+    private static int vboPositions, vboColors, vboTexCoords, vboTexBounds, vboIndices;
+    private static int capPositions, capColors, capTexCoords, capTexBounds, capIndices;
 
     final boolean isSGA;
     final boolean isSplash;
@@ -95,7 +106,7 @@ public class BatchingFontRenderer {
         fontShaderId = FontAAShader.getProgram().getProgramId();
         AAMode = GL20.glGetUniformLocation(fontShaderId, "aaMode");
         AAStrength = GL20.glGetUniformLocation(fontShaderId, "strength");
-        texBoundAttrLocation = GL20.glGetAttribLocation(fontShaderId, "texBounds");
+        mvpMatrixLocation = GL20.glGetUniformLocation(fontShaderId, "u_MVPMatrix");
     }
 
     // === Batched rendering
@@ -104,7 +115,7 @@ public class BatchingFontRenderer {
 
     private int vtxWriterIndex = 0;
     private int idxWriterIndex = 0;
-    private static final int INITIAL_BATCH_SIZE = 256;
+    private static final int INITIAL_BATCH_SIZE = 2048;
     private static final ResourceLocation DUMMY_RESOURCE_LOCATION = new ResourceLocation("angelica$dummy",
         "this is invalid!");
     private FloatBuffer batchVtxPositions = memAllocFloat(INITIAL_BATCH_SIZE * 2);
@@ -271,9 +282,21 @@ public class BatchingFontRenderer {
         }
     }
 
-    int lastActiveProgram;
-    int fontAAModeLast = -1;
-    int fontAAStrengthLast = -1;
+    private static int streamUpload(int target, int vbo, long address, int bytes, int cap) {
+        GL15.glBindBuffer(target, vbo);
+        final ByteBuffer data = memByteBuffer(address, bytes);
+        if (bytes > cap) {
+            GL15.glBufferData(target, data, GL15.GL_STREAM_DRAW);
+            return bytes;
+        }
+        GL15.glBufferData(target, cap, GL15.GL_STREAM_DRAW);
+        GL15.glBufferSubData(target, 0, data);
+        return cap;
+    }
+
+    private static final Matrix4f scratchMvp = new Matrix4f();
+    private int fontAAModeLast = -1;
+    private int fontAAStrengthLast = -1;
     private void flushBatch() {
         final int prevProgram = GLStateManager.glGetInteger(GL20.GL_CURRENT_PROGRAM);
 
@@ -291,11 +314,8 @@ public class BatchingFontRenderer {
         GLStateManager.tryBlendFuncSeparate(blendSrcRGB, blendDstRGB, GL11.GL_ONE, GL11.GL_ZERO);
         GLStateManager.glShadeModel(GL11.GL_FLAT);
 
-        final boolean canUseAA = FontConfig.fontAAMode != 0 && prevProgram == 0;
-        if (canUseAA) {
-            GL20.glVertexAttribPointer(texBoundAttrLocation, 4, false, 0, batchVtxTexBounds);
-            GL20.glEnableVertexAttribArray(texBoundAttrLocation);
-            lastActiveProgram = prevProgram;
+        final boolean useFontShader = prevProgram == 0;
+        if (useFontShader) {
             GLStateManager.glUseProgram(fontShaderId);
             if (FontConfig.fontAAMode != fontAAModeLast) {
                 fontAAModeLast = FontConfig.fontAAMode;
@@ -305,19 +325,56 @@ public class BatchingFontRenderer {
                 fontAAStrengthLast = FontConfig.fontAAStrength;
                 GL20.glUniform1f(AAStrength, FontConfig.fontAAStrength / 120.f);
             }
+            try (MemoryStack stack = stackPush()) {
+                final FloatBuffer mvpBuf = stack.mallocFloat(16);
+                GLStateManager.getProjectionMatrix().mul(GLStateManager.getModelViewMatrix(), scratchMvp);
+                scratchMvp.get(mvpBuf);
+                GL20.glUniformMatrix4(mvpMatrixLocation, false, mvpBuf);
+            }
         }
 
-        GL13.glClientActiveTexture(GL13.GL_TEXTURE0);
-        GL11.glTexCoordPointer(2, 0, batchVtxTexCoords);
-        GL11.glEnableClientState(GL11.GL_TEXTURE_COORD_ARRAY);
-        GL11.glColorPointer(4, GL11.GL_UNSIGNED_BYTE, 0, batchVtxColors);
-        GL11.glEnableClientState(GL11.GL_COLOR_ARRAY);
-        GL11.glVertexPointer(2, 0, batchVtxPositions);
-        GL11.glEnableClientState(GL11.GL_VERTEX_ARRAY);
+        if (fontVAO == 0) {
+            fontVAO = org.lwjgl.opengl.GL30.glGenVertexArrays();
+            vboPositions = GL15.glGenBuffers();
+            vboColors = GL15.glGenBuffers();
+            vboTexCoords = GL15.glGenBuffers();
+            vboTexBounds = GL15.glGenBuffers();
+            vboIndices = GL15.glGenBuffers();
+        }
+        GLStateManager.glBindVertexArray(fontVAO);
+
+        final int vtxCount = vtxWriterIndex;
+
+        // Location 0: position (vec2, float)
+        batchVtxPositions.position(0).limit(vtxCount * 2);
+        capPositions = streamUpload(GL15.GL_ARRAY_BUFFER, vboPositions, memAddress(batchVtxPositions), batchVtxPositions.remaining() * 4, capPositions);
+        GL20.glVertexAttribPointer(0, 2, GL11.GL_FLOAT, false, 0, 0L);
+        GL20.glEnableVertexAttribArray(0);
+
+        // Location 1: color (vec4, unsigned byte normalized)
+        batchVtxColors.position(0).limit(vtxCount * 4);
+        capColors = streamUpload(GL15.GL_ARRAY_BUFFER, vboColors, memAddress(batchVtxColors), batchVtxColors.remaining(), capColors);
+        GL20.glVertexAttribPointer(1, 4, GL11.GL_UNSIGNED_BYTE, true, 0, 0L);
+        GL20.glEnableVertexAttribArray(1);
+
+        // Location 2: texcoord0 (vec2, float)
+        batchVtxTexCoords.position(0).limit(vtxCount * 2);
+        capTexCoords = streamUpload(GL15.GL_ARRAY_BUFFER, vboTexCoords, memAddress(batchVtxTexCoords), batchVtxTexCoords.remaining() * 4, capTexCoords);
+        GL20.glVertexAttribPointer(2, 2, GL11.GL_FLOAT, false, 0, 0L);
+        GL20.glEnableVertexAttribArray(2);
+
+        // Location 3: texbounds (vec4, float)
+        batchVtxTexBounds.position(0).limit(vtxCount * 4);
+        capTexBounds = streamUpload(GL15.GL_ARRAY_BUFFER, vboTexBounds, memAddress(batchVtxTexBounds), batchVtxTexBounds.remaining() * 4, capTexBounds);
+        GL20.glVertexAttribPointer(3, 4, GL11.GL_FLOAT, false, 0, 0L);
+        GL20.glEnableVertexAttribArray(3);
+
+        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
         GLStateManager.glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
 
-        GL11.glDisableClientState(GL11.GL_NORMAL_ARRAY);
-        GL11.glNormal3f(0.0f, 0.0f, 1.0f);
+        // Stream upload index buffer
+        batchIndices.position(0).limit(idxWriterIndex);
+        capIndices = streamUpload(GL15.GL_ELEMENT_ARRAY_BUFFER, vboIndices, memAddress(batchIndices), batchIndices.remaining() * 4, capIndices);
 
         // Use plain for loop to avoid allocations
         final FontDrawCmd[] cmdsData = batchCommands.elements();
@@ -336,19 +393,14 @@ public class BatchingFontRenderer {
                 }
                 lastTexture = cmd.texture;
             }
-            batchIndices.limit(cmd.startVtx + cmd.idxCount);
-            batchIndices.position(cmd.startVtx);
 
-            GL11.glDrawElements(GL11.GL_TRIANGLES, batchIndices);
+            GL11.glDrawElements(GL11.GL_TRIANGLES, cmd.idxCount, GL11.GL_UNSIGNED_INT, (long) cmd.startVtx * 4L);
         }
-        if (canUseAA) {
-            GLStateManager.glUseProgram(lastActiveProgram);
-            GL20.glDisableVertexAttribArray(texBoundAttrLocation);
+        if (useFontShader) {
+            GLStateManager.glUseProgram(prevProgram);
         }
 
-        GL11.glDisableClientState(GL11.GL_TEXTURE_COORD_ARRAY);
-        GL11.glDisableClientState(GL11.GL_COLOR_ARRAY);
-        GL11.glDisableClientState(GL11.GL_VERTEX_ARRAY);
+        GLStateManager.glBindVertexArray(0);
 
         if (isTextureEnabledBefore) {
         	GLStateManager.glEnable(GL11.GL_TEXTURE_2D);
@@ -362,8 +414,11 @@ public class BatchingFontRenderer {
         batchCommands.clear();
         vtxWriterIndex = 0;
         idxWriterIndex = 0;
+        batchVtxPositions.limit(batchVtxPositions.capacity());
+        batchVtxColors.limit(batchVtxColors.capacity());
+        batchVtxTexCoords.limit(batchVtxTexCoords.capacity());
+        batchVtxTexBounds.limit(batchVtxTexBounds.capacity());
         batchIndices.limit(batchIndices.capacity());
-        batchIndices.position(0);
     }
 
     // === Actual text mesh generation
@@ -429,6 +484,7 @@ public class BatchingFontRenderer {
             boolean curUnderline = false;
 
             float glyphScaleY = getGlyphScaleY();
+            float glyphScaleX = getGlyphScaleX();
             float heightNorth = anchorY + (underlying.FONT_HEIGHT - 1.0f) * (0.5f - glyphScaleY / 2);
 
             final float underlineY = heightNorth + (underlying.FONT_HEIGHT - 1.0f) * glyphScaleY;
@@ -534,8 +590,8 @@ public class BatchingFontRenderer {
 
                 final float uStart = fontProvider.getUStart(chr);
                 final float vStart = fontProvider.getVStart(chr);
-                final float xAdvance = fontProvider.getXAdvance(chr) * getGlyphScaleX();
-                final float glyphW = fontProvider.getGlyphW(chr) * getGlyphScaleX();
+                final float xAdvance = fontProvider.getXAdvance(chr) * glyphScaleX;
+                final float glyphW = fontProvider.getGlyphW(chr) * glyphScaleX;
                 final float uSz = fontProvider.getUSize(chr);
                 final float vSz = fontProvider.getVSize(chr);
                 final float itOff = curItalic ? 1.0F : 0.0F; // italic offset

src/main/java/com/gtnewhorizons/angelica/client/font/FontProviderMC.java

@@ -28,16 +28,14 @@ public final class FontProviderMC implements FontProvider {
     public int[] charWidth;
 
     static {
+        MCFONT_ASCII_MAP.defaultReturnValue((short) -1);
         for (short i = 0; i < MCFONT_CHARS.length(); i++) {
             MCFONT_ASCII_MAP.put(MCFONT_CHARS.charAt(i), i);
         }
     }
 
     public int lookupMcFontPosition(char ch) {
-        if (isGlyphAvailable(ch)) {
-            return MCFONT_ASCII_MAP.get(ch);
-        }
-        return -1;
+        return MCFONT_ASCII_MAP.get(ch);
     }
 
     @Override

src/main/java/com/gtnewhorizons/angelica/client/gui/SliderClone.java

@@ -1,12 +1,12 @@
 package com.gtnewhorizons.angelica.client.gui;
 
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import lombok.AllArgsConstructor;
 import lombok.Setter;
 import lombok.experimental.Accessors;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.GuiButton;
 import net.minecraft.client.resources.I18n;
-import org.lwjgl.opengl.GL11;
 
 import java.util.function.Consumer;
 import java.util.function.Function;
@@ -123,7 +123,7 @@ public class SliderClone extends GuiButton {
                 this.displayString = displayStringFormatter.apply(f);
             }
 
-            GL11.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);
+            GLStateManager.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);
             this.drawTexturedModalRect(this.xPosition + (int)(this.sliderPercentage * (float)(this.width - 8)), this.yPosition, 0, 66, 4, 20);
             this.drawTexturedModalRect(this.xPosition + (int)(this.sliderPercentage * (float)(this.width - 8)) + 4, this.yPosition, 196, 66, 4, 20);
         }

src/main/java/com/gtnewhorizons/angelica/compat/ModStatus.java

@@ -11,7 +11,6 @@ import org.apache.logging.log4j.Logger;
 public class ModStatus {
     public static final Logger LOGGER = LogManager.getLogger("ModCompat");
 
-    public static BackhandReflectionCompat backhandCompat;
     public static boolean isBetterCrashesLoaded;
     public static boolean isNEIDLoaded;
     public static boolean isNEIDMetadataExtended;
@@ -27,9 +26,8 @@ public class ModStatus {
     public static boolean isBaublesLoaded;
     public static boolean isFluidLoggedLoaded;
 
-    public static void preInit(){
-        isBackhandLoaded = Loader.isModLoaded("backhand");
-        if(isBackhandLoaded) {
+    public static void preInit() {
+        if (Loader.isModLoaded("backhand")) {
             isBackhandLoaded = BackhandReflectionCompat.isBackhandLoaded();
         }
 

src/main/java/com/gtnewhorizons/angelica/compat/mojang/InteractionHand.java

@@ -2,6 +2,7 @@ package com.gtnewhorizons.angelica.compat.mojang;
 
 
 import com.gtnewhorizons.angelica.compat.ModStatus;
+import com.gtnewhorizons.angelica.compat.backhand.BackhandReflectionCompat;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.ItemStack;
 
@@ -9,14 +10,10 @@ public enum InteractionHand {
     MAIN_HAND,
     OFF_HAND;
 
-    InteractionHand() {
-    }
-
-    public ItemStack getItemInHand(EntityPlayer player){
-        if (ModStatus.isBackhandLoaded && this == InteractionHand.OFF_HAND){ // off hand (requires backhand)
-            return ModStatus.backhandCompat.getOffhandItem(player);
-        }
-        else { // main hand
+    public ItemStack getItemInHand(EntityPlayer player) {
+        if (ModStatus.isBackhandLoaded && this == InteractionHand.OFF_HAND) { // off hand (requires backhand)
+            return BackhandReflectionCompat.getOffhandItem(player);
+        } else { // main hand
             return player.getHeldItem();
         }
     }

src/main/java/com/gtnewhorizons/angelica/config/AngelicaConfig.java

@@ -112,7 +112,7 @@ public class AngelicaConfig {
     @Config.RequiresMcRestart
     public static boolean optimizeWorldUpdateLight;
 
-    @Config.Comment("Speedup Animations. [From Hodgepodge]")
+    @Config.Comment("Optimize Texture Animations. [From Hodgepodge]")
     @Config.DefaultBoolean(true)
     @Config.RequiresMcRestart
     public static boolean speedupAnimations;
@@ -235,4 +235,8 @@ public class AngelicaConfig {
     @Config.DefaultBoolean(false)
     public static boolean disableF3Additions;
 
+    @Config.Comment("Replaces various FFP uploads with statically allocated VBO's.")
+    @Config.DefaultBoolean(true)
+    public static boolean replaceFFPUploads;
+
 }

src/main/java/com/gtnewhorizons/angelica/debug/ChunkDebugMinimap.java

@@ -29,6 +29,7 @@ import cpw.mods.fml.common.eventhandler.SubscribeEvent;
 import lombok.Getter;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.multiplayer.ChunkProviderClient;
+import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.world.chunk.EmptyChunk;
 import net.minecraftforge.client.event.RenderGameOverlayEvent;
 import net.minecraftforge.common.MinecraftForge;
@@ -97,17 +98,18 @@ public class ChunkDebugMinimap {
         GLStateManager.enableBlend();
         GLStateManager.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
 
-        GLStateManager.glBegin(GL11.GL_QUADS);
+        final Tessellator tess = Tessellator.instance;
+        tess.startDrawingQuads();
 
         final ChunkProviderClient chunkProvider = (ChunkProviderClient) mc.theWorld.getChunkProvider();
 
         for (int x = playerChunkX - RANGE; x < playerChunkX + RANGE; x++) {
             for (int z = playerChunkZ - RANGE; z < playerChunkZ + RANGE; z++) {
-                drawChunk(x, z, playerChunkX, playerChunkZ, manager, chunkProvider);
+                drawChunk(tess, x, z, playerChunkX, playerChunkZ, manager, chunkProvider);
             }
         }
 
-        GL11.glEnd();
+        tess.draw();
 
         // Restore GL state
         GLStateManager.enableLighting();
@@ -117,7 +119,7 @@ public class ChunkDebugMinimap {
         GLStateManager.glPopAttrib();
     }
 
-    private void drawChunk(int chunkX, int chunkZ, int playerChunkX, int playerChunkZ, AngelicaRenderSectionManager manager, ChunkProviderClient chunkProvider) {
+    private void drawChunk(Tessellator tess, int chunkX, int chunkZ, int playerChunkX, int playerChunkZ, AngelicaRenderSectionManager manager, ChunkProviderClient chunkProvider) {
         boolean initialized = false;
         float r = 0, g = 0, b = 0;
 
@@ -143,16 +145,16 @@ public class ChunkDebugMinimap {
             }
         }
 
-        GL11.glColor4f(r, g, b, 0.8f);
+        tess.setColorRGBA_F(r, g, b, 0.8f);
 
         final int xStart = chunkX - playerChunkX;
         final int zStart = chunkZ - playerChunkZ;
         final int xEnd = xStart + 1;
         final int zEnd = zStart + 1;
 
-        GLStateManager.glVertex3d(xStart, zStart, 0);
-        GLStateManager.glVertex3d(xStart, zEnd, 0);
-        GLStateManager.glVertex3d(xEnd, zEnd, 0);
-        GLStateManager.glVertex3d(xEnd, zStart, 0);
+        tess.addVertex(xStart, zStart, 0);
+        tess.addVertex(xStart, zEnd, 0);
+        tess.addVertex(xEnd, zEnd, 0);
+        tess.addVertex(xEnd, zStart, 0);
     }
 }

src/main/java/com/gtnewhorizons/angelica/debug/F3Direction.java

@@ -1,5 +1,6 @@
 package com.gtnewhorizons.angelica.debug;
 
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.ScaledResolution;
 import net.minecraft.client.renderer.Tessellator;
@@ -10,31 +11,31 @@ import org.lwjgl.opengl.GL11;
 public class F3Direction {
     public static void renderWorldDirectionsEvent(Minecraft mc, RenderGameOverlayEvent.Pre event) {
         if (mc.gameSettings.showDebugInfo && mc.gameSettings.thirdPersonView == 0) {
-            ScaledResolution scaledresolution = new ScaledResolution(mc, mc.displayWidth, mc.displayHeight);
-            int width = scaledresolution.getScaledWidth();
-            int height = scaledresolution.getScaledHeight();
+            final ScaledResolution scaledresolution = new ScaledResolution(mc, mc.displayWidth, mc.displayHeight);
+            final int width = scaledresolution.getScaledWidth();
+            final int height = scaledresolution.getScaledHeight();
 
-            GL11.glPushMatrix();
+            GLStateManager.glPushMatrix();
 
-            GL11.glTranslatef((float) (width / 2), (float) (height / 2), -90);
+            GLStateManager.glTranslatef((float) (width / 2), (float) (height / 2), -90);
 
-            Entity entity = mc.renderViewEntity;
-            GL11.glRotatef(entity.prevRotationPitch + (entity.rotationPitch - entity.prevRotationPitch) * event.partialTicks, -1.0F, 0.0F, 0.0F);
-            GL11.glRotatef(entity.prevRotationYaw + (entity.rotationYaw - entity.prevRotationYaw) * event.partialTicks, 0.0F, 1.0F, 0.0F);
+            final Entity entity = mc.renderViewEntity;
+            GLStateManager.glRotatef(entity.prevRotationPitch + (entity.rotationPitch - entity.prevRotationPitch) * event.partialTicks, -1.0F, 0.0F, 0.0F);
+            GLStateManager.glRotatef(entity.prevRotationYaw + (entity.rotationYaw - entity.prevRotationYaw) * event.partialTicks, 0.0F, 1.0F, 0.0F);
 
-            GL11.glScalef(-1.0F, -1.0F, -1.0F);
+            GLStateManager.glScalef(-1.0F, -1.0F, -1.0F);
 
             renderWorldDirections();
 
-            GL11.glPopMatrix();
+            GLStateManager.glPopMatrix();
         }
     }
     public static void renderWorldDirections() {
-        GL11.glDisable(GL11.GL_TEXTURE_2D);
-        GL11.glDepthMask(false);
-        Tessellator tessellator = Tessellator.instance;
+        GLStateManager.disableTexture();
+        GLStateManager.glDepthMask(false);
+        final Tessellator tessellator = Tessellator.instance;
 
-        GL11.glLineWidth(2.0F);
+        GLStateManager.glLineWidth(2.0F);
         tessellator.startDrawing(GL11.GL_LINES);
 
         //X
@@ -54,8 +55,8 @@ public class F3Direction {
 
         tessellator.draw();
 
-        GL11.glLineWidth(1.0F);
-        GL11.glDepthMask(true);
-        GL11.glEnable(GL11.GL_TEXTURE_2D);
+        GLStateManager.glLineWidth(1.0F);
+        GLStateManager.glDepthMask(true);
+        GLStateManager.enableTexture();
     }
 }

src/main/java/com/gtnewhorizons/angelica/debug/F3Graph.java

@@ -1,44 +1,33 @@
 package com.gtnewhorizons.angelica.debug;
 
-import static org.lwjgl.opengl.GL11.GL_ALPHA_TEST;
-import static org.lwjgl.opengl.GL11.GL_BLEND;
-import static org.lwjgl.opengl.GL11.GL_CULL_FACE;
-import static org.lwjgl.opengl.GL11.GL_DEPTH_TEST;
-import static org.lwjgl.opengl.GL11.GL_FLOAT;
-import static org.lwjgl.opengl.GL11.GL_ONE_MINUS_SRC_ALPHA;
-import static org.lwjgl.opengl.GL11.GL_SRC_ALPHA;
-import static org.lwjgl.opengl.GL11.GL_TEXTURE_2D;
-import static org.lwjgl.opengl.GL11.GL_TRIANGLE_STRIP;
-import static org.lwjgl.opengl.GL11.GL_VERTEX_ARRAY;
-import static org.lwjgl.opengl.GL11.glBlendFunc;
-import static org.lwjgl.opengl.GL11.glColor4f;
-import static org.lwjgl.opengl.GL11.glDisable;
-import static org.lwjgl.opengl.GL11.glDisableClientState;
-import static org.lwjgl.opengl.GL11.glDrawArrays;
-import static org.lwjgl.opengl.GL11.glEnable;
-import static org.lwjgl.opengl.GL11.glEnableClientState;
-import static org.lwjgl.opengl.GL15.GL_ARRAY_BUFFER;
-import static org.lwjgl.opengl.GL15.GL_STATIC_DRAW;
-import static com.gtnewhorizons.angelica.glsm.GLStateManager.glBindBuffer;
-import static org.lwjgl.opengl.GL15.glBufferData;
-import static org.lwjgl.opengl.GL15.glGenBuffers;
-import static org.lwjgl.opengl.GL20.glDisableVertexAttribArray;
-import static org.lwjgl.opengl.GL20.glEnableVertexAttribArray;
-import static org.lwjgl.opengl.GL20.glUniform1;
-import static org.lwjgl.opengl.GL20.glUniform1f;
-import static org.lwjgl.opengl.GL20.glUniform1i;
-import static org.lwjgl.opengl.GL20.glVertexAttribPointer;
-import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryStack.*;
-
 import com.gtnewhorizon.gtnhlib.bytebuf.MemoryStack;
 import com.gtnewhorizon.gtnhlib.client.renderer.shader.ShaderProgram;
-import java.nio.FloatBuffer;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.FontRenderer;
 import net.minecraft.client.gui.ScaledResolution;
 import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.util.ResourceLocation;
 import org.lwjgl.BufferUtils;
+import org.lwjgl.opengl.GL30;
+
+import java.nio.FloatBuffer;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryStack.stackPush;
+import static com.gtnewhorizons.angelica.glsm.GLStateManager.glBindBuffer;
+import static org.lwjgl.opengl.GL11.GL_FLOAT;
+import static org.lwjgl.opengl.GL11.GL_ONE_MINUS_SRC_ALPHA;
+import static org.lwjgl.opengl.GL11.GL_SRC_ALPHA;
+import static org.lwjgl.opengl.GL11.GL_TRIANGLE_STRIP;
+import static org.lwjgl.opengl.GL15.GL_ARRAY_BUFFER;
+import static org.lwjgl.opengl.GL15.GL_STATIC_DRAW;
+import static org.lwjgl.opengl.GL15.glBufferData;
+import static org.lwjgl.opengl.GL15.glGenBuffers;
+import static org.lwjgl.opengl.GL20.glEnableVertexAttribArray;
+import static org.lwjgl.opengl.GL20.glUniform1;
+import static org.lwjgl.opengl.GL20.glUniform1f;
+import static org.lwjgl.opengl.GL20.glUniform1i;
+import static org.lwjgl.opengl.GL20.glVertexAttribPointer;
 
 public abstract class F3Graph {
     private static final int NUM_SAMPLES = 240;
@@ -63,6 +52,7 @@ public abstract class F3Graph {
     private int uHeadIdx;
     private int uSamples;
     private int vertBuf;
+    private int vao;
     private final ResourceLocation texture;
     private final float pxPerNs;
     private final boolean left;
@@ -117,8 +107,8 @@ public abstract class F3Graph {
             "shaders/debug_graph.frag.glsl");
         shader.use();
 
-        // Register attributes
-        aPos = shader.getAttribLocation("pos");
+        // Attribute location is declared in shader via layout(location = 0)
+        aPos = 0;
 
         // Register uniforms
         uFBWidth = shader.getUniformLocation("fbWidth");
@@ -129,7 +119,9 @@ public abstract class F3Graph {
         final int uPxPerNs = shader.getUniformLocation("pxPerNs");
         final int uLeft = shader.getUniformLocation("left");
 
-        // Load vertex buffer
+        vao = GL30.glGenVertexArrays();
+        GLStateManager.glBindVertexArray(vao);
+
         vertBuf = glGenBuffers();
         glBindBuffer(GL_ARRAY_BUFFER, vertBuf);
         try (final MemoryStack stack = stackPush()) {
@@ -146,7 +138,13 @@ public abstract class F3Graph {
 
             glBufferData(GL_ARRAY_BUFFER, vertices, GL_STATIC_DRAW);
         }
+
+        // Configure vertex attribute in the VAO
+        glVertexAttribPointer(aPos, VERT_FLOATS, GL_FLOAT, false, VERT_FLOATS * 4, 0);
+        glEnableVertexAttribArray(aPos);
+
         glBindBuffer(GL_ARRAY_BUFFER, 0);
+        GLStateManager.glBindVertexArray(0);
 
         final Minecraft mc = Minecraft.getMinecraft();
         final ScaledResolution sr = new ScaledResolution(mc, mc.displayWidth, mc.displayHeight);
@@ -186,21 +184,21 @@ public abstract class F3Graph {
 
         // Setup GL state
         final Tessellator tess = Tessellator.instance;
-        glDisable(GL_DEPTH_TEST);
-        glEnable(GL_ALPHA_TEST);
-        glEnable(GL_BLEND);
-        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+        GLStateManager.disableDepthTest();
+        GLStateManager.enableAlphaTest();
+        GLStateManager.enableBlend();
+        GLStateManager.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
         // Draw background
-        glDisable(GL_TEXTURE_2D);
-        glColor4f(0x50 / 255.0F, 0x50 / 255.0F, 0x50 / 255.0F, 0x90 / 255.0F);
+        GLStateManager.disableTexture();
+        GLStateManager.glColor4f(0x50 / 255.0F, 0x50 / 255.0F, 0x50 / 255.0F, 0x90 / 255.0F);
         tess.startDrawingQuads();
         for (int i = 0; i < 4; ++i) {
             tess.addVertex(getVertX(sr, i), getVertY(sr, i), 0);
         }
         tess.draw();
-        glColor4f(1.0F, 1.0F, 1.0F, 1.0F);
-        glEnable(GL_TEXTURE_2D);
+        GLStateManager.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);
+        GLStateManager.enableTexture();
 
 
         // Draw samples
@@ -213,21 +211,16 @@ public abstract class F3Graph {
         glUniform1i(uHeadIdx, samplesHead);
         glUniform1(uSamples, sampleBuf);
 
-        glBindBuffer(GL_ARRAY_BUFFER, vertBuf);
-        glEnableVertexAttribArray(aPos);
-        glVertexAttribPointer(aPos, VERT_FLOATS, GL_FLOAT, false, VERT_FLOATS * 4, 0);
-        glEnableClientState(GL_VERTEX_ARRAY);
+        GLStateManager.glBindVertexArray(vao);
 
         // Left side graphs are inverted, so temporarily disable culling
-        if (!left) glDisable(GL_CULL_FACE);
+        if (!left) GLStateManager.disableCull();
 
-        glDrawArrays(GL_TRIANGLE_STRIP, 0, VERT_COUNT);
+        GLStateManager.glDrawArrays(GL_TRIANGLE_STRIP, 0, VERT_COUNT);
 
-        if (!left) glEnable(GL_CULL_FACE);
+        if (!left) GLStateManager.enableCull();
 
-        glDisableClientState(GL_VERTEX_ARRAY);
-        glDisableVertexAttribArray(aPos);
-        glBindBuffer(GL_ARRAY_BUFFER, 0);
+        GLStateManager.glBindVertexArray(0);
 
         ShaderProgram.clear();
 
@@ -242,9 +235,9 @@ public abstract class F3Graph {
         tess.draw();
 
         // Reset GL state
-        glEnable(GL_DEPTH_TEST);
-        glDisable(GL_ALPHA_TEST);
-        glDisable(GL_BLEND);
+        GLStateManager.enableDepthTest();
+        GLStateManager.disableAlphaTest();
+        GLStateManager.disableBlend();
 
         // Draw text
         // Ensure running counters are reset on first sample

src/main/java/com/gtnewhorizons/angelica/dynamiclights/DynamicLights.java

@@ -6,6 +6,7 @@ import com.gtnewhorizon.gtnhlib.blockpos.IBlockPos;
 import com.gtnewhorizon.gtnhlib.util.CoordinatePacker;
 import com.gtnewhorizons.angelica.api.IDynamicLightProducer;
 import com.gtnewhorizons.angelica.compat.ModStatus;
+import com.gtnewhorizons.angelica.compat.backhand.BackhandReflectionCompat;
 import com.gtnewhorizons.angelica.compat.battlegear2.Battlegear2Compat;
 import com.gtnewhorizons.angelica.config.AngelicaConfig;
 import com.gtnewhorizons.angelica.dynamiclights.config.EntityLightConfig;
@@ -552,7 +553,7 @@ public class DynamicLights {
                     }
                 }
                 else if (ModStatus.isBackhandLoaded){
-                    ItemStack offhand = ModStatus.backhandCompat.getOffhandItem(player);
+                    ItemStack offhand = BackhandReflectionCompat.getOffhandItem(player);
                     if (offhand != null) {
                         luminance = Math.max(luminance, getLuminanceFromItemStack(offhand));
                     }

src/main/java/com/gtnewhorizons/angelica/glsm/AngelicaGLStateManagerService.java

@@ -160,7 +160,7 @@ public class AngelicaGLStateManagerService implements GLStateManagerService {
 
     @Override
     public void glDeleteVertexArrays(int array) {
-        UniversalVAO.deleteVertexArrays(array);
+        GLStateManager.glDeleteVertexArrays(array);
     }
 
     // ===================== BUFFER OPERATIONS =====================

src/main/java/com/gtnewhorizons/angelica/glsm/CompatShaderTransformer.java

@@ -0,0 +1,460 @@
+package com.gtnewhorizons.angelica.glsm;
+
+import net.minecraft.launchwrapper.Launch;
+import org.taumc.glsl.ShaderParser;
+import org.taumc.glsl.Transformer;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import static com.gtnewhorizons.angelica.loading.AngelicaTweaker.LOGGER;
+
+/**
+ * Compat transformation for mod shaders running under core profile.
+ *
+ * <p>Handles:
+ * <ul>
+ *   <li>Matrix builtin replacement (gl_ModelViewMatrix, gl_ProjectionMatrix, etc.)</li>
+ *   <li>Vertex attribute replacement (gl_Vertex, gl_Color, gl_MultiTexCoord0/1, gl_Normal)</li>
+ *   <li>gl_TexCoord[N] varying array → per-index in/out declarations</li>
+ *   <li>Texture function renames (texture2D → texture, etc.)</li>
+ *   <li>Fragment output handling (gl_FragColor → layout-qualified out declarations)</li>
+ *   <li>Fog builtins (gl_Fog, gl_FogFragCoord)</li>
+ *   <li>gl_FrontColor → local variable in vertex shaders</li>
+ *   <li>shadow2D/shadow2DLod → texture/textureLod with vec4 wrapping</li>
+ *   <li>Version upgrade to 330 core minimum</li>
+ *   <li>Reserved word pre-parse renaming (texture-as-variable, sample, etc.)</li>
+ * </ul>
+ */
+public class CompatShaderTransformer {
+
+    private static final Pattern VERSION_PATTERN =
+        Pattern.compile("#version\\s+(\\d+)(?:\\s+(\\w+))?");
+
+    private static final Pattern DEFINE_PATTERN =
+        Pattern.compile("^\\s*#\\s*define\\s+.+$", Pattern.MULTILINE);
+
+    /** Compat builtins that trigger AST transformation.  */
+    private static final Set<String> COMPAT_BUILTINS = Set.of(
+        "gl_ModelView", "gl_Projection", "gl_NormalMatrix", "gl_TextureMatrix",
+        "gl_FragColor", "gl_Fog", "gl_FrontColor", "gl_Color",
+        "gl_Vertex", "gl_MultiTexCoord", "gl_TexCoord", "gl_Normal", "ftransform",
+        "texture2D", "texture3D", "texelFetch2D", "texelFetch3D", "textureSize2D",
+        "shadow2D", "gl_FrontLightModelProduct",
+        "gl_LightSource", "gl_FrontMaterial"
+    );
+
+    private static final Pattern NEEDS_TRANSFORM_PATTERN = Pattern.compile(
+        String.join("|", COMPAT_BUILTINS) + "|\\b(?:attribute|varying)\\b"
+    );
+
+    private static final Map<String, String> MATRIX_RENAMES = Map.of(
+        "gl_ModelViewMatrix", "angelica_ModelViewMatrix",
+        "gl_ModelViewMatrixInverse", "angelica_ModelViewMatrixInverse",
+        "gl_ProjectionMatrix", "angelica_ProjectionMatrix",
+        "gl_ProjectionMatrixInverse", "angelica_ProjectionMatrixInverse",
+        "gl_NormalMatrix", "angelica_NormalMatrix"
+    );
+
+    private static final Path DUMP_DIR;
+    private static final AtomicInteger dumpCounter = new AtomicInteger(0);
+    static {
+        boolean isDev = false;
+        try {
+            final Object deobfEnv = Launch.blackboard != null ? Launch.blackboard.get("fml.deobfuscatedEnvironment") : null;
+            isDev = Boolean.TRUE.equals(deobfEnv);
+        } catch (Exception ignored) {}
+        DUMP_DIR = (isDev || Boolean.parseBoolean(System.getProperty("angelica.compat.dumpShaders", "false")))
+            ? Paths.get("compat_shaders") : null;
+    }
+
+    private static final int CACHE_SIZE = 32;
+    private record CacheKey(String source, boolean isFragment) {}
+    private static final Map<CacheKey, String> cache = Collections.synchronizedMap(
+        new LinkedHashMap<>(32, 0.75f, true) {
+            @Override protected boolean removeEldestEntry(Map.Entry<CacheKey, String> eldest) {
+                return size() > CACHE_SIZE;
+            }
+        });
+
+    public static void clearCache() {
+        cache.clear();
+    }
+
+    /**
+     * Transform a mod shader source for core profile compatibility.
+     */
+    public static String transform(String source, boolean isFragment) {
+        final boolean needsTransform = needsTransformation(source);
+        String result;
+        if (!needsTransform) {
+            result = fixupVersion(source);
+        } else {
+            final CacheKey key = new CacheKey(source, isFragment);
+            final String cached = cache.get(key);
+            if (cached != null) {
+                dumpShader(source, cached, isFragment, needsTransform);
+                return cached;
+            }
+
+            try {
+                result = transformInternal(source, isFragment);
+                cache.put(key, result);
+            } catch (Exception e) {
+                LOGGER.warn("CompatShaderTransformer: AST transformation failed, falling back to version fixup only", e);
+                result = fixupVersion(source);
+            }
+        }
+
+        dumpShader(source, result, isFragment, needsTransform);
+        return result;
+    }
+
+    private static boolean needsTransformation(String source) {
+        // Shaders already at 330+ core don't need compat transformation
+        final Matcher vm = VERSION_PATTERN.matcher(source);
+        if (vm.find()) {
+            final int version = Integer.parseInt(vm.group(1));
+            if (version >= 330 && "core".equals(vm.group(2))) return false;
+        }
+
+        return NEEDS_TRANSFORM_PATTERN.matcher(source).find();
+    }
+
+    private static String transformInternal(String source, boolean isFragment) {
+        final Matcher versionMatcher = VERSION_PATTERN.matcher(source);
+        int declaredVersion = 110;
+        if (versionMatcher.find()) {
+            declaredVersion = Integer.parseInt(versionMatcher.group(1));
+        }
+
+        final int targetVersion = Math.max(declaredVersion, 330);
+
+        // Pre-parse reserved word renaming — prevents ANTLR parse failures
+        source = GlslTransformUtils.replaceTexture(source);
+        source = GlslTransformUtils.renameReservedWords(source, targetVersion);
+
+        final ShaderParser.ParsedShader parsedShader = ShaderParser.parseShader(source);
+        final Transformer transformer = new Transformer(parsedShader.full());
+
+        injectMatrixUniforms(transformer);
+
+        transformFog(transformer, isFragment, source);
+
+        // gl_FrontLightModelProduct.sceneColor → angelica_SceneColor uniform
+        if (source.contains("gl_FrontLightModelProduct")) {
+            transformer.injectVariable("uniform vec4 angelica_SceneColor;");
+            transformer.replaceExpression("gl_FrontLightModelProduct.sceneColor", "angelica_SceneColor");
+        }
+
+        // gl_LightSource[i] → struct + uniform array (both via injectFunction to keep struct before uniform)
+        if (source.contains("gl_LightSource")) {
+            transformer.injectFunction(
+                "struct angelica_LightSourceParameters {"
+                + "vec4 ambient;vec4 diffuse;vec4 specular;vec4 position;vec4 halfVector;"
+                + "vec3 spotDirection;float spotExponent;float spotCutoff;float spotCosCutoff;"
+                + "float constantAttenuation;float linearAttenuation;float quadraticAttenuation;"
+                + "};");
+            transformer.injectFunction("uniform angelica_LightSourceParameters angelica_LightSource[2];");
+            transformer.rename("gl_LightSource", "angelica_LightSource");
+        }
+
+        // gl_FrontMaterial → struct + uniform (both via injectFunction to keep struct before uniform)
+        if (source.contains("gl_FrontMaterial")) {
+            transformer.injectFunction(
+                "struct angelica_MaterialParameters {"
+                + "vec4 emission;vec4 ambient;vec4 diffuse;vec4 specular;float shininess;"
+                + "};");
+            transformer.injectFunction("uniform angelica_MaterialParameters angelica_FrontMaterial;");
+            transformer.rename("gl_FrontMaterial", "angelica_FrontMaterial");
+        }
+
+        // gl_FrontColor (vertex) → gl_Color (fragment) varying chain
+        // Vertex side is unconditional: fragment may read gl_Color without vertex writing gl_FrontColor.
+        // Uses angelica_ prefix to avoid colliding with user-declared varyings (e.g. "v_Color").
+        if (!isFragment) {
+            transformer.injectVariable("out vec4 angelica_FrontColor;");
+            transformer.rename("gl_FrontColor", "angelica_FrontColor");
+            transformer.prependMain("angelica_FrontColor = vec4(1.0);");
+
+            // Vertex attributes — replaces removed FFP vertex inputs with explicit in declarations
+            transformVertexAttributes(transformer, source);
+        } else {
+            if (source.contains("gl_Color")) {
+                transformer.injectVariable("in vec4 angelica_FrontColor;");
+                transformer.rename("gl_Color", "angelica_FrontColor");
+            }
+        }
+
+        // gl_TexCoord[N] varying array → per-index in/out declarations
+        final Set<Integer> texCoordIndices = new HashSet<>();
+        transformer.renameArray("gl_TexCoord", "angelica_TexCoord", texCoordIndices);
+        for (Integer i : texCoordIndices) {
+            final String qualifier = isFragment ? "in" : "out";
+            transformer.injectVariable(qualifier + " vec4 angelica_TexCoord" + i + ";");
+        }
+
+        // Fragment output handling + alpha test discard
+        if (isFragment) {
+            transformFragmentOutputs(transformer);
+        }
+
+        // texture-as-variable collision handling
+        if (transformer.containsCall("texture") && transformer.hasVariable("texture")) {
+            transformer.rename("texture", "gtexture");
+        }
+        if (transformer.hasVariable("angelica_renamed_texture")) {
+            transformer.rename("angelica_renamed_texture", "gtexture");
+        }
+
+        transformer.renameFunctionCall(GlslTransformUtils.TEXTURE_RENAMES);
+
+        transformer.renameAndWrapShadow("shadow2D", "texture");
+        transformer.renameAndWrapShadow("shadow2DLod", "textureLod");
+
+        final String versionDirective = "#version " + targetVersion + " core\n";
+        final String extensions = VERSION_PATTERN.matcher(GlslTransformUtils.getFormattedShader(parsedShader.pre(), "")).replaceFirst("").trim();
+
+        // Preserve #define directives
+        final StringBuilder defines = new StringBuilder();
+        final Matcher defineMatcher = DEFINE_PATTERN.matcher(source);
+        while (defineMatcher.find()) {
+            defines.append(defineMatcher.group().trim()).append('\n');
+        }
+
+        final String header = versionDirective + (extensions.isEmpty() ? "" : "\n" + extensions) + (defines.isEmpty() ? "" : "\n" + defines);
+        final StringBuilder result = new StringBuilder();
+        transformer.mutateTree(tree -> result.append(GlslTransformUtils.getFormattedShader(tree, header)));
+
+        // Restore pre-parse renames
+        String output = GlslTransformUtils.restoreReservedWords(result.toString());
+
+        // Core profile: attribute → in, varying → out (vertex) / in (fragment)
+        output = fixupQualifiers(output, isFragment);
+
+        return output;
+    }
+
+    /**
+     * Inject matrix uniforms and rename compat builtins.
+     */
+    private static void injectMatrixUniforms(Transformer transformer) {
+        transformer.injectVariable("uniform mat4 angelica_ModelViewMatrix;");
+        transformer.injectVariable("uniform mat4 angelica_ModelViewMatrixInverse;");
+        transformer.injectVariable("uniform mat4 angelica_ProjectionMatrix;");
+        transformer.injectVariable("uniform mat4 angelica_ProjectionMatrixInverse;");
+        transformer.injectVariable("uniform mat3 angelica_NormalMatrix;");
+        transformer.injectVariable("uniform mat4 angelica_LightmapTextureMatrix;");
+
+        transformer.rename(MATRIX_RENAMES);
+
+        // Expression replacements
+        transformer.replaceExpression("gl_ModelViewProjectionMatrix", "(angelica_ProjectionMatrix * angelica_ModelViewMatrix)");
+        transformer.replaceExpression("gl_TextureMatrix[0]", "mat4(1.0)");
+        transformer.replaceExpression("gl_TextureMatrix[1]", "angelica_LightmapTextureMatrix");
+        transformer.replaceExpression("gl_TextureMatrix", "mat4[8](mat4(1.0), angelica_LightmapTextureMatrix, mat4(1.0), mat4(1.0), mat4(1.0), mat4(1.0), mat4(1.0), mat4(1.0))");
+    }
+
+    /**
+     * Transform fragment outputs for core profile.
+     */
+    private static void transformFragmentOutputs(Transformer transformer) {
+        if (transformer.containsCall("gl_FragColor")) {
+            transformer.replaceExpression("gl_FragColor", "gl_FragData[0]");
+        }
+
+        final Set<Integer> found = new HashSet<>();
+        transformer.renameArray("gl_FragData", "angelica_FragData", found);
+
+        for (Integer i : found) {
+            transformer.injectVariable("layout (location = " + i + ") out vec4 angelica_FragData" + i + ";");
+        }
+
+        // Core profile: GL_ALPHA_TEST is removed - inject runtime discard using GLSM-tracked alpha reference (uploaded by CompatUniformManager).
+        if (found.contains(0)) {
+            transformer.injectVariable("uniform float angelica_currentAlphaTest;");
+            transformer.appendMain("if (angelica_FragData0.a <= angelica_currentAlphaTest) discard;");
+        }
+    }
+
+    private static void transformFog(Transformer transformer, boolean isFragment, String source) {
+        // Vertex side is unconditional: fragment may read gl_FogFragCoord without vertex writing it
+        transformer.rename("gl_FogFragCoord", "angelica_FogFragCoord");
+        if (!isFragment) {
+            transformer.injectVariable("out float angelica_FogFragCoord;");
+            transformer.prependMain("angelica_FogFragCoord = 0.0;");
+        } else {
+            if (source.contains("gl_FogFragCoord")) {
+                transformer.injectVariable("in float angelica_FogFragCoord;");
+            }
+        }
+
+        transformer.rename("gl_Fog", "angelica_Fog");
+        transformer.injectVariable("uniform float angelica_FogDensity;");
+        transformer.injectVariable("uniform float angelica_FogStart;");
+        transformer.injectVariable("uniform float angelica_FogEnd;");
+        transformer.injectVariable("uniform vec4 angelica_FogColor;");
+        transformer.injectFunction("struct angelica_FogParameters {vec4 color;float density;float start;float end;float scale;};");
+        transformer.injectFunction(
+            "angelica_FogParameters angelica_Fog = angelica_FogParameters("
+            + "angelica_FogColor, angelica_FogDensity, angelica_FogStart, angelica_FogEnd, "
+            + "1.0 / (angelica_FogEnd - angelica_FogStart));");
+    }
+
+    /**
+     * Replace removed FFP vertex attributes with explicit {@code in} declarations at core profile attribute locations.
+     */
+    private static void transformVertexAttributes(Transformer transformer, String source) {
+        if (source.contains("gl_Vertex") || source.contains("ftransform")) {
+            transformer.injectVariable("layout(location = 0) in vec4 angelica_Vertex;");
+            transformer.rename("gl_Vertex", "angelica_Vertex");
+        }
+        // gl_Color in vertex shaders is the per-vertex color attribute, distinct from the fragment gl_Color (interpolated gl_FrontColor) handled above
+        if (source.contains("gl_Color")) {
+            transformer.injectVariable("layout(location = 1) in vec4 angelica_Color;");
+            transformer.rename("gl_Color", "angelica_Color");
+        }
+        if (source.contains("gl_MultiTexCoord0")) {
+            transformer.injectVariable("layout(location = 2) in vec4 angelica_MultiTexCoord0;");
+            transformer.rename("gl_MultiTexCoord0", "angelica_MultiTexCoord0");
+        }
+        if (source.contains("gl_MultiTexCoord1")) {
+            transformer.injectVariable("layout(location = 3) in vec4 angelica_MultiTexCoord1;");
+            transformer.rename("gl_MultiTexCoord1", "angelica_MultiTexCoord1");
+        }
+        if (source.contains("gl_Normal")) {
+            transformer.injectVariable("layout(location = 4) in vec3 angelica_Normal;");
+            transformer.rename("gl_Normal", "angelica_Normal");
+        }
+        if (source.contains("ftransform")) {
+            transformer.replaceExpression("ftransform()", "(angelica_ProjectionMatrix * angelica_ModelViewMatrix * angelica_Vertex)");
+        }
+    }
+
+    private static void dumpShader(String original, String transformed, boolean isFragment, boolean wasTransformed) {
+        if (DUMP_DIR == null) return;
+        final int id = dumpCounter.getAndIncrement();
+        final String suffix = isFragment ? ".frag.glsl" : ".vert.glsl";
+        try {
+            Files.createDirectories(DUMP_DIR);
+            // Capture caller info for identification
+            final String caller = identifyCaller();
+            final String header = "// Compat shader dump #" + id + " (" + (isFragment ? "fragment" : "vertex") + ")"
+                + "\n// Transformed: " + wasTransformed
+                + "\n// Caller: " + caller + "\n\n";
+            Files.writeString(DUMP_DIR.resolve(id + "_original" + suffix), header + original, StandardCharsets.UTF_8);
+            Files.writeString(DUMP_DIR.resolve(id + "_transformed" + suffix), header + transformed, StandardCharsets.UTF_8);
+        } catch (IOException e) {
+            LOGGER.warn("Failed to dump compat shader: {}", e.getMessage());
+        }
+    }
+
+    private static String identifyCaller() {
+        for (StackTraceElement frame : Thread.currentThread().getStackTrace()) {
+            final String cls = frame.getClassName();
+            if (!cls.startsWith("com.gtnewhorizons.angelica.glsm.")
+                && !cls.startsWith("java.")
+                && !cls.equals("org.lwjgl.opengl.GL20")) {
+                return cls + "." + frame.getMethodName() + ":" + frame.getLineNumber();
+            }
+        }
+        return "unknown";
+    }
+
+    private static final Pattern ATTRIBUTE_PATTERN = Pattern.compile("\\battribute\\b");
+    private static final Pattern VARYING_PATTERN = Pattern.compile("\\bvarying\\b");
+
+    /** Replace legacy storage qualifiers removed in core profile. Safe on AST-serialized output (no comments). */
+    public static String fixupQualifiers(String source, boolean isFragment) {
+        source = ATTRIBUTE_PATTERN.matcher(source).replaceAll("in");
+        source = VARYING_PATTERN.matcher(source).replaceAll(isFragment ? "in" : "out");
+        return source;
+    }
+
+    // Patterns for parsing fragment shader in declarations to generate passthrough vertex shaders
+    private static final Pattern FRAG_IN_COLOR = Pattern.compile("\\bin\\s+vec4\\s+angelica_FrontColor\\b");
+    private static final Pattern FRAG_IN_TEXCOORD = Pattern.compile("\\bin\\s+vec4\\s+angelica_TexCoord(\\d+)\\b");
+    private static final Pattern FRAG_IN_FOGCOORD = Pattern.compile("\\bin\\s+float\\s+angelica_FogFragCoord\\b");
+
+    /**
+     * Generate a passthrough vertex shader for a fragment-only program.
+     *
+     * @param fragmentSource the transformed fragment shader source
+     * @return a complete vertex shader source string
+     */
+    public static String generatePassthroughVertexShader(String fragmentSource) {
+        final StringBuilder sb = new StringBuilder(512);
+        sb.append("#version 330 core\n\n");
+
+        // Always have position
+        sb.append("layout(location = 0) in vec4 a_Position;\n");
+
+        // Matrix uniforms for position transform
+        sb.append("uniform mat4 angelica_ModelViewMatrix;\n");
+        sb.append("uniform mat4 angelica_ProjectionMatrix;\n");
+
+        final StringBuilder varyings = new StringBuilder();
+        final StringBuilder assignments = new StringBuilder();
+        if (FRAG_IN_COLOR.matcher(fragmentSource).find()) {
+            sb.append("layout(location = 1) in vec4 a_Color;\n");
+            varyings.append("out vec4 angelica_FrontColor;\n");
+            assignments.append("  angelica_FrontColor = a_Color;\n");
+        }
+
+        final Matcher texCoordMatcher = FRAG_IN_TEXCOORD.matcher(fragmentSource);
+        final Set<Integer> texCoordIndices = new HashSet<>();
+        while (texCoordMatcher.find()) {
+            texCoordIndices.add(Integer.parseInt(texCoordMatcher.group(1)));
+        }
+        for (int i : texCoordIndices) {
+            // PRIMARY_UV=2, SECONDARY_UV=3. Only indices 0 and 1 are supported; higher indices collide at location 3.
+            final int location = i == 0 ? 2 : 3;
+            sb.append("layout(location = ").append(location).append(") in vec4 a_TexCoord").append(i).append(";\n");
+            varyings.append("out vec4 angelica_TexCoord").append(i).append(";\n");
+            assignments.append("  angelica_TexCoord").append(i).append(" = a_TexCoord").append(i).append(";\n");
+        }
+
+        if (FRAG_IN_FOGCOORD.matcher(fragmentSource).find()) {
+            varyings.append("out float angelica_FogFragCoord;\n");
+            assignments.append("  angelica_FogFragCoord = abs((angelica_ModelViewMatrix * a_Position).z);\n");
+        }
+
+        sb.append(varyings);
+        sb.append("\nvoid main() {\n");
+        sb.append("  gl_Position = angelica_ProjectionMatrix * angelica_ModelViewMatrix * a_Position;\n");
+        sb.append(assignments);
+        sb.append("}\n");
+
+        return sb.toString();
+    }
+
+    /** Ensure #version is at least 330 core, strip 'compatibility' profile. */
+    private static String fixupVersion(String source) {
+        final Matcher m = VERSION_PATTERN.matcher(source);
+        if (!m.find()) {
+            return "#version 330 core\n" + source;
+        }
+
+        final int version = Integer.parseInt(m.group(1));
+        final String profile = m.group(2);
+
+        if (version >= 330 && !"compatibility".equals(profile)) {
+            if ("core".equals(profile)) return source;
+            return m.replaceFirst("#version " + version + " core");
+        }
+
+        final int targetVersion = Math.max(version, 330);
+        return m.replaceFirst("#version " + targetVersion + " core");
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/CompatUniformManager.java

@@ -0,0 +1,411 @@
+package com.gtnewhorizons.angelica.glsm;
+
+import com.gtnewhorizons.angelica.glsm.stacks.FogStateStack;
+import com.gtnewhorizons.angelica.glsm.stacks.LightStateStack;
+import com.gtnewhorizons.angelica.glsm.states.ClipPlaneState;
+import com.gtnewhorizons.angelica.glsm.states.LightModelState;
+import com.gtnewhorizons.angelica.glsm.states.LightState;
+import com.gtnewhorizons.angelica.glsm.states.MaterialState;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+import org.joml.Matrix3f;
+import org.joml.Matrix4f;
+import org.lwjgl.BufferUtils;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL20;
+
+import java.nio.FloatBuffer;
+
+import static com.gtnewhorizons.angelica.loading.AngelicaTweaker.LOGGER;
+
+/**
+ * Per-program compat uniform location cache and upload manager.
+ *
+ * <p>Manages {@code angelica_*} uniforms injected by {@link CompatShaderTransformer} and {@code iris_*} matrix uniforms used by Iris/celeritas shader programs.
+ */
+public class CompatUniformManager {
+
+    // Uniform location indices within the cached array (package-private for tests)
+    static final int LOC_MODELVIEW = 0;
+    static final int LOC_MODELVIEW_INVERSE = 1;
+    static final int LOC_PROJECTION = 2;
+    static final int LOC_PROJECTION_INVERSE = 3;
+    static final int LOC_NORMAL = 4;
+    static final int LOC_LIGHTMAP_TEXTURE_MATRIX = 5;
+    static final int LOC_FOG_DENSITY = 6;
+    static final int LOC_FOG_START = 7;
+    static final int LOC_FOG_END = 8;
+    static final int LOC_FOG_COLOR = 9;
+    static final int LOC_IRIS_MODELVIEW = 10;
+    static final int LOC_IRIS_PROJECTION = 11;
+    static final int LOC_IRIS_NORMAL = 12;
+    static final int LOC_IRIS_LIGHTMAP_TEXTURE_MATRIX = 13;
+    static final int LOC_ALPHA_TEST_REF = 14;
+    static final int LOC_SCENE_COLOR = 15;
+    static final int LOC_CLIP_PLANES = 16;
+    static final int LOC_CLIP_PLANES_ENABLED = 17;
+
+    // Light source fields: 12 per light × 2 lights = 24 locations
+    static final int LIGHT_FIELDS = 12;
+    static final int LF_AMBIENT = 0, LF_DIFFUSE = 1, LF_SPECULAR = 2, LF_POSITION = 3;
+    static final int LF_HALF_VECTOR = 4, LF_SPOT_DIRECTION = 5, LF_SPOT_EXPONENT = 6;
+    static final int LF_SPOT_CUTOFF = 7, LF_SPOT_COS_CUTOFF = 8;
+    static final int LF_CONSTANT_ATTEN = 9, LF_LINEAR_ATTEN = 10, LF_QUADRATIC_ATTEN = 11;
+    static final int LOC_LIGHT_BASE = 18;
+
+    // Material fields: 5 locations
+    static final int MF_EMISSION = 0, MF_AMBIENT = 1, MF_DIFFUSE = 2, MF_SPECULAR = 3, MF_SHININESS = 4;
+    static final int MAT_FIELDS = 5;
+    static final int LOC_MAT_BASE = LOC_LIGHT_BASE + 2 * LIGHT_FIELDS; // 42
+
+    static final int LOC_COUNT = LOC_MAT_BASE + MAT_FIELDS; // 47
+
+    private static final String[] LIGHT_FIELD_NAMES = {
+        "ambient", "diffuse", "specular", "position", "halfVector",
+        "spotDirection", "spotExponent", "spotCutoff", "spotCosCutoff",
+        "constantAttenuation", "linearAttenuation", "quadraticAttenuation",
+    };
+    private static final String[] MAT_FIELD_NAMES = {
+        "emission", "ambient", "diffuse", "specular", "shininess",
+    };
+
+    private static final String[] UNIFORM_NAMES;
+    static {
+        UNIFORM_NAMES = new String[LOC_COUNT];
+        UNIFORM_NAMES[LOC_MODELVIEW] = "angelica_ModelViewMatrix";
+        UNIFORM_NAMES[LOC_MODELVIEW_INVERSE] = "angelica_ModelViewMatrixInverse";
+        UNIFORM_NAMES[LOC_PROJECTION] = "angelica_ProjectionMatrix";
+        UNIFORM_NAMES[LOC_PROJECTION_INVERSE] = "angelica_ProjectionMatrixInverse";
+        UNIFORM_NAMES[LOC_NORMAL] = "angelica_NormalMatrix";
+        UNIFORM_NAMES[LOC_LIGHTMAP_TEXTURE_MATRIX] = "angelica_LightmapTextureMatrix";
+        UNIFORM_NAMES[LOC_FOG_DENSITY] = "angelica_FogDensity";
+        UNIFORM_NAMES[LOC_FOG_START] = "angelica_FogStart";
+        UNIFORM_NAMES[LOC_FOG_END] = "angelica_FogEnd";
+        UNIFORM_NAMES[LOC_FOG_COLOR] = "angelica_FogColor";
+        UNIFORM_NAMES[LOC_IRIS_MODELVIEW] = "iris_ModelViewMatrix";
+        UNIFORM_NAMES[LOC_IRIS_PROJECTION] = "iris_ProjectionMatrix";
+        UNIFORM_NAMES[LOC_IRIS_NORMAL] = "iris_NormalMatrix";
+        UNIFORM_NAMES[LOC_IRIS_LIGHTMAP_TEXTURE_MATRIX] = "iris_LightmapTextureMatrix";
+        UNIFORM_NAMES[LOC_ALPHA_TEST_REF] = "angelica_currentAlphaTest";
+        UNIFORM_NAMES[LOC_SCENE_COLOR] = "angelica_SceneColor";
+        UNIFORM_NAMES[LOC_CLIP_PLANES] = "angelica_ClipPlane[0]";
+        UNIFORM_NAMES[LOC_CLIP_PLANES_ENABLED] = "angelica_ClipPlanesEnabled";
+        for (int li = 0; li < 2; li++) {
+            for (int fi = 0; fi < LIGHT_FIELDS; fi++) {
+                UNIFORM_NAMES[LOC_LIGHT_BASE + li * LIGHT_FIELDS + fi] =
+                    "angelica_LightSource[" + li + "]." + LIGHT_FIELD_NAMES[fi];
+            }
+        }
+        for (int fi = 0; fi < MAT_FIELDS; fi++) {
+            UNIFORM_NAMES[LOC_MAT_BASE + fi] = "angelica_FrontMaterial." + MAT_FIELD_NAMES[fi];
+        }
+    }
+
+    /** Per-program cached uniform locations. Maps program ID → int[LOC_COUNT]. */
+    private static final Int2ObjectOpenHashMap<int[]> programLocations = new Int2ObjectOpenHashMap<>();
+
+    // Reusable NIO buffers for upload
+    private static final FloatBuffer mat4Buf = BufferUtils.createFloatBuffer(16);
+    private static final FloatBuffer mat3Buf = BufferUtils.createFloatBuffer(9);
+    private static final FloatBuffer vec4Buf = BufferUtils.createFloatBuffer(4);
+    private static final FloatBuffer clipPlaneBuf = BufferUtils.createFloatBuffer(32); // 8 planes * vec4
+    private static final Matrix3f normalMatrix = new Matrix3f();
+    private static final Matrix4f scratchMatrix = new Matrix4f();
+
+    private static final float LIGHTMAP_SCALE = 1.0f / 256.0f;
+    private static final FloatBuffer lightmapMatrixBuf;
+    static {
+        lightmapMatrixBuf = BufferUtils.createFloatBuffer(16);
+        new Matrix4f().scale(LIGHTMAP_SCALE).translate(8.0f, 8.0f, 8.0f).get(lightmapMatrixBuf);
+    }
+
+    // Dirty tracking: skip uploads when state hasn't changed and program is the same
+    private static int lastProgram = -1;
+    private static int lastMvGen = -1;
+    private static int lastProjGen = -1;
+    private static int lastTexMatGen = -1;
+    private static int lastFragmentGen = -1;
+    private static int lastLightingGen = -1;
+    private static int lastClipPlaneGen = -1;
+
+    private CompatUniformManager() {}
+
+    public static void onLinkProgram(int program) {
+        int[] locs = new int[LOC_COUNT];
+        boolean hasAny = false;
+
+        for (int i = 0; i < LOC_COUNT; i++) {
+            locs[i] = GL20.glGetUniformLocation(program, UNIFORM_NAMES[i]);
+            if (locs[i] != -1) hasAny = true;
+        }
+
+        if (hasAny) {
+            programLocations.put(program, locs);
+            LOGGER.debug("CompatUniformManager: program {} has compat uniforms", program);
+        }
+    }
+
+    public static void onUseProgram(int program) {
+        if (program == 0) return;
+
+        int[] locs = programLocations.get(program);
+        if (locs == null) return;
+
+        final boolean programChanged = program != lastProgram;
+        lastProgram = program;
+
+        // Matrix uniforms — skip if generation unchanged and same program
+        final int mvGen = GLStateManager.mvGeneration;
+        final int projGen = GLStateManager.projGeneration;
+        final int texMatGen = GLStateManager.texMatrixGeneration;
+        final boolean mvChanged = programChanged || mvGen != lastMvGen;
+        final boolean projChanged = programChanged || projGen != lastProjGen;
+        final boolean texMatChanged = programChanged || texMatGen != lastTexMatGen;
+        if (mvChanged || projChanged || texMatChanged) {
+            uploadMatrices(locs, mvChanged, projChanged, texMatChanged);
+            lastMvGen = mvGen;
+            lastProjGen = projGen;
+            lastTexMatGen = texMatGen;
+        }
+
+        // Fragment-category uniforms (fog, alpha) — skip if generation unchanged
+        final int fragGen = GLStateManager.fragmentGeneration;
+        if (programChanged || fragGen != lastFragmentGen) {
+            lastFragmentGen = fragGen;
+            uploadFragmentUniforms(locs);
+        }
+
+        // Lighting-derived uniforms (scene color, light sources, material)
+        final int litGen = GLStateManager.lightingGeneration;
+        if (programChanged || litGen != lastLightingGen) {
+            lastLightingGen = litGen;
+            if (locs[LOC_SCENE_COLOR] != -1) uploadSceneColor(locs);
+            uploadLightSources(locs);
+            uploadMaterial(locs);
+        }
+
+        // Clip plane equations + enabled bool — uploaded when enable state or equations change
+        if (locs[LOC_CLIP_PLANES] != -1 || locs[LOC_CLIP_PLANES_ENABLED] != -1) {
+            final int cpGen = GLStateManager.clipPlaneGeneration;
+            if (programChanged || cpGen != lastClipPlaneGen) {
+                lastClipPlaneGen = cpGen;
+                uploadClipPlanes(locs);
+            }
+        }
+    }
+
+    private static void uploadMatrices(int[] locs, boolean mvChanged, boolean projChanged, boolean texMatChanged) {
+        final Matrix4f mv = GLStateManager.getModelViewMatrix();
+        final Matrix4f proj = GLStateManager.getProjectionMatrix();
+
+        if (mvChanged) {
+            // ModelView
+            if (locs[LOC_MODELVIEW] != -1 || locs[LOC_IRIS_MODELVIEW] != -1) {
+                mv.get(mat4Buf);
+                if (locs[LOC_MODELVIEW] != -1) {
+                    GL20.glUniformMatrix4(locs[LOC_MODELVIEW], false, mat4Buf);
+                }
+                if (locs[LOC_IRIS_MODELVIEW] != -1) {
+                    GL20.glUniformMatrix4(locs[LOC_IRIS_MODELVIEW], false, mat4Buf);
+                }
+            }
+
+            // ModelView Inverse
+            if (locs[LOC_MODELVIEW_INVERSE] != -1) {
+                mv.invert(scratchMatrix);
+                scratchMatrix.get(mat4Buf);
+                GL20.glUniformMatrix4(locs[LOC_MODELVIEW_INVERSE], false, mat4Buf);
+            }
+
+            // Normal Matrix (inverse-transpose of upper-left 3x3 of ModelView)
+            if (locs[LOC_NORMAL] != -1 || locs[LOC_IRIS_NORMAL] != -1) {
+                mv.normal(normalMatrix);
+                normalMatrix.get(mat3Buf);
+                if (locs[LOC_NORMAL] != -1) {
+                    GL20.glUniformMatrix3(locs[LOC_NORMAL], false, mat3Buf);
+                }
+                if (locs[LOC_IRIS_NORMAL] != -1) {
+                    GL20.glUniformMatrix3(locs[LOC_IRIS_NORMAL], false, mat3Buf);
+                }
+            }
+        }
+
+        if (projChanged) {
+            // Projection
+            if (locs[LOC_PROJECTION] != -1 || locs[LOC_IRIS_PROJECTION] != -1) {
+                proj.get(mat4Buf);
+                if (locs[LOC_PROJECTION] != -1) {
+                    GL20.glUniformMatrix4(locs[LOC_PROJECTION], false, mat4Buf);
+                }
+                if (locs[LOC_IRIS_PROJECTION] != -1) {
+                    GL20.glUniformMatrix4(locs[LOC_IRIS_PROJECTION], false, mat4Buf);
+                }
+            }
+
+            // Projection Inverse
+            if (locs[LOC_PROJECTION_INVERSE] != -1) {
+                proj.invert(scratchMatrix);
+                scratchMatrix.get(mat4Buf);
+                GL20.glUniformMatrix4(locs[LOC_PROJECTION_INVERSE], false, mat4Buf);
+            }
+        }
+
+        if (texMatChanged) {
+            // Iris lightmap texture matrix (constant)
+            if (locs[LOC_IRIS_LIGHTMAP_TEXTURE_MATRIX] != -1) {
+                GL20.glUniformMatrix4(locs[LOC_IRIS_LIGHTMAP_TEXTURE_MATRIX], false, lightmapMatrixBuf);
+            }
+
+            // angelica_LightmapTextureMatrix — actual GLSM texture unit 1 matrix (set by enableLightmap())
+            if (locs[LOC_LIGHTMAP_TEXTURE_MATRIX] != -1) {
+                GLStateManager.getTextures().getTextureUnitMatrix(1).get(mat4Buf);
+                GL20.glUniformMatrix4(locs[LOC_LIGHTMAP_TEXTURE_MATRIX], false, mat4Buf);
+            }
+        }
+    }
+
+    private static void uploadFragmentUniforms(int[] locs) {
+        // Fog uniforms
+        FogStateStack fog = GLStateManager.getFogState();
+        if (locs[LOC_FOG_DENSITY] != -1) {
+            GL20.glUniform1f(locs[LOC_FOG_DENSITY], Math.max(0.0f, fog.getDensity()));
+        }
+        if (locs[LOC_FOG_START] != -1) {
+            GL20.glUniform1f(locs[LOC_FOG_START], fog.getStart());
+        }
+        if (locs[LOC_FOG_END] != -1) {
+            GL20.glUniform1f(locs[LOC_FOG_END], fog.getEnd());
+        }
+        if (locs[LOC_FOG_COLOR] != -1) {
+            vec4Buf.clear();
+            vec4Buf.put((float) fog.getFogColor().x).put((float) fog.getFogColor().y)
+                   .put((float) fog.getFogColor().z).put(fog.getFogAlpha());
+            vec4Buf.flip();
+            GL20.glUniform4(locs[LOC_FOG_COLOR], vec4Buf);
+        }
+
+        // Alpha test reference — core profile replacement for GL_ALPHA_TEST
+        // Return -1.0f for ALWAYS or disabled so `alpha <= ref` never discards.
+        if (locs[LOC_ALPHA_TEST_REF] != -1) {
+            final float ref;
+            if (!GLStateManager.getAlphaTest().isEnabled()
+                || GLStateManager.getAlphaState().getFunction() == GL11.GL_ALWAYS) {
+                ref = -1.0f;
+            } else {
+                ref = GLStateManager.getAlphaState().getReference();
+            }
+            GL20.glUniform1f(locs[LOC_ALPHA_TEST_REF], ref);
+        }
+    }
+
+    /**
+     * Scene color = emission + ambient * lightModel.ambient, alpha = diffuse.a
+     * Same computation as {@code Uniforms.uploadLightingPreComputed()}.
+     */
+    private static void uploadSceneColor(int[] locs) {
+        final MaterialState mat = GLStateManager.getFrontMaterial();
+        final LightModelState lm = GLStateManager.getLightModel();
+        vec4Buf.clear();
+        vec4Buf.put(mat.emission.x + mat.ambient.x * lm.ambient.x)
+               .put(mat.emission.y + mat.ambient.y * lm.ambient.y)
+               .put(mat.emission.z + mat.ambient.z * lm.ambient.z)
+               .put(mat.diffuse.w);
+        vec4Buf.flip();
+        GL20.glUniform4(locs[LOC_SCENE_COLOR], vec4Buf);
+    }
+
+    private static void uploadLightSources(int[] locs) {
+        // Early exit: if the first light field isn't present, no lighting uniforms exist
+        if (locs[LOC_LIGHT_BASE] == -1) return;
+        final LightStateStack[] lights = GLStateManager.getLightDataStates();
+        for (int li = 0; li < 2; li++) {
+            final int base = LOC_LIGHT_BASE + li * LIGHT_FIELDS;
+            final LightState light = lights[li];
+
+            if (locs[base + LF_AMBIENT] != -1)
+                GL20.glUniform4f(locs[base + LF_AMBIENT], light.ambient.x, light.ambient.y, light.ambient.z, light.ambient.w);
+            if (locs[base + LF_DIFFUSE] != -1)
+                GL20.glUniform4f(locs[base + LF_DIFFUSE], light.diffuse.x, light.diffuse.y, light.diffuse.z, light.diffuse.w);
+            if (locs[base + LF_SPECULAR] != -1)
+                GL20.glUniform4f(locs[base + LF_SPECULAR], light.specular.x, light.specular.y, light.specular.z, light.specular.w);
+            if (locs[base + LF_POSITION] != -1)
+                GL20.glUniform4f(locs[base + LF_POSITION], light.position.x, light.position.y, light.position.z, light.position.w);
+            if (locs[base + LF_HALF_VECTOR] != -1) {
+                // halfVector = normalize(normalize(position.xyz) + eye), eye=(0,0,1) for infinite viewer
+                float hx, hy, hz;
+                if (light.position.w == 0.0f) {
+                    float len = (float) Math.sqrt(light.position.x * light.position.x
+                        + light.position.y * light.position.y + light.position.z * light.position.z);
+                    if (len > 0) {
+                        hx = light.position.x / len;
+                        hy = light.position.y / len;
+                        hz = light.position.z / len + 1.0f;
+                    } else {
+                        hx = 0; hy = 0; hz = 1;
+                    }
+                } else {
+                    hx = 0; hy = 0; hz = 1;
+                }
+                float hlen = (float) Math.sqrt(hx * hx + hy * hy + hz * hz);
+                if (hlen > 0) { hx /= hlen; hy /= hlen; hz /= hlen; }
+                GL20.glUniform4f(locs[base + LF_HALF_VECTOR], hx, hy, hz, 0.0f);
+            }
+            if (locs[base + LF_SPOT_DIRECTION] != -1)
+                GL20.glUniform3f(locs[base + LF_SPOT_DIRECTION], light.spotDirection.x, light.spotDirection.y, light.spotDirection.z);
+            if (locs[base + LF_SPOT_EXPONENT] != -1)
+                GL20.glUniform1f(locs[base + LF_SPOT_EXPONENT], light.spotExponent);
+            if (locs[base + LF_SPOT_CUTOFF] != -1)
+                GL20.glUniform1f(locs[base + LF_SPOT_CUTOFF], light.spotCutoff);
+            if (locs[base + LF_SPOT_COS_CUTOFF] != -1)
+                GL20.glUniform1f(locs[base + LF_SPOT_COS_CUTOFF], light.spotCosCutoff);
+            if (locs[base + LF_CONSTANT_ATTEN] != -1)
+                GL20.glUniform1f(locs[base + LF_CONSTANT_ATTEN], light.constantAttenuation);
+            if (locs[base + LF_LINEAR_ATTEN] != -1)
+                GL20.glUniform1f(locs[base + LF_LINEAR_ATTEN], light.linearAttenuation);
+            if (locs[base + LF_QUADRATIC_ATTEN] != -1)
+                GL20.glUniform1f(locs[base + LF_QUADRATIC_ATTEN], light.quadraticAttenuation);
+        }
+    }
+
+    private static void uploadMaterial(int[] locs) {
+        // Early exit: if the first material field isn't present, no material uniforms exist
+        if (locs[LOC_MAT_BASE] == -1) return;
+        final MaterialState mat = GLStateManager.getFrontMaterial();
+        if (locs[LOC_MAT_BASE + MF_EMISSION] != -1)
+            GL20.glUniform4f(locs[LOC_MAT_BASE + MF_EMISSION], mat.emission.x, mat.emission.y, mat.emission.z, mat.emission.w);
+        if (locs[LOC_MAT_BASE + MF_AMBIENT] != -1)
+            GL20.glUniform4f(locs[LOC_MAT_BASE + MF_AMBIENT], mat.ambient.x, mat.ambient.y, mat.ambient.z, mat.ambient.w);
+        if (locs[LOC_MAT_BASE + MF_DIFFUSE] != -1)
+            GL20.glUniform4f(locs[LOC_MAT_BASE + MF_DIFFUSE], mat.diffuse.x, mat.diffuse.y, mat.diffuse.z, mat.diffuse.w);
+        if (locs[LOC_MAT_BASE + MF_SPECULAR] != -1)
+            GL20.glUniform4f(locs[LOC_MAT_BASE + MF_SPECULAR], mat.specular.x, mat.specular.y, mat.specular.z, mat.specular.w);
+        if (locs[LOC_MAT_BASE + MF_SHININESS] != -1)
+            GL20.glUniform1f(locs[LOC_MAT_BASE + MF_SHININESS], mat.shininess);
+    }
+
+    private static void uploadClipPlanes(int[] locs) {
+        if (locs[LOC_CLIP_PLANES_ENABLED] != -1) {
+            GL20.glUniform1i(locs[LOC_CLIP_PLANES_ENABLED], GLStateManager.anyClipPlaneEnabled() ? 1 : 0);
+        }
+        if (locs[LOC_CLIP_PLANES] != -1) {
+            final ClipPlaneState cps = GLStateManager.getClipPlaneState();
+            clipPlaneBuf.clear();
+            for (int i = 0; i < GLStateManager.MAX_CLIP_PLANES; i++) {
+                cps.putEyePlane(i, clipPlaneBuf);
+            }
+            clipPlaneBuf.flip();
+            GL20.glUniform4(locs[LOC_CLIP_PLANES], clipPlaneBuf);
+        }
+    }
+
+    public static void onDeleteProgram(int program) {
+        programLocations.remove(program);
+    }
+
+    public static boolean hasProgram(int program) {
+        return programLocations.containsKey(program);
+    }
+
+    public static int[] getLocations(int program) {
+        return programLocations.get(program);
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/DisplayListIDAllocator.java

@@ -0,0 +1,187 @@
+package com.gtnewhorizons.angelica.glsm;
+
+/*
+ * Ported from Mesa's util_idalloc (src/util/u_idalloc.c).
+ *
+ * Original copyright and license:
+ *
+ * Copyright 2017 Valve Corporation
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Original author: Samuel Pitoiset <[email protected]>
+ */
+
+/**
+ * Bitmap ID allocator for display list IDs.
+ *
+ * <p>Bitmap-based: each bit in the {@code data} array represents one ID.
+ * Bit set = allocated, bit clear = free. ID 0 is reserved (never returned).
+ */
+public class DisplayListIDAllocator {
+
+    private int[] data;
+    private int numElements;       // number of uint32 words allocated
+    private int numSetElements;    // highest word index with any bit set + 1
+    private int lowestFreeIdx;     // optimization: skip fully-allocated words
+
+    public DisplayListIDAllocator() {
+        this(32); // 1024 IDs initially
+    }
+
+    public DisplayListIDAllocator(int initialWords) {
+        if (initialWords < 1) initialWords = 1;
+        this.data = new int[initialWords];
+        this.numElements = initialWords;
+        this.numSetElements = 0;
+        this.lowestFreeIdx = 0;
+        // Reserve ID 0 (never returned), matching Mesa's skip_zero pattern
+        data[0] = 1;
+        numSetElements = 1;
+    }
+
+    public int allocRange(int count) {
+        if (count <= 0) throw new IllegalArgumentException("count must be > 0");
+        if (count == 1) return allocSingle();
+        return allocMultiple(count);
+    }
+
+    private int allocSingle() {
+        for (int i = lowestFreeIdx; i < numElements; i++) {
+            if (data[i] == 0xFFFFFFFF) continue;
+
+            int bit = Integer.numberOfTrailingZeros(~data[i]);
+            data[i] |= 1 << bit;
+            lowestFreeIdx = i;
+            numSetElements = Math.max(numSetElements, i + 1);
+            return i * 32 + bit;
+        }
+
+        // No slots available, grow. Record old end, then mark first bit there.
+        int oldNumElements = numElements;
+        resize(Math.max(numElements, 1) * 2);
+        lowestFreeIdx = oldNumElements;
+        data[oldNumElements] |= 1;
+        numSetElements = Math.max(numSetElements, oldNumElements + 1);
+        return oldNumElements * 32;
+    }
+
+    private int allocMultiple(int num) {
+        int numWords = divRoundUp(num, 32);
+        int base = findFreeBlock(lowestFreeIdx);
+        boolean found = false;
+
+        while (!found) {
+            int i;
+            for (i = base; i < numElements && i - base < numWords && data[i] == 0; i++)
+                ;
+
+            if (i - base == numWords) {
+                found = true;
+            } else if (i == numElements) {
+                // Hit end — base is valid: data[base..end] are zero, resize extends the run into newly zeroed words.
+                resize(numElements * 2 + numWords);
+                found = true;
+            } else {
+                // Non-zero word at i, skip past it
+                base = i + 1;
+            }
+        }
+
+        // Mark bits as used
+        int fullWords = num / 32;
+        int remainder = num % 32;
+        for (int i = base; i < base + fullWords; i++) {
+            data[i] = 0xFFFFFFFF;
+        }
+        if (remainder != 0) {
+            data[base + fullWords] |= (1 << remainder) - 1;
+        }
+
+        if (lowestFreeIdx == base) {
+            lowestFreeIdx = base + num / 32;
+        }
+        numSetElements = Math.max(numSetElements, base + numWords);
+
+        return base * 32;
+    }
+
+    private int findFreeBlock(int start) {
+        for (int i = start; i < numElements; i++) {
+            if (data[i] == 0) return i;
+        }
+        return numElements;
+    }
+
+    public void free(int id) {
+        if (id <= 0) return; // ID 0 is reserved
+        int idx = id / 32;
+        if (idx >= numElements) return;
+
+        lowestFreeIdx = Math.min(idx, lowestFreeIdx);
+        data[idx] &= ~(1 << (id % 32));
+
+        if (numSetElements == idx + 1) {
+            while (numSetElements > 0 && data[numSetElements - 1] == 0) {
+                numSetElements--;
+            }
+        }
+    }
+
+    public void freeRange(int base, int count) {
+        if (count <= 0 || base <= 0) return;
+
+        int startIdx = base / 32;
+        if (startIdx >= numElements) return;
+
+        int end = base + count;
+        for (int id = base; id < end; id++) {
+            int idx = id / 32;
+            if (idx >= numElements) break;
+            data[idx] &= ~(1 << (id % 32));
+        }
+
+        lowestFreeIdx = Math.min(startIdx, lowestFreeIdx);
+        while (numSetElements > 0 && data[numSetElements - 1] == 0) {
+            numSetElements--;
+        }
+    }
+
+    public boolean isAllocated(int id) {
+        if (id <= 0) return false;
+        int idx = id / 32;
+        if (idx >= numSetElements) return false;
+        return (data[idx] & (1 << (id % 32))) != 0;
+    }
+
+    private void resize(int newNumElements) {
+        if (newNumElements <= numElements) return;
+        int[] newData = new int[newNumElements];
+        System.arraycopy(data, 0, newData, 0, numElements);
+        data = newData;
+        numElements = newNumElements;
+    }
+
+    private static int divRoundUp(int a, int b) {
+        return (a + b - 1) / b;
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/DisplayListManager.java

@@ -27,14 +27,14 @@ import org.joml.Vector3f;
 import org.lwjgl.opengl.GL11;
 
 import java.nio.ByteBuffer;
-import java.nio.FloatBuffer;
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Deque;
 import java.util.List;
 
-import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.*;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAddress;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memGetInt;
 
 /**
  * VBO-based display list emulation with command recording, transform collapsing, and format-based batching.
@@ -103,9 +103,6 @@ public class DisplayListManager {
     private static List<List<String>> multMatrixSources = null;  // Source ops for each MULT_MATRIX in raw buffer
     private static List<String> drawRangeSources = null;  // Source type for each DRAW_RANGE in final buffer
 
-    // For flushMatrix() - reusable buffer for executing collapsed transforms
-    private static final FloatBuffer flushMatrixBuffer = org.lwjgl.BufferUtils.createFloatBuffer(16);
-
     // Nested compilation support - stack of parent contexts
     private static final Deque<CompilationContext> compilationStack = new ArrayDeque<>();
 
@@ -177,11 +174,8 @@ public class DisplayListManager {
             stateGeneration++;
         }
 
-        // COMPILE_AND_EXECUTE: execute now. Bypass GLSM to avoid re-entering recording path.
+        // COMPILE_AND_EXECUTE: apply to GLSM software stack
         if (glListMode == GL11.GL_COMPILE_AND_EXECUTE) {
-            flushMatrixBuffer.clear();
-            relativeTransform.get(flushMatrixBuffer);
-            GL11.glMultMatrix(flushMatrixBuffer);
             GLStateManager.getMatrixStack().mul(relativeTransform);
         }
 
@@ -358,6 +352,12 @@ public class DisplayListManager {
         currentRecorder.recordViewport(x, y, width, height);
     }
 
+    public static void recordScissor(int x, int y, int width, int height) {
+        if (currentRecorder == null) return;
+        drawBarrier();
+        currentRecorder.recordScissor(x, y, width, height);
+    }
+
     public static void recordPointSize(float size) {
         if (currentRecorder == null) return;
         drawBarrier();
@@ -497,6 +497,12 @@ public class DisplayListManager {
         currentRecorder.recordMaterial(face, pname, params);
     }
 
+    public static void recordClipPlane(int plane, double a, double b, double c, double d) {
+        if (currentRecorder == null) return;
+        drawBarrier();
+        currentRecorder.recordClipPlane(plane, a, b, c, d);
+    }
+
     public static void recordStencilFunc(int func, int ref, int mask) {
         if (currentRecorder == null) return;
         drawBarrier();
@@ -619,9 +625,6 @@ public class DisplayListManager {
             applyTransformOp(singleTransform, x, y, z, op, rotationAxis);
             if (currentRecorder != null) currentRecorder.recordMultMatrix(singleTransform);
             if (glListMode == GL11.GL_COMPILE_AND_EXECUTE) {
-                flushMatrixBuffer.clear();
-                singleTransform.get(flushMatrixBuffer);
-                GL11.glMultMatrix(flushMatrixBuffer);
                 GLStateManager.getMatrixStack().mul(singleTransform);
             }
             return;
@@ -659,9 +662,6 @@ public class DisplayListManager {
             }
 
             if (glListMode == GL11.GL_COMPILE_AND_EXECUTE) {
-                flushMatrixBuffer.clear();
-                matrix.get(flushMatrixBuffer);
-                GL11.glMultMatrix(flushMatrixBuffer);
                 GLStateManager.getMatrixStack().mul(matrix);
             }
             return;
@@ -686,9 +686,6 @@ public class DisplayListManager {
         if (DEBUG_DISPLAY_LISTS) {
             if (currentRecorder != null) currentRecorder.recordMultMatrix(orthoFrustumTemp);
             if (glListMode == GL11.GL_COMPILE_AND_EXECUTE) {
-                flushMatrixBuffer.clear();
-                orthoFrustumTemp.get(flushMatrixBuffer);
-                GL11.glMultMatrix(flushMatrixBuffer);
                 GLStateManager.getMatrixStack().mul(orthoFrustumTemp);
             }
             return;
@@ -709,9 +706,6 @@ public class DisplayListManager {
         if (DEBUG_DISPLAY_LISTS) {
             if (currentRecorder != null) currentRecorder.recordMultMatrix(orthoFrustumTemp);
             if (glListMode == GL11.GL_COMPILE_AND_EXECUTE) {
-                flushMatrixBuffer.clear();
-                orthoFrustumTemp.get(flushMatrixBuffer);
-                GL11.glMultMatrix(flushMatrixBuffer);
                 GLStateManager.getMatrixStack().mul(orthoFrustumTemp);
             }
             return;
@@ -956,11 +950,8 @@ public class DisplayListManager {
                 vbo.render();
             }
             // Per OpenGL spec: if list is undefined, glCallList has no effect
-        } else {
-            // Positive IDs - fall back to native GL display lists
-            // This happens for lists allocated but never compiled via glNewList
-            GL11.glCallList(list);
         }
+        // An uncached positive-ID list = no-op (per OpenGL spec)
     }
 
     /**
@@ -971,8 +962,6 @@ public class DisplayListManager {
             CompiledDisplayList compiled = displayListCache.remove(i);
             if (compiled != null) {
                 compiled.delete();
-            } else {
-                GL11.glDeleteLists(i, 1);
             }
         }
     }

src/main/java/com/gtnewhorizons/angelica/glsm/Feature.java

@@ -2,6 +2,7 @@ package com.gtnewhorizons.angelica.glsm;
 
 import com.google.common.collect.ImmutableSet;
 import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
+import com.gtnewhorizons.angelica.glsm.ffp.ShaderManager;
 import com.gtnewhorizons.angelica.glsm.stacks.BooleanStateStack;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
@@ -87,22 +88,20 @@ public class Feature {
               GLStateManager.alphaTest  // GL_ALPHA_TEST enable bit
             , GLStateManager.alphaState // Alpha test function and reference value
             , GLStateManager.blendMode  // GL_BLEND enable bit
-            , GLStateManager.blendState // Blending source and destination functions
-            // Constant blend color
-            // Blending equation
+            , GLStateManager.blendState // Blending source/destination functions, equation, blend color
             , GLStateManager.colorLogicOpState // GL_COLOR_LOGIC_OP enable bit
             , GLStateManager.ditherState // GL_DITHER enable bit
             , GLStateManager.drawBuffer // GL_DRAW_BUFFER setting
             , GLStateManager.indexLogicOpState // GL_INDEX_LOGIC_OP enable bit
-            // Logic op function
+            , GLStateManager.logicOpMode // Logic op function
             , GLStateManager.colorMask   // Color-mode and index-mode writemasks
             , GLStateManager.clearColor  // Color-mode and index-mode clear values
         ));
         attribToFeatures.put(GL11.GL_CURRENT_BIT, ImmutableSet.of(
               GLStateManager.color  // Current RGBA color
+            , ShaderManager.getNormalStack()    // Current normal vector
+            , ShaderManager.getTexCoordStack()  // Current texture coordinates
             // Current color index
-            // Current normal vector
-            // Current texture coordinates
             // Current raster position
             // GL_CURRENT_RASTER_POSITION_VALID flag
             // RGBA color associated with current raster position
@@ -300,6 +299,7 @@ public class Feature {
         ));
         final Set<IStateStack<?>> textureAttribs = new HashSet<>(ImmutableSet.of(
             GLStateManager.activeTextureUnit // Active texture unit
+                // GL_TEXTURE_ENV_MODE + GL_TEXTURE_ENV_COLOR — now per-unit in TexEnvState (added below)
                 // Enable bits for the four texture coordinates
 
                 // Border color for each texture image
@@ -307,17 +307,16 @@ public class Feature {
                 // Magnification function for each texture image
                 // Texture coordinates and wrap mode for each texture image
 
-                // Color and mode for each texture environment
                 // Enable bits GL_TEXTURE_GEN_x, x is S, T, R, and Q
                 // GL_TEXTURE_GEN_MODE setting for S, T, R, and Q
                 // glTexGen plane equations for S, T, R, and Q
                 // Current texture bindings (for example, GL_TEXTURE_BINDING_2D) - Below
         ));
 
-        // Current Texture Bindings - GL_TEXTURE_BINDING_2D
+        // Current Texture Bindings - GL_TEXTURE_BINDING_2D + per-unit TexEnvState
         for(int i = 0 ; i < GLStateManager.MAX_TEXTURE_UNITS; i++) {
             textureAttribs.add(GLStateManager.textures.getTextureUnitBindings(i));
-//            textureAttribs.add(GLStateManager.textures.getInfo(i))
+            textureAttribs.add(GLStateManager.textures.getTexEnvState(i));
         }
 
         // Enable bits GL_TEXTURE_GEN_x where x is S, T, R, or Q

src/main/java/com/gtnewhorizons/angelica/glsm/FeedbackManager.java

@@ -0,0 +1,388 @@
+package com.gtnewhorizons.angelica.glsm;
+
+import com.gtnewhorizons.angelica.glsm.states.ViewportState;
+import com.gtnewhorizons.angelica.loading.AngelicaTweaker;
+import org.joml.Matrix4f;
+import org.joml.Vector4f;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL15;
+import org.lwjgl.opengl.GL20;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.nio.FloatBuffer;
+import java.nio.IntBuffer;
+import java.nio.ShortBuffer;
+
+/**
+ * Software emulation of GL feedback mode
+ */
+public class FeedbackManager {
+
+    private static final int FB_3D = 0x01;
+    private static final int FB_4D = 0x02;
+    private static final int FB_COLOR = 0x04;
+    private static final int FB_TEXTURE = 0x08;
+
+    private static int renderMode = GL11.GL_RENDER;
+    private static FloatBuffer feedbackBuffer;
+    private static int feedbackBufferSize;
+    private static int feedbackMask;
+    private static int feedbackCount;
+
+    private static final Matrix4f mvpMatrix = new Matrix4f();
+    private static final Vector4f clipVec = new Vector4f();
+
+    private static ByteBuffer readbackBuf = ByteBuffer.allocateDirect(256 * 1024).order(ByteOrder.nativeOrder());
+    private static ByteBuffer indexReadbackBuf = ByteBuffer.allocateDirect(4 * 1024).order(ByteOrder.nativeOrder());
+    private static final IntBuffer attribBuf = ByteBuffer.allocateDirect(16 * 4).order(ByteOrder.nativeOrder()).asIntBuffer();
+
+    @FunctionalInterface
+    private interface IndexReader {
+        int read(int i);
+    }
+
+    public static boolean isFeedbackMode() {
+        return renderMode == GL11.GL_FEEDBACK;
+    }
+
+    public static void glFeedbackBuffer(int type, FloatBuffer buffer) {
+        if (renderMode == GL11.GL_FEEDBACK) {
+            AngelicaTweaker.LOGGER.error("glFeedbackBuffer called while already in feedback mode");
+            return;
+        }
+        feedbackBuffer = buffer;
+        feedbackBufferSize = buffer.remaining();
+        feedbackMask = computeMask(type);
+        feedbackCount = 0;
+    }
+
+    public static int glRenderMode(int mode) {
+        int result = 0;
+        switch (renderMode) {
+            case GL11.GL_FEEDBACK:
+                result = (feedbackCount > feedbackBufferSize) ? -1 : feedbackCount;
+                break;
+            case GL11.GL_RENDER:
+            case GL11.GL_SELECT:
+                result = 0;
+                break;
+        }
+
+        if (mode == GL11.GL_SELECT) {
+            AngelicaTweaker.LOGGER.warn("glRenderMode(GL_SELECT): selection mode not emulated");
+        }
+
+        feedbackCount = 0;
+        renderMode = mode;
+        return result;
+    }
+
+    public static void glPassThrough(float token) {
+        if (renderMode == GL11.GL_FEEDBACK) {
+            feedbackToken(GL11.GL_PASS_THROUGH_TOKEN);
+            feedbackToken(token);
+        }
+    }
+
+    private static void feedbackToken(float token) {
+        if (feedbackCount < feedbackBufferSize) {
+            feedbackBuffer.put(feedbackBuffer.position() + feedbackCount, token);
+        }
+        feedbackCount++;
+    }
+
+    private static void feedbackVertex(float winX, float winY, float winZ, float winW) {
+        feedbackToken(winX);
+        feedbackToken(winY);
+        if ((feedbackMask & FB_3D) != 0) feedbackToken(winZ);
+        if ((feedbackMask & FB_4D) != 0) feedbackToken(winW);
+        if ((feedbackMask & FB_COLOR) != 0) {
+            feedbackToken(1f);
+            feedbackToken(1f);
+            feedbackToken(1f);
+            feedbackToken(1f);
+        }
+        if ((feedbackMask & FB_TEXTURE) != 0) {
+            feedbackToken(0f);
+            feedbackToken(0f);
+            feedbackToken(0f);
+            feedbackToken(1f);
+        }
+    }
+
+    private static void transformAndEmitVertex(float x, float y, float z) {
+        clipVec.set(x, y, z, 1.0f);
+        mvpMatrix.transform(clipVec);
+
+        final float w = clipVec.w;
+        final float ndcX = clipVec.x / w;
+        final float ndcY = clipVec.y / w;
+        final float ndcZ = clipVec.z / w;
+
+        final ViewportState vp = GLStateManager.getViewportState();
+        final float winX = vp.x + vp.width * (ndcX + 1.0f) * 0.5f;
+        final float winY = vp.y + vp.height * (ndcY + 1.0f) * 0.5f;
+        final float winZ = (float) ((vp.depthRangeFar - vp.depthRangeNear) * ndcZ
+            + (vp.depthRangeFar + vp.depthRangeNear)) * 0.5f;
+        final float winW = 1.0f / w;
+
+        feedbackVertex(winX, winY, winZ, winW);
+    }
+
+    public static void processDrawArrays(int mode, int first, int count) {
+        computeMVP();
+        int stride = queryPositionStride();
+        if (stride == 0) stride = 12; // tightly packed 3 floats
+
+        final long posOffset = queryPositionOffset();
+        final int byteCount = count * stride;
+        ensureReadbackCapacity(byteCount);
+        readbackBuf.clear().limit(byteCount);
+        GL15.glGetBufferSubData(GL15.GL_ARRAY_BUFFER, (long) first * stride + posOffset, readbackBuf);
+
+        emitAllPrimitives(mode, count, i -> i, stride);
+    }
+
+    public static void processDrawElements(int mode, int indexCount, int type, long eboOffset) {
+        computeMVP();
+        int stride = queryPositionStride();
+        if (stride == 0) stride = 12;
+
+        final int elementSize = elementSizeForType(type);
+        final int indexByteCount = indexCount * elementSize;
+        ensureIndexReadbackCapacity(indexByteCount);
+        indexReadbackBuf.clear().limit(indexByteCount);
+        GL15.glGetBufferSubData(GL15.GL_ELEMENT_ARRAY_BUFFER, eboOffset, indexReadbackBuf);
+        final ByteBuffer indexBuf = indexReadbackBuf;
+
+        int minIdx = Integer.MAX_VALUE, maxIdx = Integer.MIN_VALUE;
+        for (int i = 0; i < indexCount; i++) {
+            final int idx = readIndex(indexBuf, type, i);
+            if (idx < minIdx) minIdx = idx;
+            if (idx > maxIdx) maxIdx = idx;
+        }
+
+        final long posOffset = queryPositionOffset();
+        final int vertexCount = maxIdx - minIdx + 1;
+        final int byteCount = vertexCount * stride;
+        ensureReadbackCapacity(byteCount);
+        readbackBuf.clear().limit(byteCount);
+        GL15.glGetBufferSubData(GL15.GL_ARRAY_BUFFER, (long) minIdx * stride + posOffset, readbackBuf);
+
+        final int base = minIdx;
+        emitAllPrimitives(mode, indexCount, i -> readIndex(indexBuf, type, i) - base, stride);
+    }
+
+    public static void processDrawElements(int mode, ByteBuffer indices) {
+        final int basePos = indices.position();
+        processDrawElementsImpl(mode, indices.remaining(), i -> indices.get(basePos + i) & 0xFF);
+    }
+
+    public static void processDrawElements(int mode, ShortBuffer indices) {
+        final int basePos = indices.position();
+        processDrawElementsImpl(mode, indices.remaining(), i -> indices.get(basePos + i) & 0xFFFF);
+    }
+
+    public static void processDrawElements(int mode, IntBuffer indices) {
+        final int basePos = indices.position();
+        processDrawElementsImpl(mode, indices.remaining(), i -> indices.get(basePos + i));
+    }
+
+    public static void processDrawElements(int mode, int count, int type, ByteBuffer indices) {
+        final int pos = indices.position();
+        final IndexReader reader = switch (type) {
+            case GL11.GL_UNSIGNED_BYTE -> i -> indices.get(pos + i) & 0xFF;
+            case GL11.GL_UNSIGNED_SHORT -> i -> indices.getShort(pos + i * 2) & 0xFFFF;
+            case GL11.GL_UNSIGNED_INT -> i -> indices.getInt(pos + i * 4);
+            default -> i -> 0;
+        };
+        processDrawElementsImpl(mode, count, reader);
+    }
+
+    private static void processDrawElementsImpl(int mode, int count, IndexReader reader) {
+        computeMVP();
+        int stride = queryPositionStride();
+        if (stride == 0) stride = 12;
+
+        int minIdx = Integer.MAX_VALUE, maxIdx = Integer.MIN_VALUE;
+        for (int i = 0; i < count; i++) {
+            final int idx = reader.read(i);
+            if (idx < minIdx) minIdx = idx;
+            if (idx > maxIdx) maxIdx = idx;
+        }
+
+        readVerticesFromVBO(minIdx, maxIdx, stride);
+        final int base = minIdx;
+        emitAllPrimitives(mode, count, i -> reader.read(i) - base, stride);
+    }
+
+    private static void computeMVP() {
+        mvpMatrix.set(GLStateManager.getProjectionMatrix()).mul(GLStateManager.getModelViewMatrix());
+    }
+
+    private static int queryPositionStride() {
+        attribBuf.clear();
+        GL20.glGetVertexAttrib(0, GL20.GL_VERTEX_ATTRIB_ARRAY_STRIDE, attribBuf);
+        return attribBuf.get(0);
+    }
+
+    private static int computeMask(int type) {
+        return switch (type) {
+            case GL11.GL_2D -> 0;
+            case GL11.GL_3D -> FB_3D;
+            case GL11.GL_3D_COLOR -> FB_3D | FB_COLOR;
+            case GL11.GL_3D_COLOR_TEXTURE -> FB_3D | FB_COLOR | FB_TEXTURE;
+            case GL11.GL_4D_COLOR_TEXTURE -> FB_3D | FB_4D | FB_COLOR | FB_TEXTURE;
+            default -> 0;
+        };
+    }
+
+    private static int elementSizeForType(int type) {
+        return switch (type) {
+            case GL11.GL_UNSIGNED_BYTE -> 1;
+            case GL11.GL_UNSIGNED_SHORT -> 2;
+            case GL11.GL_UNSIGNED_INT -> 4;
+            default -> 4;
+        };
+    }
+
+    private static int readIndex(ByteBuffer buf, int type, int i) {
+        return switch (type) {
+            case GL11.GL_UNSIGNED_BYTE -> buf.get(i) & 0xFF;
+            case GL11.GL_UNSIGNED_SHORT -> buf.getShort(i * 2) & 0xFFFF;
+            case GL11.GL_UNSIGNED_INT -> buf.getInt(i * 4);
+            default -> 0;
+        };
+    }
+
+    private static void ensureReadbackCapacity(int bytes) {
+        if (readbackBuf.capacity() < bytes) {
+            readbackBuf = ByteBuffer.allocateDirect(bytes).order(ByteOrder.nativeOrder());
+        }
+    }
+
+    private static void ensureIndexReadbackCapacity(int bytes) {
+        if (indexReadbackBuf.capacity() < bytes) {
+            indexReadbackBuf = ByteBuffer.allocateDirect(bytes).order(ByteOrder.nativeOrder());
+        }
+    }
+
+    private static long queryPositionOffset() {
+        final ByteBuffer buf = GL20.glGetVertexAttribPointer(0, GL20.GL_VERTEX_ATTRIB_ARRAY_POINTER, 8);
+        return buf == null ? 0L : buf.getLong(0);
+    }
+
+    private static void readVerticesFromVBO(int minIdx, int maxIdx, int stride) {
+        final long posOffset = queryPositionOffset();
+        final int vertexCount = maxIdx - minIdx + 1;
+        final int byteCount = vertexCount * stride;
+        ensureReadbackCapacity(byteCount);
+        readbackBuf.clear().limit(byteCount);
+        GL15.glGetBufferSubData(GL15.GL_ARRAY_BUFFER, (long) minIdx * stride + posOffset, readbackBuf);
+    }
+
+    private static void emitVertex(int vertexIndex, int stride) {
+        final float x = readbackBuf.getFloat(vertexIndex * stride);
+        final float y = readbackBuf.getFloat(vertexIndex * stride + 4);
+        final float z = readbackBuf.getFloat(vertexIndex * stride + 8);
+        transformAndEmitVertex(x, y, z);
+    }
+
+    private static void emitAllPrimitives(int mode, int count, IndexReader reader, int stride) {
+        switch (mode) {
+            case GL11.GL_POINTS:
+                for (int i = 0; i < count; i++) {
+                    feedbackToken(GL11.GL_POINT_TOKEN);
+                    emitVertex(reader.read(i), stride);
+                }
+                break;
+
+            case GL11.GL_LINES:
+                for (int i = 0; i + 1 < count; i += 2) {
+                    feedbackToken(i == 0 ? GL11.GL_LINE_RESET_TOKEN : GL11.GL_LINE_TOKEN);
+                    emitVertex(reader.read(i), stride);
+                    emitVertex(reader.read(i + 1), stride);
+                }
+                break;
+
+            case GL11.GL_LINE_STRIP:
+                for (int i = 0; i + 1 < count; i++) {
+                    feedbackToken(i == 0 ? GL11.GL_LINE_RESET_TOKEN : GL11.GL_LINE_TOKEN);
+                    emitVertex(reader.read(i), stride);
+                    emitVertex(reader.read(i + 1), stride);
+                }
+                break;
+
+            case GL11.GL_LINE_LOOP:
+                for (int i = 0; i + 1 < count; i++) {
+                    feedbackToken(i == 0 ? GL11.GL_LINE_RESET_TOKEN : GL11.GL_LINE_TOKEN);
+                    emitVertex(reader.read(i), stride);
+                    emitVertex(reader.read(i + 1), stride);
+                }
+                if (count > 2) {
+                    feedbackToken(GL11.GL_LINE_TOKEN);
+                    emitVertex(reader.read(count - 1), stride);
+                    emitVertex(reader.read(0), stride);
+                }
+                break;
+
+            case GL11.GL_TRIANGLES:
+                for (int i = 0; i + 2 < count; i += 3) {
+                    feedbackToken(GL11.GL_POLYGON_TOKEN);
+                    feedbackToken(3);
+                    emitVertex(reader.read(i), stride);
+                    emitVertex(reader.read(i + 1), stride);
+                    emitVertex(reader.read(i + 2), stride);
+                }
+                break;
+
+            case GL11.GL_TRIANGLE_STRIP:
+                for (int i = 0; i + 2 < count; i++) {
+                    feedbackToken(GL11.GL_POLYGON_TOKEN);
+                    feedbackToken(3);
+                    if ((i & 1) == 0) {
+                        emitVertex(reader.read(i), stride);
+                        emitVertex(reader.read(i + 1), stride);
+                    } else {
+                        emitVertex(reader.read(i + 1), stride);
+                        emitVertex(reader.read(i), stride);
+                    }
+                    emitVertex(reader.read(i + 2), stride);
+                }
+                break;
+
+            case GL11.GL_TRIANGLE_FAN:
+                for (int i = 1; i + 1 < count; i++) {
+                    feedbackToken(GL11.GL_POLYGON_TOKEN);
+                    feedbackToken(3);
+                    emitVertex(reader.read(0), stride);
+                    emitVertex(reader.read(i), stride);
+                    emitVertex(reader.read(i + 1), stride);
+                }
+                break;
+
+            case GL11.GL_QUADS:
+                for (int i = 0; i + 3 < count; i += 4) {
+                    feedbackToken(GL11.GL_POLYGON_TOKEN);
+                    feedbackToken(4);
+                    emitVertex(reader.read(i), stride);
+                    emitVertex(reader.read(i + 1), stride);
+                    emitVertex(reader.read(i + 2), stride);
+                    emitVertex(reader.read(i + 3), stride);
+                }
+                break;
+
+            default:
+                throw new UnsupportedOperationException("Feedback mode: unsupported primitive mode 0x" + Integer.toHexString(mode));
+        }
+    }
+
+    static void reset() {
+        renderMode = GL11.GL_RENDER;
+        feedbackBuffer = null;
+        feedbackBufferSize = 0;
+        feedbackMask = 0;
+        feedbackCount = 0;
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/GLDebug.java

@@ -620,6 +620,7 @@ public final class GLDebug {
 		private int depth = 0;
         private static final int maxDepth = GL11.glGetInteger(KHRDebug.GL_MAX_DEBUG_GROUP_STACK_DEPTH);
         private static final int maxNameLength = GL11.glGetInteger(KHRDebug.GL_MAX_LABEL_LENGTH);
+        private final String[] groupStack = new String[maxDepth + 1];
 
 		@Override
 		public void nameObject(int id, int object, String name) {
@@ -628,20 +629,28 @@ public final class GLDebug {
 
 		@Override
 		public void pushGroup(String name) {
-            depth++;
-            if (depth > maxDepth) {
-                throw new RuntimeException("Stack overflow");
+            if (depth + 1 > maxDepth) {
+                final StringBuilder sb = new StringBuilder();
+                sb.append("Debug group stack overflow (maxDepth=").append(maxDepth).append("), current stack:\n");
+                for (int i = 0; i < depth; i++) {
+                    sb.append("  [").append(i).append("] ").append(groupStack[i]).append('\n');
+                }
+                sb.append("  -> ").append(name).append(" (rejected)");
+                throw new RuntimeException(sb.toString());
             }
+            groupStack[depth] = name;
 			KHRDebug.glPushDebugGroup(KHRDebug.GL_DEBUG_SOURCE_APPLICATION, ID, name);
+            depth++;
 		}
 
 		@Override
 		public void popGroup() {
-            depth--;
-            if (depth < 0) {
+            if (depth - 1 < 0) {
                 throw new RuntimeException("Stack underflow");
             }
             KHRDebug.glPopDebugGroup();
+            depth--;
+            groupStack[depth] = null;
 		}
 
         @Override

src/main/java/com/gtnewhorizons/angelica/glsm/GlslTransformUtils.java

@@ -0,0 +1,111 @@
+package com.gtnewhorizons.angelica.glsm;
+
+import org.antlr.v4.runtime.tree.ParseTree;
+import org.antlr.v4.runtime.tree.TerminalNode;
+
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Shared GLSL shader transformation utilities.
+ */
+public class GlslTransformUtils {
+
+    private static final String RENAMED_PREFIX = "angelica_renamed_";
+
+    /** Texture function renames */
+    public static final Map<String, String> TEXTURE_RENAMES = Map.ofEntries(
+        Map.entry("texture2D", "texture"),
+        Map.entry("texture3D", "texture"),
+        Map.entry("texture2DLod", "textureLod"),
+        Map.entry("texture3DLod", "textureLod"),
+        Map.entry("texture2DProj", "textureProj"),
+        Map.entry("texture3DProj", "textureProj"),
+        Map.entry("texture2DGrad", "textureGrad"),
+        Map.entry("texture2DGradARB", "textureGrad"),
+        Map.entry("texture3DGrad", "textureGrad"),
+        Map.entry("texelFetch2D", "texelFetch"),
+        Map.entry("texelFetch3D", "texelFetch"),
+        Map.entry("textureSize2D", "textureSize")
+    );
+
+    private static final Pattern TEXTURE_PATTERN = Pattern.compile("\\btexture\\s*\\(|(\\btexture\\b)");
+
+    /** Reserved words added in later GLSL versions that may appear as identifiers in older shaders. */
+    private record ReservedWordRename(Pattern pattern, String replacement) {}
+    private static final Map<Integer, List<ReservedWordRename>> VERSIONED_RESERVED_WORDS = Map.of(
+        400, List.of(new ReservedWordRename(Pattern.compile("\\bsample\\b"), RENAMED_PREFIX + "sample"))
+    );
+
+    public static String replaceTexture(String input) {
+        final Matcher matcher = TEXTURE_PATTERN.matcher(input);
+        final StringBuilder builder = new StringBuilder();
+        while (matcher.find()) {
+            if (matcher.group(1) != null) {
+                matcher.appendReplacement(builder, RENAMED_PREFIX + "texture");
+            } else {
+                matcher.appendReplacement(builder, Matcher.quoteReplacement(matcher.group(0)));
+            }
+        }
+        matcher.appendTail(builder);
+        return builder.toString();
+    }
+
+    public static String renameReservedWords(String source, int targetVersion) {
+        for (var entry : VERSIONED_RESERVED_WORDS.entrySet()) {
+            if (targetVersion < entry.getKey()) {
+                for (var rename : entry.getValue()) {
+                    source = rename.pattern().matcher(source).replaceAll(rename.replacement());
+                }
+            }
+        }
+        return source;
+    }
+
+    public static String restoreReservedWords(String source) {
+        source = source.replace(RENAMED_PREFIX + "texture", "texture");
+        source = source.replace(RENAMED_PREFIX + "sample", "sample");
+        return source;
+    }
+
+    public static String getFormattedShader(ParseTree tree, String header) {
+        final StringBuilder sb = new StringBuilder(header + "\n");
+        final String[] tabHolder = {""};
+        getFormattedShader(tree, sb, tabHolder);
+        return sb.toString();
+    }
+
+    private static void getFormattedShader(ParseTree tree, StringBuilder stringBuilder, String[] tabHolder) {
+        if (tree instanceof TerminalNode) {
+            final String text = tree.getText();
+            if (text.equals("<EOF>")) {
+                return;
+            }
+            if (text.equals("#")) {
+                stringBuilder.append("\n#");
+                return;
+            }
+            stringBuilder.append(text);
+            if (text.equals("{")) {
+                stringBuilder.append(" \n\t");
+                tabHolder[0] = "\t";
+            }
+
+            if (text.equals("}")) {
+                if (stringBuilder.length() >= 2) {
+                    stringBuilder.deleteCharAt(stringBuilder.length() - 2);
+                }
+                tabHolder[0] = "";
+                stringBuilder.append(" \n");
+            } else {
+                stringBuilder.append(text.equals(";") ? " \n" + tabHolder[0] : " ");
+            }
+        } else {
+            for (int i = 0; i < tree.getChildCount(); ++i) {
+                getFormattedShader(tree.getChild(i), stringBuilder, tabHolder);
+            }
+        }
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/QuadConverter.java

@@ -0,0 +1,299 @@
+package com.gtnewhorizons.angelica.glsm;
+
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL15;
+
+import java.nio.ByteBuffer;
+import java.nio.IntBuffer;
+import java.nio.ShortBuffer;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAddress0;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAlloc;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memFree;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memGetByte;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memGetInt;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memGetShort;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutInt;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutShort;
+
+/**
+ * Shared quad-to-triangle EBO for core profile GL_QUADS emulation.
+ *
+ * <p>Maintains a single growable element buffer with pre-computed indices mapping
+ * GL_QUADS vertex order to GL_TRIANGLES: {@code (0,1,3, 1,2,3)} per quad.
+ * Uses {@code GL_LAST_VERTEX_CONVENTION} winding (Mesa {@code do_quad} LAST path)
+ * so both emitted triangles share the quad's provoking vertex (v3).
+ */
+public final class QuadConverter {
+    public static final int INDEX_TYPE = GL11.GL_UNSIGNED_INT;
+
+    private static int eboId;
+    private static int maxQuads;
+
+    /** Scratch EBO for converted quad-element draws (drawQuadElementsAsTriangles). */
+    private static int scratchEboId;
+    private static int scratchEboCapacity; // in bytes
+
+    private QuadConverter() {}
+
+    private static void ensureCapacity(int quadCount) {
+        if (quadCount <= maxQuads) return;
+
+        // Round up to power of 2 for amortized growth
+        int newMaxQuads = Math.max(256, maxQuads);
+        while (newMaxQuads < quadCount) {
+            newMaxQuads *= 2;
+        }
+
+        if (eboId == 0) {
+            eboId = GL15.glGenBuffers();
+        }
+
+        // Generate index data: 6 ints per quad
+        final ByteBuffer indexData = memAlloc(newMaxQuads * 6 * 4);
+        long ptr = memAddress0(indexData);
+        for (int i = 0; i < newMaxQuads; i++) {
+            final int base = i * 4;
+            // GL_LAST_VERTEX_CONVENTION: both triangles share v3 as provoking vertex
+            // Triangle 1: 0, 1, 3
+            memPutInt(ptr, base);
+            memPutInt(ptr + 4, base + 1);
+            memPutInt(ptr + 8, base + 3);
+            // Triangle 2: 1, 2, 3
+            memPutInt(ptr + 12, base + 1);
+            memPutInt(ptr + 16, base + 2);
+            memPutInt(ptr + 20, base + 3);
+            ptr += 24;
+        }
+
+        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, eboId);
+        GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, indexData, GL15.GL_STATIC_DRAW);
+
+        memFree(indexData);
+        maxQuads = newMaxQuads;
+    }
+
+    /**
+     * Convert a GL_QUADS glDrawArrays call to indexed GL_TRIANGLES.
+     * Binds the shared EBO to the current VAO and issues glDrawElements.
+     *
+     * @param first       first vertex index (must be aligned to quad boundary, i.e. multiple of 4)
+     * @param vertexCount number of vertices (must be multiple of 4)
+     */
+    public static void drawQuadsAsTriangles(int first, int vertexCount) {
+        assert first % 4 == 0 : "QuadConverter: first (" + first + ") must be a multiple of 4";
+        assert vertexCount % 4 == 0 : "QuadConverter: vertexCount (" + vertexCount + ") must be a multiple of 4";
+        final int quadCount = vertexCount / 4;
+        final int prevEbo = GLStateManager.getBoundEBO();
+        ensureCapacity(first / 4 + quadCount);
+        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, eboId);
+        // Index offset: first vertex / 4 quads * 6 indices * 4 bytes per int
+        final long indexOffset = (long) (first / 4) * 6 * 4;
+        GL11.glDrawElements(GL11.GL_TRIANGLES, quadCount * 6, INDEX_TYPE, indexOffset);
+        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, prevEbo);
+    }
+
+    /**
+     * Upload converted triangle indices to the scratch EBO and draw.
+     * Saves/restores the caller's EBO binding so subsequent indexed draws
+     * (or glGetBufferSubData reads) still see the original EBO.
+     *
+     * @param dst            off-heap buffer with triangle index data (freed by this method)
+     * @param triIndexCount  number of triangle indices
+     * @param indexType       GL_UNSIGNED_INT or GL_UNSIGNED_SHORT
+     * @param bytesPerIndex  bytes per index element
+     */
+    private static void uploadAndDraw(ByteBuffer dst, int triIndexCount, int indexType, int bytesPerIndex) {
+        final int needed = triIndexCount * bytesPerIndex;
+        final int prevEbo = GLStateManager.getBoundEBO();
+
+        if (scratchEboId == 0) {
+            scratchEboId = GL15.glGenBuffers();
+        }
+
+        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, scratchEboId);
+
+        if (needed > scratchEboCapacity) {
+            // Power-of-2 growth — allocate full capacity, upload actual data
+            int newCap = Math.max(4096, scratchEboCapacity);
+            while (newCap < needed) newCap *= 2;
+            GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, newCap, GL15.GL_STREAM_DRAW);
+            scratchEboCapacity = newCap;
+        }
+        GL15.glBufferSubData(GL15.GL_ELEMENT_ARRAY_BUFFER, 0, dst);
+
+        GL11.glDrawElements(GL11.GL_TRIANGLES, triIndexCount, indexType, 0L);
+
+        GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, prevEbo);
+        memFree(dst);
+    }
+
+    /**
+     * Convert an indexed GL_QUADS draw to GL_TRIANGLES by reading the source EBO,
+     * building a triangle index buffer, and issuing the converted draw.
+     *
+     * @param indexCount number of quad indices (must be multiple of 4)
+     * @param type       GL_UNSIGNED_INT, GL_UNSIGNED_SHORT, or GL_UNSIGNED_BYTE
+     * @param offset     byte offset into the currently bound EBO
+     */
+    public static void drawQuadElementsAsTriangles(int indexCount, int type, long offset) {
+        if (indexCount == 0) return;
+        assert indexCount % 4 == 0 : "QuadConverter: indexCount must be multiple of 4";
+        final int quadCount = indexCount / 4;
+        final int triIndexCount = quadCount * 6;
+
+        final int bytesPerIndex;
+        switch (type) {
+            case GL11.GL_UNSIGNED_INT: bytesPerIndex = 4; break;
+            case GL11.GL_UNSIGNED_SHORT: bytesPerIndex = 2; break;
+            case GL11.GL_UNSIGNED_BYTE: bytesPerIndex = 1; break;
+            default: return;
+        }
+
+        // Read source indices from caller's EBO
+        final ByteBuffer src = memAlloc(indexCount * bytesPerIndex);
+        GL15.glGetBufferSubData(GL15.GL_ELEMENT_ARRAY_BUFFER, offset, src);
+        final long srcAddr = memAddress0(src);
+
+        // Allocate output as GL_UNSIGNED_INT
+        final ByteBuffer dst = memAlloc(triIndexCount * 4);
+        final long dstAddr = memAddress0(dst);
+
+        for (int i = 0; i < quadCount; i++) {
+            final int a, b, c, d;
+            switch (type) {
+                case GL11.GL_UNSIGNED_INT -> {
+                    final long p = srcAddr + (long) i * 16;
+                    a = memGetInt(p); b = memGetInt(p + 4); c = memGetInt(p + 8); d = memGetInt(p + 12);
+                }
+                case GL11.GL_UNSIGNED_SHORT -> {
+                    final long p = srcAddr + (long) i * 8;
+                    a = memGetShort(p) & 0xFFFF; b = memGetShort(p + 2) & 0xFFFF;
+                    c = memGetShort(p + 4) & 0xFFFF; d = memGetShort(p + 6) & 0xFFFF;
+                }
+                default /* GL_UNSIGNED_BYTE */ -> {
+                    final long p = srcAddr + (long) i * 4;
+                    a = memGetByte(p) & 0xFF; b = memGetByte(p + 1) & 0xFF;
+                    c = memGetByte(p + 2) & 0xFF; d = memGetByte(p + 3) & 0xFF;
+                }
+            }
+            // GL_LAST_VERTEX_CONVENTION: (a,b,d), (b,c,d)
+            final long o = (long) i * 24;
+            memPutInt(dstAddr + o, a);
+            memPutInt(dstAddr + o + 4, b);
+            memPutInt(dstAddr + o + 8, d);
+            memPutInt(dstAddr + o + 12, b);
+            memPutInt(dstAddr + o + 16, c);
+            memPutInt(dstAddr + o + 20, d);
+        }
+
+        memFree(src);
+        uploadAndDraw(dst, triIndexCount, GL11.GL_UNSIGNED_INT, 4);
+    }
+
+    /**
+     * Convert a client-side IntBuffer of quad indices to triangles.
+     */
+    public static void drawQuadElementsAsTriangles(IntBuffer indices) {
+        final int indexCount = indices.remaining();
+        if (indexCount == 0) return;
+        assert indexCount % 4 == 0;
+        final int quadCount = indexCount / 4;
+        final int triIndexCount = quadCount * 6;
+
+        final ByteBuffer dst = memAlloc(triIndexCount * 4);
+        final long dstAddr = memAddress0(dst);
+        final int basePos = indices.position();
+
+        for (int i = 0; i < quadCount; i++) {
+            final int base = basePos + i * 4;
+            final int a = indices.get(base), b = indices.get(base + 1), c = indices.get(base + 2), d = indices.get(base + 3);
+            final long o = (long) i * 24;
+            memPutInt(dstAddr + o, a);     memPutInt(dstAddr + o + 4, b);  memPutInt(dstAddr + o + 8, d);
+            memPutInt(dstAddr + o + 12, b); memPutInt(dstAddr + o + 16, c); memPutInt(dstAddr + o + 20, d);
+        }
+
+        uploadAndDraw(dst, triIndexCount, GL11.GL_UNSIGNED_INT, 4);
+    }
+
+    /**
+     * Convert a client-side ShortBuffer of quad indices to triangles.
+     */
+    public static void drawQuadElementsAsTriangles(ShortBuffer indices) {
+        final int indexCount = indices.remaining();
+        if (indexCount == 0) return;
+        assert indexCount % 4 == 0;
+        final int quadCount = indexCount / 4;
+        final int triIndexCount = quadCount * 6;
+
+        final ByteBuffer dst = memAlloc(triIndexCount * 2);
+        final long dstAddr = memAddress0(dst);
+        final int basePos = indices.position();
+
+        for (int i = 0; i < quadCount; i++) {
+            final int base = basePos + i * 4;
+            final short a = indices.get(base), b = indices.get(base + 1), c = indices.get(base + 2), d = indices.get(base + 3);
+            final long o = (long) i * 12;
+            memPutShort(dstAddr + o, a);     memPutShort(dstAddr + o + 2, b);  memPutShort(dstAddr + o + 4, d);
+            memPutShort(dstAddr + o + 6, b); memPutShort(dstAddr + o + 8, c);  memPutShort(dstAddr + o + 10, d);
+        }
+
+        uploadAndDraw(dst, triIndexCount, GL11.GL_UNSIGNED_SHORT, 2);
+    }
+
+    /**
+     * Convert a client-side ByteBuffer of quad indices (type-agnostic) to triangles.
+     */
+    public static void drawQuadElementsAsTriangles(int count, int type, ByteBuffer indices) {
+        if (count == 0) return;
+        assert count % 4 == 0;
+        final int quadCount = count / 4;
+        final int triIndexCount = quadCount * 6;
+        final long srcAddr = memAddress0(indices) + indices.position();
+
+        final ByteBuffer dst = memAlloc(triIndexCount * 4);
+        final long dstAddr = memAddress0(dst);
+
+        for (int i = 0; i < quadCount; i++) {
+            final int a, b, c, d;
+            switch (type) {
+                case GL11.GL_UNSIGNED_INT -> {
+                    final long p = srcAddr + (long) i * 16;
+                    a = memGetInt(p); b = memGetInt(p + 4); c = memGetInt(p + 8); d = memGetInt(p + 12);
+                }
+                case GL11.GL_UNSIGNED_SHORT -> {
+                    final long p = srcAddr + (long) i * 8;
+                    a = memGetShort(p) & 0xFFFF; b = memGetShort(p + 2) & 0xFFFF;
+                    c = memGetShort(p + 4) & 0xFFFF; d = memGetShort(p + 6) & 0xFFFF;
+                }
+                case GL11.GL_UNSIGNED_BYTE -> {
+                    final long p = srcAddr + (long) i * 4;
+                    a = memGetByte(p) & 0xFF; b = memGetByte(p + 1) & 0xFF;
+                    c = memGetByte(p + 2) & 0xFF; d = memGetByte(p + 3) & 0xFF;
+                }
+                default -> { memFree(dst); return; }
+            }
+            final long o = (long) i * 24;
+            memPutInt(dstAddr + o, a);     memPutInt(dstAddr + o + 4, b);  memPutInt(dstAddr + o + 8, d);
+            memPutInt(dstAddr + o + 12, b); memPutInt(dstAddr + o + 16, c); memPutInt(dstAddr + o + 20, d);
+        }
+
+        uploadAndDraw(dst, triIndexCount, GL11.GL_UNSIGNED_INT, 4);
+    }
+
+    /**
+     * Clean up the shared EBO.
+     */
+    public static void destroy() {
+        if (eboId != 0) {
+            GL15.glDeleteBuffers(eboId);
+            eboId = 0;
+            maxQuads = 0;
+        }
+        if (scratchEboId != 0) {
+            GL15.glDeleteBuffers(scratchEboId);
+            scratchEboId = 0;
+            scratchEboCapacity = 0;
+        }
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/RenderSystem.java

@@ -1,10 +1,13 @@
 package com.gtnewhorizons.angelica.glsm;
 
-import com.gtnewhorizons.angelica.glsm.dsa.DSAARB;
 import com.gtnewhorizons.angelica.glsm.dsa.DSAAccess;
+import com.gtnewhorizons.angelica.glsm.dsa.DSAARB;
 import com.gtnewhorizons.angelica.glsm.dsa.DSACore;
+import com.gtnewhorizons.angelica.glsm.dsa.DSAEXT;
 import com.gtnewhorizons.angelica.glsm.dsa.DSAUnsupported;
+import com.gtnewhorizons.angelica.glsm.ffp.ShaderManager;
 import com.gtnewhorizons.angelica.glsm.texture.TextureInfoCache;
+import net.coderbot.iris.gl.shader.StandardMacros;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.jetbrains.annotations.Nullable;
@@ -22,6 +25,7 @@ import org.lwjgl.opengl.GL12;
 import org.lwjgl.opengl.GL15;
 import org.lwjgl.opengl.GL20;
 import org.lwjgl.opengl.GL30;
+import org.lwjgl.opengl.GL32;
 import org.lwjgl.opengl.GL33;
 import org.lwjgl.opengl.GL40;
 import org.lwjgl.opengl.GL42;
@@ -29,8 +33,6 @@ import org.lwjgl.opengl.GL43;
 import org.lwjgl.opengl.GL44;
 import org.lwjgl.opengl.NVXGpuMemoryInfo;
 
-import net.coderbot.iris.gl.shader.StandardMacros;
-
 import java.nio.ByteBuffer;
 import java.nio.FloatBuffer;
 import java.nio.IntBuffer;
@@ -62,7 +64,7 @@ public class RenderSystem {
 	public static void initRenderer() {
         try {
             if (GLStateManager.capabilities.OpenGL45) {
-                dsaState = new DSACore();
+                dsaState = (Runtime.version().feature() > 8 && GLStateManager.capabilities.GL_EXT_direct_state_access) ? new DSAEXT() : new DSACore();
                 LOGGER.info("OpenGL 4.5 detected, enabling DSA.");
             }
 
@@ -124,6 +126,15 @@ public class RenderSystem {
 		LOGGER.info("Image Load/Store: {}, Max Image Units: {}", supportsImageLoadStore, maxImageUnits);
 		LOGGER.info("SSBO: {}, Max SSBO Bindings: {}", supportsSSBO, maxSSBOBindings);
 		LOGGER.info("Buffer Storage: {}, Clear Texture: {}, Sampler Objects: {}", supportsBufferStorage, supportsClearTexture, supportsSamplerObjects);
+
+		if (GLStateManager.capabilities.OpenGL32) {
+			final int profileMask = GL11.glGetInteger(GL32.GL_CONTEXT_PROFILE_MASK);
+			if ((profileMask & GL32.GL_CONTEXT_CORE_PROFILE_BIT) != 0) {
+				LOGGER.info("GL 3.3 core profile detected, enabling FFP shader emulation.");
+				ShaderManager.getInstance().enable();
+				GLStateManager.lineWidthMax = 1.0f;
+			}
+		}
 	}
 
 	public static void generateMipmaps(int texture, int mipmapTarget) {
@@ -347,10 +358,12 @@ public class RenderSystem {
 
 	public static void disableBufferBlend(int buffer) {
 		GL30.glDisablei(GL11.GL_BLEND, buffer);
+		GLStateManager.getBlendMode().setUnknownState();
 	}
 
 	public static void enableBufferBlend(int buffer) {
 		GL30.glEnablei(GL11.GL_BLEND, buffer);
+		GLStateManager.getBlendMode().setUnknownState();
 	}
 
 	public static void blendFuncSeparatei(int buffer, int srcRGB, int dstRGB, int srcAlpha, int dstAlpha) {

src/main/java/com/gtnewhorizons/angelica/glsm/dsa/DSAARB.java

@@ -40,6 +40,7 @@ public class DSAARB extends DSAUnsupported {
 
     @Override
     public void texParameteri(int texture, int target, int pname, int param) {
+        param = GLStateManager.remapTexClamp(pname, param);
         if(!GLStateManager.updateTexParameteriCache(target, texture, pname, param)) return;
 
         ARBDirectStateAccess.glTextureParameteri(texture, pname, param);
@@ -47,6 +48,7 @@ public class DSAARB extends DSAUnsupported {
 
     @Override
     public void texParameterf(int texture, int target, int pname, float param) {
+        param = GLStateManager.remapTexClamp(pname, param);
         if(!GLStateManager.updateTexParameterfCache(target, texture, pname, param)) return;
 
         ARBDirectStateAccess.glTextureParameterf(texture, pname, param);
@@ -54,6 +56,7 @@ public class DSAARB extends DSAUnsupported {
 
     @Override
     public void texParameteriv(int texture, int target, int pname, IntBuffer params) {
+        GLStateManager.remapTexClampBuffer(pname, params);
         ARBDirectStateAccess.glTextureParameter(texture, pname, params);
     }
 

src/main/java/com/gtnewhorizons/angelica/glsm/dsa/DSAEXT.java

@@ -0,0 +1,18 @@
+package com.gtnewhorizons.angelica.glsm.dsa;
+
+import org.lwjgl.opengl.EXTDirectStateAccess;
+
+import java.nio.ByteBuffer;
+import java.nio.IntBuffer;
+
+public class DSAEXT extends DSACore {
+    @Override
+    public void textureImage2D(int texture, int target, int level, int internalformat, int width, int height, int border, int format, int type, ByteBuffer pixels) {
+        EXTDirectStateAccess.glTextureImage2DEXT(texture, target, level, internalformat, width, height, border, format, type, pixels);
+    }
+
+    @Override
+    public void textureImage2D(int texture, int target, int level, int internalformat, int width, int height, int border, int format, int type, IntBuffer pixels) {
+        EXTDirectStateAccess.glTextureImage2DEXT(texture, target, level, internalformat, width, height, border, format, type, pixels);
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/DeferredBatchTessellator.java

@@ -0,0 +1,92 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.github.bsideup.jabel.Desugar;
+import com.gtnewhorizon.gtnhlib.client.renderer.DirectTessellator;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFlags;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFormat;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import net.minecraft.client.renderer.Tessellator;
+import org.joml.Matrix4f;
+import org.joml.Matrix4fc;
+import org.joml.Vector3f;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memCopy;
+
+/**
+ * DirectTessellator subclass for deferred particle batching. Accumulates vertex data from
+ * multiple interceptDraw() calls, recording per-draw metadata as {@link DrawRange} entries.
+ * Computes a delta modelview matrix at each intercept to pre-transform vertices.
+ */
+class DeferredBatchTessellator extends DirectTessellator {
+
+    @Desugar
+    record DrawRange(long stateKey, int byteOffset, int byteLength, int vertexCount, int drawMode, int flags) {}
+
+    private final List<DrawRange> ranges = new ArrayList<>();
+    private final Matrix4f defaultModelview = new Matrix4f();
+    private final Matrix4f defaultModelviewInverse = new Matrix4f();
+    private final Matrix4f deltaMatrix = new Matrix4f(); // reusable scratch
+    private final Vector3f scratch = new Vector3f();
+    private Matrix4fc currentTransform;
+
+    DeferredBatchTessellator(ByteBuffer buffer) {
+        super(buffer, false); // deleteAfter=false: keep buffer across resets for reuse
+    }
+
+    @Override
+    protected long writeVertexData(VertexFormat format, int[] rawBuffer, int rawBufferIndex) {
+        if (currentTransform != null) {
+            return format.writeToBuffer0(writePtr, rawBuffer, rawBufferIndex, currentTransform, scratch);
+        }
+        return super.writeVertexData(format, rawBuffer, rawBufferIndex);
+    }
+
+    /** Snapshot the current modelview as the "default" for this bracket. */
+    void snapshotDefaultModelview() {
+        defaultModelview.set(GLStateManager.getModelViewMatrix());
+        defaultModelview.invert(defaultModelviewInverse);
+    }
+
+    @Override
+    protected int interceptDraw(Tessellator tess) {
+        // Compute delta: if current MV differs from default, pre-transform vertices
+        final Matrix4f currentMV = GLStateManager.getModelViewMatrix();
+        if (!currentMV.equals(defaultModelview)) {
+            defaultModelviewInverse.mul(currentMV, deltaMatrix);
+            this.currentTransform = deltaMatrix;
+        } else {
+            this.currentTransform = null;
+        }
+
+        final int byteOffsetBefore = bufferLimit();
+        final int vertCount = tess.vertexCount;
+        final int drawMode = tess.drawMode;
+        final int flags = VertexFlags.convertToFlags(tess.hasTexture, tess.hasColor, tess.hasNormals, tess.hasBrightness);
+        final long stateKey = DeferredDrawBatcher.captureStateKey();
+
+        final int result = super.interceptDraw(tess); // repacks int[] → ByteBuffer + transforms if vertexTransform set
+
+        final int byteOffsetAfter = bufferLimit();
+        ranges.add(new DrawRange(stateKey, byteOffsetBefore, byteOffsetAfter - byteOffsetBefore, vertCount, drawMode, flags));
+        this.currentTransform = null; // clear for next draw
+        return result;
+    }
+
+    List<DrawRange> getRanges() { return ranges; }
+
+    void clearRanges() { ranges.clear(); }
+
+    void copyRange(int byteOffset, int byteLength, long destAddress) {
+        memCopy(startPtr + byteOffset, destAddress, byteLength);
+    }
+
+    @Override
+    protected void onRemovedFromStack() {
+        clearRanges();
+        super.onRemovedFromStack(); // calls reset(), keeps baseBuffer (deleteAfter=false)
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/DeferredDrawBatcher.java

@@ -0,0 +1,173 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.TessellatorManager;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import lombok.Getter;
+import org.lwjgl.opengl.GL11;
+
+import java.util.Comparator;
+import java.util.List;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAlloc;
+
+/**
+ * Deferred draw batching coordinator. During rendering regions (e.g. particles),
+ * intercepts tessellator.draw() calls via DirectTessellator, captures pre-packed vertex data
+ * + GL state, then flushes all captured batches sorted by state key.
+ * <p>
+ * Vertices are pre-transformed at capture time.
+ */
+public class DeferredDrawBatcher {
+
+    private static final int INITIAL_BUFFER_SIZE = 64 * 1024;
+
+    @Getter private static boolean active = false;
+    private static DeferredBatchTessellator batchTessellator;
+
+    private DeferredDrawBatcher() {}
+
+    /**
+     * Begin deferred capture mode. Called after startDrawingQuads().
+     * Pushes a DeferredBatchTessellator onto the DirectTessellator stack so that
+     * subsequent tessellator.draw() calls are intercepted and accumulated.
+     */
+    public static void enter() {
+        active = true;
+        if (batchTessellator == null) {
+            batchTessellator = new DeferredBatchTessellator(memAlloc(INITIAL_BUFFER_SIZE));
+        }
+        batchTessellator.clearRanges();
+        batchTessellator.snapshotDefaultModelview();
+        TessellatorManager.startCapturingDirect(batchTessellator);
+    }
+
+    /**
+     * Exit deferred mode and flush all captured batches. Groups entries by state key
+     * and vertex format, issues one draw per unique group. Restores the GL state that
+     * was active for the last group so vanilla sees consistent state.
+     */
+    public static void exitAndFlush() {
+        active = false;
+        final List<DeferredBatchTessellator.DrawRange> ranges = batchTessellator.getRanges();
+
+        if (!ranges.isEmpty()) {
+            ranges.sort(Comparator.comparingLong(DeferredBatchTessellator.DrawRange::stateKey));
+            flushSorted(ranges);
+        }
+
+        TessellatorManager.stopCapturingDirect();
+    }
+
+    private static void flushSorted(List<DeferredBatchTessellator.DrawRange> ranges) {
+        long currentKey = ranges.get(0).stateKey();
+        int groupStart = 0;
+
+        for (int i = 0; i <= ranges.size(); i++) {
+            final boolean endOfList = (i == ranges.size());
+            final boolean keyChanged = !endOfList && ranges.get(i).stateKey() != currentKey;
+
+            if (endOfList || keyChanged) {
+                applyStateKey(currentKey);
+                flushGroup(ranges, groupStart, i);
+
+                if (!endOfList) {
+                    currentKey = ranges.get(i).stateKey();
+                    groupStart = i;
+                }
+            }
+        }
+    }
+
+    /**
+     * Flush a group of ranges sharing the same state key.
+     * Subgroups by (drawMode, format flags) since those must match for merged draws.
+     */
+    private static void flushGroup(List<DeferredBatchTessellator.DrawRange> ranges, int from, int to) {
+        int i = from;
+        while (i < to) {
+            final DeferredBatchTessellator.DrawRange first = ranges.get(i);
+            final int drawMode = first.drawMode();
+            final int flags = first.flags();
+
+            int totalBytes = 0;
+            int totalVertices = 0;
+            int subEnd = i;
+
+            while (subEnd < to) {
+                final DeferredBatchTessellator.DrawRange e = ranges.get(subEnd);
+                if (e.drawMode() != drawMode || e.flags() != flags) break;
+                totalBytes += e.byteLength();
+                totalVertices += e.vertexCount();
+                subEnd++;
+            }
+
+            TessellatorStreamingDrawer.drawPackedBatch(
+                batchTessellator, ranges, i, subEnd, totalBytes, totalVertices, drawMode, flags);
+
+            i = subEnd;
+        }
+    }
+
+    /**
+     * Pack current GLSM state into a long key for grouping.
+     * Layout: [tex1En:1][tex0En:1][textureId:20][srcRgb:12][dstRgb:12][blendEnabled:1][depthMask:1] = 48 bits
+     * GL blend constants (e.g. GL_SRC_ALPHA=0x0302) need 12 bits.
+     *
+     * NOT captured (uniform within a particle layer bracket — set once before startDrawingQuads,
+     * not changed by individual particles):
+     * - depth test enable (always GL_LEQUAL for particles)
+     * - alpha test func/ref (set per-layer, not per-particle)
+     * - separate blend alpha factors (srcAlpha/dstAlpha) — particles use glBlendFunc not glBlendFuncSeparate
+     * - fog state (mode, color, start/end — constant for the frame)
+     */
+    static long captureStateKey() {
+        final int textureId = GLStateManager.getTextures().getTextureUnitBindings(0).getBinding();
+        final int srcRgb = GLStateManager.getBlendState().getSrcRgb();
+        final int dstRgb = GLStateManager.getBlendState().getDstRgb();
+        final boolean blendEnabled = GLStateManager.getBlendMode().isEnabled();
+        final boolean depthMask = GLStateManager.getDepthState().isEnabled();
+        final boolean tex0Enabled = GLStateManager.getTextures().getTextureUnitStates(0).isEnabled();
+        final boolean tex1Enabled = GLStateManager.getTextures().getTextureUnitStates(1).isEnabled();
+
+        return packStateKey(textureId, srcRgb, dstRgb, blendEnabled, depthMask, tex0Enabled, tex1Enabled);
+    }
+
+    static long packStateKey(int textureId, int srcRgb, int dstRgb, boolean blendEnabled, boolean depthMask, boolean tex0Enabled, boolean tex1Enabled) {
+        return ((long) (textureId & 0xFFFFF) << 26)
+            | ((long) (srcRgb & 0xFFF) << 14)
+            | ((long) (dstRgb & 0xFFF) << 2)
+            | (blendEnabled ? 2L : 0L)
+            | (depthMask ? 1L : 0L)
+            | (tex0Enabled ? (1L << 46) : 0L)
+            | (tex1Enabled ? (1L << 47) : 0L);
+    }
+
+    static int unpackTextureId(long key) { return (int) ((key >> 26) & 0xFFFFF); }
+    static int unpackSrcRgb(long key) { return (int) ((key >> 14) & 0xFFF); }
+    static int unpackDstRgb(long key) { return (int) ((key >> 2) & 0xFFF); }
+    static boolean unpackBlendEnabled(long key) { return (key & 2L) != 0; }
+    static boolean unpackDepthMask(long key) { return (key & 1L) != 0; }
+    static boolean unpackTex0Enabled(long key) { return (key & (1L << 46)) != 0; }
+    static boolean unpackTex1Enabled(long key) { return (key & (1L << 47)) != 0; }
+
+    static void applyStateKey(long key) {
+        final int textureId = unpackTextureId(key);
+        final int srcRgb = unpackSrcRgb(key);
+        final int dstRgb = unpackDstRgb(key);
+        final boolean blendEnabled = unpackBlendEnabled(key);
+        final boolean depthMask = unpackDepthMask(key);
+        final boolean tex0Enabled = unpackTex0Enabled(key);
+        final boolean tex1Enabled = unpackTex1Enabled(key);
+
+        GLStateManager.getTextures().getTextureUnitStates(0).setEnabled(tex0Enabled);
+        GLStateManager.getTextures().getTextureUnitStates(1).setEnabled(tex1Enabled);
+        GLStateManager.glBindTexture(GL11.GL_TEXTURE_2D, textureId);
+        GLStateManager.glBlendFunc(srcRgb, dstRgb);
+        if (blendEnabled) {
+            GLStateManager.enableBlend();
+        } else {
+            GLStateManager.disableBlend();
+        }
+        GLStateManager.glDepthMask(depthMask);
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/FragmentKey.java

@@ -0,0 +1,368 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import java.util.Arrays;
+
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.states.TexEnvState;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL12;
+import org.lwjgl.opengl.GL13;
+
+/**
+ * Packed-long fragment shader permutation key for FFP emulation.
+ *
+ * Layout:
+ *   long[0]: global bits (10) + unit 0 (47 bits at offset 10)
+ *   long[1..3]: unit 1..3 (47 bits each, low-aligned)
+ * Only max(1, nrEnabledUnits) longs are significant.
+ *
+ * Per-unit packing (47 bits):
+ *   0:     enabled
+ *   1-3:   mode (MODULATE=0..COMBINE=5)
+ *   4:     needsEnvColor
+ *   5-8:   combineRgb (encoded 0-7)
+ *   9-12:  combineAlpha (encoded 0-7)
+ *   13-14: scaleShiftRgb
+ *   15-16: scaleShiftAlpha
+ *   17-21: arg0 RGB (source:3 + operand:2)
+ *   22-26: arg1 RGB
+ *   27-31: arg2 RGB
+ *   32-36: arg0 Alpha
+ *   37-41: arg1 Alpha
+ *   42-46: arg2 Alpha
+ */
+public final class FragmentKey {
+    private static final Logger LOGGER = LogManager.getLogger("FragmentKey");
+
+    public static final int TEX_ENV_MODULATE = 0;
+    public static final int TEX_ENV_REPLACE  = 1;
+    public static final int TEX_ENV_ADD      = 2;
+    public static final int TEX_ENV_DECAL    = 3;
+    public static final int TEX_ENV_BLEND    = 4;
+    public static final int TEX_ENV_COMBINE  = 5;
+
+    public static final int COMBINE_REPLACE      = 0;
+    public static final int COMBINE_MODULATE     = 1;
+    public static final int COMBINE_ADD          = 2;
+    public static final int COMBINE_ADD_SIGNED   = 3;
+    public static final int COMBINE_INTERPOLATE  = 4;
+    public static final int COMBINE_SUBTRACT     = 5;
+    public static final int COMBINE_DOT3_RGB     = 6;
+    public static final int COMBINE_DOT3_RGBA    = 7;
+
+    public static final int SRC_TEXTURE       = 0;
+    public static final int SRC_CONSTANT      = 1;
+    public static final int SRC_PRIMARY_COLOR = 2;
+    public static final int SRC_PREVIOUS      = 3;
+
+    public static final int OP_SRC_COLOR           = 0;
+    public static final int OP_ONE_MINUS_SRC_COLOR = 1;
+    public static final int OP_SRC_ALPHA           = 2;
+    public static final int OP_ONE_MINUS_SRC_ALPHA = 3;
+
+    public static final int FOG_NONE   = 0;
+    public static final int FOG_LINEAR = 1;
+    public static final int FOG_EXP    = 2;
+    public static final int FOG_EXP2   = 3;
+
+    private static final int GLOBAL_BITS = 10;
+    private static final int BIT_FOG_MODE          = 0;  // 2 bits
+    private static final int BIT_ALPHA_TEST        = 2;  // 1 bit
+    private static final int BIT_ALPHA_FUNC        = 3;  // 3 bits
+    private static final int BIT_SEPARATE_SPECULAR = 6;  // 1 bit
+    private static final int BIT_NR_ENABLED_UNITS  = 7;  // 3 bits
+
+    private static final int U_ENABLED         = 0;
+    private static final int U_MODE            = 1;   // 3 bits
+    private static final int U_NEEDS_ENV_COLOR = 4;   // 1 bit
+    private static final int U_COMBINE_RGB     = 5;   // 4 bits
+    private static final int U_COMBINE_ALPHA   = 9;   // 4 bits
+    private static final int U_SCALE_RGB       = 13;  // 2 bits
+    private static final int U_SCALE_ALPHA     = 15;  // 2 bits
+    private static final int U_ARG0_RGB        = 17;  // 5 bits (source:3 + operand:2)
+    private static final int U_ARG1_RGB        = 22;  // 5 bits
+    private static final int U_ARG2_RGB        = 27;  // 5 bits
+    private static final int U_ARG0_ALPHA      = 32;  // 5 bits
+    private static final int U_ARG1_ALPHA      = 37;  // 5 bits
+    private static final int U_ARG2_ALPHA      = 42;  // 5 bits
+
+    static final int MAX_UNITS = 4;
+
+    private final long[] packed;
+    private final int hash;
+
+    private FragmentKey(long[] packed, int hash) {
+        this.packed = packed;
+        this.hash = hash;
+    }
+
+    /**
+     * Pack current GLSM fragment state into pre-allocated output array.
+     * @param out must be at least MAX_UNITS (4) longs
+     * @return number of significant longs (1..4)
+     */
+    public static int packFromState(long[] out) {
+        long global = 0;
+
+        // Fog
+        if (GLStateManager.getFogMode().isEnabled()) {
+            final int fogMode = switch (GLStateManager.getFogState().getFogMode()) {
+                case GL11.GL_LINEAR -> FOG_LINEAR;
+                case GL11.GL_EXP    -> FOG_EXP;
+                case GL11.GL_EXP2   -> FOG_EXP2;
+                default -> FOG_NONE;
+            };
+            global |= (long) fogMode;
+        }
+
+        // Alpha test
+        if (GLStateManager.getAlphaTest().isEnabled()) {
+            global |= (1L << BIT_ALPHA_TEST);
+            global |= ((long) (encodeAlphaFunc(GLStateManager.getAlphaState().getFunction()) & 0x7)) << BIT_ALPHA_FUNC;
+        }
+
+        // Separate specular
+        if (GLStateManager.getLightingState().isEnabled()
+            && GLStateManager.getLightModel().colorControl == GL12.GL_SEPARATE_SPECULAR_COLOR) {
+            global |= (1L << BIT_SEPARATE_SPECULAR);
+        }
+
+        // Per-unit state
+        int highestEnabled = -1;
+        long unit0Bits = 0;
+        for (int i = 0; i < MAX_UNITS; i++) {
+            final boolean texEnabled = GLStateManager.getTextures().getTextureUnitStates(i).isEnabled();
+            if (texEnabled) highestEnabled = i;
+
+            final long unitBits = packUnit(i, texEnabled);
+            if (i == 0) {
+                unit0Bits = unitBits;
+            } else {
+                out[i] = unitBits;
+            }
+        }
+
+        final int nrEnabled = highestEnabled + 1;
+        global |= ((long) (nrEnabled & 0x7)) << BIT_NR_ENABLED_UNITS;
+        global |= (unit0Bits << GLOBAL_BITS);
+        out[0] = global;
+
+        return Math.max(1, nrEnabled);
+    }
+
+    private static long packUnit(int unitIndex, boolean texEnabled) {
+        if (!texEnabled) return 0;
+
+        final TexEnvState envState = GLStateManager.getTextures().getTexEnvState(unitIndex);
+        final int mode = encodeTexEnvMode(envState.mode);
+
+        long bits = 1L; // enabled
+        bits |= ((long) (mode & 0x7)) << U_MODE;
+
+        boolean needsEnvColor = (mode == TEX_ENV_BLEND);
+
+        if (mode == TEX_ENV_COMBINE) {
+            final int combRgb = encodeCombineFunc(envState.combineRgb);
+            final int combAlpha = encodeCombineFunc(envState.combineAlpha);
+            bits |= ((long) (combRgb & 0xF)) << U_COMBINE_RGB;
+            bits |= ((long) (combAlpha & 0xF)) << U_COMBINE_ALPHA;
+            bits |= ((long) (encodeScale(envState.scaleRgb) & 0x3)) << U_SCALE_RGB;
+            bits |= ((long) (encodeScale(envState.scaleAlpha) & 0x3)) << U_SCALE_ALPHA;
+
+            // Only pack args actually used by each channel's combine function.
+            // Unused arg slots stay 0, preventing TexEnvState defaults from inflating the cache.
+            final int numArgsRgb = combineNumArgs(combRgb);
+            final int numArgsAlpha = combineNumArgs(combAlpha);
+            final int maxArgs = Math.max(numArgsRgb, numArgsAlpha);
+
+            for (int a = 0; a < maxArgs; a++) {
+                if (a < numArgsRgb) {
+                    final int srcR = encodeSource(envState.sourceRgb[a]);
+                    final int opR = encodeOperand(envState.operandRgb[a]);
+                    bits |= ((long) ((srcR & 0x7) | ((opR & 0x3) << 3))) << (U_ARG0_RGB + a * 5);
+                    if (srcR == SRC_CONSTANT) needsEnvColor = true;
+                }
+                if (a < numArgsAlpha) {
+                    final int srcA = encodeSource(envState.sourceAlpha[a]);
+                    final int opA = encodeOperand(envState.operandAlpha[a]);
+                    bits |= ((long) ((srcA & 0x7) | ((opA & 0x3) << 3))) << (U_ARG0_ALPHA + a * 5);
+                    if (srcA == SRC_CONSTANT) needsEnvColor = true;
+                }
+            }
+        }
+
+        if (needsEnvColor) {
+            bits |= (1L << U_NEEDS_ENV_COLOR);
+        }
+
+        return bits;
+    }
+
+    /** Create FragmentKey from packed scratch data. Only called on cache miss. */
+    public static FragmentKey fromPacked(long[] scratch, int len) {
+        final long[] copy = Arrays.copyOf(scratch, len);
+        return new FragmentKey(copy, Arrays.hashCode(copy));
+    }
+
+    /** Convenience: pack + create. Allocates. For infrequent paths. */
+    public static FragmentKey fromState() {
+        final long[] scratch = new long[MAX_UNITS];
+        final int len = packFromState(scratch);
+        return fromPacked(scratch, len);
+    }
+
+    @Override
+    public int hashCode() {
+        return hash;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+        if (!(obj instanceof FragmentKey other)) return false;
+        if (hash != other.hash) return false;
+        return Arrays.equals(packed, other.packed);
+    }
+
+    public int fogMode()              { return (int) (packed[0] & 0x3); }
+    public boolean alphaTestEnabled() { return ((packed[0] >> BIT_ALPHA_TEST) & 1) != 0; }
+    public int alphaTestFunc()        { return (int) ((packed[0] >> BIT_ALPHA_FUNC) & 0x7); }
+    public boolean separateSpecular() { return ((packed[0] >> BIT_SEPARATE_SPECULAR) & 1) != 0; }
+    public int nrEnabledUnits()       { return (int) ((packed[0] >> BIT_NR_ENABLED_UNITS) & 0x7); }
+
+    private long unitBits(int i) {
+        return (i == 0) ? (packed[0] >>> GLOBAL_BITS) : packed[i];
+    }
+
+    public boolean unitEnabled(int i)       { return (unitBits(i) & 1) != 0; }
+    public int unitMode(int i)              { return (int) ((unitBits(i) >> U_MODE) & 0x7); }
+    public boolean unitNeedsEnvColor(int i) { return ((unitBits(i) >> U_NEEDS_ENV_COLOR) & 1) != 0; }
+    public int unitCombineRgb(int i)        { return (int) ((unitBits(i) >> U_COMBINE_RGB) & 0xF); }
+    public int unitCombineAlpha(int i)      { return (int) ((unitBits(i) >> U_COMBINE_ALPHA) & 0xF); }
+    public int unitScaleShiftRgb(int i)     { return (int) ((unitBits(i) >> U_SCALE_RGB) & 0x3); }
+    public int unitScaleShiftAlpha(int i)   { return (int) ((unitBits(i) >> U_SCALE_ALPHA) & 0x3); }
+
+    public int unitSourceRgb(int i, int arg)    { return (int) ((unitBits(i) >> (U_ARG0_RGB + arg * 5)) & 0x7); }
+    public int unitOperandRgb(int i, int arg)   { return (int) ((unitBits(i) >> (U_ARG0_RGB + arg * 5 + 3)) & 0x3); }
+    public int unitSourceAlpha(int i, int arg)  { return (int) ((unitBits(i) >> (U_ARG0_ALPHA + arg * 5)) & 0x7); }
+    public int unitOperandAlpha(int i, int arg) { return (int) ((unitBits(i) >> (U_ARG0_ALPHA + arg * 5 + 3)) & 0x3); }
+
+    public boolean textureEnabled() {
+        for (int i = 0; i < nrEnabledUnits(); i++) {
+            if (unitEnabled(i)) return true;
+        }
+        return false;
+    }
+
+    public boolean lightmapEnabled() {
+        return nrEnabledUnits() > 1 && unitEnabled(1);
+    }
+
+    private static int encodeAlphaFunc(int glFunc) {
+        return glFunc & 0x7;
+    }
+
+    static int encodeTexEnvMode(int glMode) {
+        return switch (glMode) {
+            case GL11.GL_MODULATE -> TEX_ENV_MODULATE;
+            case GL11.GL_REPLACE  -> TEX_ENV_REPLACE;
+            case GL11.GL_ADD      -> TEX_ENV_ADD;
+            case GL11.GL_DECAL    -> TEX_ENV_DECAL;
+            case GL11.GL_BLEND    -> TEX_ENV_BLEND;
+            case GL13.GL_COMBINE -> TEX_ENV_COMBINE;
+            default -> TEX_ENV_MODULATE;
+        };
+    }
+
+    static int encodeCombineFunc(int glFunc) {
+        return switch (glFunc) {
+            case GL11.GL_REPLACE     -> COMBINE_REPLACE;
+            case GL11.GL_MODULATE    -> COMBINE_MODULATE;
+            case GL11.GL_ADD         -> COMBINE_ADD;
+            case GL13.GL_ADD_SIGNED  -> COMBINE_ADD_SIGNED;
+            case GL13.GL_INTERPOLATE -> COMBINE_INTERPOLATE;
+            case GL13.GL_SUBTRACT    -> COMBINE_SUBTRACT;
+            case GL13.GL_DOT3_RGB    -> COMBINE_DOT3_RGB;
+            case GL13.GL_DOT3_RGBA   -> COMBINE_DOT3_RGBA;
+            default -> COMBINE_REPLACE;
+        };
+    }
+
+    static int encodeSource(int glSource) {
+        return switch (glSource) {
+            case GL11.GL_TEXTURE       -> SRC_TEXTURE;
+            case GL13.GL_CONSTANT      -> SRC_CONSTANT;
+            case GL13.GL_PRIMARY_COLOR -> SRC_PRIMARY_COLOR;
+            case GL13.GL_PREVIOUS      -> SRC_PREVIOUS;
+            default -> {
+                LOGGER.debug("Unknown TexEnv source 0x{}, falling back to SRC_PREVIOUS", Integer.toHexString(glSource));
+                yield SRC_PREVIOUS;
+            }
+        };
+    }
+
+    static int encodeOperand(int glOperand) {
+        return switch (glOperand) {
+            case GL11.GL_SRC_COLOR           -> OP_SRC_COLOR;
+            case GL11.GL_ONE_MINUS_SRC_COLOR -> OP_ONE_MINUS_SRC_COLOR;
+            case GL11.GL_SRC_ALPHA           -> OP_SRC_ALPHA;
+            case GL11.GL_ONE_MINUS_SRC_ALPHA -> OP_ONE_MINUS_SRC_ALPHA;
+            default -> OP_SRC_COLOR;
+        };
+    }
+
+    /** Number of source/operand args used by the given (encoded) combine function. */
+    public static int combineNumArgs(int func) {
+        return switch (func) {
+            case COMBINE_REPLACE -> 1;
+            case COMBINE_INTERPOLATE -> 3;
+            default -> 2; // MODULATE, ADD, ADD_SIGNED, SUBTRACT, DOT3_*
+        };
+    }
+
+    private static int encodeScale(float scale) {
+        if (scale >= 4.0f) return 2;
+        if (scale >= 2.0f) return 1;
+        return 0;
+    }
+
+    public static int decodeAlphaFunc(int encoded) {
+        return 0x0200 | encoded;
+    }
+
+    @Override
+    public String toString() {
+        final String fogName = switch (fogMode()) {
+            case FOG_NONE   -> "NONE";
+            case FOG_LINEAR -> "LINEAR";
+            case FOG_EXP    -> "EXP";
+            case FOG_EXP2   -> "EXP2";
+            default -> "?";
+        };
+        final StringBuilder sb = new StringBuilder();
+        sb.append(String.format("FFPFragmentKey[fog=%s alpha=%b(%s) specSep=%b units=%d",
+            fogName, alphaTestEnabled(),
+            alphaTestEnabled() ? String.format("0x%04X", decodeAlphaFunc(alphaTestFunc())) : "-",
+            separateSpecular(), nrEnabledUnits()));
+        for (int i = 0; i < nrEnabledUnits(); i++) {
+            if (!unitEnabled(i)) {
+                sb.append(String.format(" u%d=OFF", i));
+            } else {
+                final String modeName = switch (unitMode(i)) {
+                    case TEX_ENV_MODULATE -> "MOD";
+                    case TEX_ENV_REPLACE  -> "REPL";
+                    case TEX_ENV_ADD      -> "ADD";
+                    case TEX_ENV_DECAL    -> "DEC";
+                    case TEX_ENV_BLEND    -> "BL";
+                    case TEX_ENV_COMBINE  -> "COMB";
+                    default -> "?";
+                };
+                sb.append(String.format(" u%d=%s", i, modeName));
+            }
+        }
+        sb.append(']');
+        return sb.toString();
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/FragmentShaderGenerator.java

@@ -0,0 +1,316 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import org.lwjgl.opengl.GL11;
+
+/**
+ * Generates GLSL 330 core fragment shaders for FFP emulation.
+ * Supports per-unit texenv chain including GL_COMBINE mode.
+ * Follows Mesa's ff_fragment_shader.c and st_nir_lower_fog.c.
+ */
+public final class FragmentShaderGenerator {
+
+    private FragmentShaderGenerator() {}
+
+    public static String generate(FragmentKey key) {
+        final StringBuilder sb = new StringBuilder(2048);
+        sb.append("#version 330 core\n\n");
+
+        emitInputs(sb, key);
+        emitUniforms(sb, key);
+        sb.append("out vec4 fragColor;\n\n");
+
+        sb.append("void main() {\n");
+        emitTextureSampling(sb, key);
+        emitTexEnvChain(sb, key);
+        emitSpecularAdd(sb, key);
+        emitAlphaTest(sb, key);
+        emitFog(sb, key);
+        sb.append("  fragColor = color;\n");
+        sb.append("}\n");
+
+        return sb.toString();
+    }
+
+    private static void emitInputs(StringBuilder sb, FragmentKey key) {
+        sb.append("// Inputs from vertex shader\n");
+        sb.append("in vec4 v_Color;\n");
+        if (key.separateSpecular()) {
+            sb.append("in vec3 v_SpecularColor;\n");
+        }
+        if (key.textureEnabled()) {
+            sb.append("in vec4 v_TexCoord0;\n");
+        }
+        if (key.lightmapEnabled()) {
+            sb.append("in vec4 v_TexCoord1;\n");
+        }
+        if (key.fogMode() != FragmentKey.FOG_NONE) {
+            sb.append("in float v_FogCoord;\n");
+        }
+        sb.append('\n');
+    }
+
+    private static void emitUniforms(StringBuilder sb, FragmentKey key) {
+        // Samplers for each enabled unit
+        for (int i = 0; i < key.nrEnabledUnits(); i++) {
+            if (key.unitEnabled(i)) {
+                sb.append("uniform sampler2D u_Sampler").append(i).append(";\n");
+            }
+        }
+        if (key.alphaTestEnabled()) {
+            sb.append("uniform float u_AlphaRef;\n");
+        }
+        // Per-unit texEnvColor uniforms
+        for (int i = 0; i < key.nrEnabledUnits(); i++) {
+            if (key.unitEnabled(i) && key.unitNeedsEnvColor(i)) {
+                sb.append("uniform vec4 u_TexEnvColor").append(i).append(";\n");
+            }
+        }
+        if (key.fogMode() != FragmentKey.FOG_NONE) {
+            sb.append("uniform vec4 u_FogParams;\n");
+            sb.append("uniform vec4 u_FogColor;\n");
+        }
+        sb.append('\n');
+    }
+
+    private static void emitTextureSampling(StringBuilder sb, FragmentKey key) {
+        for (int i = 0; i < key.nrEnabledUnits(); i++) {
+            if (!key.unitEnabled(i)) continue;
+            // Unit 1 is the lightmap — uses v_TexCoord1.
+            // Units 2-3 intentionally share unit 0's texture coordinates since
+            // the vertex shader only provides 2 tex coord varyings (unit 0 and unit 1/lightmap).
+            final String texCoord = (i == 1) ? "v_TexCoord1.st" : "v_TexCoord0.st";
+            sb.append("  vec4 tex").append(i).append("Color = texture(u_Sampler").append(i).append(", ").append(texCoord).append(");\n");
+        }
+    }
+
+    private static void emitTexEnvChain(StringBuilder sb, FragmentKey key) {
+        if (!key.textureEnabled()) {
+            sb.append("  // No texture — vertex color only\n");
+            sb.append("  vec4 color = v_Color;\n");
+            return;
+        }
+
+        // Process units in order; "previous" starts as vertex color
+        boolean firstUnit = true;
+        for (int i = 0; i < key.nrEnabledUnits(); i++) {
+            if (!key.unitEnabled(i)) continue;
+
+            final String texVar = "tex" + i + "Color";
+            final String envColorVar = "u_TexEnvColor" + i;
+            final String prevVar = firstUnit ? "v_Color" : "color";
+            final String assign = firstUnit ? "  vec4 color = " : "  color = ";
+
+            if (key.unitMode(i) == FragmentKey.TEX_ENV_COMBINE) {
+                emitCombineUnit(sb, key, i, texVar, envColorVar, prevVar, assign);
+            } else {
+                emitSimpleUnit(sb, key, i, texVar, envColorVar, prevVar, assign);
+            }
+            firstUnit = false;
+        }
+    }
+
+    private static void emitSimpleUnit(StringBuilder sb, FragmentKey key, int unit, String texVar, String envColorVar, String prevVar, String assign) {
+        switch (key.unitMode(unit)) {
+            case FragmentKey.TEX_ENV_REPLACE -> {
+                sb.append("  // Unit ").append(unit).append(" (REPLACE)\n");
+                sb.append(assign).append(texVar).append(";\n");
+            }
+            case FragmentKey.TEX_ENV_ADD -> {
+                sb.append("  // Unit ").append(unit).append(" (ADD)\n");
+                sb.append(assign).append("vec4(clamp(").append(prevVar).append(".rgb + ").append(texVar).append(".rgb, 0.0, 1.0), ")
+                    .append(prevVar).append(".a * ").append(texVar).append(".a);\n");
+            }
+            case FragmentKey.TEX_ENV_DECAL -> {
+                sb.append("  // Unit ").append(unit).append(" (DECAL)\n");
+                sb.append(assign).append("vec4(mix(").append(prevVar).append(".rgb, ").append(texVar).append(".rgb, ").append(texVar).append(".a), ")
+                    .append(prevVar).append(".a);\n");
+            }
+            case FragmentKey.TEX_ENV_BLEND -> {
+                sb.append("  // Unit ").append(unit).append(" (BLEND)\n");
+                sb.append(assign).append("vec4(").append(prevVar).append(".rgb * (vec3(1.0) - ").append(texVar).append(".rgb) + ")
+                    .append(envColorVar).append(".rgb * ").append(texVar).append(".rgb, ")
+                    .append(prevVar).append(".a * ").append(texVar).append(".a);\n");
+            }
+            default -> { // MODULATE
+                sb.append("  // Unit ").append(unit).append(" (MODULATE)\n");
+                sb.append(assign).append(prevVar).append(" * ").append(texVar).append(";\n");
+            }
+        }
+    }
+
+    /** Emit a GL_COMBINE texenv unit */
+    private static void emitCombineUnit(StringBuilder sb, FragmentKey key, int unit, String texVar, String envColorVar, String prevVar, String assign) {
+        sb.append("  // Unit ").append(unit).append(" (COMBINE)\n");
+
+        final String rgbResult = "combRgb" + unit;
+        final String alphaResult = "combAlpha" + unit;
+
+        if (key.unitCombineRgb(unit) == FragmentKey.COMBINE_DOT3_RGBA) {
+            sb.append("  vec3 ").append(rgbResult).append(";\n");
+            sb.append("  {\n");
+            emitCombineChannel(sb, key, unit, texVar, envColorVar, prevVar, true);
+            sb.append("  }\n");
+            sb.append(assign).append("vec4(").append(rgbResult).append(", ").append(rgbResult).append(".x);\n");
+        } else {
+            sb.append("  vec3 ").append(rgbResult).append(";\n");
+            sb.append("  float ").append(alphaResult).append(";\n");
+            sb.append("  {\n");
+            emitCombineChannel(sb, key, unit, texVar, envColorVar, prevVar, true);
+            emitCombineChannel(sb, key, unit, texVar, envColorVar, prevVar, false);
+            sb.append("  }\n");
+            sb.append(assign).append("vec4(").append(rgbResult).append(", ").append(alphaResult).append(");\n");
+        }
+    }
+
+    /**
+     * Emit one channel (RGB or Alpha) of a GL_COMBINE unit.
+     */
+    private static void emitCombineChannel(StringBuilder sb, FragmentKey key, int unit, String texVar, String envColorVar, String prevVar, boolean isRgb) {
+        final String suffix = isRgb ? "Rgb" : "Alpha";
+        final String type = isRgb ? "vec3" : "float";
+        final int combineFunc = isRgb ? key.unitCombineRgb(unit) : key.unitCombineAlpha(unit);
+        final int scaleShift = isRgb ? key.unitScaleShiftRgb(unit) : key.unitScaleShiftAlpha(unit);
+
+        // Guard: DOT3 is invalid for alpha channel — fallback to REPLACE
+        final int effectiveFunc;
+        if (!isRgb && (combineFunc == FragmentKey.COMBINE_DOT3_RGB || combineFunc == FragmentKey.COMBINE_DOT3_RGBA)) {
+            effectiveFunc = FragmentKey.COMBINE_REPLACE;
+        } else {
+            effectiveFunc = combineFunc;
+        }
+
+        // Determine how many args we need
+        final int numArgs = combineNumArgs(effectiveFunc);
+
+        // Emit argument resolution
+        for (int a = 0; a < numArgs; a++) {
+            final int source = isRgb ? key.unitSourceRgb(unit, a) : key.unitSourceAlpha(unit, a);
+            final int operand = isRgb ? key.unitOperandRgb(unit, a) : key.unitOperandAlpha(unit, a);
+            final String argName = "arg" + suffix + a + "_" + unit;
+            final String sourceExpr = resolveSource(source, texVar, envColorVar, prevVar);
+            final String operandExpr = applyOperand(sourceExpr, operand, isRgb);
+            sb.append("    ").append(type).append(" ").append(argName).append(" = ").append(operandExpr).append(";\n");
+        }
+
+        // Emit combine operation
+        final String resultName = "comb" + suffix + unit;
+        final String a0 = "arg" + suffix + "0_" + unit;
+        final String a1 = "arg" + suffix + "1_" + unit;
+        final String a2 = "arg" + suffix + "2_" + unit;
+
+        sb.append("    ").append(resultName).append(" = ");
+        switch (effectiveFunc) {
+            case FragmentKey.COMBINE_REPLACE -> sb.append(a0);
+            case FragmentKey.COMBINE_MODULATE -> sb.append(a0).append(" * ").append(a1);
+            case FragmentKey.COMBINE_ADD -> sb.append(a0).append(" + ").append(a1);
+            case FragmentKey.COMBINE_ADD_SIGNED ->
+                sb.append(a0).append(" + ").append(a1).append(" - ").append(isRgb ? "vec3(0.5)" : "0.5");
+            case FragmentKey.COMBINE_SUBTRACT -> sb.append(a0).append(" - ").append(a1);
+            case FragmentKey.COMBINE_INTERPOLATE ->
+                sb.append("mix(").append(a1).append(", ").append(a0).append(", ").append(a2).append(")");
+            case FragmentKey.COMBINE_DOT3_RGB, FragmentKey.COMBINE_DOT3_RGBA ->
+                sb.append("vec3(4.0 * dot(").append(a0).append(" - vec3(0.5), ").append(a1).append(" - vec3(0.5)))");
+            default -> sb.append(a0); // fallback to REPLACE
+        }
+        sb.append(";\n");
+
+        // Apply scale
+        if (scaleShift > 0) {
+            final String scaleFactor = scaleShift == 1 ? "2.0" : "4.0";
+            sb.append("    ").append(resultName).append(" *= ").append(scaleFactor).append(";\n");
+        }
+
+        // Clamp
+        sb.append("    ").append(resultName).append(" = clamp(").append(resultName).append(", ")
+            .append(isRgb ? "vec3(0.0), vec3(1.0)" : "0.0, 1.0").append(");\n");
+    }
+
+    private static String resolveSource(int source, String texVar, String envColorVar, String prevVar) {
+        return switch (source) {
+            case FragmentKey.SRC_TEXTURE -> texVar;
+            case FragmentKey.SRC_CONSTANT -> envColorVar;
+            case FragmentKey.SRC_PRIMARY_COLOR -> "v_Color";
+            case FragmentKey.SRC_PREVIOUS -> prevVar;
+            default -> prevVar;
+        };
+    }
+
+    private static String applyOperand(String sourceExpr, int operand, boolean isRgb) {
+        if (isRgb) {
+            return switch (operand) {
+                case FragmentKey.OP_SRC_COLOR -> sourceExpr + ".rgb";
+                case FragmentKey.OP_ONE_MINUS_SRC_COLOR -> "(vec3(1.0) - " + sourceExpr + ".rgb)";
+                case FragmentKey.OP_SRC_ALPHA -> "vec3(" + sourceExpr + ".a)";
+                case FragmentKey.OP_ONE_MINUS_SRC_ALPHA -> "vec3(1.0 - " + sourceExpr + ".a)";
+                default -> sourceExpr + ".rgb";
+            };
+        } else {
+            return switch (operand) {
+                case FragmentKey.OP_SRC_ALPHA -> sourceExpr + ".a";
+                case FragmentKey.OP_ONE_MINUS_SRC_ALPHA -> "(1.0 - " + sourceExpr + ".a)";
+                // Per GL spec, alpha channel operands are SRC_ALPHA or ONE_MINUS_SRC_ALPHA only, but handle color operands gracefully
+                case FragmentKey.OP_SRC_COLOR -> sourceExpr + ".a";
+                case FragmentKey.OP_ONE_MINUS_SRC_COLOR -> "(1.0 - " + sourceExpr + ".a)";
+                default -> sourceExpr + ".a";
+            };
+        }
+    }
+
+    private static int combineNumArgs(int func) {
+        return FragmentKey.combineNumArgs(func);
+    }
+
+    private static void emitSpecularAdd(StringBuilder sb, FragmentKey key) {
+        if (key.separateSpecular()) {
+            sb.append("  // Add separate specular\n");
+            sb.append("  color.rgb += v_SpecularColor;\n");
+        }
+    }
+
+    private static void emitAlphaTest(StringBuilder sb, FragmentKey key) {
+        if (!key.alphaTestEnabled()) return;
+
+        sb.append("  // Alpha test\n");
+        final int func = FragmentKey.decodeAlphaFunc(key.alphaTestFunc());
+
+        switch (func) {
+            case GL11.GL_NEVER ->
+                sb.append("  discard;\n");
+            case GL11.GL_LESS ->
+                sb.append("  if (color.a >= u_AlphaRef) discard;\n");
+            case GL11.GL_EQUAL ->
+                sb.append("  if (color.a != u_AlphaRef) discard;\n");
+            case GL11.GL_LEQUAL ->
+                sb.append("  if (color.a > u_AlphaRef) discard;\n");
+            case GL11.GL_GREATER ->
+                sb.append("  if (color.a <= u_AlphaRef) discard;\n");
+            case GL11.GL_NOTEQUAL ->
+                sb.append("  if (color.a == u_AlphaRef) discard;\n");
+            case GL11.GL_GEQUAL ->
+                sb.append("  if (color.a < u_AlphaRef) discard;\n");
+            case GL11.GL_ALWAYS -> {}
+        }
+    }
+
+    private static void emitFog(StringBuilder sb, FragmentKey key) {
+        final int fogMode = key.fogMode();
+        if (fogMode == FragmentKey.FOG_NONE) return;
+
+        sb.append("  // Fog\n");
+        sb.append("  float f;\n");
+
+        switch (fogMode) {
+            case FragmentKey.FOG_LINEAR ->
+                sb.append("  f = v_FogCoord * u_FogParams.x + u_FogParams.y;\n");
+            case FragmentKey.FOG_EXP ->
+                sb.append("  f = exp2(-(v_FogCoord * u_FogParams.z));\n");
+            case FragmentKey.FOG_EXP2 -> {
+                sb.append("  float fogTmp = v_FogCoord * u_FogParams.w;\n");
+                sb.append("  f = exp2(-(fogTmp * fogTmp));\n");
+            }
+        }
+
+        sb.append("  f = clamp(f, 0.0, 1.0);\n");
+        sb.append("  color.rgb = mix(u_FogColor.rgb, color.rgb, f);\n");
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/Program.java

@@ -0,0 +1,243 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizons.angelica.glsm.GLDebug;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.RenderSystem;
+import lombok.Getter;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL20;
+import org.lwjgl.opengl.KHRDebug;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * A compiled and linked FFP emulation program (vertex + fragment shader pair). Owns the GL program handle and caches uniform locations.
+ */
+public class Program {
+
+    private static final Logger LOGGER = LogManager.getLogger("FFPProgram");
+    private static final AtomicInteger PROGRAM_COUNTER = new AtomicInteger();
+
+    @Getter private final int programId;
+    @Getter private final VertexKey vertexKey;
+    @Getter private final FragmentKey fragmentKey;
+
+    // Uniform locations (-1 = not present in this variant)
+    // Matrices
+    public int locModelViewMatrix = -1;
+    public int locProjectionMatrix = -1;
+    public int locMVPMatrix = -1;
+    public int locNormalMatrix = -1;
+    public int locTextureMatrix0 = -1;
+
+    // Current state defaults
+    public int locCurrentNormal = -1;
+    public int locCurrentColor = -1;
+    public int locCurrentTexCoord = -1;
+    public int locCurrentLightmapCoord = -1;
+    public int locLightmapTextureMatrix = -1;
+
+    // Lighting - color material path (raw values)
+    public int locLightModelAmbient = -1;
+    public int locMaterialEmission = -1;
+    public int locMaterialAmbient = -1;
+    public int locMaterialDiffuse = -1;
+    public int locMaterialSpecular = -1;
+    public int locMaterialShininess = -1;
+    public int locLight0Ambient = -1;
+    public int locLight0Diffuse = -1;
+    public int locLight0Specular = -1;
+    public int locLight1Ambient = -1;
+    public int locLight1Diffuse = -1;
+    public int locLight1Specular = -1;
+
+    // Lighting - pre-computed path
+    public int locSceneColor = -1;
+    public int locLightProd0Ambient = -1;
+    public int locLightProd0Diffuse = -1;
+    public int locLightProd0Specular = -1;
+    public int locLightProd1Ambient = -1;
+    public int locLightProd1Diffuse = -1;
+    public int locLightProd1Specular = -1;
+
+    // Light positions
+    public int locLight0Position = -1;
+    public int locLight1Position = -1;
+
+    // Normal scale (for rescale normals)
+    public int locNormalScale = -1;
+
+    // TexGen plane uniforms
+    public int locTexGenObjPlaneS = -1;
+    public int locTexGenObjPlaneT = -1;
+    public int locTexGenObjPlaneR = -1;
+    public int locTexGenObjPlaneQ = -1;
+    public int locTexGenEyePlaneS = -1;
+    public int locTexGenEyePlaneT = -1;
+    public int locTexGenEyePlaneR = -1;
+    public int locTexGenEyePlaneQ = -1;
+
+    // Clip planes
+    public int locClipPlanes = -1;
+
+    // Fragment uniforms
+    public final int[] locSampler = { -1, -1, -1, -1 };
+    public int locAlphaRef = -1;
+    public final int[] locTexEnvColor = { -1, -1, -1, -1 };
+    public int locFogParams = -1;
+    public int locFogColor = -1;
+
+    Program(int programId, VertexKey vertexKey, FragmentKey fragmentKey) {
+        this.programId = programId;
+        this.vertexKey = vertexKey;
+        this.fragmentKey = fragmentKey;
+        resolveLocations();
+    }
+
+    private void resolveLocations() {
+        locModelViewMatrix = loc("u_ModelViewMatrix");
+        locProjectionMatrix = loc("u_ProjectionMatrix");
+        locMVPMatrix = loc("u_MVPMatrix");
+        locNormalMatrix = loc("u_NormalMatrix");
+        locTextureMatrix0 = loc("u_TextureMatrix0");
+
+        locCurrentNormal = loc("u_CurrentNormal");
+        locCurrentColor = loc("u_CurrentColor");
+        locCurrentTexCoord = loc("u_CurrentTexCoord");
+        locCurrentLightmapCoord = loc("u_CurrentLightmapCoord");
+        locLightmapTextureMatrix = loc("u_LightmapTextureMatrix");
+
+        // Color material path
+        locLightModelAmbient = loc("u_LightModelAmbient");
+        locMaterialEmission = loc("u_MaterialEmission");
+        locMaterialAmbient = loc("u_MaterialAmbient");
+        locMaterialDiffuse = loc("u_MaterialDiffuse");
+        locMaterialSpecular = loc("u_MaterialSpecular");
+        locMaterialShininess = loc("u_MaterialShininess");
+        locLight0Ambient = loc("u_Light0Ambient");
+        locLight0Diffuse = loc("u_Light0Diffuse");
+        locLight0Specular = loc("u_Light0Specular");
+        locLight1Ambient = loc("u_Light1Ambient");
+        locLight1Diffuse = loc("u_Light1Diffuse");
+        locLight1Specular = loc("u_Light1Specular");
+
+        // Pre-computed path
+        locSceneColor = loc("u_SceneColor");
+        locLightProd0Ambient = loc("u_LightProd0Ambient");
+        locLightProd0Diffuse = loc("u_LightProd0Diffuse");
+        locLightProd0Specular = loc("u_LightProd0Specular");
+        locLightProd1Ambient = loc("u_LightProd1Ambient");
+        locLightProd1Diffuse = loc("u_LightProd1Diffuse");
+        locLightProd1Specular = loc("u_LightProd1Specular");
+
+        // Light positions
+        locLight0Position = loc("u_Light0Position");
+        locLight1Position = loc("u_Light1Position");
+
+        locNormalScale = loc("u_NormalScale");
+
+        // TexGen
+        locTexGenObjPlaneS = loc("u_TexGenObjPlaneS");
+        locTexGenObjPlaneT = loc("u_TexGenObjPlaneT");
+        locTexGenObjPlaneR = loc("u_TexGenObjPlaneR");
+        locTexGenObjPlaneQ = loc("u_TexGenObjPlaneQ");
+        locTexGenEyePlaneS = loc("u_TexGenEyePlaneS");
+        locTexGenEyePlaneT = loc("u_TexGenEyePlaneT");
+        locTexGenEyePlaneR = loc("u_TexGenEyePlaneR");
+        locTexGenEyePlaneQ = loc("u_TexGenEyePlaneQ");
+
+        // Clip planes
+        locClipPlanes = loc("u_ClipPlane[0]");
+
+        // Fragment
+        for (int i = 0; i < 4; i++) {
+            locSampler[i] = loc("u_Sampler" + i);
+        }
+        locAlphaRef = loc("u_AlphaRef");
+        for (int i = 0; i < 4; i++) {
+            locTexEnvColor[i] = loc("u_TexEnvColor" + i);
+        }
+        locFogParams = loc("u_FogParams");
+        locFogColor = loc("u_FogColor");
+    }
+
+    private int loc(String name) {
+        return GL20.glGetUniformLocation(programId, name);
+    }
+
+    public void destroy() {
+        GL20.glDeleteProgram(programId);
+    }
+
+    /**
+     * Compile a shader, link it into a program, and return the FFPProgram.
+     */
+    static Program create(VertexKey vk, FragmentKey fk, String vertSrc, String fragSrc) {
+        final int id = PROGRAM_COUNTER.getAndIncrement();
+        final int vs = compileShader(GL20.GL_VERTEX_SHADER, vertSrc, "ffp_v_" + Long.toHexString(vk.pack()));
+        final int fs = compileShader(GL20.GL_FRAGMENT_SHADER, fragSrc, "ffp_f_" + id);
+
+        final int program = GL20.glCreateProgram();
+        GL20.glAttachShader(program, vs);
+        GL20.glAttachShader(program, fs);
+        GL20.glLinkProgram(program);
+
+        final String log = RenderSystem.getProgramInfoLog(program);
+        if (!log.isEmpty()) {
+            LOGGER.warn("FFP program link log (vk=0x{}, fk={}): {}", Long.toHexString(vk.pack()), fk, log);
+        }
+
+        final int linkStatus = GL20.glGetProgrami(program, GL20.GL_LINK_STATUS);
+        if (linkStatus != GL11.GL_TRUE) {
+            GL20.glDeleteProgram(program);
+            GL20.glDeleteShader(vs);
+            GL20.glDeleteShader(fs);
+            throw new RuntimeException("FFP shader link failed (vk=0x" + Long.toHexString(vk.pack()) + ", fk=" + fk + "): " + log);
+        }
+
+        final String debugName = "FFP(v=0x" + Long.toHexString(vk.pack()) + ",f=" + id + ")";
+        GLDebug.nameObject(KHRDebug.GL_PROGRAM, program, debugName);
+
+        // Detach and delete individual shaders — they're linked into the program
+        GL20.glDetachShader(program, vs);
+        GL20.glDetachShader(program, fs);
+        GL20.glDeleteShader(vs);
+        GL20.glDeleteShader(fs);
+
+        final Program ffpProgram = new Program(program, vk, fk);
+
+        final int previousProgram = GLStateManager.getActiveProgram();
+        GL20.glUseProgram(program);
+        for (int i = 0; i < 4; i++) {
+            if (ffpProgram.locSampler[i] != -1) GL20.glUniform1i(ffpProgram.locSampler[i], i);
+        }
+        GL20.glUseProgram(previousProgram);
+
+        return ffpProgram;
+    }
+
+    private static int compileShader(int type, String src, String name) {
+        final int shader = GL20.glCreateShader(type);
+        GL20.glShaderSource(shader, src);
+        GL20.glCompileShader(shader);
+
+        final String typeName = (type == GL20.GL_VERTEX_SHADER) ? "vertex" : "fragment";
+        GLDebug.nameObject(KHRDebug.GL_SHADER, shader, name + "(" + typeName + ")");
+
+        final String log = RenderSystem.getShaderInfoLog(shader);
+        if (!log.isEmpty()) {
+            LOGGER.warn("FFP {} shader compilation log for {}: {}", typeName, name, log);
+        }
+
+        final int result = GL20.glGetShaderi(shader, GL20.GL_COMPILE_STATUS);
+        if (result != GL11.GL_TRUE) {
+            LOGGER.error("FFP {} shader source:\n{}", typeName, src);
+            GL20.glDeleteShader(shader);
+            throw new RuntimeException("FFP " + typeName + " shader compilation failed for " + name + ": " + log);
+        }
+
+        return shader;
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/ShaderCache.java

@@ -0,0 +1,283 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
+import lombok.Setter;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.IdentityHashMap;
+
+
+/**
+ * Open-addressed cache for FFP shader program variants.
+ * Keyed on (vertexKey, fragmentKey) pairs stored inline as raw longs — zero allocation on cache hits.
+ * Converges on Mesa's prog_cache.c: hash+memcmp over packed bytes, open addressing.
+ *
+ * <p>Layout per slot in {@code keys[]}: {@link #SLOT_STRIDE}=6 longs
+ * <pre>
+ *   [0]: vertexKeyPacked
+ *   [1]: (fkLen &lt;&lt; 48) | (hash &amp; 0x0000_FFFF_FFFF_FFFF)  — never 0 for valid entries (fkLen &gt;= 1)
+ *   [2..5]: fk0..fk3
+ * </pre>
+ */
+public class ShaderCache {
+    private static final Logger LOGGER = LogManager.getLogger("FFPShaderCache");
+    private static final int SLOT_STRIDE = 6;
+    private static final int INITIAL_CAPACITY = 64; // power of 2
+    private static final long EMPTY_MARKER = 0L; // slot [1] == 0 means empty (fkLen >= 1 guarantees nonzero)
+
+    private final Long2ObjectOpenHashMap<String> vertexSourceCache = new Long2ObjectOpenHashMap<>();
+
+    // Open-addressed table — parallel arrays
+    private long[] keys;
+    private Program[] programs;
+    private String[] fragSources; // fragment source per slot; reused across VK variants via findFragSource
+    private int capacity;
+    private int count;
+    private int uniqueFragCount;
+
+    // Fast-path: last-used key (raw longs, no objects)
+    private long lastVK = Long.MIN_VALUE;
+    private int lastFKLen;
+    private long lastFK0, lastFK1, lastFK2, lastFK3;
+    private Program lastProgram;
+
+    private int fragmentDumpCounter;
+
+    @Setter private Path dumpDir = null;
+
+    public ShaderCache() {
+        capacity = INITIAL_CAPACITY;
+        keys = new long[capacity * SLOT_STRIDE];
+        programs = new Program[capacity];
+        fragSources = new String[capacity];
+    }
+
+    /**
+     * Get or create an FFP program for the given state keys.
+     *
+     * @param vkPacked packed vertex key
+     * @param fkPacked pre-allocated scratch array with packed fragment key longs
+     * @param fkLen number of significant longs in fkPacked (1..4)
+     */
+    public Program getOrCreate(long vkPacked, long[] fkPacked, int fkLen) {
+        // Fast-path: compare raw longs inline
+        if (vkPacked == lastVK && fkLen == lastFKLen && lastProgram != null
+            && fkPacked[0] == lastFK0
+            && (fkLen < 2 || fkPacked[1] == lastFK1)
+            && (fkLen < 3 || fkPacked[2] == lastFK2)
+            && (fkLen < 4 || fkPacked[3] == lastFK3)) {
+            return lastProgram;
+        }
+
+        final long hash = hashKey(vkPacked, fkPacked, fkLen);
+        final long storedWord = ((long) fkLen << 48) | (hash & 0x0000_FFFF_FFFF_FFFFL);
+        final int mask = capacity - 1;
+        int idx = (int) (hash & mask);
+        while (true) {
+            final int base = idx * SLOT_STRIDE;
+            final long slot1 = keys[base + 1];
+            if (slot1 == EMPTY_MARKER) {
+                break;
+            }
+            if (slot1 == storedWord && keys[base] == vkPacked && keysMatch(base + 2, fkPacked, fkLen)) {
+                final Program p = programs[idx];
+                setLastUsed(vkPacked, fkPacked, fkLen, p);
+                return p;
+            }
+            idx = (idx + 1) & mask;
+        }
+
+        if (count >= (capacity * 3) / 4) {
+            grow();
+            return getOrCreate(vkPacked, fkPacked, fkLen);
+        }
+
+        final VertexKey vk = VertexKey.fromPacked(vkPacked);
+        final String vertSrc = getOrGenerateVertex(vk);
+
+        final FragmentKey fk = FragmentKey.fromPacked(fkPacked, fkLen);
+        String fragSrc = findFragSource(fkPacked, fkLen);
+        if (fragSrc == null) {
+            fragSrc = FragmentShaderGenerator.generate(fk);
+            uniqueFragCount++;
+        }
+
+        final Program program = Program.create(vk, fk, vertSrc, fragSrc);
+
+        final int insertIdx = findEmptySlot(hash);
+        final int base = insertIdx * SLOT_STRIDE;
+        keys[base] = vkPacked;
+        keys[base + 1] = storedWord;
+        for (int i = 0; i < fkLen; i++) keys[base + 2 + i] = fkPacked[i];
+        programs[insertIdx] = program;
+        fragSources[insertIdx] = fragSrc;
+        count++;
+
+        setLastUsed(vkPacked, fkPacked, fkLen, program);
+
+        LOGGER.debug("FFP variant compiled: {} + {} (total: {} programs)", vk, fk, count);
+
+        if (dumpDir != null) {
+            dumpShader(Long.toHexString(vkPacked), ".vert.glsl", vertSrc);
+            dumpShader("frag_" + fragmentDumpCounter++, ".frag.glsl", fragSrc);
+        }
+
+        return program;
+    }
+
+    private String findFragSource(long[] fkPacked, int fkLen) {
+        for (int i = 0; i < capacity; i++) {
+            final int base = i * SLOT_STRIDE;
+            if (keys[base + 1] == EMPTY_MARKER) continue;
+            final int storedLen = (int) (keys[base + 1] >>> 48);
+            if (storedLen != fkLen) continue;
+            if (keysMatch(base + 2, fkPacked, fkLen)) {
+                return fragSources[i];
+            }
+        }
+        return null;
+    }
+
+    private boolean keysMatch(int keysOffset, long[] fkPacked, int fkLen) {
+        for (int i = 0; i < fkLen; i++) {
+            if (keys[keysOffset + i] != fkPacked[i]) return false;
+        }
+        return true;
+    }
+
+    private void setLastUsed(long vkPacked, long[] fkPacked, int fkLen, Program program) {
+        lastVK = vkPacked;
+        lastFKLen = fkLen;
+        lastFK0 = fkPacked[0];
+        lastFK1 = fkLen >= 2 ? fkPacked[1] : 0;
+        lastFK2 = fkLen >= 3 ? fkPacked[2] : 0;
+        lastFK3 = fkLen >= 4 ? fkPacked[3] : 0;
+        lastProgram = program;
+    }
+
+    private int findEmptySlot(long hash) {
+        final int mask = capacity - 1;
+        int idx = (int) (hash & mask);
+        while (keys[idx * SLOT_STRIDE + 1] != EMPTY_MARKER) {
+            idx = (idx + 1) & mask;
+        }
+        return idx;
+    }
+
+    /**
+     * Hash over (vk + fk longs). Adapted from Mesa's hash_key — mix-rotate-multiply.
+     */
+    private static long hashKey(long vkPacked, long[] fkPacked, int fkLen) {
+        long h = vkPacked * 0x9E3779B97F4A7C15L;
+        for (int i = 0; i < fkLen; i++) {
+            h ^= fkPacked[i] * 0x517CC1B727220A95L;
+            h = Long.rotateLeft(h, 31) * 0x9E3779B97F4A7C15L;
+        }
+        return h | 1L; // ensure nonzero lower bits
+    }
+
+    private void grow() {
+        final int oldCap = capacity;
+        final long[] oldKeys = keys;
+        final Program[] oldPrograms = programs;
+        final String[] oldFragSources = fragSources;
+
+        capacity = oldCap * 2;
+        keys = new long[capacity * SLOT_STRIDE];
+        programs = new Program[capacity];
+        fragSources = new String[capacity];
+        count = 0;
+
+        final int mask = capacity - 1;
+        for (int i = 0; i < oldCap; i++) {
+            final int oldBase = i * SLOT_STRIDE;
+            if (oldKeys[oldBase + 1] == EMPTY_MARKER) continue;
+
+            final long storedHash = oldKeys[oldBase + 1] & 0x0000_FFFF_FFFF_FFFFL;
+            int idx = (int) (storedHash & mask);
+            while (keys[idx * SLOT_STRIDE + 1] != EMPTY_MARKER) {
+                idx = (idx + 1) & mask;
+            }
+            final int newBase = idx * SLOT_STRIDE;
+            System.arraycopy(oldKeys, oldBase, keys, newBase, SLOT_STRIDE);
+            programs[idx] = oldPrograms[i];
+            fragSources[idx] = oldFragSources[i];
+            count++;
+        }
+    }
+
+    private String getOrGenerateVertex(VertexKey vk) {
+        return vertexSourceCache.computeIfAbsent(vk.pack(), k -> VertexShaderGenerator.generate(vk));
+    }
+
+    private void dumpShader(String name, String suffix, String source) {
+        if (dumpDir == null) return;
+        try {
+            Files.createDirectories(dumpDir);
+            final Path file = dumpDir.resolve("ffp_" + name + suffix);
+            if (!Files.exists(file)) {
+                Files.writeString(file, source, StandardCharsets.UTF_8);
+            }
+        } catch (IOException e) {
+            LOGGER.warn("Failed to dump FFP shader to {}: {}", dumpDir, e.getMessage());
+        }
+    }
+
+    /** Dump all cached shaders to disk. */
+    public void dumpAll(Path outputDir) {
+        try {
+            Files.createDirectories(outputDir);
+            for (var entry : vertexSourceCache.entrySet()) {
+                dumpShader(Long.toHexString(entry.getKey()), ".vert.glsl", entry.getValue());
+            }
+            final IdentityHashMap<String, Integer> seen = new IdentityHashMap<>();
+            for (int i = 0; i < capacity; i++) {
+                if (fragSources[i] != null && !seen.containsKey(fragSources[i])) {
+                    final int idx = seen.size();
+                    seen.put(fragSources[i], idx);
+                    dumpShader("frag_" + idx, ".frag.glsl", fragSources[i]);
+                }
+            }
+            LOGGER.info("Dumped {} vertex and {} fragment FFP shader sources to {}",
+                vertexSourceCache.size(), seen.size(), outputDir);
+        } catch (IOException e) {
+            LOGGER.warn("Failed to dump FFP shaders: {}", e.getMessage());
+        }
+    }
+
+    /** Destroy all cached programs and clear caches. */
+    public void destroy() {
+        for (int i = 0; i < capacity; i++) {
+            if (programs[i] != null) {
+                programs[i].destroy();
+            }
+        }
+        Arrays.fill(keys, 0);
+        Arrays.fill(programs, null);
+        Arrays.fill(fragSources, null);
+        count = 0;
+        uniqueFragCount = 0;
+        vertexSourceCache.clear();
+        lastProgram = null;
+        lastVK = Long.MIN_VALUE;
+        LOGGER.debug("FFP shader cache cleared");
+    }
+
+    public int getProgramCount() {
+        return count;
+    }
+
+    public int getVertexVariantCount() {
+        return vertexSourceCache.size();
+    }
+
+    public int getFragmentVariantCount() {
+        return uniqueFragCount;
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/ShaderManager.java

@@ -0,0 +1,203 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import java.util.Arrays;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFlags;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFormat;
+import com.gtnewhorizons.angelica.glsm.CompatUniformManager;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.stacks.Vec3fStack;
+import com.gtnewhorizons.angelica.glsm.stacks.Vec4fStack;
+import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
+import lombok.Getter;
+import net.coderbot.iris.gl.blending.BlendModeStorage;
+import net.minecraft.launchwrapper.Launch;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.joml.Vector3f;
+import org.joml.Vector4f;
+import org.lwjgl.opengl.GL20;
+
+import java.nio.file.Paths;
+
+/**
+ * FFP shader manager
+ */
+public class ShaderManager {
+    private static final Logger LOGGER = LogManager.getLogger("FFPShaderManager");
+
+    private static final class Holder { static final ShaderManager INSTANCE = new ShaderManager(); }
+
+    private final ShaderCache cache = new ShaderCache();
+    private final Uniforms uniforms = new Uniforms();
+    private final Int2IntOpenHashMap vaoVertexFlags = new Int2IntOpenHashMap();
+
+    @Getter
+    private boolean active = false;
+    private Program currentProgram = null;
+    private long currentVertexKeyPacked = Long.MIN_VALUE;
+    private final long[] currentFKScratch = new long[FragmentKey.MAX_UNITS];
+    private final long[] currentFKPacked = new long[FragmentKey.MAX_UNITS];
+    private int currentFKLen = 0;
+
+    @Getter private static final Vector3f currentNormal = new Vector3f(0.0f, 0.0f, 1.0f);
+    @Getter private static final Vector4f currentTexCoord = new Vector4f(0.0f, 0.0f, 0.0f, 1.0f);
+    @Getter private static final Vec3fStack normalStack = new Vec3fStack(currentNormal);
+    @Getter private static final Vec4fStack texCoordStack = new Vec4fStack(currentTexCoord);
+    @Getter private static int normalGeneration;
+    @Getter private static int texCoordGeneration;
+    @Getter private boolean enabled = false;
+    private int currentVertexFlags = VertexFlags.TEXTURE_BIT | VertexFlags.COLOR_BIT | VertexFlags.NORMAL_BIT;
+
+    private ShaderManager() {
+        vaoVertexFlags.defaultReturnValue(-1);
+        boolean isDev = false;
+        try {
+            final Object deobfEnv = Launch.blackboard != null ? Launch.blackboard.get("fml.deobfuscatedEnvironment") : null;
+            isDev = Boolean.TRUE.equals(deobfEnv);
+        } catch (Exception ignored) {}
+        if (isDev || Boolean.parseBoolean(System.getProperty("angelica.ffp.dumpShaders", "false"))) {
+            cache.setDumpDir(Paths.get("ffp_shaders"));
+        }
+    }
+
+    public static ShaderManager getInstance() {
+        return Holder.INSTANCE;
+    }
+
+    public void enable() {
+        enabled = true;
+
+        VertexFormat.registerSetupBufferStateOverride((format, offset) -> {
+            currentVertexFlags = format.getVertexFlags();
+            vaoVertexFlags.put(GLStateManager.getBoundVAO(), currentVertexFlags);
+            return false;
+        });
+
+        LOGGER.info("FFP shader emulation enabled");
+    }
+
+    public void disable() {
+        enabled = false;
+    }
+
+    public void activate() {
+        active = true;
+        updateVariant(true, true, true, true);
+        uploadUniforms();
+    }
+
+    public void deactivate() {
+        active = false;
+        currentProgram = null;
+        currentVertexKeyPacked = Long.MIN_VALUE;
+        currentFKLen = 0;
+    }
+
+
+
+    public void preDraw(boolean hasColor, boolean hasNormal, boolean hasTexCoord, boolean hasLightmap) {
+        GLStateManager.flushDeferredVertexAttribs();
+        BlendModeStorage.flushDeferredBlend();
+
+        if (!active) {
+            if (enabled) {
+                final int currentProgramId = GLStateManager.getActiveProgram();
+                if (currentProgramId != 0) {
+                    CompatUniformManager.onUseProgram(currentProgramId);
+                    return;
+                }
+                active = true;
+            } else {
+                return;
+            }
+        }
+
+        final long vkPacked = VertexKey.packFromState(hasColor, hasNormal, hasTexCoord, hasLightmap);
+        final int fkLen = FragmentKey.packFromState(currentFKScratch);
+
+        if (vkPacked != currentVertexKeyPacked || !Arrays.equals(currentFKScratch, 0, fkLen, currentFKPacked, 0, currentFKLen)) {
+            commitVariant(vkPacked, fkLen);
+        }
+
+        uploadUniforms();
+    }
+
+    public void preDraw(int vertexFlags) {
+        currentVertexFlags = vertexFlags;
+        preDraw(
+            (vertexFlags & VertexFlags.COLOR_BIT) != 0,
+            (vertexFlags & VertexFlags.NORMAL_BIT) != 0,
+            (vertexFlags & VertexFlags.TEXTURE_BIT) != 0,
+            (vertexFlags & VertexFlags.BRIGHTNESS_BIT) != 0
+        );
+    }
+
+    public void preDraw() {
+        preDraw(currentVertexFlags);
+    }
+
+    private void updateVariant(boolean hasColor, boolean hasNormal, boolean hasTexCoord, boolean hasLightmap) {
+        final long vkPacked = VertexKey.packFromState(hasColor, hasNormal, hasTexCoord, hasLightmap);
+        final int fkLen = FragmentKey.packFromState(currentFKScratch);
+        commitVariant(vkPacked, fkLen);
+    }
+
+    private void commitVariant(long vkPacked, int fkLen) {
+        currentVertexKeyPacked = vkPacked;
+        System.arraycopy(currentFKScratch, 0, currentFKPacked, 0, fkLen);
+        currentFKLen = fkLen;
+        currentProgram = cache.getOrCreate(vkPacked, currentFKPacked, currentFKLen);
+        GL20.glUseProgram(currentProgram.getProgramId());
+    }
+
+    private void uploadUniforms() {
+        if (currentProgram != null) {
+            uniforms.upload(currentProgram);
+        }
+    }
+
+    public static void setCurrentNormal(float x, float y, float z) {
+        currentNormal.set(x, y, z);
+        normalGeneration++;
+    }
+
+    public static void setCurrentTexCoord(float s, float t, float r, float q) {
+        currentTexCoord.set(s, t, r, q);
+        texCoordGeneration++;
+    }
+
+    public static void bumpNormalGeneration() { normalGeneration++; }
+    public static void bumpTexCoordGeneration() { texCoordGeneration++; }
+
+    public void enableClientVertexFlag(int flag)  { currentVertexFlags |= flag; }
+    public void disableClientVertexFlag(int flag) { currentVertexFlags &= ~flag; }
+    public int getCurrentVertexFlags() { return currentVertexFlags; }
+    public void setCurrentVertexFlags(int flags) { currentVertexFlags = flags; }
+
+    public void onBindVertexArray(int vaoId) {
+        final int flags = vaoVertexFlags.get(vaoId);
+        if (flags != -1) {
+            currentVertexFlags = flags;
+        }
+    }
+
+    public void onDeleteVertexArray(int vaoId) {
+        vaoVertexFlags.remove(vaoId);
+    }
+
+    public void destroy() {
+        cache.destroy();
+        uniforms.destroy();
+        TessellatorStreamingDrawer.destroy();
+        com.gtnewhorizons.angelica.glsm.QuadConverter.destroy();
+        active = false;
+        currentProgram = null;
+    }
+
+    public String getDebugInfo() {
+        return String.format("FFP: %d programs (%d vert, %d frag variants)",
+            cache.getProgramCount(), cache.getVertexVariantCount(), cache.getFragmentVariantCount());
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/TessellatorStreamingDrawer.java

@@ -0,0 +1,309 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.DirectTessellator;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.DefaultVertexFormat;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFlags;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFormat;
+import com.gtnewhorizons.angelica.AngelicaMod;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.QuadConverter;
+import com.gtnewhorizons.angelica.glsm.RenderSystem;
+import com.gtnewhorizons.angelica.glsm.streaming.OrphanStreamingBuffer;
+import com.gtnewhorizons.angelica.glsm.streaming.OrphanStreamingBuffer.UploadStrategy;
+import com.gtnewhorizons.angelica.glsm.streaming.PersistentStreamingBuffer;
+import net.minecraft.client.renderer.Tessellator;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL15;
+import org.lwjgl.opengl.GL30;
+
+import java.nio.ByteBuffer;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAddress0;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAlloc;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memFree;
+
+/**
+ * Replaces the vanilla Tessellator's FFP client-array draw path with a streaming VBO+VAO approach for GL 3.3 core profile compatibility.
+ * <p>
+ * Uses a persistent-mapped ring buffer on GL4.4+ hardware (zero-copy uploads with fence sync),
+ * falling back to the classic orphan pattern on older hardware or on overflow.
+ * Maintains two VAO sets (persistent + orphan) per vertex format (up to 16 combinations).
+ */
+public class TessellatorStreamingDrawer {
+
+    private static final Logger LOGGER = LogManager.getLogger("TessellatorStreamingDrawer");
+    private static final int FORMAT_COUNT = VertexFlags.BITSET_SIZE; // 16
+
+    private static PersistentStreamingBuffer persistentBuffer;
+    private static final OrphanStreamingBuffer[] orphanBuffers = new OrphanStreamingBuffer[FORMAT_COUNT];
+
+    private static final int[] persistentVAOs = new int[FORMAT_COUNT];
+    private static final int[] orphanVAOs = new int[FORMAT_COUNT];
+
+    private static ByteBuffer repackBuffer;
+    private static long repackAddress;
+    private static int repackCapacity;
+
+    private static boolean initialized = false;
+    private static UploadStrategy orphanStrategy = UploadStrategy.BUFFER_SUB_DATA;
+
+    static {
+        // Initial repack buffer: 64KB
+        repackCapacity = 0x10000;
+        repackBuffer = memAlloc(repackCapacity);
+        repackAddress = memAddress0(repackBuffer);
+    }
+
+    private static void init() {
+        if (initialized) return;
+        initialized = true;
+
+        // Select orphan upload strategy from config
+        if (AngelicaMod.options() != null && AngelicaMod.options().advanced.useMapBufferRange) {
+            orphanStrategy = UploadStrategy.MAP_BUFFER_RANGE;
+        }
+        LOGGER.info("Orphan upload strategy: {}", orphanStrategy);
+
+        if (RenderSystem.supportsBufferStorage() && !Boolean.getBoolean("angelica.forceOrphanStreaming")) {
+            try {
+                persistentBuffer = new PersistentStreamingBuffer();
+                LOGGER.info("Persistent streaming buffer created ({}MB)", PersistentStreamingBuffer.DEFAULT_CAPACITY / (1024 * 1024));
+            } catch (Exception e) {
+                LOGGER.warn("Failed to create persistent streaming buffer, using orphan fallback", e);
+                persistentBuffer = null;
+            }
+        }
+    }
+
+    /**
+     * Draw the vanilla Tessellator's data using streaming VBO+VAO instead of FFP client arrays.
+     */
+    public static int draw(Tessellator tess) {
+        if (!tess.isDrawing) {
+            throw new IllegalStateException("Not tesselating!");
+        }
+
+        tess.isDrawing = false;
+
+        final int vertexCount = tess.vertexCount;
+        if (vertexCount == 0) {
+            final int result = tess.rawBufferIndex * 4;
+            tess.reset();
+            return result;
+        }
+
+        // Determine the optimal vertex format from the tessellator's flags
+        final int flags = VertexFlags.convertToFlags(tess.hasTexture, tess.hasColor, tess.hasNormals, tess.hasBrightness);
+        final VertexFormat format = DefaultVertexFormat.ALL_FORMATS[flags];
+        final int vertexSize = format.getVertexSize();
+
+        final int requiredBytes = vertexCount * vertexSize;
+        ensureRepackCapacity(requiredBytes);
+
+        final long writePtr = format.writeToBuffer0(repackAddress, tess.rawBuffer, tess.rawBufferIndex);
+        repackBuffer.position(0);
+        repackBuffer.limit((int)(writePtr - repackAddress));
+
+        uploadAndDraw(repackBuffer, flags, format, vertexSize, tess.drawMode, vertexCount);
+
+        // Shrink rawBuffer if oversized
+        if (tess.rawBufferSize > 0x20000 && tess.rawBufferIndex < (tess.rawBufferSize << 3)) {
+            tess.rawBufferSize = 0x10000;
+            tess.rawBuffer = new int[tess.rawBufferSize];
+        }
+
+        final int result = tess.rawBufferIndex * 4;
+        tess.reset();
+        return result;
+    }
+
+    /**
+     * Draw DirectTessellator data via streaming VBO+VAO. Used for live immediate mode emulation.
+     */
+    public static void drawDirect(DirectTessellator dt) {
+        final VertexFormat format = dt.getVertexFormat();
+        if (format == null) return;
+
+        final int vertexCount = dt.getVertexCount();
+        if (vertexCount == 0) return;
+
+        final int drawMode = dt.getDrawMode();
+        final int flags = format.getVertexFlags();
+        final ByteBuffer buffer = dt.getWriteBuffer();
+        final int vertexSize = format.getVertexSize();
+
+        uploadAndDraw(buffer, flags, format, vertexSize, drawMode, vertexCount);
+    }
+
+    private static String cachedDebugInfo = "Stream: not initialized";
+    private static long lastDebugUpdateNanos;
+    private static final long DEBUG_UPDATE_INTERVAL_NS = 500_000_000L; // 500ms
+
+    public static String getDebugInfo() {
+        if (!initialized) return "Stream: not initialized";
+
+        final long now = System.nanoTime();
+        if (now - lastDebugUpdateNanos < DEBUG_UPDATE_INTERVAL_NS) {
+            return cachedDebugInfo;
+        }
+        lastDebugUpdateNanos = now;
+
+        int orphanCount = 0;
+        int orphanBytes = 0;
+        for (int i = 0; i < FORMAT_COUNT; i++) {
+            if (orphanBuffers[i] != null) {
+                orphanCount++;
+                orphanBytes += orphanBuffers[i].getCapacity();
+            }
+        }
+
+        if (persistentBuffer != null) {
+            cachedDebugInfo = String.format("Stream: Persistent %s (%s free) + %d orphan (%s)",
+                formatBytes(persistentBuffer.getCapacity()), formatBytes(persistentBuffer.getRemaining()),
+                orphanCount, formatBytes(orphanBytes));
+        } else {
+            cachedDebugInfo = String.format("Stream: Orphan (%d bufs, %s)", orphanCount, formatBytes(orphanBytes));
+        }
+        return cachedDebugInfo;
+    }
+
+    private static String formatBytes(int bytes) {
+        if (bytes >= 1024 * 1024) return String.format("%5.1fMB", bytes / (1024.0 * 1024.0));
+        if (bytes >= 1024) return String.format("%5.1fKB", bytes / 1024.0);
+        return String.format("%5dB", bytes);
+    }
+
+    public static void endFrame() {
+        if (persistentBuffer != null) {
+            persistentBuffer.postDraw();
+        }
+        for (int i = 0; i < FORMAT_COUNT; i++) {
+            if (orphanBuffers[i] != null) {
+                orphanBuffers[i].postDraw();
+            }
+        }
+    }
+
+    /**
+     * Draw a merged batch of pre-packed vertex data from a DeferredBatchTessellator.
+     * Copies byte ranges into repackBuffer, then uploads and draws.
+     */
+    static void drawPackedBatch(DeferredBatchTessellator source,
+                                java.util.List<DeferredBatchTessellator.DrawRange> ranges,
+                                int from, int to,
+                                int totalBytes, int totalVertices,
+                                int drawMode, int flags) {
+        if (totalVertices == 0) return;
+
+        final VertexFormat format = DefaultVertexFormat.ALL_FORMATS[flags];
+        final int vertexSize = format.getVertexSize();
+
+        ensureRepackCapacity(totalBytes);
+
+        long writePos = repackAddress;
+        for (int j = from; j < to; j++) {
+            final DeferredBatchTessellator.DrawRange r = ranges.get(j);
+            source.copyRange(r.byteOffset(), r.byteLength(), writePos);
+            writePos += r.byteLength();
+        }
+        repackBuffer.position(0);
+        repackBuffer.limit(totalBytes);
+
+        uploadAndDraw(repackBuffer, flags, format, vertexSize, drawMode, totalVertices);
+    }
+
+    /**
+     * Upload packed vertex data to a streaming buffer and issue the draw call.
+     * Tries the persistent ring buffer first, falls back to orphan buffer on overflow.
+     */
+    private static void uploadAndDraw(ByteBuffer packed, int flags, VertexFormat format, int vertexSize, int drawMode, int vertexCount) {
+        ensureVAO(flags, format);
+
+        int firstVertex = -1;
+
+        if (persistentBuffer != null) {
+            firstVertex = persistentBuffer.upload(packed, vertexSize);
+        }
+
+        if (firstVertex >= 0) {
+            GLStateManager.glBindVertexArray(persistentVAOs[flags]);
+        } else {
+            GLStateManager.glBindVertexArray(orphanVAOs[flags]);
+            firstVertex = orphanBuffers[flags].upload(packed, vertexSize);
+        }
+
+        ShaderManager.getInstance().preDraw(flags);
+        drawWithQuadConversion(drawMode, firstVertex, vertexCount);
+        GLStateManager.glBindVertexArray(0);
+    }
+
+    private static void drawWithQuadConversion(int drawMode, int firstVertex, int vertexCount) {
+        if (drawMode == GL11.GL_QUADS) {
+            QuadConverter.drawQuadsAsTriangles(firstVertex, vertexCount);
+        } else {
+            GL11.glDrawArrays(drawMode, firstVertex, vertexCount);
+        }
+    }
+
+    private static void ensureRepackCapacity(int requiredBytes) {
+        if (requiredBytes <= repackCapacity) return;
+
+        int newCapacity = repackCapacity;
+        while (newCapacity < requiredBytes) {
+            newCapacity *= 2;
+        }
+
+        memFree(repackBuffer);
+        repackBuffer = memAlloc(newCapacity);
+        repackAddress = memAddress0(repackBuffer);
+        repackCapacity = newCapacity;
+    }
+
+    private static void ensureVAO(int flags, VertexFormat format) {
+        init();
+
+        if (orphanVAOs[flags] == 0) {
+            orphanBuffers[flags] = new OrphanStreamingBuffer(orphanStrategy);
+
+            orphanVAOs[flags] = GL30.glGenVertexArrays();
+            GLStateManager.glBindVertexArray(orphanVAOs[flags]);
+            GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, orphanBuffers[flags].getBufferId());
+            format.setupBufferState(0L);
+            GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
+            GLStateManager.glBindVertexArray(0);
+        }
+
+        if (persistentBuffer != null && persistentVAOs[flags] == 0) {
+            persistentVAOs[flags] = GL30.glGenVertexArrays();
+            GLStateManager.glBindVertexArray(persistentVAOs[flags]);
+            GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, persistentBuffer.getBufferId());
+            format.setupBufferState(0L);
+            GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
+            GLStateManager.glBindVertexArray(0);
+        }
+    }
+
+    /**
+     * Clean up all VAOs, streaming buffers, and the repack buffer.
+     */
+    public static void destroy() {
+        for (int i = 0; i < FORMAT_COUNT; i++) {
+            if (persistentVAOs[i] != 0) { GLStateManager.glDeleteVertexArrays(persistentVAOs[i]); persistentVAOs[i] = 0; }
+            if (orphanVAOs[i] != 0) { GLStateManager.glDeleteVertexArrays(orphanVAOs[i]); orphanVAOs[i] = 0; }
+            if (orphanBuffers[i] != null) { orphanBuffers[i].destroy(); orphanBuffers[i] = null; }
+        }
+        if (persistentBuffer != null) {
+            persistentBuffer.destroy();
+            persistentBuffer = null;
+        }
+        if (repackBuffer != null) {
+            memFree(repackBuffer);
+            repackBuffer = null;
+            repackAddress = 0;
+            repackCapacity = 0;
+        }
+        initialized = false;
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/Uniforms.java

@@ -0,0 +1,471 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.states.ClipPlaneState;
+import com.gtnewhorizons.angelica.glsm.states.FogState;
+import com.gtnewhorizons.angelica.glsm.states.LightState;
+import com.gtnewhorizons.angelica.glsm.states.MaterialState;
+import com.gtnewhorizons.angelica.glsm.states.TexGenState;
+import net.minecraft.client.renderer.OpenGlHelper;
+import org.joml.Matrix3f;
+import org.joml.Matrix4f;
+import org.joml.Vector4f;
+import org.lwjgl.opengl.GL20;
+
+import java.nio.FloatBuffer;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAllocFloat;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memFree;
+
+/**
+ * Uploads GLSM cached state to the active FFP program's uniforms.
+ *
+ * Follows Mesa's prog_statevars.c patterns:
+ * - Pre-computed derived state (light products, scene color) when material is static
+ * - Raw light/material values when color material is active
+ * - Optimized fog params (pre-divided for single MAD in shader)
+ */
+public class Uniforms {
+    // Reusable temp buffers for uniform upload
+    private final FloatBuffer mat4Buf = memAllocFloat(16);
+    private final FloatBuffer mat3Buf = memAllocFloat(9);
+    private final FloatBuffer vec4Buf = memAllocFloat(4);
+    private final FloatBuffer vec3Buf = memAllocFloat(3);
+    private final FloatBuffer clipPlaneBuf = memAllocFloat(32); // 8 planes * vec4
+
+    // Derived matrices (computed on CPU)
+    private final Matrix4f mvpMatrix = new Matrix4f();
+    private final Matrix3f normalMatrix = new Matrix3f();
+
+    // Temp vectors for light product and normal scale computation
+    private final Vector4f tempVec4 = new Vector4f();
+    private final org.joml.Vector3f tempVec3 = new org.joml.Vector3f();
+
+    // Pre-computed constants for fog params (Mesa STATE_FOG_PARAMS_OPTIMIZED)
+    private static final double LN2 = Math.log(2.0);
+    private static final double SQRT_LN2 = Math.sqrt(LN2);
+
+    // Dirty tracking: last-uploaded generation per category + program ID.
+    // Program change forces full re-upload since uniform locations differ.
+    private int lastProgramId = -1;
+    private int lastMvGen = -1;
+    private int lastProjGen = -1;
+    private int lastTexMatGen = -1;
+    private int lastLightingGen = -1;
+    private int lastFragmentGen = -1;
+    private int lastColorGen = -1;
+    private int lastNormalGen = -1;
+    private int lastTexCoordGen = -1;
+    private float lastLightmapX = Float.NaN;
+    private float lastLightmapY = Float.NaN;
+    private int lastTexGenGen = -1;
+    private int lastClipPlaneGen = -1;
+
+    /**
+     * Upload all relevant uniforms to the given FFP program based on current GLSM state.
+     * Uses generation counters to skip categories that haven't changed since last upload.
+     */
+    public void upload(Program program) {
+        final boolean programChanged = program.getProgramId() != lastProgramId;
+        lastProgramId = program.getProgramId();
+
+        final int mvGen = GLStateManager.mvGeneration;
+        final int projGen = GLStateManager.projGeneration;
+        final int texMatGen = GLStateManager.texMatrixGeneration;
+        final boolean mvChanged = programChanged || mvGen != lastMvGen;
+        final boolean projChanged = programChanged || projGen != lastProjGen;
+        final boolean texMatChanged = programChanged || texMatGen != lastTexMatGen;
+        if (mvChanged || projChanged || texMatChanged) {
+            uploadMatrices(program, mvChanged, projChanged, texMatChanged);
+            lastMvGen = mvGen;
+            lastProjGen = projGen;
+            lastTexMatGen = texMatGen;
+        }
+
+        if (program.getVertexKey().lightingEnabled()) {
+            final int litGen = GLStateManager.lightingGeneration;
+            if (programChanged || litGen != lastLightingGen) {
+                uploadLighting(program);
+                lastLightingGen = litGen;
+            }
+        }
+
+        // Current color/normal/texcoord — skip if generation unchanged
+        if (!program.getVertexKey().hasVertexColor()) {
+            final int colorGen = GLStateManager.colorGeneration;
+            if (programChanged || colorGen != lastColorGen) {
+                uploadCurrentColor(program);
+                lastColorGen = colorGen;
+            }
+        }
+
+        if (!program.getVertexKey().hasVertexNormal() && program.getVertexKey().lightingEnabled()) {
+            final int normalGen = ShaderManager.getNormalGeneration();
+            if (programChanged || normalGen != lastNormalGen) {
+                uploadCurrentNormal(program);
+                lastNormalGen = normalGen;
+            }
+        }
+
+        if (!program.getVertexKey().hasVertexTexCoord() && program.getVertexKey().textureEnabled()) {
+            final int texGen = ShaderManager.getTexCoordGeneration();
+            if (programChanged || texGen != lastTexCoordGen) {
+                uploadCurrentTexCoord(program);
+                lastTexCoordGen = texGen;
+            }
+        }
+
+        if (program.getVertexKey().lightmapEnabled() && !program.getVertexKey().hasVertexLightmap()) {
+            if (programChanged || OpenGlHelper.lastBrightnessX != lastLightmapX || OpenGlHelper.lastBrightnessY != lastLightmapY) {
+                uploadCurrentLightmapCoord(program);
+                lastLightmapX = OpenGlHelper.lastBrightnessX;
+                lastLightmapY = OpenGlHelper.lastBrightnessY;
+            }
+        }
+
+        if (program.getVertexKey().texGenEnabled()) {
+            final int tgGen = GLStateManager.texGenGeneration;
+            if (programChanged || tgGen != lastTexGenGen) {
+                uploadTexGen(program);
+                lastTexGenGen = tgGen;
+            }
+        }
+
+        if (program.getVertexKey().clipPlanesEnabled()) {
+            final int cpGen = GLStateManager.clipPlaneGeneration;
+            if (programChanged || cpGen != lastClipPlaneGen) {
+                uploadClipPlanes(program);
+                lastClipPlaneGen = cpGen;
+            }
+        }
+
+        final int fragGen = GLStateManager.fragmentGeneration;
+        if (programChanged || fragGen != lastFragmentGen) {
+            uploadFragmentUniforms(program);
+            lastFragmentGen = fragGen;
+        }
+    }
+
+    private void uploadMatrices(Program program, boolean mvChanged, boolean projChanged, boolean texMatChanged) {
+        final Matrix4f mv = GLStateManager.getModelViewMatrix();
+        final Matrix4f proj = GLStateManager.getProjectionMatrix();
+
+        // ModelView + derived (normal matrix, normal scale)
+        if (mvChanged) {
+            if (program.locModelViewMatrix != -1) {
+                mv.get(mat4Buf);
+                GL20.glUniformMatrix4(program.locModelViewMatrix, false, mat4Buf);
+            }
+
+            // Normal matrix = inverse transpose of upper-left 3x3 of ModelView
+            if (program.locNormalMatrix != -1 || program.locNormalScale != -1) {
+                mv.normal(normalMatrix);
+            }
+            if (program.locNormalMatrix != -1) {
+                normalMatrix.get(mat3Buf);
+                GL20.glUniformMatrix3(program.locNormalMatrix, false, mat3Buf);
+            }
+
+            // Normal scale (for GL_RESCALE_NORMAL without GL_NORMALIZE)
+            if (program.locNormalScale != -1) {
+                // Scale factor = 1/length of first column of normal matrix
+                final float scale = 1.0f / normalMatrix.getColumn(0, tempVec3).length();
+                GL20.glUniform1f(program.locNormalScale, scale);
+            }
+        }
+
+        // Projection
+        if (projChanged) {
+            if (program.locProjectionMatrix != -1) {
+                proj.get(mat4Buf);
+                GL20.glUniformMatrix4(program.locProjectionMatrix, false, mat4Buf);
+            }
+        }
+
+        // MVP = Projection * ModelView — needs recompute if either input changed
+        if ((mvChanged || projChanged) && program.locMVPMatrix != -1) {
+            proj.mul(mv, mvpMatrix);
+            mvpMatrix.get(mat4Buf);
+            GL20.glUniformMatrix4(program.locMVPMatrix, false, mat4Buf);
+        }
+
+        // Texture matrices
+        if (texMatChanged) {
+            // Texture matrix unit 0
+            if (program.locTextureMatrix0 != -1) {
+                final Matrix4f texMat = GLStateManager.getTextures().getTextureUnitMatrix(0);
+                texMat.get(mat4Buf);
+                GL20.glUniformMatrix4(program.locTextureMatrix0, false, mat4Buf);
+            }
+
+            // Texture matrix unit 1 (lightmap)
+            if (program.locLightmapTextureMatrix != -1) {
+                final Matrix4f lmTexMat = GLStateManager.getTextures().getTextureUnitMatrix(1);
+                lmTexMat.get(mat4Buf);
+                GL20.glUniformMatrix4(program.locLightmapTextureMatrix, false, mat4Buf);
+            }
+        }
+    }
+
+    private void uploadLighting(Program program) {
+        final VertexKey vk = program.getVertexKey();
+
+        if (vk.colorMaterialEnabled()) {
+            uploadLightingColorMaterial(program, vk);
+        } else {
+            uploadLightingPreComputed(program, vk);
+        }
+    }
+
+    /**
+     * Color material active: upload raw light and material values.
+     * The shader multiplies them with vertex color at runtime.
+     */
+    private void uploadLightingColorMaterial(Program program, VertexKey vk) {
+        final MaterialState mat = GLStateManager.getFrontMaterial();
+
+        uploadVec4(program.locLightModelAmbient, GLStateManager.getLightModel().ambient);
+        uploadVec4(program.locMaterialEmission, mat.emission);
+        uploadVec4(program.locMaterialAmbient, mat.ambient);
+        uploadVec4(program.locMaterialDiffuse, mat.diffuse);
+        uploadVec4(program.locMaterialSpecular, mat.specular);
+        if (program.locMaterialShininess != -1) {
+            GL20.glUniform1f(program.locMaterialShininess, mat.shininess);
+        }
+
+        if (vk.light0Enabled()) {
+            final LightState light0 = GLStateManager.getLightDataStates()[0];
+            uploadVec4(program.locLight0Ambient, light0.ambient);
+            uploadVec4(program.locLight0Diffuse, light0.diffuse);
+            uploadVec4(program.locLight0Specular, light0.specular);
+            uploadVec4(program.locLight0Position, light0.position);
+        }
+        if (vk.light1Enabled()) {
+            final LightState light1 = GLStateManager.getLightDataStates()[1];
+            uploadVec4(program.locLight1Ambient, light1.ambient);
+            uploadVec4(program.locLight1Diffuse, light1.diffuse);
+            uploadVec4(program.locLight1Specular, light1.specular);
+            uploadVec4(program.locLight1Position, light1.position);
+        }
+    }
+
+    /**
+     * No color material: upload pre-computed light products and scene color.
+     * Fewer shader multiplies since material is static.
+     */
+    private void uploadLightingPreComputed(Program program, VertexKey vk) {
+        final MaterialState mat = GLStateManager.getFrontMaterial();
+
+        // Scene color = emission + ambient * lightModel.ambient
+        // Alpha = material.diffuse.a
+        if (program.locSceneColor != -1) {
+            tempVec4.set(
+                mat.emission.x + mat.ambient.x * GLStateManager.getLightModel().ambient.x,
+                mat.emission.y + mat.ambient.y * GLStateManager.getLightModel().ambient.y,
+                mat.emission.z + mat.ambient.z * GLStateManager.getLightModel().ambient.z,
+                mat.diffuse.w  // alpha from diffuse
+            );
+            uploadVec4(program.locSceneColor, tempVec4);
+        }
+
+        if (program.locMaterialShininess != -1) {
+            GL20.glUniform1f(program.locMaterialShininess, mat.shininess);
+        }
+
+        // Per-light products
+        if (vk.light0Enabled()) {
+            final LightState light0 = GLStateManager.getLightDataStates()[0];
+            uploadVec4(program.locLight0Position, light0.position);
+            uploadLightProduct(program.locLightProd0Ambient, light0.ambient, mat.ambient);
+            uploadLightProduct(program.locLightProd0Diffuse, light0.diffuse, mat.diffuse);
+            uploadLightProduct(program.locLightProd0Specular, light0.specular, mat.specular);
+        }
+        if (vk.light1Enabled()) {
+            final LightState light1 = GLStateManager.getLightDataStates()[1];
+            uploadVec4(program.locLight1Position, light1.position);
+            uploadLightProduct(program.locLightProd1Ambient, light1.ambient, mat.ambient);
+            uploadLightProduct(program.locLightProd1Diffuse, light1.diffuse, mat.diffuse);
+            uploadLightProduct(program.locLightProd1Specular, light1.specular, mat.specular);
+        }
+    }
+
+    /**
+     * Upload pre-multiplied light product: light.X * material.X (RGB only).
+     */
+    private void uploadLightProduct(int loc, Vector4f lightVal, Vector4f materialVal) {
+        if (loc == -1) return;
+        vec3Buf.clear();
+        vec3Buf.put(lightVal.x * materialVal.x);
+        vec3Buf.put(lightVal.y * materialVal.y);
+        vec3Buf.put(lightVal.z * materialVal.z);
+        vec3Buf.flip();
+        GL20.glUniform3(loc, vec3Buf);
+    }
+
+    private void uploadCurrentColor(Program program) {
+        if (program.locCurrentColor == -1) return;
+        // Upload the current color from GLSM
+        final var color = GLStateManager.getColor();
+        vec4Buf.clear();
+        vec4Buf.put(color.getRed());
+        vec4Buf.put(color.getGreen());
+        vec4Buf.put(color.getBlue());
+        vec4Buf.put(color.getAlpha());
+        vec4Buf.flip();
+        GL20.glUniform4(program.locCurrentColor, vec4Buf);
+    }
+
+    private void uploadCurrentTexCoord(Program program) {
+        if (program.locCurrentTexCoord == -1) return;
+        final var tc = ShaderManager.getCurrentTexCoord();
+        uploadVec4(program.locCurrentTexCoord, tc);
+    }
+
+    private void uploadCurrentLightmapCoord(Program program) {
+        if (program.locCurrentLightmapCoord == -1) return;
+        GL20.glUniform2f(program.locCurrentLightmapCoord,
+            OpenGlHelper.lastBrightnessX, OpenGlHelper.lastBrightnessY);
+    }
+
+    private void uploadCurrentNormal(Program program) {
+        if (program.locCurrentNormal == -1) return;
+        // Upload current normal from FFPShaderManager's tracked normal
+        final var normal = ShaderManager.getCurrentNormal();
+        vec3Buf.clear();
+        vec3Buf.put(normal.x);
+        vec3Buf.put(normal.y);
+        vec3Buf.put(normal.z);
+        vec3Buf.flip();
+        GL20.glUniform3(program.locCurrentNormal, vec3Buf);
+    }
+
+    private void uploadTexGen(Program program) {
+        final VertexKey vk = program.getVertexKey();
+        final TexGenState tg = GLStateManager.getTextures().getTexGenState(0);
+
+        if (vk.texGenModeS() == VertexKey.TG_OBJ_LINEAR) {
+            uploadPlane(program.locTexGenObjPlaneS, tg.getObjectPlane(org.lwjgl.opengl.GL11.GL_S));
+        } else if (vk.texGenModeS() == VertexKey.TG_EYE_LINEAR) {
+            uploadPlane(program.locTexGenEyePlaneS, tg.getEyePlane(org.lwjgl.opengl.GL11.GL_S));
+        }
+
+        if (vk.texGenModeT() == VertexKey.TG_OBJ_LINEAR) {
+            uploadPlane(program.locTexGenObjPlaneT, tg.getObjectPlane(org.lwjgl.opengl.GL11.GL_T));
+        } else if (vk.texGenModeT() == VertexKey.TG_EYE_LINEAR) {
+            uploadPlane(program.locTexGenEyePlaneT, tg.getEyePlane(org.lwjgl.opengl.GL11.GL_T));
+        }
+
+        if (vk.texGenModeR() == VertexKey.TG_OBJ_LINEAR) {
+            uploadPlane(program.locTexGenObjPlaneR, tg.getObjectPlane(org.lwjgl.opengl.GL11.GL_R));
+        } else if (vk.texGenModeR() == VertexKey.TG_EYE_LINEAR) {
+            uploadPlane(program.locTexGenEyePlaneR, tg.getEyePlane(org.lwjgl.opengl.GL11.GL_R));
+        }
+
+        if (vk.texGenModeQ() == VertexKey.TG_OBJ_LINEAR) {
+            uploadPlane(program.locTexGenObjPlaneQ, tg.getObjectPlane(org.lwjgl.opengl.GL11.GL_Q));
+        } else if (vk.texGenModeQ() == VertexKey.TG_EYE_LINEAR) {
+            uploadPlane(program.locTexGenEyePlaneQ, tg.getEyePlane(org.lwjgl.opengl.GL11.GL_Q));
+        }
+    }
+
+    private void uploadPlane(int loc, float[] plane) {
+        if (loc == -1) return;
+        vec4Buf.clear();
+        vec4Buf.put(plane[0]);
+        vec4Buf.put(plane[1]);
+        vec4Buf.put(plane[2]);
+        vec4Buf.put(plane[3]);
+        vec4Buf.flip();
+        GL20.glUniform4(loc, vec4Buf);
+    }
+
+    private void uploadClipPlanes(Program program) {
+        if (program.locClipPlanes == -1) return;
+        final ClipPlaneState cps = GLStateManager.getClipPlaneState();
+        clipPlaneBuf.clear();
+        for (int i = 0; i < GLStateManager.MAX_CLIP_PLANES; i++) {
+            cps.putEyePlane(i, clipPlaneBuf);
+        }
+        clipPlaneBuf.flip();
+        GL20.glUniform4(program.locClipPlanes, clipPlaneBuf);
+    }
+
+    private void uploadFragmentUniforms(Program program) {
+        final FragmentKey fk = program.getFragmentKey();
+
+        // Alpha test reference
+        if (fk.alphaTestEnabled() && program.locAlphaRef != -1) {
+            GL20.glUniform1f(program.locAlphaRef, GLStateManager.getAlphaState().getReference());
+        }
+
+        // Per-unit tex env color
+        for (int i = 0; i < 4; i++) {
+            if (program.locTexEnvColor[i] != -1) {
+                final var envState = GLStateManager.getTextures().getTexEnvState(i);
+                vec4Buf.clear();
+                vec4Buf.put(envState.envColorR);
+                vec4Buf.put(envState.envColorG);
+                vec4Buf.put(envState.envColorB);
+                vec4Buf.put(envState.envColorA);
+                vec4Buf.flip();
+                GL20.glUniform4(program.locTexEnvColor[i], vec4Buf);
+            }
+        }
+
+        // Fog
+        if (fk.fogMode() != FragmentKey.FOG_NONE) {
+            uploadFog(program);
+        }
+    }
+
+    /**
+     * Upload optimized fog params (following Mesa's STATE_FOG_PARAMS_OPTIMIZED):
+     */
+    private void uploadFog(Program program) {
+        final FogState fog = GLStateManager.getFogState();
+
+        if (program.locFogParams != -1) {
+            final float start = fog.getStart();
+            final float end = fog.getEnd();
+            final float density = fog.getDensity();
+            final float range = end - start;
+
+            vec4Buf.clear();
+            vec4Buf.put(range != 0.0f ? -1.0f / range : 0.0f);     // [0]: -1/(end-start)
+            vec4Buf.put(range != 0.0f ? end / range : 1.0f);         // [1]: end/(end-start)
+            vec4Buf.put((float)(density / LN2));        // [2]: density/ln(2)
+            vec4Buf.put((float)(density / SQRT_LN2));  // [3]: density/sqrt(ln(2))
+            vec4Buf.flip();
+            GL20.glUniform4(program.locFogParams, vec4Buf);
+        }
+
+        if (program.locFogColor != -1) {
+            vec4Buf.clear();
+            vec4Buf.put((float) fog.getFogColor().x);
+            vec4Buf.put((float) fog.getFogColor().y);
+            vec4Buf.put((float) fog.getFogColor().z);
+            vec4Buf.put(fog.getFogAlpha());
+            vec4Buf.flip();
+            GL20.glUniform4(program.locFogColor, vec4Buf);
+        }
+    }
+
+    private void uploadVec4(int loc, Vector4f v) {
+        if (loc == -1) return;
+        vec4Buf.clear();
+        vec4Buf.put(v.x);
+        vec4Buf.put(v.y);
+        vec4Buf.put(v.z);
+        vec4Buf.put(v.w);
+        vec4Buf.flip();
+        GL20.glUniform4(loc, vec4Buf);
+    }
+
+    public void destroy() {
+        memFree(mat4Buf);
+        memFree(mat3Buf);
+        memFree(vec4Buf);
+        memFree(vec3Buf);
+        memFree(clipPlaneBuf);
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/VertexKey.java

@@ -0,0 +1,257 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizons.angelica.glsm.DisplayListManager;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.states.TexGenState;
+import org.joml.Matrix4f;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL12;
+
+/**
+ * Compact key capturing the vertex shader permutation axes for FFP emulation.
+ * Packed into a single long for fast hash/compare.
+ */
+public final class VertexKey {
+
+    private final long packed;
+
+    private static final int BIT_LIGHTING            = 0;
+    private static final int BIT_LIGHT0              = 1;
+    private static final int BIT_LIGHT1              = 2;
+    private static final int BIT_LIGHT0_DIR          = 3;
+    private static final int BIT_LIGHT1_DIR          = 4;
+    private static final int BIT_COLOR_MATERIAL      = 5;
+    private static final int BIT_SEPARATE_SPECULAR   = 6;
+    private static final int BIT_FOG                 = 7;
+    private static final int BIT_FOG_DIST_MODE       = 8;
+    private static final int BIT_NORMALIZE           = 10;
+    private static final int BIT_RESCALE_NORMAL      = 11;
+    private static final int BIT_TEXTURE             = 12;
+    private static final int BIT_LIGHTMAP            = 13;
+    private static final int BIT_TEX_MATRIX          = 14;
+    private static final int BIT_HAS_VERTEX_COLOR    = 15;
+    private static final int BIT_HAS_VERTEX_NORMAL   = 16;
+    private static final int BIT_HAS_VERTEX_TEX      = 17;
+    private static final int BIT_HAS_VERTEX_LIGHTMAP = 18;
+    private static final int BIT_COLOR_MAT_MODE      = 19;
+    // bits 19-21: colorMaterialMode (3 bits)
+    // TexGen modes: 3 bits each (0=NONE, 1=OBJ_LINEAR, 2=EYE_LINEAR)
+    private static final int BIT_TEXGEN_S            = 22;
+    private static final int BIT_TEXGEN_T            = 25;
+    private static final int BIT_TEXGEN_R            = 28;
+    private static final int BIT_TEXGEN_Q            = 31;
+    // bits 31-33: texGenModeQ (3 bits)
+    private static final int BIT_CLIP_PLANES         = 34;
+
+    public static final int TG_NONE                  = 0;
+    public static final int TG_OBJ_LINEAR            = 1;
+    public static final int TG_EYE_LINEAR            = 2;
+
+    public static final int CM_AMBIENT               = 0;
+    public static final int CM_DIFFUSE               = 1;
+    public static final int CM_SPECULAR              = 2;
+    public static final int CM_EMISSION              = 3;
+    public static final int CM_AMBIENT_AND_DIFFUSE   = 4;
+
+    private VertexKey(long packed) {
+        this.packed = packed;
+    }
+
+    public long pack() { return packed; }
+
+    public boolean lightingEnabled()       { return bit(BIT_LIGHTING); }
+    public boolean light0Enabled()         { return bit(BIT_LIGHT0); }
+    public boolean light1Enabled()         { return bit(BIT_LIGHT1); }
+    public boolean light0Directional()     { return bit(BIT_LIGHT0_DIR); }
+    public boolean light1Directional()     { return bit(BIT_LIGHT1_DIR); }
+    public boolean colorMaterialEnabled()  { return bit(BIT_COLOR_MATERIAL); }
+    public boolean separateSpecular()      { return bit(BIT_SEPARATE_SPECULAR); }
+    public boolean fogEnabled()            { return bit(BIT_FOG); }
+    public int fogDistanceMode()           { return (int)((packed >> BIT_FOG_DIST_MODE) & 0x3); }
+    public boolean normalizeEnabled()      { return bit(BIT_NORMALIZE); }
+    public boolean rescaleNormalsEnabled() { return bit(BIT_RESCALE_NORMAL); }
+    public boolean textureEnabled()        { return bit(BIT_TEXTURE); }
+    public boolean lightmapEnabled()       { return bit(BIT_LIGHTMAP); }
+    public boolean textureMatrixEnabled()  { return bit(BIT_TEX_MATRIX); }
+    public boolean hasVertexColor()        { return bit(BIT_HAS_VERTEX_COLOR); }
+    public boolean hasVertexNormal()       { return bit(BIT_HAS_VERTEX_NORMAL); }
+    public boolean hasVertexTexCoord()     { return bit(BIT_HAS_VERTEX_TEX); }
+    public boolean hasVertexLightmap()    { return bit(BIT_HAS_VERTEX_LIGHTMAP); }
+    /** Color material mode (CM_AMBIENT, CM_DIFFUSE, CM_SPECULAR, CM_EMISSION, CM_AMBIENT_AND_DIFFUSE). Only meaningful when colorMaterialEnabled(). */
+    public int colorMaterialMode()        { return (int)((packed >> BIT_COLOR_MAT_MODE) & 0x7); }
+
+    /** TexGen mode for S coordinate (TG_NONE, TG_OBJ_LINEAR, TG_EYE_LINEAR). */
+    public int texGenModeS()              { return (int)((packed >> BIT_TEXGEN_S) & 0x7); }
+    /** TexGen mode for T coordinate. */
+    public int texGenModeT()              { return (int)((packed >> BIT_TEXGEN_T) & 0x7); }
+    /** TexGen mode for R coordinate. */
+    public int texGenModeR()              { return (int)((packed >> BIT_TEXGEN_R) & 0x7); }
+    /** TexGen mode for Q coordinate. */
+    public int texGenModeQ()              { return (int)((packed >> BIT_TEXGEN_Q) & 0x7); }
+    /** Whether any texgen coordinate is enabled. */
+    public boolean texGenEnabled()        { return texGenModeS() != TG_NONE || texGenModeT() != TG_NONE || texGenModeR() != TG_NONE || texGenModeQ() != TG_NONE; }
+    /** Whether any clip plane is enabled. */
+    public boolean clipPlanesEnabled()    { return bit(BIT_CLIP_PLANES); }
+
+    /** Whether vertex color replaces material ambient in this variant. */
+    public boolean cmReplacesAmbient()    { final int m = colorMaterialMode(); return m == CM_AMBIENT || m == CM_AMBIENT_AND_DIFFUSE; }
+    /** Whether vertex color replaces material diffuse in this variant. */
+    public boolean cmReplacesDiffuse()    { final int m = colorMaterialMode(); return m == CM_DIFFUSE || m == CM_AMBIENT_AND_DIFFUSE; }
+    /** Whether vertex color replaces material specular in this variant. */
+    public boolean cmReplacesSpecular()   { return colorMaterialMode() == CM_SPECULAR; }
+    /** Whether vertex color replaces material emission in this variant. */
+    public boolean cmReplacesEmission()   { return colorMaterialMode() == CM_EMISSION; }
+
+    private boolean bit(int pos) { return ((packed >> pos) & 1) != 0; }
+
+    static int encodeTexGenMode(int glMode) {
+        return switch (glMode) {
+            case GL11.GL_OBJECT_LINEAR -> TG_OBJ_LINEAR;
+            case GL11.GL_EYE_LINEAR -> TG_EYE_LINEAR;
+            default -> TG_NONE;
+        };
+    }
+
+    static int encodeColorMaterialMode(int glMode) {
+        return switch (glMode) {
+            case GL11.GL_AMBIENT -> CM_AMBIENT;
+            case GL11.GL_DIFFUSE -> CM_DIFFUSE;
+            case GL11.GL_SPECULAR -> CM_SPECULAR;
+            case GL11.GL_EMISSION -> CM_EMISSION;
+            case GL11.GL_AMBIENT_AND_DIFFUSE -> CM_AMBIENT_AND_DIFFUSE;
+            default -> CM_AMBIENT_AND_DIFFUSE;
+        };
+    }
+
+    public static long packFromState(boolean hasColor, boolean hasNormal, boolean hasTexCoord, boolean hasLightmap) {
+        long bits = 0;
+
+        final boolean lighting = GLStateManager.getLightingState().isEnabled();
+        if (lighting) {
+            bits |= (1L << BIT_LIGHTING);
+
+            if (GLStateManager.getLightStates()[0].isEnabled()) {
+                bits |= (1L << BIT_LIGHT0);
+                // position.w == 0 means directional
+                if (GLStateManager.getLightDataStates()[0].position.w == 0.0f) {
+                    bits |= (1L << BIT_LIGHT0_DIR);
+                }
+            }
+            if (GLStateManager.getLightStates()[1].isEnabled()) {
+                bits |= (1L << BIT_LIGHT1);
+                if (GLStateManager.getLightDataStates()[1].position.w == 0.0f) {
+                    bits |= (1L << BIT_LIGHT1_DIR);
+                }
+            }
+
+            if (GLStateManager.getColorMaterial().isEnabled()) {
+                bits |= (1L << BIT_COLOR_MATERIAL);
+                final int cmMode = encodeColorMaterialMode(GLStateManager.getColorMaterialParameter().getValue());
+                bits |= ((long) cmMode & 0x7) << BIT_COLOR_MAT_MODE;
+            }
+
+            if (GLStateManager.getLightModel().colorControl == GL12.GL_SEPARATE_SPECULAR_COLOR) {
+                bits |= (1L << BIT_SEPARATE_SPECULAR);
+            }
+        }
+
+        if (GLStateManager.getFogMode().isEnabled()) {
+            bits |= (1L << BIT_FOG);
+            final int fogDistMode = GLStateManager.getFogState().getFogDistanceMode();
+            bits |= ((long) fogDistMode & 0x3) << BIT_FOG_DIST_MODE;
+        }
+
+        if (GLStateManager.getNormalizeState().isEnabled()) {
+            bits |= (1L << BIT_NORMALIZE);
+        }
+        if (GLStateManager.getRescaleNormalState().isEnabled()) {
+            bits |= (1L << BIT_RESCALE_NORMAL);
+        }
+
+        // Texture unit 0 (base texture)
+        if (GLStateManager.getTextures().getTextureUnitStates(0).isEnabled()) {
+            bits |= (1L << BIT_TEXTURE);
+        }
+        // Texture unit 1 (lightmap)
+        if (GLStateManager.getTextures().getTextureUnitStates(1).isEnabled()) {
+            bits |= (1L << BIT_LIGHTMAP);
+        }
+
+        // Check if texture matrix unit 0 is non-identity
+        final Matrix4f texMat = GLStateManager.getTextures().getTextureUnitMatrix(0);
+        if (!DisplayListManager.isIdentity(texMat)) {
+            bits |= (1L << BIT_TEX_MATRIX);
+        }
+
+        // TexGen (unit 0 only) — encode per-coordinate mode if enabled
+        final var texUnit = GLStateManager.getTextures();
+        final TexGenState tg = texUnit.getTexGenState(0);
+        boolean anyTexGen = false;
+        if (texUnit.getTexGenSStates(0).isEnabled() && tg.getMode(GL11.GL_S) != 0) {
+            final int m = encodeTexGenMode(tg.getMode(GL11.GL_S));
+            bits |= ((long) m & 0x7) << BIT_TEXGEN_S;
+            if (m != TG_NONE) anyTexGen = true;
+        }
+        if (texUnit.getTexGenTStates(0).isEnabled() && tg.getMode(GL11.GL_T) != 0) {
+            final int m = encodeTexGenMode(tg.getMode(GL11.GL_T));
+            bits |= ((long) m & 0x7) << BIT_TEXGEN_T;
+            if (m != TG_NONE) anyTexGen = true;
+        }
+        if (texUnit.getTexGenRStates(0).isEnabled() && tg.getMode(GL11.GL_R) != 0) {
+            final int m = encodeTexGenMode(tg.getMode(GL11.GL_R));
+            bits |= ((long) m & 0x7) << BIT_TEXGEN_R;
+            if (m != TG_NONE) anyTexGen = true;
+        }
+        if (texUnit.getTexGenQStates(0).isEnabled() && tg.getMode(GL11.GL_Q) != 0) {
+            final int m = encodeTexGenMode(tg.getMode(GL11.GL_Q));
+            bits |= ((long) m & 0x7) << BIT_TEXGEN_Q;
+            if (m != TG_NONE) anyTexGen = true;
+        }
+        // Force texture matrix on when texgen is active (end portal pattern always uses it)
+        if (anyTexGen) {
+            bits |= (1L << BIT_TEX_MATRIX);
+        }
+
+        // Vertex format flags
+        if (hasColor) bits |= (1L << BIT_HAS_VERTEX_COLOR);
+        if (hasNormal) bits |= (1L << BIT_HAS_VERTEX_NORMAL);
+        if (hasTexCoord) bits |= (1L << BIT_HAS_VERTEX_TEX);
+        if (hasLightmap) bits |= (1L << BIT_HAS_VERTEX_LIGHTMAP);
+
+        // Clip planes
+        if (GLStateManager.anyClipPlaneEnabled()) {
+            bits |= (1L << BIT_CLIP_PLANES);
+        }
+
+        return bits;
+    }
+
+    public static VertexKey fromState(boolean hasColor, boolean hasNormal, boolean hasTexCoord, boolean hasLightmap) {
+        return new VertexKey(packFromState(hasColor, hasNormal, hasTexCoord, hasLightmap));
+    }
+
+    static VertexKey fromPacked(long packed) {
+        return new VertexKey(packed);
+    }
+
+    @Override
+    public int hashCode() {
+        return Long.hashCode(packed);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) return true;
+        if (!(obj instanceof VertexKey other)) return false;
+        return packed == other.packed;
+    }
+
+    @Override
+    public String toString() {
+        return String.format("FFPVertexKey[0x%09X: lit=%b l0=%b l1=%b cm=%b fog=%b tex=%b lm=%b col=%b nrm=%b vtex=%b vlm=%b tg=%d/%d/%d/%d clip=%b]",
+            packed, lightingEnabled(), light0Enabled(), light1Enabled(),
+            colorMaterialEnabled(), fogEnabled(), textureEnabled(), lightmapEnabled(),
+            hasVertexColor(), hasVertexNormal(), hasVertexTexCoord(), hasVertexLightmap(),
+            texGenModeS(), texGenModeT(), texGenModeR(), texGenModeQ(), clipPlanesEnabled());
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/ffp/VertexShaderGenerator.java

@@ -0,0 +1,408 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFormatElement;
+
+/**
+ * Generates GLSL 330 core vertex shaders for FFP emulation.
+ * Follows Mesa's ffvertex_prog.c build order.
+ *
+ * Attribute locations are sourced from {@link VertexFormatElement.Usage} to stay in sync with GTNHLib's vertex format setup.
+ */
+public final class VertexShaderGenerator {
+
+    private VertexShaderGenerator() {}
+
+    public static String generate(VertexKey key) {
+        final StringBuilder sb = new StringBuilder(2048);
+        sb.append("#version 330 core\n\n");
+
+        emitAttributes(sb, key);
+        emitUniforms(sb, key);
+        emitOutputs(sb, key);
+
+        sb.append("void main() {\n");
+        emitPositionTransform(sb, key);
+        if (key.lightingEnabled()) {
+            emitNormalTransform(sb, key);
+            emitLighting(sb, key);
+        } else {
+            emitColorPassthrough(sb, key);
+        }
+        emitTexCoordPassthrough(sb, key);
+        if (key.fogEnabled()) {
+            emitFogDistance(sb, key);
+        }
+        if (key.clipPlanesEnabled()) {
+            emitClipDistances(sb);
+        }
+        sb.append("}\n");
+
+        return sb.toString();
+    }
+
+    private static void emitAttributes(StringBuilder sb, VertexKey key) {
+        sb.append("// Vertex attributes\n");
+        sb.append("layout(location = ").append(VertexFormatElement.Usage.POSITION.getAttributeLocation()).append(") in vec3 a_Position;\n");
+        if (key.hasVertexColor()) {
+            sb.append("layout(location = ").append(VertexFormatElement.Usage.COLOR.getAttributeLocation()).append(") in vec4 a_Color;\n");
+        }
+        if (key.hasVertexTexCoord()) {
+            sb.append("layout(location = ").append(VertexFormatElement.Usage.PRIMARY_UV.getAttributeLocation()).append(") in vec2 a_TexCoord0;\n");
+        }
+        if (key.hasVertexLightmap()) {
+            sb.append("layout(location = ").append(VertexFormatElement.Usage.SECONDARY_UV.getAttributeLocation()).append(") in vec2 a_TexCoord1;\n");
+        }
+        if (key.hasVertexNormal()) {
+            sb.append("layout(location = ").append(VertexFormatElement.Usage.NORMAL.getAttributeLocation()).append(") in vec3 a_Normal;\n");
+        }
+        sb.append('\n');
+    }
+
+    private static void emitUniforms(StringBuilder sb, VertexKey key) {
+        sb.append("// Matrices\n");
+        sb.append("uniform mat4 u_ModelViewMatrix;\n");
+        sb.append("uniform mat4 u_ProjectionMatrix;\n");
+        sb.append("uniform mat4 u_MVPMatrix;\n");
+
+        if (key.lightingEnabled()) {
+            sb.append("uniform mat3 u_NormalMatrix;\n");
+        }
+
+        if (key.textureMatrixEnabled()) {
+            sb.append("uniform mat4 u_TextureMatrix0;\n");
+        }
+
+        // TexGen plane uniforms
+        if (key.texGenModeS() == VertexKey.TG_OBJ_LINEAR) sb.append("uniform vec4 u_TexGenObjPlaneS;\n");
+        if (key.texGenModeS() == VertexKey.TG_EYE_LINEAR) sb.append("uniform vec4 u_TexGenEyePlaneS;\n");
+        if (key.texGenModeT() == VertexKey.TG_OBJ_LINEAR) sb.append("uniform vec4 u_TexGenObjPlaneT;\n");
+        if (key.texGenModeT() == VertexKey.TG_EYE_LINEAR) sb.append("uniform vec4 u_TexGenEyePlaneT;\n");
+        if (key.texGenModeR() == VertexKey.TG_OBJ_LINEAR) sb.append("uniform vec4 u_TexGenObjPlaneR;\n");
+        if (key.texGenModeR() == VertexKey.TG_EYE_LINEAR) sb.append("uniform vec4 u_TexGenEyePlaneR;\n");
+        if (key.texGenModeQ() == VertexKey.TG_OBJ_LINEAR) sb.append("uniform vec4 u_TexGenObjPlaneQ;\n");
+        if (key.texGenModeQ() == VertexKey.TG_EYE_LINEAR) sb.append("uniform vec4 u_TexGenEyePlaneQ;\n");
+
+        if (!key.hasVertexNormal() && key.lightingEnabled()) {
+            sb.append("uniform vec3 u_CurrentNormal;\n");
+        }
+
+        if (!key.hasVertexColor()) {
+            sb.append("uniform vec4 u_CurrentColor;\n");
+        }
+
+        if (!key.hasVertexTexCoord() && key.textureEnabled()) {
+            sb.append("uniform vec4 u_CurrentTexCoord;\n");
+        }
+
+        if (key.lightmapEnabled() && !key.hasVertexLightmap()) {
+            sb.append("uniform vec2 u_CurrentLightmapCoord;\n");
+        }
+
+        if (key.lightmapEnabled()) {
+            sb.append("uniform mat4 u_LightmapTextureMatrix;\n");
+        }
+
+        if (key.lightingEnabled()) {
+            emitLightingUniforms(sb, key);
+        }
+
+        if (key.lightingEnabled() && (key.normalizeEnabled() || key.rescaleNormalsEnabled())) {
+            // normalize is done in shader; rescale uses normalScale
+            if (key.rescaleNormalsEnabled() && !key.normalizeEnabled()) {
+                sb.append("uniform float u_NormalScale;\n");
+            }
+        }
+
+        if (key.clipPlanesEnabled()) {
+            sb.append("uniform vec4 u_ClipPlane[8];\n");
+        }
+
+        sb.append('\n');
+    }
+
+    private static void emitLightingUniforms(StringBuilder sb, VertexKey key) {
+        sb.append("\n// Lighting\n");
+
+        if (key.colorMaterialEnabled()) {
+            // When color material is active, we can't pre-compute light products so we upload raw light and material values
+            sb.append("uniform vec4 u_LightModelAmbient;\n");
+            sb.append("uniform vec4 u_MaterialEmission;\n");
+            sb.append("uniform vec4 u_MaterialAmbient;\n");
+            sb.append("uniform vec4 u_MaterialDiffuse;\n");
+            sb.append("uniform vec4 u_MaterialSpecular;\n");
+            sb.append("uniform float u_MaterialShininess;\n");
+
+            if (key.light0Enabled()) {
+                sb.append("uniform vec4 u_Light0Ambient;\n");
+                sb.append("uniform vec4 u_Light0Diffuse;\n");
+                sb.append("uniform vec4 u_Light0Specular;\n");
+                sb.append("uniform vec4 u_Light0Position;\n");
+            }
+            if (key.light1Enabled()) {
+                sb.append("uniform vec4 u_Light1Ambient;\n");
+                sb.append("uniform vec4 u_Light1Diffuse;\n");
+                sb.append("uniform vec4 u_Light1Specular;\n");
+                sb.append("uniform vec4 u_Light1Position;\n");
+            }
+        } else {
+            // Pre-computed: sceneColor + lightProducts
+            sb.append("uniform vec4 u_SceneColor;\n");
+
+            if (key.light0Enabled()) {
+                sb.append("uniform vec4 u_Light0Position;\n");
+                sb.append("uniform vec3 u_LightProd0Ambient;\n");
+                sb.append("uniform vec3 u_LightProd0Diffuse;\n");
+                sb.append("uniform vec3 u_LightProd0Specular;\n");
+            }
+            if (key.light1Enabled()) {
+                sb.append("uniform vec4 u_Light1Position;\n");
+                sb.append("uniform vec3 u_LightProd1Ambient;\n");
+                sb.append("uniform vec3 u_LightProd1Diffuse;\n");
+                sb.append("uniform vec3 u_LightProd1Specular;\n");
+            }
+            sb.append("uniform float u_MaterialShininess;\n");
+        }
+    }
+
+    private static void emitOutputs(StringBuilder sb, VertexKey key) {
+        sb.append("// Outputs\n");
+        sb.append("out vec4 v_Color;\n");
+        if (key.separateSpecular()) {
+            sb.append("out vec3 v_SpecularColor;\n");
+        }
+        if (key.textureEnabled() || key.hasVertexTexCoord() || key.texGenEnabled()) {
+            sb.append("out vec4 v_TexCoord0;\n");
+        }
+        if (key.lightmapEnabled()) {
+            sb.append("out vec4 v_TexCoord1;\n");
+        }
+        if (key.fogEnabled()) {
+            sb.append("out float v_FogCoord;\n");
+        }
+        sb.append('\n');
+    }
+
+    private static void emitPositionTransform(StringBuilder sb, VertexKey key) {
+        sb.append("  // Position transform\n");
+        sb.append("  vec4 pos4 = vec4(a_Position, 1.0);\n");
+        sb.append("  gl_Position = u_MVPMatrix * pos4;\n");
+
+        // Eye position needed for lighting, fog, EYE_LINEAR texgen, and clip planes
+        if (key.lightingEnabled() || key.fogEnabled() || texGenNeedsEyePos(key) || key.clipPlanesEnabled()) {
+            sb.append("  vec4 eyePos = u_ModelViewMatrix * pos4;\n");
+        }
+        sb.append('\n');
+    }
+
+    private static void emitNormalTransform(StringBuilder sb, VertexKey key) {
+        sb.append("  // Normal transform\n");
+        if (key.hasVertexNormal()) {
+            sb.append("  vec3 normal = u_NormalMatrix * a_Normal;\n");
+        } else {
+            sb.append("  vec3 normal = u_NormalMatrix * u_CurrentNormal;\n");
+        }
+
+        if (key.normalizeEnabled()) {
+            sb.append("  normal = normalize(normal);\n");
+        } else if (key.rescaleNormalsEnabled()) {
+            sb.append("  normal *= u_NormalScale;\n");
+        }
+        sb.append('\n');
+    }
+
+    private static void emitLighting(StringBuilder sb, VertexKey key) {
+        sb.append("  // Gouraud lighting\n");
+
+        if (key.colorMaterialEnabled()) {
+            // Color material: vertex color replaces specific material properties per glColorMaterial mode (Mesa ffvertex_prog.c get_material() bitmask approach)
+            sb.append("  vec4 matColor = ");
+            sb.append(key.hasVertexColor() ? "a_Color" : "u_CurrentColor");
+            sb.append(";\n");
+
+            // Emission source: vertex color for CM_EMISSION, else material uniform
+            final String emSrc = key.cmReplacesEmission() ? "matColor.rgb" : "u_MaterialEmission.rgb";
+            // Ambient source for scene color: vertex color for CM_AMBIENT / CM_AMBIENT_AND_DIFFUSE
+            final String amSrc = key.cmReplacesAmbient() ? "matColor.rgb" : "u_MaterialAmbient.rgb";
+            sb.append("  vec3 sceneColor = ").append(emSrc).append(" + ").append(amSrc).append(" * u_LightModelAmbient.rgb;\n");
+
+            // Alpha from diffuse source (per GL spec)
+            sb.append("  float outAlpha = ").append(key.cmReplacesDiffuse() ? "matColor.a" : "u_MaterialDiffuse.a").append(";\n");
+        } else {
+            // Pre-computed scene color
+            sb.append("  vec3 sceneColor = u_SceneColor.rgb;\n");
+            sb.append("  float outAlpha = u_SceneColor.a;\n");
+        }
+
+        sb.append("  vec3 color0 = sceneColor;\n");
+        if (key.separateSpecular()) {
+            sb.append("  vec3 specAccum = vec3(0.0);\n");
+        }
+
+        // Per-light accumulation
+        if (key.light0Enabled()) {
+            emitLightContribution(sb, key, 0);
+        }
+        if (key.light1Enabled()) {
+            emitLightContribution(sb, key, 1);
+        }
+
+        sb.append("  v_Color = vec4(clamp(color0, 0.0, 1.0), outAlpha);\n");
+        if (key.separateSpecular()) {
+            sb.append("  v_SpecularColor = clamp(specAccum, 0.0, 1.0);\n");
+        }
+        sb.append('\n');
+    }
+
+    private static void emitLightContribution(StringBuilder sb, VertexKey key, int lightIndex) {
+        final String li = String.valueOf(lightIndex);
+        final boolean directional = (lightIndex == 0) ? key.light0Directional() : key.light1Directional();
+        final String posUniform = "u_Light" + li + "Position";
+
+        sb.append("  { // Light ").append(li).append('\n');
+
+        // Light vector
+        if (directional) {
+            // Directional: position is already normalized direction
+            sb.append("    vec3 VPpli = normalize(").append(posUniform).append(".xyz);\n");
+        } else {
+            // Positional light
+            sb.append("    vec3 VPpli = ").append(posUniform).append(".xyz - eyePos.xyz;\n");
+            sb.append("    VPpli = normalize(VPpli);\n");
+        }
+
+        // Dot products
+        sb.append("    float NdotVP = max(dot(normal, VPpli), 0.0);\n");
+
+        // Half vector for specular (infinite viewer: H = normalize(L + (0,0,1)))
+        sb.append("    vec3 halfVec = normalize(VPpli + vec3(0.0, 0.0, 1.0));\n");
+        sb.append("    float NdotHV = max(dot(normal, halfVec), 0.0);\n");
+
+        // Specular power
+        sb.append("    float spec = (NdotVP > 0.0 && u_MaterialShininess > 0.0) ? pow(NdotHV, u_MaterialShininess) : 0.0;\n");
+
+        // Accumulate — per-property source depends on color material mode
+        if (key.colorMaterialEnabled()) {
+            final String ambU = "u_Light" + li + "Ambient";
+            final String difU = "u_Light" + li + "Diffuse";
+            final String speU = "u_Light" + li + "Specular";
+            // Ambient product: light.ambient * (vertex color or material)
+            final String ambMat = key.cmReplacesAmbient() ? "matColor.rgb" : "u_MaterialAmbient.rgb";
+            sb.append("    vec3 ambient = ").append(ambU).append(".rgb * ").append(ambMat).append(";\n");
+            // Diffuse product
+            final String difMat = key.cmReplacesDiffuse() ? "matColor.rgb" : "u_MaterialDiffuse.rgb";
+            sb.append("    vec3 diffuse = ").append(difU).append(".rgb * ").append(difMat).append(";\n");
+            // Specular product
+            final String speMat = key.cmReplacesSpecular() ? "matColor.rgb" : "u_MaterialSpecular.rgb";
+            sb.append("    vec3 specular = ").append(speU).append(".rgb * ").append(speMat).append(";\n");
+        } else {
+            sb.append("    vec3 ambient = u_LightProd").append(li).append("Ambient;\n");
+            sb.append("    vec3 diffuse = u_LightProd").append(li).append("Diffuse;\n");
+            sb.append("    vec3 specular = u_LightProd").append(li).append("Specular;\n");
+        }
+
+        sb.append("    color0 += ambient + NdotVP * diffuse;\n");
+        if (key.separateSpecular()) {
+            sb.append("    specAccum += spec * specular;\n");
+        } else {
+            sb.append("    color0 += spec * specular;\n");
+        }
+
+        sb.append("  }\n");
+    }
+
+    private static void emitColorPassthrough(StringBuilder sb, VertexKey key) {
+        sb.append("  // Color passthrough (no lighting)\n");
+        if (key.hasVertexColor()) {
+            sb.append("  v_Color = a_Color;\n");
+        } else {
+            sb.append("  v_Color = u_CurrentColor;\n");
+        }
+        sb.append('\n');
+    }
+
+    private static void emitTexCoordPassthrough(StringBuilder sb, VertexKey key) {
+        if (key.texGenEnabled()) {
+            emitTexGenCoordGeneration(sb, key);
+        } else if (key.textureEnabled() || key.hasVertexTexCoord()) {
+            sb.append("  // Texture coordinates\n");
+            if (key.hasVertexTexCoord()) {
+                if (key.textureMatrixEnabled()) {
+                    sb.append("  v_TexCoord0 = u_TextureMatrix0 * vec4(a_TexCoord0, 0.0, 1.0);\n");
+                } else {
+                    sb.append("  v_TexCoord0 = vec4(a_TexCoord0, 0.0, 1.0);\n");
+                }
+            } else {
+                if (key.textureMatrixEnabled()) {
+                    sb.append("  v_TexCoord0 = u_TextureMatrix0 * u_CurrentTexCoord;\n");
+                } else {
+                    sb.append("  v_TexCoord0 = u_CurrentTexCoord;\n");
+                }
+            }
+        }
+        if (key.lightmapEnabled()) {
+            if (key.hasVertexLightmap()) {
+                sb.append("  v_TexCoord1 = u_LightmapTextureMatrix * vec4(a_TexCoord1, 0.0, 1.0);\n");
+            } else {
+                sb.append("  v_TexCoord1 = u_LightmapTextureMatrix * vec4(u_CurrentLightmapCoord, 0.0, 1.0);\n");
+            }
+        }
+    }
+
+    /**
+     * Emit per-coordinate texgen code following Mesa's ffvertex_prog.c build order.
+     * OBJ_LINEAR: dot(pos4, objPlane), EYE_LINEAR: dot(eyePos, eyePlane).
+     * Coordinates without texgen use vertex attrib or default (0,0,0,1).
+     */
+    private static void emitTexGenCoordGeneration(StringBuilder sb, VertexKey key) {
+        sb.append("  // TexGen coordinate generation\n");
+        sb.append("  vec4 texGenCoord = vec4(0.0, 0.0, 0.0, 1.0);\n");
+
+        emitTexGenComponent(sb, key.texGenModeS(), "s", "S", key);
+        emitTexGenComponent(sb, key.texGenModeT(), "t", "T", key);
+        emitTexGenComponent(sb, key.texGenModeR(), "r", "R", key);
+        emitTexGenComponent(sb, key.texGenModeQ(), "q", "Q", key);
+
+        // Always apply texture matrix when texgen is active (forced on in VertexKey)
+        sb.append("  v_TexCoord0 = u_TextureMatrix0 * texGenCoord;\n");
+    }
+
+    private static void emitTexGenComponent(StringBuilder sb, int mode, String swizzle, String coordName, VertexKey key) {
+        switch (mode) {
+            case VertexKey.TG_OBJ_LINEAR ->
+                sb.append("  texGenCoord.").append(swizzle).append(" = dot(pos4, u_TexGenObjPlane").append(coordName).append(");\n");
+            case VertexKey.TG_EYE_LINEAR ->
+                sb.append("  texGenCoord.").append(swizzle).append(" = dot(eyePos, u_TexGenEyePlane").append(coordName).append(");\n");
+            // TG_NONE: keep default (0 for s/t/r, 1 for q) — already set in texGenCoord init
+        }
+    }
+
+    private static boolean texGenNeedsEyePos(VertexKey key) {
+        return key.texGenModeS() == VertexKey.TG_EYE_LINEAR
+            || key.texGenModeT() == VertexKey.TG_EYE_LINEAR
+            || key.texGenModeR() == VertexKey.TG_EYE_LINEAR
+            || key.texGenModeQ() == VertexKey.TG_EYE_LINEAR;
+    }
+
+    private static void emitFogDistance(StringBuilder sb, VertexKey key) {
+        sb.append("  // Fog distance\n");
+        // Mesa ffvertex_prog.c build_fog(): FDM_EYE_RADIAL/EYE_PLANE/EYE_PLANE_ABS
+        final int fogDistMode = key.fogDistanceMode();
+        switch (fogDistMode) {
+            case 0 -> // FDM_EYE_RADIAL: Euclidean distance
+                sb.append("  v_FogCoord = length(eyePos.xyz);\n");
+            case 1 -> // FDM_EYE_PLANE: raw Z (can be negative, clamped by fog factor)
+                sb.append("  v_FogCoord = eyePos.z;\n");
+            case 2 -> // FDM_EYE_PLANE_ABS: absolute Z
+                sb.append("  v_FogCoord = abs(eyePos.z);\n");
+            default ->
+                sb.append("  v_FogCoord = abs(eyePos.z);\n");
+        }
+    }
+
+    private static void emitClipDistances(StringBuilder sb) {
+        sb.append("  // Clip distances\n");
+        for (int i = 0; i < 8; i++) {
+            sb.append("  gl_ClipDistance[").append(i).append("] = dot(u_ClipPlane[").append(i).append("], eyePos);\n");
+        }
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/recording/CommandBuffer.java

@@ -263,6 +263,15 @@ public final class CommandBuffer {
         writeInt(height);
     }
 
+    public void writeScissor(int x, int y, int width, int height) {
+        ensureCapacity(20);
+        writeInt(GLCommand.SCISSOR);
+        writeInt(x);
+        writeInt(y);
+        writeInt(width);
+        writeInt(height);
+    }
+
     public void writeBlendFunc(int srcRgb, int dstRgb, int srcAlpha, int dstAlpha) {
         ensureCapacity(20);
         writeInt(GLCommand.BLEND_FUNC);
@@ -545,6 +554,16 @@ public final class CommandBuffer {
         }
     }
 
+    public void writeClipPlane(int plane, double a, double b, double c, double d) {
+        ensureCapacity(40);
+        writeInt(GLCommand.CLIP_PLANE);
+        writeInt(plane);
+        writeDouble(a);
+        writeDouble(b);
+        writeDouble(c);
+        writeDouble(d);
+    }
+
     // === Draw commands ===
 
     public void writeDrawRange(int vboIndex) {

src/main/java/com/gtnewhorizons/angelica/glsm/recording/CommandBufferExecutor.java

@@ -10,6 +10,7 @@ import org.lwjgl.opengl.GL11;
 import org.lwjgl.opengl.GL15;
 
 import java.nio.ByteBuffer;
+import java.nio.DoubleBuffer;
 import java.nio.FloatBuffer;
 import java.nio.IntBuffer;
 
@@ -25,6 +26,8 @@ public final class CommandBufferExecutor {
     private static final FloatBuffer MATRIX_BUFFER = BufferUtils.createFloatBuffer(16);
     // Static reusable buffer for fog/light/material params
     private static final FloatBuffer PARAMS_BUFFER = BufferUtils.createFloatBuffer(4);
+    // Static reusable buffer for clip plane equation
+    private static final DoubleBuffer PARAMS_DOUBLE_BUFFER = BufferUtils.createDoubleBuffer(4);
     // Static reusable buffer for draw buffers
     private static final int MAX_DRAW_BUFFERS = 8;
     private static final IntBuffer DRAW_BUFFERS_BUFFER = BufferUtils.createIntBuffer(MAX_DRAW_BUFFERS);
@@ -196,6 +199,14 @@ public final class CommandBufferExecutor {
                     ptr += 16;
                     GLStateManager.glViewport(x, y, width, height);
                 }
+                case GLCommand.SCISSOR -> {
+                    final int x = memGetInt(ptr);
+                    final int y = memGetInt(ptr + 4);
+                    final int width = memGetInt(ptr + 8);
+                    final int height = memGetInt(ptr + 12);
+                    ptr += 16;
+                    GLStateManager.glScissor(x, y, width, height);
+                }
                 case GLCommand.BLEND_FUNC -> {
                     final int srcRgb = memGetInt(ptr);
                     final int dstRgb = memGetInt(ptr + 4);
@@ -449,6 +460,19 @@ public final class CommandBufferExecutor {
                     GLStateManager.glMaterial(face, pname, PARAMS_BUFFER);
                 }
 
+                case GLCommand.CLIP_PLANE -> {
+                    final int plane = memGetInt(ptr);
+                    final double a = memGetDouble(ptr + 4);
+                    final double b = memGetDouble(ptr + 12);
+                    final double c = memGetDouble(ptr + 20);
+                    final double d = memGetDouble(ptr + 28);
+                    ptr += 36;
+                    PARAMS_DOUBLE_BUFFER.clear();
+                    PARAMS_DOUBLE_BUFFER.put(a).put(b).put(c).put(d);
+                    PARAMS_DOUBLE_BUFFER.flip();
+                    GLStateManager.glClipPlane(plane, PARAMS_DOUBLE_BUFFER);
+                }
+
                 // === Draw commands ===
                 case GLCommand.DRAW_RANGE -> {
                     final int vboIndex = memGetInt(ptr);
@@ -519,7 +543,7 @@ public final class CommandBufferExecutor {
                     ptr += 4;
                 }
                 case GLCommand.BIND_VAO -> {
-                    UniversalVAO.bindVertexArray(memGetInt(ptr));
+                    GLStateManager.glBindVertexArray(memGetInt(ptr));
                     ptr += 4;
                 }
 

src/main/java/com/gtnewhorizons/angelica/glsm/recording/CommandBufferProcessor.java

@@ -67,6 +67,7 @@ public final class CommandBufferProcessor {
 
             // Four int commands
             case GLCommand.VIEWPORT -> out.writeViewport(raw.readInt(), raw.readInt(), raw.readInt(), raw.readInt());
+            case GLCommand.SCISSOR -> out.writeScissor(raw.readInt(), raw.readInt(), raw.readInt(), raw.readInt());
             case GLCommand.BLEND_FUNC -> out.writeBlendFunc(raw.readInt(), raw.readInt(), raw.readInt(), raw.readInt());
             case GLCommand.COLOR_MASK -> out.writeColorMask(raw.readInt() != 0, raw.readInt() != 0, raw.readInt() != 0, raw.readInt() != 0);
             case GLCommand.STENCIL_FUNC_SEPARATE -> out.writeStencilFuncSeparate(raw.readInt(), raw.readInt(), raw.readInt(), raw.readInt());
@@ -142,6 +143,16 @@ public final class CommandBufferProcessor {
                 out.writeMaterial(face, pname, fb);
             }
 
+            // Clip plane command (4 doubles)
+            case GLCommand.CLIP_PLANE -> {
+                final int plane = raw.readInt();
+                final double a = raw.readDouble();
+                final double b = raw.readDouble();
+                final double c = raw.readDouble();
+                final double d = raw.readDouble();
+                out.writeClipPlane(plane, a, b, c, d);
+            }
+
             // Draw/call commands
             case GLCommand.DRAW_RANGE -> out.writeDrawRange(raw.readInt());
             case GLCommand.CALL_LIST -> out.writeCallList(raw.readInt());

src/main/java/com/gtnewhorizons/angelica/glsm/recording/CommandRecorder.java

@@ -172,6 +172,11 @@ public final class CommandRecorder {
         commandCount++;
     }
 
+    public void recordScissor(int x, int y, int width, int height) {
+        buffer.writeScissor(x, y, width, height);
+        commandCount++;
+    }
+
     public void recordPointSize(float size) {
         buffer.writePointSize(size);
         commandCount++;
@@ -287,6 +292,11 @@ public final class CommandRecorder {
         commandCount++;
     }
 
+    public void recordClipPlane(int plane, double a, double b, double c, double d) {
+        buffer.writeClipPlane(plane, a, b, c, d);
+        commandCount++;
+    }
+
     public void recordStencilFunc(int func, int ref, int mask) {
         buffer.writeStencilFunc(func, ref, mask);
         commandCount++;

src/main/java/com/gtnewhorizons/angelica/glsm/recording/DisplayListVBO.java

@@ -1,8 +1,6 @@
 package com.gtnewhorizons.angelica.glsm.recording;
 
 import com.gtnewhorizon.gtnhlib.client.renderer.vao.IVertexArrayObject;
-import com.gtnewhorizon.gtnhlib.client.renderer.vbo.IVertexBuffer;
-import org.lwjgl.opengl.GL15;
 
 /**
  * A class that stores multiple vertex formats & their corresponding buffers.

src/main/java/com/gtnewhorizons/angelica/glsm/recording/DisplayListVBOBuilder.java

@@ -14,7 +14,11 @@ import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;
 
-import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.*;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAddress0;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAlloc;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memCopy;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memFree;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.nmemFree;
 
 /**
  * Compiles multiple ByteBuffers of the same Vertex format into a VBO. Any buffer added to the builder will be freed afterward.
@@ -69,7 +73,7 @@ public final class DisplayListVBOBuilder {
                     vertexCount = format.getVertexCount(size);
                 }
                 if (data.drawMode == GL11.GL_QUADS) {
-                    IVertexArrayObject indexedVAO = new IndexedVAO(vbo, IndexBuffer.convertQuadsToTrigs(start, start + vertexCount));
+                    final IVertexArrayObject indexedVAO = new IndexedVAO(vbo, IndexBuffer.convertQuadsToTrigs(start, start + vertexCount));
                     vbos[data.drawIndex] = new DisplayListVBO.SubVBO(indexedVAO, GL11.GL_TRIANGLES, 0, vertexCount / 4 * 6);
                 } else {
                     vbos[data.drawIndex] = new DisplayListVBO.SubVBO(vao, data.drawMode, start, vertexCount);

src/main/java/com/gtnewhorizons/angelica/glsm/recording/GLCommand.java

@@ -51,6 +51,7 @@ public final class GLCommand {
     public static final int COLOR_MASK = 42;         // [cmd:4][r:4][g:4][b:4][a:4] (0 or 1 each)
     public static final int STENCIL_FUNC_SEPARATE = 43; // [cmd:4][face:4][func:4][ref:4][mask:4]
     public static final int STENCIL_OP_SEPARATE = 44; // [cmd:4][face:4][sfail:4][dpfail:4][dppass:4]
+    public static final int SCISSOR = 45;             // [cmd:4][x:4][y:4][width:4][height:4]
 
     // === Float commands ===
     public static final int POINT_SIZE = 50;         // [cmd:4][size:4f]
@@ -88,6 +89,7 @@ public final class GLCommand {
     public static final int LIGHT = 91;              // [cmd:4][light:4][pname:4][count:4][params:16f] = 32 bytes
     public static final int LIGHT_MODEL = 92;        // [cmd:4][pname:4][count:4][params:16f] = 28 bytes
     public static final int MATERIAL = 93;           // [cmd:4][face:4][pname:4][count:4][params:16f] = 32 bytes
+    public static final int CLIP_PLANE = 94;         // [cmd:4][plane:4][a:8d][b:8d][c:8d][d:8d] = 40 bytes
 
     // === Draw commands ===
     public static final int DRAW_RANGE = 100;        // [cmd:4][vboIndex:4] = 8 bytes
@@ -147,6 +149,7 @@ public final class GLCommand {
             case STENCIL_OP -> "STENCIL_OP";
             case TEX_PARAMETERI -> "TEX_PARAMETERI";
             case VIEWPORT -> "VIEWPORT";
+            case SCISSOR -> "SCISSOR";
             case BLEND_FUNC -> "BLEND_FUNC";
             case COLOR_MASK -> "COLOR_MASK";
             case STENCIL_FUNC_SEPARATE -> "STENCIL_FUNC_SEPARATE";
@@ -177,6 +180,7 @@ public final class GLCommand {
             case LIGHT -> "LIGHT";
             case LIGHT_MODEL -> "LIGHT_MODEL";
             case MATERIAL -> "MATERIAL";
+            case CLIP_PLANE -> "CLIP_PLANE";
             case DRAW_RANGE -> "DRAW_RANGE";
             case CALL_LIST -> "CALL_LIST";
             case DRAW_BUFFER -> "DRAW_BUFFER";
@@ -220,6 +224,7 @@ public final class GLCommand {
             // Four int commands (20 bytes)
             case GLCommand.VIEWPORT, GLCommand.BLEND_FUNC, GLCommand.COLOR_MASK,
                  GLCommand.STENCIL_FUNC_SEPARATE, GLCommand.STENCIL_OP_SEPARATE,
+                 GLCommand.SCISSOR,
                  GLCommand.COLOR, GLCommand.CLEAR_COLOR, GLCommand.BLEND_COLOR -> 20;
 
             case GLCommand.DRAW_ELEMENTS -> 24;
@@ -251,6 +256,7 @@ public final class GLCommand {
                 final int count = memGetInt(ptr + 12);  // light/face at +4, pname at +8, count at +12
                 yield 16 + count * 4;
             }
+            case GLCommand.CLIP_PLANE -> 40;  // cmd + plane + 4 doubles
 
             default -> throw new IllegalStateException("Unknown command: " + cmd);
         };

src/main/java/com/gtnewhorizons/angelica/glsm/recording/ImmediateModeRecorder.java

@@ -4,8 +4,6 @@ import com.gtnewhorizon.gtnhlib.client.renderer.DirectTessellator;
 import com.gtnewhorizon.gtnhlib.client.renderer.TessellatorManager;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.ClientArrayState;
-import net.minecraft.client.renderer.Tessellator;
-import org.lwjgl.BufferUtils;
 import org.lwjgl.opengl.GL11;
 
 import java.nio.Buffer;
@@ -16,28 +14,57 @@ import java.nio.IntBuffer;
 import java.nio.ShortBuffer;
 
 /**
- * Records immediate mode GL calls (glBegin/glEnd/glVertex) during display list compilation.
- * Converts immediate mode geometry to ByteBuffer directly via {@link DirectTessellator}
- * <p>
- * Currently only used for display list compilation, should be perfectly usable outside of display lists too though.
+ * Records immediate mode GL calls (glBegin/glEnd/glVertex) via {@link DirectTessellator}.
+ * Used both during display list compilation and for live immediate mode emulation in core profile.
  */
 public final class ImmediateModeRecorder {
     private static final DirectTessellator tessellator = new DirectTessellator(TessellatorManager.DEFAULT_BUFFER_SIZE);
 
+    /** Separate tessellator for the splash thread. Nulled after splash completes. */
+    private static DirectTessellator splashTessellator;
+
     private ImmediateModeRecorder() {
 
     }
 
-    public static DirectTessellator getInternalTessellator() {
+    public static void initSplashTessellator() {
+        splashTessellator = new DirectTessellator(TessellatorManager.DEFAULT_BUFFER_SIZE);
+    }
+
+    public static void destroySplashTessellator() {
+        splashTessellator = null;
+    }
+
+    private static DirectTessellator tessellator() {
+        final DirectTessellator splash = splashTessellator;
+        if (splash != null && Thread.currentThread() != GLStateManager.getMainThread()) {
+            return splash;
+        }
         return tessellator;
     }
 
+    public static DirectTessellator getInternalTessellator() {
+        return tessellator();
+    }
+
+    public static boolean isDrawing() {
+        return tessellator().isDrawing;
+    }
+
     /**
      * Set the current texture coordinate.
      * Called by GLStateManager.glTexCoord*.
      */
     public static void setTexCoord(float s, float t) {
-        tessellator.setTextureUV(s, t);
+        tessellator().setTextureUV(s, t);
+    }
+
+    /**
+     * Set the current lightmap coordinate as packed brightness.
+     * Called by GLStateManager.glMultiTexCoord2f for unit 1 during recording/drawing.
+     */
+    public static void setLightmapCoord(float s, float t) {
+        tessellator().setBrightness(((int) t << 16) | ((int) s & 0xFFFF));
     }
 
     /**
@@ -45,14 +72,39 @@ public final class ImmediateModeRecorder {
      * Called by GLStateManager.glNormal*.
      */
     public static void setNormal(float x, float y, float z) {
-        tessellator.setNormal(x, y, z);
+        tessellator().setNormal(x, y, z);
+    }
+
+    /**
+     * Set the current color on the internal tessellator.
+     * Called by GLStateManager.glColor* when inside a glBegin/glEnd block.
+     */
+    public static void setColor(float r, float g, float b, float a) {
+        tessellator().setColorRGBA((int) (r * 255.0f), (int) (g * 255.0f), (int) (b * 255.0f), (int) (a * 255.0f));
     }
 
     /**
      * Start recording a new primitive.
+     * Resets the tessellator to clear any data from the previous draw.
+     *
+     * @param primitiveType GL primitive type (GL_QUADS, GL_TRIANGLES, etc.)
      */
     public static void begin(int primitiveType) {
-        tessellator.startDrawing(primitiveType);
+        final DirectTessellator t = tessellator();
+        t.reset();
+        t.startDrawing(primitiveType);
+    }
+
+    /**
+     * Start recording a new primitive with initial color sync from GLSM cache.
+     * Used for live immediate mode emulation only (not display list recording).
+     */
+    public static void beginLive(int primitiveType) {
+        final DirectTessellator t = tessellator();
+        t.reset();
+        t.startDrawing(primitiveType);
+        final var c = GLStateManager.getColor();
+        t.setColorRGBA((int) (c.getRed() * 255.0f), (int) (c.getGreen() * 255.0f), (int) (c.getBlue() * 255.0f), (int) (c.getAlpha() * 255.0f));
     }
 
     /**
@@ -62,15 +114,16 @@ public final class ImmediateModeRecorder {
      * @return Result containing quads, lines, and flags, or null if no geometry was produced
      */
     public static DirectTessellator end() {
-        if (!tessellator.isDrawing) {
+        final DirectTessellator t = tessellator();
+        if (!t.isDrawing) {
             throw new IllegalStateException("glEnd called without glBegin");
         }
 
-        tessellator.isDrawing = false;
+        t.isDrawing = false;
 
-        if (tessellator.isEmpty()) return null;
+        if (t.isEmpty()) return null;
 
-        return tessellator;
+        return t;
     }
 
     /**
@@ -78,10 +131,11 @@ public final class ImmediateModeRecorder {
      * Color is read from GLStateManager at call time.
      */
     public static void vertex(float x, float y, float z) {
-        if (!tessellator.isDrawing) {
+        final DirectTessellator t = tessellator();
+        if (!t.isDrawing) {
             throw new IllegalStateException("glVertex called outside glBegin/glEnd");
         }
-        tessellator.addVertex(x, y, z);
+        t.addVertex(x, y, z);
     }
 
     /**
@@ -92,7 +146,7 @@ public final class ImmediateModeRecorder {
      * where primitives might fail to convert (e.g., incomplete quads).
      */
     public static boolean hasGeometry() {
-        return tessellator.vertexCount != 0;
+        return tessellator().vertexCount != 0;
     }
 
     /**
@@ -100,7 +154,7 @@ public final class ImmediateModeRecorder {
      * Called when starting a new display list.
      */
     public static void reset() {
-        tessellator.reset();
+        tessellator().reset();
     }
 
     /**
@@ -116,13 +170,19 @@ public final class ImmediateModeRecorder {
         final ClientArrayState cas = GLStateManager.getClientArrayState();
         final Buffer vertexPointer = cas.isVertexArrayEnabled() ? cas.getVertexPointer() : null;
         final Buffer colorPointer = cas.isColorArrayEnabled() ? cas.getColorPointer() : null;
+        final Buffer normalPointer = cas.isNormalArrayEnabled() ? cas.getNormalPointer() : null;
+        final Buffer texCoordPointer = cas.isTexCoordArrayEnabled() ? cas.getTexCoordPointer() : null;
 
         return convertClientArrays(
             mode, first, count,
             vertexPointer,
             cas.getVertexPointerType(), cas.getVertexPointerSize(), cas.getVertexPointerStride(),
             colorPointer,
-            cas.getColorPointerType(), cas.getColorPointerSize(), cas.getColorPointerStride()
+            cas.getColorPointerType(), cas.getColorPointerSize(), cas.getColorPointerStride(),
+            normalPointer,
+            cas.getNormalPointerType(), cas.getNormalPointerStride(),
+            texCoordPointer,
+            cas.getTexCoordPointerType(), cas.getTexCoordPointerSize(), cas.getTexCoordPointerStride()
         );
     }
 
@@ -130,33 +190,23 @@ public final class ImmediateModeRecorder {
      * Convert client array data to immediate mode.
      * Called by glDrawArrays during display list recording.
      * Like Mesa's save_DrawArrays, reads vertex data from arrays and emits as immediate mode.
-     *
-     * @param mode Primitive type (GL_QUADS, GL_LINES, etc.)
-     * @param first Starting index in arrays
-     * @param count Number of vertices
-     * @param vertexPointer Vertex position buffer (or null if not enabled)
-     * @param vertexType GL type (GL_FLOAT, GL_DOUBLE, etc.)
-     * @param vertexSize Size of vertex (2, 3, or 4)
-     * @param vertexStride Stride in bytes (0 for tightly packed)
-     * @param colorPointer Color buffer (or null if not enabled)
-     * @param colorType GL type (GL_FLOAT, GL_UNSIGNED_BYTE, etc.)
-     * @param colorSize Size of color (3 or 4)
-     * @param colorStride Stride in bytes (0 for tightly packed)
-     * @return Result containing converted geometry, or null if no geometry produced
      */
     public static DirectTessellator convertClientArrays(
         int mode, int first, int count,
         java.nio.Buffer vertexPointer, int vertexType, int vertexSize, int vertexStride,
-        java.nio.Buffer colorPointer, int colorType, int colorSize, int colorStride
+        java.nio.Buffer colorPointer, int colorType, int colorSize, int colorStride,
+        java.nio.Buffer normalPointer, int normalType, int normalStride,
+        java.nio.Buffer texCoordPointer, int texCoordType, int texCoordSize, int texCoordStride
     ) {
         begin(mode);
+        final DirectTessellator t = tessellator();
 
         // Hoist type checks and stride calculations outside the loop for performance.
         // Mesa's algorithm: offset_bytes = index * effective_stride
         // effective_stride = (stride == 0) ? (numComponents * sizeof(element)) : stride
 
-        // Determine color reader (hoisted out of loop)
-        final ColorReader colorReader;
+        // Determine color reader
+        final ArrayReader colorReader;
         if (colorPointer == null) {
             colorReader = null;
         } else if (colorType == GL11.GL_FLOAT && colorPointer instanceof FloatBuffer fb) {
@@ -185,8 +235,46 @@ public final class ImmediateModeRecorder {
             colorReader = (idx) -> GLStateManager.glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
         }
 
-        // Determine vertex reader (hoisted out of loop)
-        final VertexReader vertexReader;
+        // Determine normal reader
+        final ArrayReader normalReader;
+        if (normalPointer == null) {
+            normalReader = null;
+        } else if (normalType == GL11.GL_FLOAT && normalPointer instanceof FloatBuffer fb) {
+            final int effectiveStride = (normalStride == 0) ? 3 * 4 : normalStride;
+            final int strideInFloats = effectiveStride / 4;
+            normalReader = (idx) -> {
+                final int offset = idx * strideInFloats;
+                setNormal(fb.get(offset), fb.get(offset + 1), fb.get(offset + 2));
+            };
+        } else if (normalType == GL11.GL_BYTE && normalPointer instanceof ByteBuffer bb) {
+            final int effectiveStride = (normalStride == 0) ? 3 : normalStride;
+            normalReader = (idx) -> {
+                final int offset = idx * effectiveStride;
+                setNormal(bb.get(offset) / 127.0f, bb.get(offset + 1) / 127.0f, bb.get(offset + 2) / 127.0f);
+            };
+        } else {
+            normalReader = null;
+        }
+
+        // Determine texcoord reader
+        final ArrayReader texCoordReader;
+        if (texCoordPointer == null) {
+            texCoordReader = null;
+        } else if (texCoordType == GL11.GL_FLOAT && texCoordPointer instanceof FloatBuffer fb) {
+            final int effectiveStride = (texCoordStride == 0) ? texCoordSize * 4 : texCoordStride;
+            final int strideInFloats = effectiveStride / 4;
+            texCoordReader = (idx) -> {
+                final int offset = idx * strideInFloats;
+                final float s = fb.get(offset);
+                final float tt = (texCoordSize >= 2) ? fb.get(offset + 1) : 0.0f;
+                setTexCoord(s, tt);
+            };
+        } else {
+            texCoordReader = null;
+        }
+
+        // Determine vertex reader
+        final ArrayReader vertexReader;
         if (vertexPointer == null) {
             vertexReader = null;
         } else if (vertexType == GL11.GL_FLOAT && vertexPointer instanceof FloatBuffer fb) {
@@ -197,7 +285,7 @@ public final class ImmediateModeRecorder {
                 final float x = fb.get(offset);
                 final float y = fb.get(offset + 1);
                 final float z = (vertexSize >= 3) ? fb.get(offset + 2) : 0.0f;
-                vertex(x, y, z);
+                t.addVertex(x, y, z);
             };
         } else if (vertexType == GL11.GL_DOUBLE && vertexPointer instanceof DoubleBuffer db) {
             final int effectiveStride = (vertexStride == 0) ? vertexSize * 8 : vertexStride;
@@ -207,7 +295,7 @@ public final class ImmediateModeRecorder {
                 final float x = (float) db.get(offset);
                 final float y = (float) db.get(offset + 1);
                 final float z = (vertexSize >= 3) ? (float) db.get(offset + 2) : 0.0f;
-                vertex(x, y, z);
+                t.addVertex(x, y, z);
             };
         } else if (vertexType == GL11.GL_INT && vertexPointer instanceof IntBuffer ib) {
             final int effectiveStride = (vertexStride == 0) ? vertexSize * 4 : vertexStride;
@@ -217,7 +305,7 @@ public final class ImmediateModeRecorder {
                 final float x = ib.get(offset);
                 final float y = ib.get(offset + 1);
                 final float z = (vertexSize >= 3) ? ib.get(offset + 2) : 0.0f;
-                vertex(x, y, z);
+                t.addVertex(x, y, z);
             };
         } else if (vertexType == GL11.GL_SHORT && vertexPointer instanceof ShortBuffer sb) {
             final int effectiveStride = (vertexStride == 0) ? vertexSize * 2 : vertexStride;
@@ -227,7 +315,7 @@ public final class ImmediateModeRecorder {
                 final float x = sb.get(offset);
                 final float y = sb.get(offset + 1);
                 final float z = (vertexSize >= 3) ? sb.get(offset + 2) : 0.0f;
-                vertex(x, y, z);
+                t.addVertex(x, y, z);
             };
         } else {
             // Unsupported vertex type
@@ -236,6 +324,12 @@ public final class ImmediateModeRecorder {
 
         // Main loop - no type checks, just function calls
         for (int i = first; i < first + count; i++) {
+            if (normalReader != null) {
+                normalReader.read(i);
+            }
+            if (texCoordReader != null) {
+                texCoordReader.read(i);
+            }
             if (colorReader != null) {
                 colorReader.read(i);
             }
@@ -247,15 +341,8 @@ public final class ImmediateModeRecorder {
         return end();
     }
 
-
-
     @FunctionalInterface
-    private interface ColorReader {
-        void read(int index);
-    }
-
-    @FunctionalInterface
-    private interface VertexReader {
+    private interface ArrayReader {
         void read(int index);
     }
 }

src/main/java/com/gtnewhorizons/angelica/glsm/stacks/BooleanStateStack.java

@@ -22,8 +22,7 @@ public class BooleanStateStack extends BooleanState implements IStateStack<Boole
     protected int savedDepth;
 
     public BooleanStateStack(int glCap) {
-        // Most booleans default to false
-        this(glCap, false);
+        this(glCap, false, false);
     }
 
     /**
@@ -34,7 +33,18 @@ public class BooleanStateStack extends BooleanState implements IStateStack<Boole
      * @param initialState initial enabled state
      */
     public BooleanStateStack(int glCap, boolean initialState) {
-        super(glCap);
+        this(glCap, initialState, false);
+    }
+
+    /**
+     * Create a BooleanStateStack with custom initial state and FFP flag.
+     *
+     * @param glCap GL capability constant
+     * @param initialState initial enabled state
+     * @param ffpStateOnly when true, GL calls are skipped when FFP emulation is active
+     */
+    public BooleanStateStack(int glCap, boolean initialState, boolean ffpStateOnly) {
+        super(glCap, ffpStateOnly);
         this.enabled = initialState;
         stack = new boolean[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
     }

src/main/java/com/gtnewhorizons/angelica/glsm/stacks/TextureUnitBooleanStateStack.java

@@ -12,12 +12,12 @@ public class TextureUnitBooleanStateStack extends BooleanStateStack {
     private final int unitIndex;
 
     public TextureUnitBooleanStateStack(int glCap, int unitIndex) {
-        super(glCap);
+        super(glCap, false, true); // All texture enable/disable states are FFP-only
         this.unitIndex = unitIndex;
     }
 
     public TextureUnitBooleanStateStack(int glCap, int unitIndex, boolean initialState) {
-        super(glCap, initialState);
+        super(glCap, initialState, true);
         this.unitIndex = unitIndex;
     }
 
@@ -41,12 +41,14 @@ public class TextureUnitBooleanStateStack extends BooleanStateStack {
         if (bypass || enabled != this.enabled) {
             if (!bypass) this.enabled = enabled;
 
-            int currentUnit = GLStateManager.getActiveTextureUnit();
-            boolean needsSwitch = currentUnit != unitIndex;
+            if (!ffpStateOnly) {
+                final int currentUnit = GLStateManager.getActiveTextureUnit();
+                final boolean needsSwitch = currentUnit != unitIndex;
 
-            if (needsSwitch) GL13.glActiveTexture(GL13.GL_TEXTURE0 + unitIndex);
-            if (enabled) GL11.glEnable(glCap); else GL11.glDisable(glCap);
-            if (needsSwitch) GL13.glActiveTexture(GL13.GL_TEXTURE0 + currentUnit);
+                if (needsSwitch) GL13.glActiveTexture(GL13.GL_TEXTURE0 + unitIndex);
+                if (enabled) GL11.glEnable(glCap); else GL11.glDisable(glCap);
+                if (needsSwitch) GL13.glActiveTexture(GL13.GL_TEXTURE0 + currentUnit);
+            }
         }
     }
 

src/main/java/com/gtnewhorizons/angelica/glsm/stacks/Vec3fStack.java

@@ -0,0 +1,47 @@
+package com.gtnewhorizons.angelica.glsm.stacks;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import org.joml.Vector3f;
+
+/**
+ * Stack for a Vector3f value (e.g. current normal).
+ */
+public class Vec3fStack implements IStateStack<Vec3fStack> {
+
+    private final Vector3f value;
+    private final float[][] stack;
+    private int pointer;
+
+    public Vec3fStack(Vector3f value) {
+        this.value = value;
+        stack = new float[GLStateManager.MAX_ATTRIB_STACK_DEPTH][3];
+    }
+
+    @Override
+    public Vec3fStack push() {
+        if (pointer == stack.length) {
+            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
+        }
+        stack[pointer][0] = value.x;
+        stack[pointer][1] = value.y;
+        stack[pointer][2] = value.z;
+        pointer++;
+        return this;
+    }
+
+    @Override
+    public Vec3fStack pop() {
+        if (pointer == 0) {
+            throw new IllegalStateException("Stack underflow");
+        }
+        pointer--;
+        value.set(stack[pointer][0], stack[pointer][1], stack[pointer][2]);
+        return this;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return pointer == 0;
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/stacks/Vec4fStack.java

@@ -0,0 +1,48 @@
+package com.gtnewhorizons.angelica.glsm.stacks;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import org.joml.Vector4f;
+
+/**
+ * Stack for a Vector4f value (e.g. current texture coordinates).
+ */
+public class Vec4fStack implements IStateStack<Vec4fStack> {
+
+    private final Vector4f value;
+    private final float[][] stack;
+    private int pointer;
+
+    public Vec4fStack(Vector4f value) {
+        this.value = value;
+        stack = new float[GLStateManager.MAX_ATTRIB_STACK_DEPTH][4];
+    }
+
+    @Override
+    public Vec4fStack push() {
+        if (pointer == stack.length) {
+            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
+        }
+        stack[pointer][0] = value.x;
+        stack[pointer][1] = value.y;
+        stack[pointer][2] = value.z;
+        stack[pointer][3] = value.w;
+        pointer++;
+        return this;
+    }
+
+    @Override
+    public Vec4fStack pop() {
+        if (pointer == 0) {
+            throw new IllegalStateException("Stack underflow");
+        }
+        pointer--;
+        value.set(stack[pointer][0], stack[pointer][1], stack[pointer][2], stack[pointer][3]);
+        return this;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return pointer == 0;
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/states/AlphaState.java

@@ -7,7 +7,7 @@ import org.lwjgl.opengl.GL11;
 @Getter
 public class AlphaState implements ISettableState<AlphaState> {
     @Setter protected int function = GL11.GL_ALWAYS;
-    @Setter protected float reference = -1.0F;
+    @Setter protected float reference = 0.0F;
 
     @Override
     public AlphaState set(AlphaState state) {

src/main/java/com/gtnewhorizons/angelica/glsm/states/BlendState.java

@@ -3,6 +3,7 @@ package com.gtnewhorizons.angelica.glsm.states;
 import lombok.Getter;
 import lombok.Setter;
 import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL14;
 
 
 @Getter @Setter
@@ -11,6 +12,12 @@ public class BlendState implements ISettableState<BlendState> {
     protected int dstRgb = GL11.GL_ZERO;
     protected int srcAlpha = GL11.GL_ONE;
     protected int dstAlpha = GL11.GL_ZERO;
+    protected int equationRgb = GL14.GL_FUNC_ADD;
+    protected int equationAlpha = GL14.GL_FUNC_ADD;
+    protected float blendColorR = 0.0f;
+    protected float blendColorG = 0.0f;
+    protected float blendColorB = 0.0f;
+    protected float blendColorA = 0.0f;
 
     public BlendState() {}
 
@@ -39,6 +46,12 @@ public class BlendState implements ISettableState<BlendState> {
         this.dstRgb = state.dstRgb;
         this.srcAlpha = state.srcAlpha;
         this.dstAlpha = state.dstAlpha;
+        this.equationRgb = state.equationRgb;
+        this.equationAlpha = state.equationAlpha;
+        this.blendColorR = state.blendColorR;
+        this.blendColorG = state.blendColorG;
+        this.blendColorB = state.blendColorB;
+        this.blendColorA = state.blendColorA;
         return this;
     }
 
@@ -46,7 +59,13 @@ public class BlendState implements ISettableState<BlendState> {
     public boolean sameAs(Object state) {
         if (this == state) return true;
         if (!(state instanceof BlendState blendState)) return false;
-        return srcRgb == blendState.srcRgb && dstRgb == blendState.dstRgb && srcAlpha == blendState.srcAlpha && dstAlpha == blendState.dstAlpha;
+        return srcRgb == blendState.srcRgb && dstRgb == blendState.dstRgb
+            && srcAlpha == blendState.srcAlpha && dstAlpha == blendState.dstAlpha
+            && equationRgb == blendState.equationRgb && equationAlpha == blendState.equationAlpha
+            && Float.compare(blendColorR, blendState.blendColorR) == 0
+            && Float.compare(blendColorG, blendState.blendColorG) == 0
+            && Float.compare(blendColorB, blendState.blendColorB) == 0
+            && Float.compare(blendColorA, blendState.blendColorA) == 0;
     }
 
     @Override

src/main/java/com/gtnewhorizons/angelica/glsm/states/BooleanState.java

@@ -6,11 +6,22 @@ import org.lwjgl.opengl.GL11;
 
 public class BooleanState implements ISettableState<BooleanState> {
     protected final int glCap;
+    protected final boolean ffpStateOnly;
 
     @Getter protected boolean enabled;
+    protected boolean stateUnknown;
 
     public BooleanState(int glCap) {
+        this(glCap, false);
+    }
+
+    public BooleanState(int glCap, boolean ffpStateOnly) {
         this.glCap = glCap;
+        this.ffpStateOnly = ffpStateOnly;
+    }
+
+    public void setUnknownState() {
+        stateUnknown = true;
     }
 
     public void disable() {
@@ -23,15 +34,17 @@ public class BooleanState implements ISettableState<BooleanState> {
 
     public void setEnabled(boolean enabled) {
         final boolean bypass = GLStateManager.shouldBypassCache();
-        if (bypass || enabled != this.enabled || (this.glCap == GL11.GL_BLEND && GLStateManager.vendorIsAMD() && GLStateManager.isPoppingAttributes())) {
+        if (stateUnknown || bypass || enabled != this.enabled || (this.glCap == GL11.GL_BLEND && GLStateManager.vendorIsAMD() && GLStateManager.isPoppingAttributes())) {
+            stateUnknown = false;
             if (!bypass) {
                 this.enabled = enabled;
             }
-            // Always call GL - the calling method controls whether we reach here based on recording mode
-            if (enabled) {
-                GL11.glEnable(this.glCap);
-            } else {
-                GL11.glDisable(this.glCap);
+            if (!ffpStateOnly) {
+                if (enabled) {
+                    GL11.glEnable(this.glCap);
+                } else {
+                    GL11.glDisable(this.glCap);
+                }
             }
         }
     }

src/main/java/com/gtnewhorizons/angelica/glsm/states/ClientArrayState.java

@@ -60,6 +60,19 @@ public class ClientArrayState {
         return vertexPointerStride;
     }
 
+    // Normal array state
+    private boolean normalArrayEnabled = false;
+    private Buffer normalPointer = null;
+    private int normalPointerType = GL11.GL_FLOAT;
+    private int normalPointerStride = 0;
+
+    // TexCoord array state
+    private boolean texCoordArrayEnabled = false;
+    private Buffer texCoordPointer = null;
+    private int texCoordPointerSize = 4;
+    private int texCoordPointerType = GL11.GL_FLOAT;
+    private int texCoordPointerStride = 0;
+
     // Color array methods
     public void setColorPointer(int size, int type, int stride, Buffer pointer) {
         this.colorPointerSize = size;
@@ -91,4 +104,63 @@ public class ClientArrayState {
     public int getColorPointerStride() {
         return colorPointerStride;
     }
+
+    // Normal array methods
+    public void setNormalPointer(int type, int stride, Buffer pointer) {
+        this.normalPointerType = type;
+        this.normalPointerStride = stride;
+        this.normalPointer = pointer;
+    }
+
+    public boolean isNormalArrayEnabled() {
+        return normalArrayEnabled;
+    }
+
+    public void setNormalArrayEnabled(boolean enabled) {
+        this.normalArrayEnabled = enabled;
+    }
+
+    public Buffer getNormalPointer() {
+        return normalPointer;
+    }
+
+    public int getNormalPointerType() {
+        return normalPointerType;
+    }
+
+    public int getNormalPointerStride() {
+        return normalPointerStride;
+    }
+
+    // TexCoord array methods
+    public void setTexCoordPointer(int size, int type, int stride, Buffer pointer) {
+        this.texCoordPointerSize = size;
+        this.texCoordPointerType = type;
+        this.texCoordPointerStride = stride;
+        this.texCoordPointer = pointer;
+    }
+
+    public boolean isTexCoordArrayEnabled() {
+        return texCoordArrayEnabled;
+    }
+
+    public void setTexCoordArrayEnabled(boolean enabled) {
+        this.texCoordArrayEnabled = enabled;
+    }
+
+    public Buffer getTexCoordPointer() {
+        return texCoordPointer;
+    }
+
+    public int getTexCoordPointerSize() {
+        return texCoordPointerSize;
+    }
+
+    public int getTexCoordPointerType() {
+        return texCoordPointerType;
+    }
+
+    public int getTexCoordPointerStride() {
+        return texCoordPointerStride;
+    }
 }

src/main/java/com/gtnewhorizons/angelica/glsm/states/ClipPlaneState.java

@@ -0,0 +1,34 @@
+package com.gtnewhorizons.angelica.glsm.states;
+
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import org.joml.Matrix4f;
+import org.joml.Vector4f;
+
+import java.nio.FloatBuffer;
+
+/**
+ * Stores eye-space clip plane equations for core profile emulation.
+ */
+public class ClipPlaneState {
+    private final float[][] eyePlanes = new float[GLStateManager.MAX_CLIP_PLANES][4];
+
+    private static final Vector4f tempPlane = new Vector4f();
+    private static final Matrix4f tempInverse = new Matrix4f();
+
+    public void setPlane(int index, double a, double b, double c, double d, Matrix4f modelView) {
+        final float[] dest = eyePlanes[index];
+        modelView.invert(tempInverse);
+        tempPlane.set((float) a, (float) b, (float) c, (float) d);
+        tempInverse.transformTranspose(tempPlane);
+        dest[0] = tempPlane.x;
+        dest[1] = tempPlane.y;
+        dest[2] = tempPlane.z;
+        dest[3] = tempPlane.w;
+    }
+
+    /** Writes the 4-component eye-space plane equation into {@code buf} at its current position. */
+    public void putEyePlane(int index, FloatBuffer buf) {
+        final float[] p = eyePlanes[index];
+        buf.put(p[0]).put(p[1]).put(p[2]).put(p[3]);
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/states/DepthState.java

@@ -8,11 +8,13 @@ import org.lwjgl.opengl.GL11;
 public class DepthState implements ISettableState<DepthState> {
     protected boolean enabled = true;
     protected int func = GL11.GL_LESS;
+    protected double clearValue = 1.0;
 
     @Override
     public DepthState set(DepthState state) {
         this.enabled = state.enabled;
         this.func = state.func;
+        this.clearValue = state.clearValue;
         return this;
     }
 
@@ -20,7 +22,7 @@ public class DepthState implements ISettableState<DepthState> {
     public boolean sameAs(Object state) {
         if (this == state) return true;
         if (!(state instanceof DepthState depthState)) return false;
-        return enabled == depthState.enabled && func == depthState.func;
+        return enabled == depthState.enabled && func == depthState.func && Double.compare(clearValue, depthState.clearValue) == 0;
     }
     @Override
     public DepthState copy() {

src/main/java/com/gtnewhorizons/angelica/glsm/states/FogState.java

@@ -16,6 +16,8 @@ public class FogState implements ISettableState<FogState> {
     protected float density = 1.0F;
     protected float start;
     protected float end = 1.0F;
+    /** Fog distance computation mode: 0=EYE_RADIAL, 1=EYE_PLANE, 2=EYE_PLANE_ABS */
+    protected int fogDistanceMode = 2;
 
     @Override
     public FogState set(FogState state) {
@@ -23,16 +25,20 @@ public class FogState implements ISettableState<FogState> {
         this.fogColor.set(state.fogColor);
         this.fogAlpha = state.fogAlpha;
         this.fogColorBuffer.put(0, state.fogColorBuffer.get(0));
+        this.fogColorBuffer.put(1, state.fogColorBuffer.get(1));
+        this.fogColorBuffer.put(2, state.fogColorBuffer.get(2));
+        this.fogColorBuffer.put(3, state.fogColorBuffer.get(3));
         this.density = state.density;
         this.start = state.start;
         this.end = state.end;
+        this.fogDistanceMode = state.fogDistanceMode;
         return this;
     }
     @Override
     public boolean sameAs(Object state) {
         if (this == state) return true;
         if (!(state instanceof FogState fogState)) return false;
-        return fogMode == fogState.fogMode && Float.compare(fogState.fogAlpha, fogAlpha) == 0 && Float.compare(fogState.density, density) == 0 && Float.compare(fogState.start, start) == 0 && Float.compare(fogState.end, end) == 0 && fogColor.equals(fogState.fogColor);
+        return fogMode == fogState.fogMode && fogDistanceMode == fogState.fogDistanceMode && Float.compare(fogState.fogAlpha, fogAlpha) == 0 && Float.compare(fogState.density, density) == 0 && Float.compare(fogState.start, start) == 0 && Float.compare(fogState.end, end) == 0 && fogColor.equals(fogState.fogColor);
     }
 
     @Override

src/main/java/com/gtnewhorizons/angelica/glsm/states/LightModelState.java

@@ -3,7 +3,6 @@ package com.gtnewhorizons.angelica.glsm.states;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import org.joml.Vector4f;
 import org.joml.Vector4i;
-import org.lwjgl.opengl.GL11;
 import org.lwjgl.opengl.GL12;
 
 import java.nio.FloatBuffer;
@@ -32,7 +31,6 @@ public class LightModelState implements ISettableState<LightModelState> {
         vector4f.set(newBuffer);
         if (GLStateManager.shouldBypassCache() || !this.ambient.equals(vector4f)) {
             this.ambient.set(vector4f);
-            GL11.glLightModel(GL11.GL_LIGHT_MODEL_AMBIENT, newBuffer);
         }
     }
 
@@ -41,14 +39,12 @@ public class LightModelState implements ISettableState<LightModelState> {
         vector4f.set(i2f(vector4i.x), i2f(vector4i.y), i2f(vector4i.z), i2f(vector4i.w));
         if (GLStateManager.shouldBypassCache() || !this.ambient.equals(vector4f)) {
             this.ambient.set(vector4f);
-            GL11.glLightModel(GL11.GL_LIGHT_MODEL_AMBIENT, newBuffer);
         }
     }
 
     public void setColorControl(int val) {
         if (GLStateManager.shouldBypassCache() || this.colorControl != val) {
             this.colorControl = val;
-            GL11.glLightModeli(GL12.GL_LIGHT_MODEL_COLOR_CONTROL, val);
         }
     }
 
@@ -59,7 +55,6 @@ public class LightModelState implements ISettableState<LightModelState> {
     public void setLocalViewer(float val) {
         if (GLStateManager.shouldBypassCache() || Float.compare(this.localViewer, val) != 0) {
             this.localViewer = val;
-            GL11.glLightModelf(GL11.GL_LIGHT_MODEL_LOCAL_VIEWER, val);
         }
     }
 
@@ -78,7 +73,6 @@ public class LightModelState implements ISettableState<LightModelState> {
     public void setTwoSide(float val) {
         if (GLStateManager.shouldBypassCache() || Float.compare(this.twoSide, val) != 0) {
             this.twoSide = val;
-            GL11.glLightModelf(GL11.GL_LIGHT_MODEL_TWO_SIDE, val);
         }
     }
 

src/main/java/com/gtnewhorizons/angelica/glsm/states/LightState.java

@@ -29,6 +29,7 @@ public class LightState implements ISettableState<LightState> {
     public final Vector3f spotDirection;
     public float spotExponent;
     public float spotCutoff;
+    public float spotCosCutoff;
     public float constantAttenuation;
     public float linearAttenuation;
     public float quadraticAttenuation;
@@ -60,6 +61,7 @@ public class LightState implements ISettableState<LightState> {
         this.specular = specular;
         this.spotExponent = spotExponent;
         this.spotCutoff = spotCutoff;
+        this.spotCosCutoff = (float) Math.cos(Math.toRadians(spotCutoff));
         this.constantAttenuation = constantAttenuation;
         this.linearAttenuation = linearAttenuation;
         this.quadraticAttenuation = quadraticAttenuation;
@@ -76,7 +78,6 @@ public class LightState implements ISettableState<LightState> {
         vector4f.set(newBuffer);
         if (GLStateManager.shouldBypassCache() || !this.ambient.equals(vector4f)) {
             this.ambient.set(vector4f);
-            GL11.glLight(this.light, GL11.GL_AMBIENT, newBuffer);
         }
     }
 
@@ -85,7 +86,6 @@ public class LightState implements ISettableState<LightState> {
         vector4f.set(i2f(vector4i.x), i2f(vector4i.y), i2f(vector4i.z), i2f(vector4i.w));
         if (GLStateManager.shouldBypassCache() || !this.ambient.equals(vector4f)) {
             this.ambient.set(vector4f);
-            GL11.glLight(this.light, GL11.GL_AMBIENT, newBuffer);
         }
     }
 
@@ -93,7 +93,6 @@ public class LightState implements ISettableState<LightState> {
         vector4f.set(newBuffer);
         if (GLStateManager.shouldBypassCache() || !this.diffuse.equals(vector4f)) {
             this.diffuse.set(vector4f);
-            GL11.glLight(this.light, GL11.GL_DIFFUSE, newBuffer);
         }
     }
 
@@ -102,7 +101,6 @@ public class LightState implements ISettableState<LightState> {
         vector4f.set(i2f(vector4i.x), i2f(vector4i.y), i2f(vector4i.z), i2f(vector4i.w));
         if (GLStateManager.shouldBypassCache() || !this.diffuse.equals(vector4f)) {
             this.diffuse.set(vector4f);
-            GL11.glLight(this.light, GL11.GL_DIFFUSE, newBuffer);
         }
     }
 
@@ -110,7 +108,6 @@ public class LightState implements ISettableState<LightState> {
         vector4f.set(newBuffer);
         if (GLStateManager.shouldBypassCache() || !this.specular.equals(vector4f)) {
             this.specular.set(vector4f);
-            GL11.glLight(this.light, GL11.GL_SPECULAR, newBuffer);
         }
     }
 
@@ -119,7 +116,6 @@ public class LightState implements ISettableState<LightState> {
         vector4f.set(i2f(vector4i.x), i2f(vector4i.y), i2f(vector4i.z), i2f(vector4i.w));
         if (GLStateManager.shouldBypassCache() || !this.specular.equals(vector4f)) {
             this.specular.set(vector4f);
-            GL11.glLight(this.light, GL11.GL_SPECULAR, newBuffer);
         }
     }
 
@@ -129,14 +125,12 @@ public class LightState implements ISettableState<LightState> {
         // with and the untransformed coordinates in addition to the final transformation.
         this.position.set(newBuffer);
         this.position.mul(GLStateManager.getModelViewMatrix());
-        GL11.glLight(this.light, GL11.GL_POSITION, newBuffer);
     }
 
     public void setPosition(IntBuffer newBuffer) {
         vector4i.set(newBuffer);
         this.position.set((float) vector4i.x, (float) vector4i.y, (float) vector4i.z, (float) vector4i.w);
         this.position.mul(GLStateManager.getModelViewMatrix());
-        GL11.glLight(this.light, GL11.GL_POSITION, newBuffer);
     }
 
     public void setSpotDirection(FloatBuffer newBuffer) {
@@ -146,7 +140,6 @@ public class LightState implements ISettableState<LightState> {
         GLStateManager.getModelViewMatrix().get3x3(matrix3f);
         this.spotDirection.set(newBuffer);
         this.spotDirection.mul(matrix3f);
-        GL11.glLight(this.light, GL11.GL_SPOT_DIRECTION, newBuffer);
     }
 
     public void setSpotDirection(IntBuffer newBuffer) {
@@ -154,7 +147,6 @@ public class LightState implements ISettableState<LightState> {
         GLStateManager.getModelViewMatrix().get3x3(matrix3f);
         this.spotDirection.set((float) vector3i.x, (float) vector3i.y, (float) vector3i.z);
         this.spotDirection.mul(matrix3f);
-        GL11.glLight(this.light, GL11.GL_SPOT_DIRECTION, newBuffer);
     }
 
     public void setSpotExponent(FloatBuffer newBuffer) {
@@ -172,7 +164,6 @@ public class LightState implements ISettableState<LightState> {
     public void setSpotExponent(float f) {
         if (GLStateManager.shouldBypassCache() || Float.compare(f, this.spotExponent) != 0) {
             this.spotExponent = f;
-            GL11.glLightf(this.light, GL11.GL_SPOT_EXPONENT, f);
         }
     }
 
@@ -191,7 +182,7 @@ public class LightState implements ISettableState<LightState> {
     public void setSpotCutoff(float f) {
         if (GLStateManager.shouldBypassCache() || Float.compare(f, this.spotCutoff) != 0) {
             this.spotCutoff = f;
-            GL11.glLightf(this.light, GL11.GL_SPOT_CUTOFF, f);
+            this.spotCosCutoff = (float) Math.cos(Math.toRadians(f));
         }
     }
 
@@ -210,7 +201,6 @@ public class LightState implements ISettableState<LightState> {
     public void setConstantAttenuation(float f) {
         if (GLStateManager.shouldBypassCache() || Float.compare(f, this.constantAttenuation) != 0) {
             this.constantAttenuation = f;
-            GL11.glLightf(this.light, GL11.GL_CONSTANT_ATTENUATION, f);
         }
     }
 
@@ -229,7 +219,6 @@ public class LightState implements ISettableState<LightState> {
     public void setLinearAttenuation(float f) {
         if (GLStateManager.shouldBypassCache() || Float.compare(f, this.linearAttenuation) != 0) {
             this.linearAttenuation = f;
-            GL11.glLightf(this.light, GL11.GL_LINEAR_ATTENUATION, f);
         }
     }
 
@@ -248,7 +237,6 @@ public class LightState implements ISettableState<LightState> {
     public void setQuadraticAttenuation(float f) {
         if (GLStateManager.shouldBypassCache() || Float.compare(f, this.quadraticAttenuation) != 0) {
             this.quadraticAttenuation = f;
-            GL11.glLightf(this.light, GL11.GL_QUADRATIC_ATTENUATION, f);
         }
     }
 
@@ -261,6 +249,7 @@ public class LightState implements ISettableState<LightState> {
         this.spotDirection.set(state.spotDirection);
         this.spotExponent = state.spotExponent;
         this.spotCutoff = state.spotCutoff;
+        this.spotCosCutoff = state.spotCosCutoff;
         this.constantAttenuation = state.constantAttenuation;
         this.linearAttenuation = state.linearAttenuation;
         this.quadraticAttenuation = state.quadraticAttenuation;

src/main/java/com/gtnewhorizons/angelica/glsm/states/MaterialState.java

@@ -5,7 +5,6 @@ import org.joml.Vector3f;
 import org.joml.Vector3i;
 import org.joml.Vector4f;
 import org.joml.Vector4i;
-import org.lwjgl.opengl.GL11;
 
 import java.nio.FloatBuffer;
 import java.nio.IntBuffer;
@@ -42,7 +41,6 @@ public class MaterialState implements ISettableState<MaterialState> {
         vector4f.set(newBuffer);
         if (GLStateManager.shouldBypassCache() || !this.ambient.equals(vector4f)) {
             this.ambient.set(vector4f);
-            GL11.glMaterial(face, GL11.GL_AMBIENT, newBuffer);
         }
     }
 
@@ -51,7 +49,6 @@ public class MaterialState implements ISettableState<MaterialState> {
         vector4f.set(i2f(vector4i.x), i2f(vector4i.y), i2f(vector4i.z), i2f(vector4i.w));
         if (GLStateManager.shouldBypassCache() || !this.ambient.equals(vector4f)) {
             this.ambient.set(vector4f);
-            GL11.glMaterial(face, GL11.GL_AMBIENT, newBuffer);
         }
     }
 
@@ -59,7 +56,6 @@ public class MaterialState implements ISettableState<MaterialState> {
         vector4f.set(newBuffer);
         if (GLStateManager.shouldBypassCache() || !this.diffuse.equals(vector4f)) {
             this.diffuse.set(vector4f);
-            GL11.glMaterial(face, GL11.GL_DIFFUSE, newBuffer);
         }
     }
 
@@ -68,7 +64,6 @@ public class MaterialState implements ISettableState<MaterialState> {
         vector4f.set(i2f(vector4i.x), i2f(vector4i.y), i2f(vector4i.z), i2f(vector4i.w));
         if (GLStateManager.shouldBypassCache() || !this.diffuse.equals(vector4f)) {
             this.diffuse.set(vector4f);
-            GL11.glMaterial(face, GL11.GL_DIFFUSE, newBuffer);
         }
     }
 
@@ -76,7 +71,6 @@ public class MaterialState implements ISettableState<MaterialState> {
         vector4f.set(newBuffer);
         if (GLStateManager.shouldBypassCache() || !this.specular.equals(vector4f)) {
             this.specular.set(vector4f);
-            GL11.glMaterial(face, GL11.GL_SPECULAR, newBuffer);
         }
     }
 
@@ -85,7 +79,6 @@ public class MaterialState implements ISettableState<MaterialState> {
         vector4f.set(i2f(vector4i.x), i2f(vector4i.y), i2f(vector4i.z), i2f(vector4i.w));
         if (GLStateManager.shouldBypassCache() || !this.specular.equals(vector4f)) {
             this.specular.set(vector4f);
-            GL11.glMaterial(face, GL11.GL_SPECULAR, newBuffer);
         }
     }
 
@@ -93,7 +86,6 @@ public class MaterialState implements ISettableState<MaterialState> {
         vector4f.set(newBuffer);
         if (GLStateManager.shouldBypassCache() || !this.emission.equals(vector4f)) {
             this.emission.set(vector4f);
-            GL11.glMaterial(face, GL11.GL_EMISSION, newBuffer);
         }
     }
 
@@ -102,14 +94,12 @@ public class MaterialState implements ISettableState<MaterialState> {
         vector4f.set(i2f(vector4i.x), i2f(vector4i.y), i2f(vector4i.z), i2f(vector4i.w));
         if (GLStateManager.shouldBypassCache() || !this.emission.equals(vector4f)) {
             this.emission.set(vector4f);
-            GL11.glMaterial(face, GL11.GL_EMISSION, newBuffer);
         }
     }
 
     public void setShininess(float val) {
         if (GLStateManager.shouldBypassCache() || Float.compare(this.shininess, val) != 0) {
             this.shininess = val;
-            GL11.glMaterialf(face, GL11.GL_SHININESS, val);
         }
     }
 
@@ -132,7 +122,6 @@ public class MaterialState implements ISettableState<MaterialState> {
 
         if (GLStateManager.shouldBypassCache() || !this.colorIndexes.equals(vector3f)) {
             this.colorIndexes.set(vector3f);
-            GL11.glMaterial(face, GL11.GL_COLOR_INDEXES, newBuffer);
         }
     }
 
@@ -141,7 +130,6 @@ public class MaterialState implements ISettableState<MaterialState> {
         vector3f.set((float) vector3i.x, (float) vector3i.y, (float) vector3i.z);
         if (GLStateManager.shouldBypassCache() || !this.colorIndexes.equals(vector3f)) {
             this.colorIndexes.set(vector3f);
-            GL11.glMaterial(face, GL11.GL_COLOR_INDEXES, newBuffer);
         }
     }
 

src/main/java/com/gtnewhorizons/angelica/glsm/states/MatrixMode.java

@@ -10,8 +10,7 @@ public class MatrixMode implements ISettableState<MatrixMode> {
 
     public void setMode(int mode) {
         if(mode != GL11.GL_MODELVIEW && mode != GL11.GL_PROJECTION && mode != GL11.GL_TEXTURE && mode != GL11.GL_COLOR) {
-            // Invalid mode, do nothing on the cache, but pass it along to OGL
-            GL11.glMatrixMode(mode);
+            // Invalid mode, do nothing on the cache
             return;
         }
 
@@ -20,7 +19,6 @@ public class MatrixMode implements ISettableState<MatrixMode> {
             if (!bypass) {
                 this.mode = mode;
             }
-            GL11.glMatrixMode(mode);
         }
     }
 

src/main/java/com/gtnewhorizons/angelica/glsm/states/TexEnvState.java

@@ -0,0 +1,110 @@
+package com.gtnewhorizons.angelica.glsm.states;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL13;
+
+/**
+ * Per-texture-unit GL_TEXTURE_ENV state for FFP emulation. Tracks the simple texenv mode and all GL_COMBINE sub-parameters.
+ */
+public class TexEnvState implements IStateStack<TexEnvState> {
+
+    public int mode;
+
+    public int combineRgb;
+    public int combineAlpha;
+
+    public final int[] sourceRgb = new int[3];
+    public final int[] sourceAlpha = new int[3];
+
+    public final int[] operandRgb = new int[3];
+    public final int[] operandAlpha = new int[3];
+
+    public float scaleRgb;
+    public float scaleAlpha;
+
+    public float envColorR;
+    public float envColorG;
+    public float envColorB;
+    public float envColorA;
+
+    private final TexEnvState[] stack;
+    private int pointer;
+    private final boolean isStackEntry;
+
+    public TexEnvState() {
+        this(false);
+    }
+
+    private TexEnvState(boolean isStackEntry) {
+        this.isStackEntry = isStackEntry;
+        if (isStackEntry) {
+            stack = null;
+        } else {
+            stack = new TexEnvState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
+            for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
+                stack[i] = new TexEnvState(true);
+            }
+        }
+        reset();
+    }
+
+    public void copyFrom(TexEnvState other) {
+        this.mode = other.mode;
+        this.combineRgb = other.combineRgb;
+        this.combineAlpha = other.combineAlpha;
+        System.arraycopy(other.sourceRgb, 0, this.sourceRgb, 0, 3);
+        System.arraycopy(other.sourceAlpha, 0, this.sourceAlpha, 0, 3);
+        System.arraycopy(other.operandRgb, 0, this.operandRgb, 0, 3);
+        System.arraycopy(other.operandAlpha, 0, this.operandAlpha, 0, 3);
+        this.scaleRgb = other.scaleRgb;
+        this.scaleAlpha = other.scaleAlpha;
+        this.envColorR = other.envColorR;
+        this.envColorG = other.envColorG;
+        this.envColorB = other.envColorB;
+        this.envColorA = other.envColorA;
+    }
+
+    public void reset() {
+        mode = GL11.GL_MODULATE;
+        combineRgb = GL11.GL_MODULATE;
+        combineAlpha = GL11.GL_MODULATE;
+        sourceRgb[0] = GL11.GL_TEXTURE; sourceRgb[1] = GL13.GL_PREVIOUS; sourceRgb[2] = GL13.GL_CONSTANT;
+        sourceAlpha[0] = GL11.GL_TEXTURE; sourceAlpha[1] = GL13.GL_PREVIOUS; sourceAlpha[2] = GL13.GL_CONSTANT;
+        operandRgb[0] = GL11.GL_SRC_COLOR; operandRgb[1] = GL11.GL_SRC_COLOR; operandRgb[2] = GL11.GL_SRC_ALPHA;
+        operandAlpha[0] = GL11.GL_SRC_ALPHA; operandAlpha[1] = GL11.GL_SRC_ALPHA; operandAlpha[2] = GL11.GL_SRC_ALPHA;
+        scaleRgb = 1.0f;
+        scaleAlpha = 1.0f;
+        envColorR = 0.0f; envColorG = 0.0f; envColorB = 0.0f; envColorA = 0.0f;
+    }
+
+    @Override
+    public TexEnvState push() {
+        if (stack == null) throw new IllegalStateException("Cannot push stack entry");
+        if (pointer >= stack.length) {
+            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
+        }
+        stack[pointer++].copyFrom(this);
+        return this;
+    }
+
+    @Override
+    public TexEnvState pop() {
+        if (stack == null) throw new IllegalStateException("Cannot pop stack entry");
+        if (pointer == 0) {
+            throw new IllegalStateException("Stack underflow");
+        }
+        copyFrom(stack[--pointer]);
+        return this;
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return pointer == 0;
+    }
+
+    public boolean isCombineMode() {
+        return mode == GL13.GL_COMBINE;
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/states/TexGenState.java

@@ -0,0 +1,83 @@
+package com.gtnewhorizons.angelica.glsm.states;
+
+import org.joml.Matrix4f;
+import org.joml.Vector4f;
+import org.lwjgl.opengl.GL11;
+
+/**
+ * Per-texture-unit storage for texgen mode and plane coefficients. Based on Mesa's texgen.c storage model.
+ */
+public class TexGenState {
+    private int modeS, modeT, modeR, modeQ;
+
+    private final float[] objectPlaneS = {1, 0, 0, 0};
+    private final float[] objectPlaneT = {0, 1, 0, 0};
+    private final float[] objectPlaneR = {0, 0, 0, 0};
+    private final float[] objectPlaneQ = {0, 0, 0, 0};
+
+    private final float[] eyePlaneS = {1, 0, 0, 0};
+    private final float[] eyePlaneT = {0, 1, 0, 0};
+    private final float[] eyePlaneR = {0, 0, 0, 0};
+    private final float[] eyePlaneQ = {0, 0, 0, 0};
+
+    private static final Vector4f tempPlane = new Vector4f();
+    private static final Matrix4f tempInverse = new Matrix4f();
+
+    public int getMode(int coord) {
+        return switch (coord) {
+            case GL11.GL_S -> modeS;
+            case GL11.GL_T -> modeT;
+            case GL11.GL_R -> modeR;
+            case GL11.GL_Q -> modeQ;
+            default -> 0;
+        };
+    }
+
+    public void setMode(int coord, int mode) {
+        switch (coord) {
+            case GL11.GL_S -> modeS = mode;
+            case GL11.GL_T -> modeT = mode;
+            case GL11.GL_R -> modeR = mode;
+            case GL11.GL_Q -> modeQ = mode;
+        }
+    }
+
+    public float[] getObjectPlane(int coord) {
+        return switch (coord) {
+            case GL11.GL_S -> objectPlaneS;
+            case GL11.GL_T -> objectPlaneT;
+            case GL11.GL_R -> objectPlaneR;
+            case GL11.GL_Q -> objectPlaneQ;
+            default -> objectPlaneS;
+        };
+    }
+
+    public float[] getEyePlane(int coord) {
+        return switch (coord) {
+            case GL11.GL_S -> eyePlaneS;
+            case GL11.GL_T -> eyePlaneT;
+            case GL11.GL_R -> eyePlaneR;
+            case GL11.GL_Q -> eyePlaneQ;
+            default -> eyePlaneS;
+        };
+    }
+
+    public void setObjectPlane(int coord, float[] plane) {
+        final float[] dest = getObjectPlane(coord);
+        System.arraycopy(plane, 0, dest, 0, 4);
+    }
+
+    /**
+     * Set eye plane coefficients. Per GL spec (Mesa texgen.c:154), the plane is transformed by the inverse of the current modelview matrix at the time of the call.
+     */
+    public void setEyePlane(int coord, float[] plane, Matrix4f modelView) {
+        final float[] dest = getEyePlane(coord);
+        modelView.invert(tempInverse);
+        tempPlane.set(plane[0], plane[1], plane[2], plane[3]);
+        tempInverse.transformTranspose(tempPlane);
+        dest[0] = tempPlane.x;
+        dest[1] = tempPlane.y;
+        dest[2] = tempPlane.z;
+        dest[3] = tempPlane.w;
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/states/TextureUnitArray.java

@@ -17,6 +17,8 @@ public class TextureUnitArray {
     private final TextureUnitBooleanStateStack[] texGenTStates;
     private final TextureUnitBooleanStateStack[] texGenRStates;
     private final TextureUnitBooleanStateStack[] texGenQStates;
+    private final TexGenState[] texGenStates;
+    private final TexEnvState[] texEnvStates;
     @Getter
     public final Matrix4fStack[] textureMatricies;
 
@@ -29,6 +31,8 @@ public class TextureUnitArray {
         texGenTStates = new TextureUnitBooleanStateStack[GLStateManager.MAX_TEXTURE_UNITS];
         texGenRStates = new TextureUnitBooleanStateStack[GLStateManager.MAX_TEXTURE_UNITS];
         texGenQStates = new TextureUnitBooleanStateStack[GLStateManager.MAX_TEXTURE_UNITS];
+        texGenStates = new TexGenState[GLStateManager.MAX_TEXTURE_UNITS];
+        texEnvStates = new TexEnvState[GLStateManager.MAX_TEXTURE_UNITS];
         textureMatricies = new Matrix4fStack[GLStateManager.MAX_TEXTURE_UNITS];
 
         for (int i = 0; i < GLStateManager.MAX_TEXTURE_UNITS; i++) {
@@ -40,6 +44,8 @@ public class TextureUnitArray {
             texGenTStates[i] = new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_GEN_T, i);
             texGenRStates[i] = new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_GEN_R, i);
             texGenQStates[i] = new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_GEN_Q, i);
+            texGenStates[i] = new TexGenState();
+            texEnvStates[i] = new TexEnvState();
             textureMatricies[i] = new Matrix4fStack(GLStateManager.MAX_TEXTURE_STACK_DEPTH);
         }
     }
@@ -76,6 +82,14 @@ public class TextureUnitArray {
         return texGenQStates[index];
     }
 
+    public TexGenState getTexGenState(int index) {
+        return texGenStates[index];
+    }
+
+    public TexEnvState getTexEnvState(int index) {
+        return texEnvStates[index];
+    }
+
     public Matrix4fStack getTextureUnitMatrix(int index) {
         return textureMatricies[index];
     }

src/main/java/com/gtnewhorizons/angelica/glsm/states/ViewportState.java

@@ -7,6 +7,8 @@ public class ViewportState implements ISettableState<ViewportState> {
     public int y;
     public int width;
     public int height;
+    public double depthRangeNear = 0.0;
+    public double depthRangeFar = 1.0;
 
     public void setViewPort(int x, int y, int width, int height) {
         this.x = x;
@@ -15,6 +17,11 @@ public class ViewportState implements ISettableState<ViewportState> {
         this.height = height;
     }
 
+    public void setDepthRange(double near, double far) {
+        this.depthRangeNear = near;
+        this.depthRangeFar = far;
+    }
+
     public void get(IntBuffer params) {
         params.put(0, x);
         params.put(1, y);
@@ -28,6 +35,8 @@ public class ViewportState implements ISettableState<ViewportState> {
         this.y = state.y;
         this.width = state.width;
         this.height = state.height;
+        this.depthRangeNear = state.depthRangeNear;
+        this.depthRangeFar = state.depthRangeFar;
 
         return this;
     }
@@ -36,7 +45,9 @@ public class ViewportState implements ISettableState<ViewportState> {
     public boolean sameAs(Object state) {
         if (this == state) return true;
         if (!(state instanceof ViewportState viewportState)) return false;
-        return x == viewportState.x && y == viewportState.y && width == viewportState.width && height == viewportState.height;
+        return x == viewportState.x && y == viewportState.y && width == viewportState.width && height == viewportState.height
+            && Double.compare(depthRangeNear, viewportState.depthRangeNear) == 0
+            && Double.compare(depthRangeFar, viewportState.depthRangeFar) == 0;
     }
 
     @Override

src/main/java/com/gtnewhorizons/angelica/glsm/streaming/OrphanStreamingBuffer.java

@@ -0,0 +1,142 @@
+package com.gtnewhorizons.angelica.glsm.streaming;
+
+import org.lwjgl.opengl.GL15;
+import org.lwjgl.opengl.GL30;
+
+import java.nio.ByteBuffer;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAddress0;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memCopy;
+import static com.mitchej123.lwjgl.LWJGLServiceProvider.LWJGL;
+
+/**
+ * Streaming buffer using the classic orphan pattern with sub-allocation.
+ * <p>
+ * Supports two upload strategies:
+ * <ul>
+ *   <li>{@link UploadStrategy#BUFFER_SUB_DATA} — glBufferData orphan + glBufferSubData (default)</li>
+ *   <li>{@link UploadStrategy#MAP_BUFFER_RANGE} — glMapBufferRange with INVALIDATE hints </li>
+ * </ul>
+ */
+public class OrphanStreamingBuffer implements StreamingBuffer {
+
+    public enum UploadStrategy {
+        BUFFER_SUB_DATA,
+        MAP_BUFFER_RANGE
+    }
+
+    private static final int MAP_WRITE_INVALIDATE_BUFFER = GL30.GL_MAP_WRITE_BIT | GL30.GL_MAP_INVALIDATE_BUFFER_BIT | GL30.GL_MAP_UNSYNCHRONIZED_BIT;
+    private static final int MAP_WRITE_INVALIDATE_RANGE = GL30.GL_MAP_WRITE_BIT | GL30.GL_MAP_INVALIDATE_RANGE_BIT | GL30.GL_MAP_UNSYNCHRONIZED_BIT;
+
+    private int bufferId;
+    private int capacity;
+    private int writePos;
+    private boolean needsOrphan = true;
+    private final UploadStrategy strategy;
+
+    public OrphanStreamingBuffer() {
+        this(UploadStrategy.BUFFER_SUB_DATA);
+    }
+
+    public OrphanStreamingBuffer(UploadStrategy strategy) {
+        this.strategy = strategy;
+        this.bufferId = GL15.glGenBuffers();
+    }
+
+    @Override
+    public int upload(ByteBuffer data, int vertexStride) {
+        final int dataSize = data.remaining();
+
+        final int alignUnit = vertexStride * 4;
+        int alignedPos = ((writePos + alignUnit - 1) / alignUnit) * alignUnit;
+
+        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, bufferId);
+
+        boolean freshAllocation = false;
+        if (alignedPos + dataSize > capacity) {
+            // Doesn't fit — grow if needed, allocate new storage, reset to offset 0
+            growIfNeeded(dataSize);
+            allocateBuffer();
+            alignedPos = 0;
+            freshAllocation = true;
+        } else if (needsOrphan) {
+            // First upload of the frame — need fresh storage
+            if (strategy == UploadStrategy.BUFFER_SUB_DATA) {
+                // SubData strategy: orphan via glBufferData to get new backing store
+                allocateBuffer();
+            }
+        }
+        if (strategy == UploadStrategy.BUFFER_SUB_DATA) {
+            GL15.glBufferSubData(GL15.GL_ARRAY_BUFFER, alignedPos, data);
+        } else {
+            // MapRange: choose flags based on whether this is the first upload of the frame
+            final int flags;
+            if (freshAllocation) {
+                // Fresh allocation — nothing to invalidate, just write
+                flags = MAP_WRITE_INVALIDATE_RANGE;
+            } else if (needsOrphan) {
+                // First upload of frame on existing buffer — invalidate entire buffer
+                flags = MAP_WRITE_INVALIDATE_BUFFER;
+            } else {
+                // Subsequent upload — invalidate only our range
+                flags = MAP_WRITE_INVALIDATE_RANGE;
+            }
+            final ByteBuffer mapped = LWJGL.glMapBufferRange(GL15.GL_ARRAY_BUFFER, alignedPos, dataSize, flags);
+            memCopy(memAddress0(data), memAddress0(mapped), dataSize);
+            GL15.glUnmapBuffer(GL15.GL_ARRAY_BUFFER);
+        }
+        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
+
+        needsOrphan = false;
+        writePos = alignedPos + dataSize;
+        return alignedPos / vertexStride;
+    }
+
+    private static final int MIN_CAPACITY = 64 * 1024;
+
+    private void growIfNeeded(int needed) {
+        if (needed > capacity) {
+            int newCapacity = Math.max(capacity, MIN_CAPACITY);
+            while (newCapacity < needed) {
+                newCapacity *= 2;
+            }
+            capacity = newCapacity;
+        }
+    }
+
+    private void allocateBuffer() {
+        GL15.glBufferData(GL15.GL_ARRAY_BUFFER, capacity, GL15.GL_STREAM_DRAW);
+    }
+
+    @Override
+    public int getCapacity() {
+        return capacity;
+    }
+
+    @Override
+    public int getBufferId() {
+        return bufferId;
+    }
+
+    @Override
+    public void postDraw() {
+        writePos = 0;
+        needsOrphan = true;
+    }
+
+    @Override
+    public void destroy() {
+        if (bufferId != 0) {
+            GL15.glDeleteBuffers(bufferId);
+            bufferId = 0;
+        }
+    }
+
+    int getWritePos() {
+        return writePos;
+    }
+
+    UploadStrategy getStrategy() {
+        return strategy;
+    }
+}

src/main/java/com/gtnewhorizons/angelica/glsm/streaming/PersistentStreamingBuffer.java

@@ -0,0 +1,180 @@
+package com.gtnewhorizons.angelica.glsm.streaming;
+
+import com.gtnewhorizons.angelica.glsm.RenderSystem;
+import it.unimi.dsi.fastutil.objects.ObjectArrayFIFOQueue;
+import org.embeddedt.embeddium.impl.gl.sync.GlFence;
+import org.lwjgl.opengl.GL15;
+import org.lwjgl.opengl.GL30;
+import org.lwjgl.opengl.GL32;
+import org.lwjgl.opengl.GL44;
+
+import java.nio.ByteBuffer;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAddress0;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memCopy;
+import static com.mitchej123.lwjgl.LWJGLServiceProvider.LWJGL;
+
+/**
+ * Persistent-mapped ring buffer for streaming vertex data on GL4.4+
+ */
+public class PersistentStreamingBuffer implements StreamingBuffer {
+
+    public static final int DEFAULT_CAPACITY = 16 * 1024 * 1024; // 16 MB
+
+    private int bufferId;
+    private final int capacity;
+    private final ByteBuffer mappedBuffer;
+    private final long mappedAddress;
+    private final ObjectArrayFIFOQueue<FencedRegion> fenceQueue = new ObjectArrayFIFOQueue<>();
+
+    private int writePos;
+    private int remaining;
+    private int pendingBytes;
+
+    public PersistentStreamingBuffer() {
+        this(DEFAULT_CAPACITY);
+    }
+
+    public PersistentStreamingBuffer(int capacity) {
+        this.capacity = capacity;
+        this.remaining = capacity;
+
+        this.bufferId = GL15.glGenBuffers();
+        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, bufferId);
+
+        final int storageFlags = GL44.GL_MAP_PERSISTENT_BIT | GL30.GL_MAP_WRITE_BIT | GL44.GL_MAP_COHERENT_BIT | GL44.GL_CLIENT_STORAGE_BIT;
+        RenderSystem.bufferStorage(GL15.GL_ARRAY_BUFFER, capacity, storageFlags);
+
+        final int mapFlags = GL44.GL_MAP_PERSISTENT_BIT | GL30.GL_MAP_WRITE_BIT | GL44.GL_MAP_COHERENT_BIT;
+        this.mappedBuffer = LWJGL.glMapBufferRange(GL15.GL_ARRAY_BUFFER, 0, capacity, mapFlags);
+
+        GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
+
+        if (this.mappedBuffer == null) {
+            GL15.glDeleteBuffers(bufferId);
+            bufferId = 0;
+            throw new RuntimeException("Failed to persistently map streaming buffer");
+        }
+        this.mappedAddress = memAddress0(mappedBuffer);
+    }
+
+    @Override
+    public int upload(ByteBuffer data, int vertexStride) {
+        final int dataSize = data.remaining();
+        if (dataSize > capacity) {
+            return -1;
+        }
+
+        reclaim();
+
+        final int alignUnit = vertexStride * 4;
+        final int alignedPos = ((writePos + alignUnit - 1) / alignUnit) * alignUnit;
+        final int alignmentWaste = alignedPos - writePos;
+        final int tailSpace = capacity - alignedPos;
+
+        if (dataSize <= tailSpace) {
+            // Fits at tail — just need enough remaining budget
+            if (ensureRemaining(alignmentWaste + dataSize)) {
+                return writeAt(alignedPos, data, dataSize, alignmentWaste, vertexStride);
+            }
+        } else {
+            // Must wrap to start — burn remaining tail space
+            final int wrapWaste = capacity - writePos;
+            if (ensureRemaining(wrapWaste + dataSize)) {
+                return writeAtStart(data, dataSize, wrapWaste);
+            }
+        }
+
+        return -1;
+    }
+
+    /** Sync fences until {@code needed} bytes are available, or no fences remain. */
+    private boolean ensureRemaining(int needed) {
+        while (remaining < needed) {
+            if (!syncOldest()) return false;
+        }
+        return true;
+    }
+
+    private int writeAt(int offset, ByteBuffer data, int dataSize, int waste, int vertexStride) {
+        memCopy(memAddress0(data) + data.position(), mappedAddress + offset, dataSize);
+
+        final int totalCost = waste + dataSize;
+        writePos = offset + dataSize;
+        remaining -= totalCost;
+        pendingBytes += totalCost;
+        return offset / vertexStride;
+    }
+
+    private int writeAtStart(ByteBuffer data, int dataSize, int wrapWaste) {
+        memCopy(memAddress0(data) + data.position(), mappedAddress, dataSize);
+
+        final int totalCost = wrapWaste + dataSize;
+        writePos = dataSize;
+        remaining -= totalCost;
+        pendingBytes += totalCost;
+        return 0;
+    }
+
+    @Override
+    public int getCapacity() {
+        return capacity;
+    }
+
+    public int getRemaining() { return remaining; }
+
+    @Override
+    public int getBufferId() {
+        return bufferId;
+    }
+
+    @Override
+    public void postDraw() {
+        if (pendingBytes > 0) {
+            final long fenceId = LWJGL.glFenceSync(GL32.GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
+            fenceQueue.enqueue(new FencedRegion(new GlFence(fenceId), pendingBytes));
+            pendingBytes = 0;
+        }
+    }
+
+    @Override
+    public void destroy() {
+        while (!fenceQueue.isEmpty()) {
+            fenceQueue.dequeue().fence.delete();
+        }
+        if (bufferId != 0) {
+            GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, bufferId);
+            GL15.glUnmapBuffer(GL15.GL_ARRAY_BUFFER);
+            GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
+            GL15.glDeleteBuffers(bufferId);
+            bufferId = 0;
+        }
+    }
+
+    private void reclaim() {
+        while (!fenceQueue.isEmpty()) {
+            final FencedRegion region = fenceQueue.first();
+            if (!region.fence.isCompleted()) break;
+            region.fence.delete();
+            fenceQueue.dequeue();
+            remaining += region.bytes;
+        }
+    }
+
+    /** Sync on oldest fence. Returns true if bytes were reclaimed. */
+    private boolean syncOldest() {
+        if (fenceQueue.isEmpty()) return false;
+        final FencedRegion region = fenceQueue.first();
+        region.fence.sync();
+        region.fence.delete();
+        fenceQueue.dequeue();
+        remaining += region.bytes;
+        reclaim(); // opportunistically reclaim any additional completed fences
+        return true;
+    }
+
+    // Package-private accessors for testing
+    ByteBuffer getMappedBuffer() { return mappedBuffer; }
+
+    private record FencedRegion(GlFence fence, int bytes) {}
+}

src/main/java/com/gtnewhorizons/angelica/glsm/streaming/StreamingBuffer.java

@@ -0,0 +1,12 @@
+package com.gtnewhorizons.angelica.glsm.streaming;
+
+import java.nio.ByteBuffer;
+
+public interface StreamingBuffer {
+
+    int upload(ByteBuffer data, int vertexStride);
+    int getBufferId();
+    void postDraw();
+    int getCapacity();
+    void destroy();
+}

src/main/java/com/gtnewhorizons/angelica/glsm/uniform/GlUniformFloat2v.java

@@ -0,0 +1,23 @@
+package com.gtnewhorizons.angelica.glsm.uniform;
+
+import org.embeddedt.embeddium.impl.gl.shader.uniform.GlUniform;
+import org.lwjgl.opengl.GL20;
+
+public class GlUniformFloat2v extends GlUniform<float[]> {
+
+    public GlUniformFloat2v(int index) {
+        super(index);
+    }
+
+    @Override
+    public void set(float[] value) {
+        if (value.length != 2) {
+            throw new IllegalArgumentException("value.length != 2");
+        }
+        GL20.glUniform2f(this.index, value[0], value[1]);
+    }
+
+    public void set(float x, float y) {
+        GL20.glUniform2f(this.index, x, y);
+    }
+}

src/main/java/com/gtnewhorizons/angelica/loading/AngelicaTweaker.java

@@ -142,6 +142,9 @@ public class AngelicaTweaker implements IFMLLoadingPlugin, IEarlyMixinLoader {
                 boolean rfbLoaded = Launch.blackboard.getOrDefault("angelica.rfbPluginLoaded", Boolean.FALSE) == Boolean.TRUE;
                 if (!rfbLoaded) {
                     tweaks.add("com.gtnewhorizons.angelica.loading.fml.tweakers.AngelicaLateTweaker");
+                    if (AngelicaConfig.enableCeleritas) {
+                        tweaks.add("com.gtnewhorizons.angelica.loading.fml.tweakers.CeleritasLateTweaker");
+                    }
                 }
             }
         }

src/main/java/com/gtnewhorizons/angelica/loading/fml/transformers/CeleritasBlockTransformer.java

@@ -2,26 +2,25 @@ package com.gtnewhorizons.angelica.loading.fml.transformers;
 
 import com.gtnewhorizons.angelica.loading.AngelicaTweaker;
 import com.gtnewhorizons.angelica.loading.shared.AngelicaClassDump;
-import com.gtnewhorizons.angelica.loading.shared.transformers.AngelicaRedirector;
-import com.gtnewhorizons.angelica.loading.shared.transformers.SodiumBlockTransform;
+import com.gtnewhorizons.angelica.loading.shared.transformers.CeleritasBlockTransform;
 import net.minecraft.launchwrapper.IClassTransformer;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassWriter;
 import org.objectweb.asm.tree.ClassNode;
 
-public class SodiumBlockTransformer implements IClassTransformer {
+public class CeleritasBlockTransformer implements IClassTransformer {
 
-    private final SodiumBlockTransform inner;
+    private final CeleritasBlockTransform inner;
     private final String[] exclusions;
 
-    public SodiumBlockTransformer() {
-        this.inner = new SodiumBlockTransform(AngelicaTweaker.isObfEnv());
+    public CeleritasBlockTransformer() {
+        this.inner = new CeleritasBlockTransform(AngelicaTweaker.isObfEnv());
         this.exclusions = inner.getTransformerExclusions();
         this.inner.setCeleritasSetting();
     }
 
     /**
-     * Delete the global vanilla bounding box fields off the Block object. {@link AngelicaRedirector}
+     * Delete the global vanilla bounding box fields off the Block object. {@link CeleritasBlockTransform}
      * replaces these with a thread-safe alternative.
      */
     @Override
@@ -31,9 +30,11 @@ public class SodiumBlockTransformer implements IClassTransformer {
             if (transformedName.startsWith(exclusion)) return basicClass;
         }
 
-        if (!inner.shouldTransform(basicClass)) {
-            return basicClass;
-        }
+        // Here could be a `inner.shouldTransform(basicClass)` check to exit early from transforming,
+        // but we also need to call `inner.trackBlockSubclasses` in this case and somehow pass
+        // the name of a class and a superclass, which we can do only after parsing the whole constant pool.
+        // This transformer is merely a fallback when FRB / lwjgl3ify is not present, so we can afford
+        // it being not fully optimized
 
         final ClassReader cr = new ClassReader(basicClass);
         final ClassNode cn = new ClassNode();

src/main/java/com/gtnewhorizons/angelica/loading/fml/tweakers/CeleritasLateTweaker.java

@@ -0,0 +1,35 @@
+package com.gtnewhorizons.angelica.loading.fml.tweakers;
+
+import cpw.mods.fml.relauncher.FMLRelaunchLog;
+import net.minecraft.launchwrapper.ITweaker;
+import net.minecraft.launchwrapper.Launch;
+import net.minecraft.launchwrapper.LaunchClassLoader;
+
+import java.io.File;
+import java.util.List;
+
+public class CeleritasLateTweaker implements ITweaker {
+
+    @Override
+    public void acceptOptions(List<String> args, File gameDir, File assetsDir, String profile) {
+        // no-op
+    }
+
+    @Override
+    public void injectIntoClassLoader(LaunchClassLoader classLoader) {
+        // no-op
+    }
+
+    @Override
+    public String getLaunchTarget() {
+        return null;
+    }
+
+    @Override
+    public String[] getLaunchArguments() {
+        String transformer = "com.gtnewhorizons.angelica.loading.fml.transformers.CeleritasBlockTransformer";
+        FMLRelaunchLog.finer("Registering transformer %s", transformer);
+        Launch.classLoader.registerTransformer(transformer);
+        return new String[0];
+    }
+}

src/main/java/com/gtnewhorizons/angelica/loading/rfb/AngelicaRfbPlugin.java

@@ -1,7 +1,7 @@
 package com.gtnewhorizons.angelica.loading.rfb;
 
 import com.gtnewhorizons.angelica.loading.rfb.transformers.RFBAngelicaRedirector;
-import com.gtnewhorizons.angelica.loading.rfb.transformers.RFBSodiumBlockTransformer;
+import com.gtnewhorizons.angelica.loading.rfb.transformers.RFBCeleritasBlockTransformer;
 import com.gtnewhorizons.retrofuturabootstrap.api.PluginContext;
 import com.gtnewhorizons.retrofuturabootstrap.api.RetroFuturaBootstrap;
 import com.gtnewhorizons.retrofuturabootstrap.api.RfbClassTransformer;
@@ -27,7 +27,7 @@ public class AngelicaRfbPlugin implements RfbPlugin {
         final boolean isObf = RetroFuturaBootstrap.API.launchClassLoader().findClassMetadata("net.minecraft.world.World") == null;
         return new RfbClassTransformer[] {
             new RFBAngelicaRedirector(),
-            new RFBSodiumBlockTransformer(isObf)
+            new RFBCeleritasBlockTransformer(isObf)
         };
     }
 }

src/main/java/com/gtnewhorizons/angelica/loading/rfb/transformers/RFBAngelicaRedirector.java

@@ -48,10 +48,6 @@ public class RFBAngelicaRedirector implements RfbClassTransformer {
         if (!classNode.isPresent()) {
             return false;
         }
-        if (!classNode.isOriginal()) {
-            // If a class is already a transformed ClassNode, conservatively continue processing.
-            return true;
-        }
         return inner.shouldTransform(classNode.getOriginalBytes());
     }
 

src/main/java/com/gtnewhorizons/angelica/loading/rfb/transformers/RFBCeleritasBlockTransformer.java

@@ -1,7 +1,8 @@
 package com.gtnewhorizons.angelica.loading.rfb.transformers;
 
 import com.gtnewhorizons.angelica.loading.shared.AngelicaClassDump;
-import com.gtnewhorizons.angelica.loading.shared.transformers.SodiumBlockTransform;
+import com.gtnewhorizons.angelica.loading.shared.transformers.CeleritasBlockTransform;
+import com.gtnewhorizons.retrofuturabootstrap.api.ClassHeaderMetadata;
 import com.gtnewhorizons.retrofuturabootstrap.api.ClassNodeHandle;
 import com.gtnewhorizons.retrofuturabootstrap.api.ExtensibleClassLoader;
 import com.gtnewhorizons.retrofuturabootstrap.api.RfbClassTransformer;
@@ -11,12 +12,12 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.jar.Manifest;
 
-public class RFBSodiumBlockTransformer implements RfbClassTransformer {
+public class RFBCeleritasBlockTransformer implements RfbClassTransformer {
 
-    private final SodiumBlockTransform inner;
+    private final CeleritasBlockTransform inner;
 
-    public RFBSodiumBlockTransformer(boolean isObf) {
-        inner = new SodiumBlockTransform(isObf);
+    public RFBCeleritasBlockTransformer(boolean isObf) {
+        inner = new CeleritasBlockTransform(isObf);
     }
 
     @Pattern("[a-z0-9-]+")
@@ -47,11 +48,20 @@ public class RFBSodiumBlockTransformer implements RfbClassTransformer {
         if (!classNode.isPresent()) {
             return false;
         }
-        if (!classNode.isOriginal()) {
-            // If a class is already a transformed ClassNode, conservatively continue processing.
+
+        ClassHeaderMetadata metadata = classNode.getOriginalMetadata();
+        if (metadata == null) {
+            return false;
+        }
+
+        if (inner.shouldTransform(classNode.getOriginalBytes())) {
             return true;
         }
-        return inner.shouldTransform(classNode.getOriginalBytes());
+
+        // Track possible block subclasses even if we don't need to transform this class
+        inner.trackBlockSubclasses(metadata.binaryThisName, metadata.binarySuperName);
+
+        return false;
     }
 
     @Override

src/main/java/com/gtnewhorizons/angelica/loading/shared/transformers/AngelicaRedirector.java

@@ -1,31 +1,23 @@
 package com.gtnewhorizons.angelica.loading.shared.transformers;
 
-import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.gtnewhorizon.gtnhlib.asm.ClassConstantPoolParser;
-import net.minecraft.launchwrapper.Launch;
-import org.apache.commons.lang3.tuple.Pair;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.objectweb.asm.Opcodes;
 import org.objectweb.asm.tree.AbstractInsnNode;
 import org.objectweb.asm.tree.ClassNode;
-import org.objectweb.asm.tree.FieldInsnNode;
-import org.objectweb.asm.tree.InsnList;
 import org.objectweb.asm.tree.InsnNode;
 import org.objectweb.asm.tree.IntInsnNode;
 import org.objectweb.asm.tree.LdcInsnNode;
 import org.objectweb.asm.tree.MethodInsnNode;
 import org.objectweb.asm.tree.MethodNode;
 
-import java.lang.invoke.MethodHandle;
-import java.lang.invoke.MethodHandles;
-import java.util.Collections;
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * This transformer redirects many GL calls to our custom GLStateManager
@@ -51,9 +43,11 @@ public final class AngelicaRedirector {
     private static final String ARBVertexArrayObject = "org/lwjgl/opengl/ARBVertexArrayObject";
     private static final String APPLEVertexArrayObject = "org/lwjgl/opengl/APPLEVertexArrayObject";
     private static final String Project = "org/lwjgl/util/glu/Project";
+    private static final String GLU = "org/lwjgl/util/glu/GLU";
     private static final String OpenGlHelper = "net/minecraft/client/renderer/OpenGlHelper";
     private static final String EXTBlendFunc = "org/lwjgl/opengl/EXTBlendFuncSeparate";
     private static final String ARBMultiTexture = "org/lwjgl/opengl/ARBMultitexture";
+    private static final String ARBShaderObjects = "org/lwjgl/opengl/ARBShaderObjects";
 
     // Redirect VAO related calls from NHLib and LWJGLService
     private static final String UniversalVAO = "com/gtnewhorizon/gtnhlib/client/opengl/UniversalVAO";
@@ -73,10 +67,10 @@ public final class AngelicaRedirector {
         "initializeTextures", "func_77474_a"
     );
 
-    private static final ClassConstantPoolParser cstPoolParser = new ClassConstantPoolParser(GL11, GL12, GL13, GL14, GL20, OpenGlHelper, EXTBlendFunc, ARBMultiTexture, Project);
-    private static final Map<String, Map<String, String>> methodRedirects = new HashMap<>();
+    private static final Map<String, Map<String, String>> methodRedirects = new HashMap<>(32);
     private static final Map<String, Map<String, String>> interfaceRedirects = new HashMap<>();
     private static final Map<Integer, String> glCapRedirects = new HashMap<>();
+    private static final ClassConstantPoolParser cstPoolParser;
 
     static {
         glCapRedirects.put(org.lwjgl.opengl.GL11.GL_ALPHA_TEST, "AlphaTest");
@@ -111,6 +105,9 @@ public final class AngelicaRedirector {
             .add("glColorMask")
             .add("glColorMaterial")
             .add("glDeleteLists")
+            .add("glGenLists")
+            .add("glGenTextures")
+            .add("glIsList")
             .add("glDeleteTextures")
             .add("glDepthFunc")
             .add("glDepthMask")
@@ -183,6 +180,13 @@ public final class AngelicaRedirector {
             .add("glTexCoord3f")
             .add("glTexCoord4d")
             .add("glTexCoord4f")
+            .add("glTexEnvi")
+            .add("glTexEnvf")
+            .add("glTexEnv")
+            .add("glTexGeni")
+            .add("glTexGenf")
+            .add("glTexGend")
+            .add("glTexGen")
             .add("glTexImage1D")
             .add("glTexImage2D")
             .add("glTexImage3D")
@@ -194,6 +198,8 @@ public final class AngelicaRedirector {
             .add("glCopyTexSubImage2D")
             .add("glPixelStoref")
             .add("glPixelStorei")
+            .add("glPixelTransferf")
+            .add("glPixelTransferi")
             .add("glTexParameter")
             .add("glTexParameterf")
             .add("glTexParameteri")
@@ -206,6 +212,8 @@ public final class AngelicaRedirector {
             .add("glPointSize")
             .add("glPolygonMode")
             .add("glPolygonOffset")
+            .add("glPolygonStipple")
+            .add("glAccum")
             .add("glReadBuffer")
             .add("glSampleCoverage")
             .add("glScissor")
@@ -223,9 +231,22 @@ public final class AngelicaRedirector {
             .add("glVertex3f")
             .add("glVertexPointer")
             .add("glColorPointer")
+            .add("glNormalPointer")
+            .add("glTexCoordPointer")
             .add("glEnableClientState")
             .add("glDisableClientState")
+            .add("glInterleavedArrays")
+            .add("glPushClientAttrib")
+            .add("glPopClientAttrib")
             .add("glViewport")
+            .add("glFeedbackBuffer")
+            .add("glRenderMode")
+            .add("glPassThrough")
+            .add("glSelectBuffer")
+            .add("glInitNames")
+            .add("glPushName")
+            .add("glPopName")
+            .add("glLoadName")
         );
         methodRedirects.put(GL12, RedirectMap.newMap()
             .add("glTexImage3D")
@@ -235,6 +256,10 @@ public final class AngelicaRedirector {
         methodRedirects.put(GL13, RedirectMap.newMap()
             .add("glActiveTexture")
             .add("glSampleCoverage")
+            .add("glClientActiveTexture")
+            .add("glMultiTexCoord2f")
+            .add("glMultiTexCoord2d")
+            .add("glMultiTexCoord2s")
         );
         methodRedirects.put(GL14, RedirectMap.newMap()
             .add("glBlendFuncSeparate", "tryBlendFuncSeparate")
@@ -251,9 +276,40 @@ public final class AngelicaRedirector {
             .add("glStencilMaskSeparate")
             .add("glStencilOpSeparate")
             .add("glUseProgram")
+            .add("glShaderSource")
+            .add("glLinkProgram")
+            .add("glDeleteProgram")
+            .add("glCreateShader")
+            .add("glCompileShader")
+            .add("glCreateProgram")
+            .add("glAttachShader")
+            .add("glDetachShader")
+            .add("glValidateProgram")
+            .add("glGetUniformLocation")
+            .add("glGetAttribLocation")
+            .add("glUniform1f")
+            .add("glUniform2f")
+            .add("glUniform3f")
+            .add("glUniform4f")
+            .add("glUniform1i")
+            .add("glUniform2i")
+            .add("glUniform3i")
+            .add("glUniform4i")
+            .add("glUniform1")
+            .add("glUniform2")
+            .add("glUniform3")
+            .add("glUniform4")
+            .add("glUniformMatrix2")
+            .add("glUniformMatrix3")
+            .add("glUniformMatrix4")
+            .add("glGetActiveUniform")
+            .add("glGetAttachedShaders")
+            .add("glGetShaderSource")
+            .add("glGetUniform")
         );
         methodRedirects.put(GL30, RedirectMap.newMap()
             .add("glBindVertexArray")
+            .add("glDeleteVertexArrays")
             .add("glBindFramebuffer")
         );
 
@@ -276,8 +332,46 @@ public final class AngelicaRedirector {
         methodRedirects.put(ARBMultiTexture, RedirectMap.newMap()
             .add("glActiveTextureARB")
         );
+        methodRedirects.put(ARBShaderObjects, RedirectMap.newMap()
+            .add("glUseProgramObjectARB", "glUseProgram")
+            .add("glShaderSourceARB", "glShaderSource")
+            .add("glLinkProgramARB", "glLinkProgram")
+            .add("glCreateShaderObjectARB", "glCreateShader")
+            .add("glCompileShaderARB", "glCompileShader")
+            .add("glCreateProgramObjectARB", "glCreateProgram")
+            .add("glAttachObjectARB", "glAttachShader")
+            .add("glDetachObjectARB", "glDetachShader")
+            .add("glValidateProgramARB", "glValidateProgram")
+            .add("glGetUniformLocationARB", "glGetUniformLocation")
+            .add("glGetAttribLocationARB", "glGetAttribLocation")
+            .add("glDeleteObjectARB")
+            .add("glGetObjectParameterARB")
+            .add("glGetObjectParameteriARB")
+            .add("glGetInfoLogARB")
+            .add("glGetHandleARB")
+            .add("glUniform1fARB", "glUniform1f")
+            .add("glUniform2fARB", "glUniform2f")
+            .add("glUniform3fARB", "glUniform3f")
+            .add("glUniform4fARB", "glUniform4f")
+            .add("glUniform1iARB", "glUniform1i")
+            .add("glUniform2iARB", "glUniform2i")
+            .add("glUniform3iARB", "glUniform3i")
+            .add("glUniform4iARB", "glUniform4i")
+            .add("glUniform1ARB", "glUniform1")
+            .add("glUniform2ARB", "glUniform2")
+            .add("glUniform3ARB", "glUniform3")
+            .add("glUniform4ARB", "glUniform4")
+            .add("glUniformMatrix2ARB", "glUniformMatrix2")
+            .add("glUniformMatrix3ARB", "glUniformMatrix3")
+            .add("glUniformMatrix4ARB", "glUniformMatrix4")
+            .add("glGetActiveUniformARB", "glGetActiveUniform")
+            .add("glGetAttachedObjectsARB", "glGetAttachedShaders")
+            .add("glGetShaderSourceARB", "glGetShaderSource")
+            .add("glGetUniformARB", "glGetUniform")
+        );
         methodRedirects.put(ARBVertexArrayObject, RedirectMap.newMap()
             .add("glBindVertexArray")
+            .add("glDeleteVertexArrays")
         );
 
 
@@ -289,30 +383,43 @@ public final class AngelicaRedirector {
         // GTNHLib VAO
         methodRedirects.put(UniversalVAO, RedirectMap.newMap()
             .add("bindVertexArray", "glBindVertexArray")
+            .add("deleteVertexArrays", "glDeleteVertexArrays")
         );
 
         // OTHER
-        methodRedirects.put(Project, RedirectMap.newMap().add("gluPerspective"));
+        methodRedirects.put(Project, RedirectMap.newMap()
+            .add("gluPerspective")
+            .add("gluLookAt")
+            .add("gluPickMatrix")
+        );
+        methodRedirects.put(GLU, RedirectMap.newMap()
+            .add("gluPerspective")
+            .add("gluLookAt")
+            .add("gluOrtho2D")
+            .add("gluPickMatrix")
+        );
 
         // Interface/virtual redirects — callers invoke these on a receiver object
         interfaceRedirects.put(VaoFunctions, RedirectMap.newMap()
             .add("glBindVertexArray")
+            .add("glDeleteVertexArrays")
         );
         interfaceRedirects.put(LWJGLService, RedirectMap.newMap()
             .add("glBindVertexArray")
         );
 
-        cstPoolParser.addString(UniversalVAO);
-        cstPoolParser.addString(VaoFunctions);
-        cstPoolParser.addString(LWJGLService);
-
+        final List<String> stringsToSearch = new ArrayList<>(32);
+        stringsToSearch.add(VaoFunctions);
+        stringsToSearch.add(LWJGLService);
         final String glPrefix = "org/lwjgl/opengl/GL";
         for (var entry : new HashMap<>(methodRedirects).entrySet()) {
+            stringsToSearch.add(entry.getKey());
             if (entry.getKey().startsWith(glPrefix)) {
                 methodRedirects.put(entry.getKey() + "C", entry.getValue());
-                cstPoolParser.addString(entry.getKey() + "C");
+                stringsToSearch.add(entry.getKey() + "C");
             }
         }
+        cstPoolParser = new ClassConstantPoolParser(stringsToSearch.toArray(new String[0]));
     }
 
     public String[] getTransformerExclusions() {
@@ -320,30 +427,27 @@ public final class AngelicaRedirector {
             "org.lwjgl",
             "com.gtnewhorizons.angelica.glsm.",
             "com.gtnewhorizons.angelica.transform",
-            "com.gtnewhorizon.gtnhlib.asm.",
             "me.eigenraven.lwjgl3ify"
         };
     }
 
     public boolean shouldTransform(byte[] basicClass) {
-        return cstPoolParser.find(basicClass, true);
+        return cstPoolParser.find(basicClass);
     }
 
     /** @return Was the class changed? */
     public boolean transformClassNode(String transformedName, ClassNode cn) {
-        if (cn == null) {
-            return false;
-        }
-
         boolean changed = false;
+        final boolean isOpenGlHelper = transformedName.equals("net.minecraft.client.renderer.OpenGlHelper");
+        final boolean isUniversalVAO = transformedName.startsWith(UniversalVAODot);
         for (MethodNode mn : cn.methods) {
-            if (transformedName.equals("net.minecraft.client.renderer.OpenGlHelper") && (mn.name.equals("glBlendFunc") || mn.name.equals("func_148821_a"))) {
+            if (isOpenGlHelper && (mn.name.equals("glBlendFunc") || mn.name.equals("func_148821_a"))) {
                 continue;
             }
             boolean redirectInMethod = false;
             for (AbstractInsnNode node : mn.instructions.toArray()) {
                 if (node instanceof MethodInsnNode mNode) {
-                    if ((mNode.owner.equals(GL11) || mNode.owner.equals(GL11C)) && (mNode.name.equals("glEnable") || mNode.name.equals("glDisable")) && mNode.desc.equals("(I)V")) {
+                    if (mNode.desc.equals("(I)V") && (mNode.owner.equals(GL11) || mNode.owner.equals(GL11C)) && (mNode.name.equals("glEnable") || mNode.name.equals("glDisable"))) {
                         final AbstractInsnNode prevNode = node.getPrevious();
                         String name = null;
                         if (prevNode instanceof LdcInsnNode ldcNode) {
@@ -373,7 +477,7 @@ public final class AngelicaRedirector {
                         }
                         changed = true;
                         redirectInMethod = true;
-                    } else if (mNode.owner.startsWith(Drawable) && mNode.name.equals("makeCurrent")) {
+                    } else if (mNode.name.equals("makeCurrent") && mNode.owner.startsWith(Drawable)) {
                         mNode.setOpcode(Opcodes.INVOKESTATIC);
                         mNode.owner = GLStateManager;
                         mNode.desc = "(L" + Drawable + ";)V";
@@ -387,7 +491,7 @@ public final class AngelicaRedirector {
                         if (redirects != null) {
                             final String glsmName = redirects.get(mNode.name);
                             // Skip VAO method redirects inside UniversalVAO
-                            if (glsmName != null && !(transformedName.startsWith(UniversalVAODot) && UniversalVAOSkippedMethods.contains(glsmName))) {
+                            if (glsmName != null && !(isUniversalVAO && UniversalVAOSkippedMethods.contains(glsmName))) {
                                 if (LOG_SPAM) {
                                     final String shortOwner = mNode.owner.substring(mNode.owner.lastIndexOf("/") + 1);
                                     LOGGER.info("Redirecting call in {} from {}.{}{} to GLStateManager.{}{}", transformedName, shortOwner, mNode.name, mNode.desc, glsmName, mNode.desc);
@@ -403,7 +507,7 @@ public final class AngelicaRedirector {
                             final Map<String, String> ifaceRedirects = interfaceRedirects.get(mNode.owner);
                             if (ifaceRedirects != null) {
                                 final String glsmName = ifaceRedirects.get(mNode.name);
-                                if (glsmName != null && !(transformedName.startsWith(UniversalVAODot) && UniversalVAOSkippedMethods.contains(glsmName))) {
+                                if (glsmName != null && !(isUniversalVAO && UniversalVAOSkippedMethods.contains(glsmName))) {
                                     if (LOG_SPAM) {
                                         final String shortOwner = mNode.owner.substring(mNode.owner.lastIndexOf("/") + 1);
                                         LOGGER.info("Redirecting interface call in {} from {}.{}{} to GLStateManager.{}{}", transformedName, shortOwner, mNode.name, mNode.desc, glsmName, "(I)V");

src/main/java/com/gtnewhorizons/angelica/loading/shared/transformers/CeleritasBlockTransform.java

@@ -19,31 +19,39 @@ import org.objectweb.asm.tree.MethodNode;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
-public class SodiumBlockTransform {
+public final class CeleritasBlockTransform {
 
-    public SodiumBlockTransform(boolean isObf) {
-        this.IS_OBF = isObf;
+    private final ClassConstantPoolParser cstPoolParser;
+    private final Map<String, String> blockFieldRedirects = new HashMap<>();
+
+    public CeleritasBlockTransform(boolean isObf) {
+        final List<Pair<String, String>> mappings = ImmutableList.of(
+            Pair.of("minX", "field_149759_B"),
+            Pair.of("minY", "field_149760_C"),
+            Pair.of("minZ", "field_149754_D"),
+            Pair.of("maxX", "field_149755_E"),
+            Pair.of("maxY", "field_149756_F"),
+            Pair.of("maxZ", "field_149757_G")
+        );
+        for (Pair<String, String> pair : mappings) {
+            final String name = isObf ? pair.getRight() : pair.getLeft();
+            this.blockFieldRedirects.put(name, pair.getLeft());
+        }
+
+        this.cstPoolParser = new ClassConstantPoolParser(this.blockFieldRedirects.keySet().toArray(new String[0]));
     }
 
-    private final boolean IS_OBF;
-
     private static final boolean LOG_SPAM = Boolean.getBoolean("angelica.redirectorLogspam");
-    private static final Logger LOGGER = LogManager.getLogger("SodiumBlockTransformer");
+    private static final Logger LOGGER = LogManager.getLogger("CeleritasBlockTransformer");
     private static final String BlockClass = "net/minecraft/block/Block";
     private static final String BlockPackage = "net/minecraft/block/Block";
     private static final String ThreadedBlockData = "com/gtnewhorizons/angelica/glsm/ThreadedBlockData";
-    private static final List<Pair<String, String>> BlockBoundsFields = ImmutableList.of(
-        Pair.of("minX", "field_149759_B"),
-        Pair.of("minY", "field_149760_C"),
-        Pair.of("minZ", "field_149754_D"),
-        Pair.of("maxX", "field_149755_E"),
-        Pair.of("maxY", "field_149756_F"),
-        Pair.of("maxZ", "field_149757_G")
-    );
     /** All classes in <tt>net.minecraft.block.*</tt> are the block subclasses save for these. */
     private static final String[] VanillaBlockExclusions = {
         "net/minecraft/block/IGrowable",
@@ -53,7 +61,6 @@ public class SodiumBlockTransform {
         "net/minecraft/block/material/"
     };
 
-    private static final ClassConstantPoolParser cstPoolParser = new ClassConstantPoolParser(BlockPackage);
     private static final Set<String> moddedBlockSubclasses = Collections.newSetFromMap(new ConcurrentHashMap<>());
     // Block owners we *shouldn't* redirect because they shadow one of our fields
     private static final Set<String> blockOwnerExclusions = Collections.newSetFromMap(new ConcurrentHashMap<>());
@@ -95,64 +102,54 @@ public class SodiumBlockTransform {
         return isVanillaBlockSubclass(className) || moddedBlockSubclasses.contains(className);
     }
 
-    private String getFieldName(Pair<String, String> fieldPair) {
-        return IS_OBF ? fieldPair.getRight() : fieldPair.getLeft();
-    }
-
     public String[] getTransformerExclusions() {
         return new String[]{
             "org.lwjgl",
             "com.gtnewhorizons.angelica.glsm.",
             "com.gtnewhorizons.angelica.transform",
-            "com.gtnewhorizon.gtnhlib.asm.",
             "me.eigenraven.lwjgl3ify"
         };
     }
 
-    public boolean shouldTransform(byte[] basicClass) {
-        return cstPoolParser.find(basicClass, true);
+    public void trackBlockSubclasses(String className, String classSuperName) {
+        if (!isVanillaBlockSubclass(className) && isBlockSubclass(classSuperName)) {
+            moddedBlockSubclasses.add(className);
+        }
+    }
+
+    public boolean shouldTransform(byte[] classBytes) {
+        return cstPoolParser.find(classBytes);
     }
 
     /** @return Was the class changed? */
     public boolean transformClassNode(String transformedName, ClassNode cn) {
-        if (cn == null) {
+        if (!isCeleritasEnabled()) {
             return false;
         }
 
-        if ("net.minecraft.block.Block".equals(transformedName) && isCeleritasEnabled()) {
-            cn.fields.removeIf(field -> BlockBoundsFields.stream().anyMatch(pair -> field.name.equals(pair.getLeft()) || field.name.equals(pair.getRight())));
+        boolean changed = false;
+
+        if ("net.minecraft.block.Block".equals(transformedName)) {
+            changed = cn.fields.removeIf(field -> blockFieldRedirects.containsKey(field.name));
         }
 
-        // Track subclasses of Block
-        if (!isVanillaBlockSubclass(cn.name) && isBlockSubclass(cn.superName)) {
-            moddedBlockSubclasses.add(cn.name);
-            cstPoolParser.addString(cn.name);
-        }
+        trackBlockSubclasses(cn.name, cn.superName);
 
         // Check if this class shadows any fields of the parent class
         if (moddedBlockSubclasses.contains(cn.name)) {
             // If a superclass shadows, then so do we, because JVM will resolve a reference on our class to that
             // superclass
-            boolean doWeShadow;
+            boolean doWeShadow = false;
             if (blockOwnerExclusions.contains(cn.superName)) {
                 doWeShadow = true;
             } else {
                 // Check if we declare any known field names
-                boolean b = false;
-                for (Pair<String, String> pair : BlockBoundsFields) {
-                    boolean result = false;
-                    for (FieldNode field : cn.fields) {
-                        if (field.name.equals(getFieldName(pair))) {
-                            result = true;
-                            break;
-                        }
-                    }
-                    if (result) {
-                        b = true;
+                for (FieldNode field : cn.fields) {
+                    if (blockFieldRedirects.containsKey(field.name)) {
+                        doWeShadow = true;
                         break;
                     }
                 }
-                doWeShadow = b;
             }
             if (doWeShadow) {
                 LOGGER.info("Class '{}' shadows one or more block bounds fields, these accesses won't be redirected!", cn.name);
@@ -160,21 +157,17 @@ public class SodiumBlockTransform {
             }
         }
 
-        boolean changed = false;
         for (MethodNode mn : cn.methods) {
             for (AbstractInsnNode node : mn.instructions.toArray()) {
                 if ((node.getOpcode() == Opcodes.GETFIELD || node.getOpcode() == Opcodes.PUTFIELD) && node instanceof FieldInsnNode fNode) {
-                    if (!blockOwnerExclusions.contains(fNode.owner) && isBlockSubclass(fNode.owner) && isCeleritasEnabled()) {
-                        Pair<String, String> fieldToRedirect = BlockBoundsFields.stream()
-                            .filter(pair -> fNode.name.equals(getFieldName(pair)))
-                            .findFirst()
-                            .orElse(null);
-                        if (fieldToRedirect != null) {
+                    if (!blockOwnerExclusions.contains(fNode.owner) && isBlockSubclass(fNode.owner)) {
+                        String fieldRedirect = blockFieldRedirects.get(fNode.name);
+                        if (fieldRedirect != null) {
                             if (LOG_SPAM) {
                                 LOGGER.info("Redirecting Block.{} in {} to thread-safe wrapper", fNode.name, transformedName);
                             }
                             // Perform the redirect
-                            fNode.name = fieldToRedirect.getLeft(); // use unobfuscated name
+                            fNode.name = fieldRedirect; // use unobfuscated name
                             fNode.owner = ThreadedBlockData;
                             // Inject getter before the field access, to turn Block -> ThreadedBlockData
                             final MethodInsnNode getter = new MethodInsnNode(Opcodes.INVOKESTATIC, ThreadedBlockData, "get", "(L" + BlockClass + ";)L" + ThreadedBlockData + ";", false);

src/main/java/com/gtnewhorizons/angelica/mixins/Mixins.java

@@ -29,6 +29,7 @@ public enum Mixins implements IMixins {
         .addClientMixins(
             "angelica.MixinActiveRenderInfo"
             , "angelica.MixinEntityRenderer"
+            , "angelica.MixinForgeHooksClient_CoreProfile"
             , "angelica.MixinGameSettings"
             , "angelica.MixinMinecraft"
             , "angelica.MixinMinecraftServer"
@@ -37,6 +38,7 @@ public enum Mixins implements IMixins {
             , "angelica.bugfixes.MixinRenderGlobal_DestroyBlock"
             , "angelica.glsm.MixinSplashProgressCaching"
             , "angelica.debug.MixinMinecraft_FPSCap"
+            , "angelica.ffp.MixinTessellator_CoreProfile"
         )
     ),
 
@@ -106,6 +108,11 @@ public enum Mixins implements IMixins {
         .setPhase(Phase.EARLY)
         .addClientMixins("angelica.optimizations.MixinGLAllocation")),
 
+    ANGELICA_DEFERRED_TESSELLATOR_BATCH(new MixinBuilder("Deferred tessellator batching for particles to reduce draw calls")
+        .setPhase(Phase.EARLY)
+        .setApplyIf(() -> AngelicaConfig.enableCeleritas)
+        .addClientMixins("angelica.particles.MixinEffectRenderer_DeferredBatch")),
+
     // Not compatible with the lwjgl debug callbacks, so disable if that's enabled
     ARCHAIC_SPLASH(new MixinBuilder()
         .setPhase(Phase.EARLY)
@@ -275,6 +282,7 @@ public enum Mixins implements IMixins {
     OPTIMIZE_WORLD_UPDATE_LIGHT(new MixinBuilder()
         .setPhase(Phase.EARLY)
         .addExcludedMod(TargetedMod.ARCHAICFIX)
+        .addExcludedMod(TargetedMod.SUPERNOVA)
         .setApplyIf(() -> AngelicaConfig.optimizeWorldUpdateLight)
         .addCommonMixins("angelica.lighting.MixinWorld_FixLightUpdateLag")),
 
@@ -344,6 +352,11 @@ public enum Mixins implements IMixins {
         .addClientMixins("angelica.textures.MixinTextureUtil_OptimizeMipmap")
         .setApplyIf(() -> AngelicaConfig.optimizeTextureLoading)),
 
+    REPLACE_FFP(new MixinBuilder()
+        .setPhase(Phase.EARLY)
+        .addClientMixins("angelica.vbo.MixinFramebuffer")
+        .setApplyIf(() -> AngelicaConfig.replaceFFPUploads)),
+
     //From NotFine
     NOTFINE_BASE_MOD(new MixinBuilder()
         .setPhase(Phase.EARLY)

src/main/java/com/gtnewhorizons/angelica/mixins/TargetedMod.java

@@ -22,6 +22,7 @@ public enum TargetedMod implements ITargetMod {
     IC2("ic2.core.coremod.IC2core", "IC2"),
     NATURA(null, "Natura"),
     SECURITYCRAFT(null, "securitycraft"),
+    SUPERNOVA("com.mitchej123.supernova.core.SupernovaCore", "supernova"),
     THAUMCRAFT(null, "Thaumcraft"),
     TINKERS_CONSTRUCT(null, "TConstruct"),
     TWILIGHT_FOREST(null, "TwilightForest"),

src/main/java/com/gtnewhorizons/angelica/render/CloudRenderer.java

@@ -25,38 +25,44 @@ import com.gtnewhorizon.gtnhlib.client.renderer.DirectTessellator;
 import com.gtnewhorizon.gtnhlib.client.renderer.TessellatorManager;
 import com.gtnewhorizon.gtnhlib.client.renderer.vao.IVertexArrayObject;
 import com.gtnewhorizon.gtnhlib.client.renderer.vao.VertexBufferType;
-import com.gtnewhorizon.gtnhlib.client.renderer.vbo.IVertexBuffer;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.uniform.GlUniformFloat2v;
 import jss.notfine.core.Settings;
 import jss.notfine.gui.options.named.GraphicsQualityOff;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.EntityRenderer;
-import net.minecraft.client.renderer.OpenGlHelper;
 import net.minecraft.client.renderer.Tessellator;
-import net.minecraft.client.renderer.texture.DynamicTexture;
 import net.minecraft.client.resources.IReloadableResourceManager;
 import net.minecraft.client.resources.IResourceManager;
 import net.minecraft.client.resources.IResourceManagerReloadListener;
 import net.minecraft.entity.Entity;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.Vec3;
+import org.embeddedt.embeddium.impl.gl.shader.GlProgram;
+import org.embeddedt.embeddium.impl.gl.shader.GlShader;
+import org.embeddedt.embeddium.impl.gl.shader.ShaderBindingContext;
+import org.embeddedt.embeddium.impl.gl.shader.ShaderConstants;
+import org.embeddedt.embeddium.impl.gl.shader.ShaderType;
+import org.embeddedt.embeddium.impl.gl.shader.uniform.GlUniformFloat3v;
+import org.embeddedt.embeddium.impl.gl.shader.uniform.GlUniformFloat4v;
+import org.embeddedt.embeddium.impl.gl.shader.uniform.GlUniformInt;
+import org.embeddedt.embeddium.impl.gl.shader.uniform.GlUniformMatrix4f;
+import org.embeddedt.embeddium.impl.render.shader.ShaderLoader;
+import org.joml.Matrix4f;
+import org.joml.Matrix4fStack;
 import org.lwjgl.opengl.GL11;
 import org.lwjgl.opengl.GL13;
 
 public class CloudRenderer implements IResourceManagerReloadListener {
-    // Shared constants.
     private static final float PX_SIZE = 1 / 256F;
 
-    // Building constants.
-    private static final int TOP_SECTIONS = 12;    // Number of slices a top face will span.
+    private static final int TOP_SECTIONS = 12;
     private static final int HEIGHT = 4;
     private static final float INSET = 0.001F;
     private static final float ALPHA = 0.8F;
 
-    // Debug
     private static final boolean WIREFRAME = false;
 
-    // Instance fields
     private final Minecraft mc = Minecraft.getMinecraft();
     private final ResourceLocation texture = new ResourceLocation("textures/environment/clouds.png");
 
@@ -66,14 +72,13 @@ public class CloudRenderer implements IResourceManagerReloadListener {
     private int cloudElevation = -1;
     private int scaleMult = -1;
 
-    private DynamicTexture COLOR_TEX = null;
-    private int texColor;
-
     private int texW;
     private int texH;
 
+    private GlProgram<CloudUniforms> program;
+    private final Matrix4f mvpScratch = new Matrix4f();
+
     public CloudRenderer() {
-        // Resource manager should always be reloadable.
         ((IReloadableResourceManager) mc.getResourceManager()).registerReloadListener(this);
     }
 
@@ -89,24 +94,28 @@ public class CloudRenderer implements IResourceManagerReloadListener {
     }
 
     private float ceilToScale(float value) {
-        float scale = getScale();
+        final float scale = getScale();
         return (float)Math.ceil(value / scale) * scale;
     }
 
+    private float meshExtent() {
+        return ceilToScale(renderDistance * 4 * 16);
+    }
+
     private void vertices(Tessellator tessellator) {
-        GraphicsQualityOff cloudGraphicsQuality = (GraphicsQualityOff)Settings.MODE_CLOUDS.option.getStore();
-        boolean fancy = cloudGraphicsQuality == GraphicsQualityOff.FANCY || cloudGraphicsQuality == GraphicsQualityOff.DEFAULT && mc.gameSettings.fancyGraphics;
+        final GraphicsQualityOff cloudGraphicsQuality = (GraphicsQualityOff)Settings.MODE_CLOUDS.option.getStore();
+        final boolean fancy = cloudGraphicsQuality == GraphicsQualityOff.FANCY || cloudGraphicsQuality == GraphicsQualityOff.DEFAULT && mc.gameSettings.fancyGraphics;
 
-        float scale = getScale();
-        float CULL_DIST = 2 * scale;
+        final float scale = getScale();
+        final float CULL_DIST = 2 * scale;
 
-        float bCol = fancy ? 0.7F : 1F;
+        final float bCol = fancy ? 0.7F : 1F;
 
-        float sectEnd = ceilToScale((renderDistance * 2) * 16);
-        float sectStart = -sectEnd;
+        final float sectEnd = meshExtent();
+        final float sectStart = -sectEnd;
 
-        float sectStep = ceilToScale(sectEnd * 2 / TOP_SECTIONS);
-        float sectPx = PX_SIZE / scale;
+        final float sectStep = ceilToScale(sectEnd * 2 / TOP_SECTIONS);
+        final float sectPx = PX_SIZE / scale;
 
         tessellator.startDrawingQuads();
 
@@ -128,10 +137,10 @@ public class CloudRenderer implements IResourceManagerReloadListener {
                 if (sectZ1 > sectEnd)
                     sectZ1 = sectEnd;
 
-                float u0 = sectX0 * sectPx;
-                float u1 = sectX1 * sectPx;
-                float v0 = sectZ0 * sectPx;
-                float v1 = sectZ1 * sectPx;
+                final float u0 = sectX0 * sectPx;
+                final float u1 = sectX1 * sectPx;
+                final float v0 = sectZ0 * sectPx;
+                final float v1 = sectZ1 * sectPx;
 
                 // Bottom
                 tessellator.setColorRGBA_F(bCol, bCol, bCol, ALPHA);
@@ -222,6 +231,10 @@ public class CloudRenderer implements IResourceManagerReloadListener {
             vao.delete();
             vao = null;
         }
+        if (program != null) {
+            program.delete();
+            program = null;
+        }
     }
 
     private void build() {
@@ -239,7 +252,7 @@ public class CloudRenderer implements IResourceManagerReloadListener {
     }
 
     public void checkSettings() {
-        GraphicsQualityOff cloudGraphicsQuality = (GraphicsQualityOff)Settings.MODE_CLOUDS.option.getStore();
+        final GraphicsQualityOff cloudGraphicsQuality = (GraphicsQualityOff)Settings.MODE_CLOUDS.option.getStore();
         final int cloudQualitySetting = cloudGraphicsQuality == GraphicsQualityOff.FANCY
             || cloudGraphicsQuality == GraphicsQualityOff.DEFAULT && mc.gameSettings.fancyGraphics ? 2 : 1;
         final boolean newEnabled = cloudGraphicsQuality != GraphicsQualityOff.OFF
@@ -273,91 +286,170 @@ public class CloudRenderer implements IResourceManagerReloadListener {
         }
     }
 
+    private void initProgram() {
+        if (program != null) return;
+
+        final GlShader vert = ShaderLoader.loadShader(ShaderType.VERTEX, "angelica:cloud.vert", ShaderConstants.EMPTY);
+        final GlShader frag = ShaderLoader.loadShader(ShaderType.FRAGMENT, "angelica:cloud.frag", ShaderConstants.EMPTY);
+        try {
+            program = GlProgram.builder("angelica:cloud")
+                .attachShader(vert)
+                .attachShader(frag)
+                .link(CloudUniforms::new);
+        } finally {
+            vert.delete();
+            frag.delete();
+        }
+
+        final CloudUniforms u = program.getInterface();
+        final float start = renderDistance * 16.0f;
+        final float end = meshExtent();
+        final float range = end - start;
+
+        program.bind();
+        u.cloudTex.setInt(0);
+        u.fogParams.set(new float[] {
+            range != 0.0f ? -1.0f / range : 0.0f,
+            range != 0.0f ? end / range : 1.0f,
+            0.0f, 0.0f
+        });
+        program.unbind();
+    }
+
+    private void uploadFogUniforms(float partialTicks) {
+        final CloudUniforms u = program.getInterface();
+        final boolean fogEnabled = GLStateManager.getFogMode().isEnabled();
+        u.setFogEnabled(fogEnabled);
+
+        if (fogEnabled) {
+            final Vec3 sky = mc.theWorld.getSkyColor(mc.renderViewEntity, partialTicks);
+            u.setFogColor((float) sky.xCoord, (float) sky.yCoord, (float) sky.zCoord);
+        }
+    }
+
+    private static class CloudUniforms {
+        final GlUniformMatrix4f mvp;
+        final GlUniformFloat3v colorMult;
+        final GlUniformFloat2v texOffset;
+        final GlUniformFloat2v fogOrigin;
+        final GlUniformFloat4v fogParams;
+        final GlUniformFloat4v fogColor;
+        final GlUniformInt fogEnabled;
+        final GlUniformInt cloudTex;
+
+        private int lastFogEnabled = -1;
+        private float lastFogR = Float.NaN, lastFogG = Float.NaN, lastFogB = Float.NaN;
+        private float lastColorR = Float.NaN, lastColorG = Float.NaN, lastColorB = Float.NaN;
+        private final float[] fogColorBuf = new float[4];
+
+        CloudUniforms(ShaderBindingContext ctx) {
+            mvp = ctx.bindUniform("u_MVPMatrix", GlUniformMatrix4f::new);
+            colorMult = ctx.bindUniform("u_ColorMultiplier", GlUniformFloat3v::new);
+            texOffset = ctx.bindUniform("u_TexOffset", GlUniformFloat2v::new);
+            fogOrigin = ctx.bindUniform("u_FogOrigin", GlUniformFloat2v::new);
+            fogParams = ctx.bindUniform("u_FogParams", GlUniformFloat4v::new);
+            fogColor = ctx.bindUniform("u_FogColor", GlUniformFloat4v::new);
+            fogEnabled = ctx.bindUniform("u_FogEnabled", GlUniformInt::new);
+            cloudTex = ctx.bindUniform("u_CloudTexture", GlUniformInt::new);
+        }
+
+        void setFogEnabled(boolean enabled) {
+            final int val = enabled ? 1 : 0;
+            if (val != lastFogEnabled) {
+                lastFogEnabled = val;
+                fogEnabled.setInt(val);
+            }
+        }
+
+        void setFogColor(float r, float g, float b) {
+            if (r != lastFogR || g != lastFogG || b != lastFogB) {
+                lastFogR = r; lastFogG = g; lastFogB = b;
+                fogColorBuf[0] = r; fogColorBuf[1] = g; fogColorBuf[2] = b; fogColorBuf[3] = 1.0f;
+                fogColor.set(fogColorBuf);
+            }
+        }
+
+        void setColorMult(float r, float g, float b) {
+            if (r != lastColorR || g != lastColorG || b != lastColorB) {
+                lastColorR = r; lastColorG = g; lastColorB = b;
+                colorMult.set(r, g, b);
+            }
+        }
+    }
+
     public boolean render(int cloudTicks, float partialTicks) {
         if (!isBuilt())
             return false;
 
-        Entity entity = mc.renderViewEntity;
+        if (program == null) {
+            initProgram();
+            if (program == null) return false;
+        }
 
-        double totalOffset = cloudTicks + partialTicks;
+        final Entity entity = mc.renderViewEntity;
 
-        double x = entity.prevPosX + (entity.posX - entity.prevPosX) * partialTicks + totalOffset * 0.03;
-        double y = cloudElevation - (entity.lastTickPosY + (entity.posY - entity.lastTickPosY) * partialTicks) + 0.33;
+        final double totalOffset = cloudTicks + partialTicks;
+
+        final double x = entity.prevPosX + (entity.posX - entity.prevPosX) * partialTicks + totalOffset * 0.03;
+        final double y = cloudElevation - (entity.lastTickPosY + (entity.posY - entity.lastTickPosY) * partialTicks) + 0.33;
         double z = entity.prevPosZ + (entity.posZ - entity.prevPosZ) * partialTicks;
 
-        int scale = getScale();
+        final int scale = getScale();
 
         if (cloudMode == 2)
             z += 0.33 * scale;
 
-        // Integer UVs to translate the texture matrix by.
         int offU = fullCoord(x, scale);
         int offV = fullCoord(z, scale);
 
         GLStateManager.glPushMatrix();
-
-        // Translate by the remainder after the UV offset.
         GLStateManager.glTranslated((offU * scale) - x, y, (offV * scale) - z);
 
-        // Modulo to prevent texture samples becoming inaccurate at extreme offsets.
+        final float fogOriginX = (float)(x - offU * scale);
+        final float fogOriginZ = (float)(z - offV * scale);
+
         offU = offU % texW;
         offV = offV % texH;
 
-        // Translate the texture.
-        GLStateManager.glMatrixMode(GL11.GL_TEXTURE);
-        GLStateManager.glTranslatef(offU * PX_SIZE, offV * PX_SIZE, 0);
-        GLStateManager.glMatrixMode(GL11.GL_MODELVIEW);
-
         GLStateManager.disableCull();
 
         GLStateManager.enableBlend();
         GLStateManager.tryBlendFuncSeparate(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA, GL11.GL_ONE, GL11.GL_ZERO);
 
-        // Color multiplier.
-        Vec3 color = mc.theWorld.getCloudColour(partialTicks);
+        final Vec3 color = mc.theWorld.getCloudColour(partialTicks);
         float r = (float) color.xCoord;
         float g = (float) color.yCoord;
         float b = (float) color.zCoord;
 
         if (mc.gameSettings.anaglyph) {
-            float tempR = r * 0.3F + g * 0.59F + b * 0.11F;
-            float tempG = r * 0.3F + g * 0.7F;
-            float tempB = r * 0.3F + b * 0.7F;
+            final float tempR = r * 0.3F + g * 0.59F + b * 0.11F;
+            final float tempG = r * 0.3F + g * 0.7F;
+            final float tempB = r * 0.3F + b * 0.7F;
             r = tempR;
             g = tempG;
             b = tempB;
         }
 
-        // Apply a color multiplier through a texture upload if shaders aren't supported.
-        final int newColor = 0xFF000000
-            | ((int) (r * 255)) << 16
-            | ((int) (g * 255)) << 8
-            | (int) (b * 255);
-        if (texColor != newColor) {
-            if (COLOR_TEX == null) {
-                COLOR_TEX = new DynamicTexture(1, 1);
-            }
-            COLOR_TEX.getTextureData()[0] = newColor;
-            COLOR_TEX.updateDynamicTexture();
-            texColor = newColor;
-        }
-
-        GLStateManager.glActiveTexture(GL13.GL_TEXTURE1);
-        GLStateManager.glBindTexture(GL11.GL_TEXTURE_2D, COLOR_TEX.getGlTextureId());
-        GLStateManager.enableTexture();
-
-        // Bind the clouds texture last so the shader's sampler2D is correct.
         GLStateManager.glActiveTexture(GL13.GL_TEXTURE0);
         mc.renderEngine.bindTexture(texture);
+        program.bind();
+
+        final CloudUniforms u = program.getInterface();
+        final Matrix4fStack mv = GLStateManager.getModelViewMatrix();
+        GLStateManager.getProjectionMatrix().mul(mv, mvpScratch);
+        u.mvp.set(mvpScratch);
+        u.texOffset.set(offU * PX_SIZE, offV * PX_SIZE);
+        u.setColorMult(r, g, b);
+        u.fogOrigin.set(fogOriginX, fogOriginZ);
+
+        uploadFogUniforms(partialTicks);
 
         vao.bind();
 
         // Depth pass to prevent insides rendering from the outside.
         GLStateManager.glColorMask(false, false, false, false);
-
         vao.draw();
 
-        // Full render.
         if (!mc.gameSettings.anaglyph) {
             GLStateManager.glColorMask(true, true, true, true);
         } else {
@@ -371,32 +463,19 @@ public class CloudRenderer implements IResourceManagerReloadListener {
             }
         }
 
-        // Wireframe for debug.
         if (WIREFRAME) {
             GL11.glPolygonMode(GL11.GL_FRONT_AND_BACK, GL11.GL_LINE);
-            GL11.glLineWidth(2.0F);
-            GLStateManager.disableTexture();
+            GLStateManager.glLineWidth(2.0F);
             GLStateManager.glDepthMask(false);
-            GLStateManager.disableFog();
             vao.draw();
             GL11.glPolygonMode(GL11.GL_FRONT_AND_BACK, GL11.GL_FILL);
             GLStateManager.glDepthMask(true);
-            GLStateManager.enableTexture();
-            GLStateManager.enableFog();
         }
 
         vao.draw();
         vao.unbind(); // Unbind buffer.
 
-        // Disable our coloring.
-        GLStateManager.glActiveTexture(GL13.GL_TEXTURE1);
-        GLStateManager.disableTexture();
-        GLStateManager.glActiveTexture(GL13.GL_TEXTURE0);
-
-        // Reset texture matrix.
-        GLStateManager.glMatrixMode(GL11.GL_TEXTURE);
-        GLStateManager.glLoadIdentity();
-        GLStateManager.glMatrixMode(GL11.GL_MODELVIEW);
+        program.unbind();
 
         GLStateManager.disableBlend();
         GLStateManager.enableCull();
@@ -417,5 +496,9 @@ public class CloudRenderer implements IResourceManagerReloadListener {
     @Override
     public void onResourceManagerReload(IResourceManager resourceManager) {
         reloadTextures();
+        if (program != null) {
+            program.delete();
+            program = null;
+        }
     }
 }

src/main/java/com/gtnewhorizons/angelica/rendering/ItemRenderListManager.java

@@ -29,11 +29,10 @@ import com.gtnewhorizon.gtnhlib.client.renderer.DirectTessellator;
 import com.gtnewhorizon.gtnhlib.client.renderer.TessellatorManager;
 import com.gtnewhorizon.gtnhlib.client.renderer.vao.IVertexArrayObject;
 import com.gtnewhorizon.gtnhlib.client.renderer.vao.IndexBuffer;
-import com.gtnewhorizon.gtnhlib.client.renderer.vao.IndexedVAO;
 import com.gtnewhorizon.gtnhlib.client.renderer.vao.VAOManager;
-import com.gtnewhorizon.gtnhlib.client.renderer.vbo.VertexBuffer;
 import com.gtnewhorizon.gtnhlib.client.renderer.vertex.DefaultVertexFormat;
 import com.gtnewhorizons.angelica.config.AngelicaConfig;
+
 import it.unimi.dsi.fastutil.objects.Object2ObjectLinkedOpenHashMap;
 import lombok.Data;
 import lombok.NoArgsConstructor;

src/main/java/com/gtnewhorizons/angelica/rendering/StateAwareTessellator.java

@@ -8,5 +8,12 @@ public interface StateAwareTessellator {
 
     void angelica$setAppliedAo(boolean flag);
 
+    /**
+     * Sets whether we're doing terrain meshing as part of celeritas -- collects additional information.
+     *
+     * Enables per-vertex AO state collection into {@link #angelica$getVertexStates()}.
+     */
+    void angelica$setCeleritasMeshing(boolean active);
+
     int[] angelica$getVertexStates();
 }

src/main/java/com/gtnewhorizons/angelica/rendering/celeritas/AngelicaChunkBuildContext.java

@@ -142,6 +142,7 @@ public class AngelicaChunkBuildContext extends ChunkBuildContext {
         final int worldZ = originZ + blockZ;
 
         int stateIdx = 0;
+        int facesAtBaseMaterial = 0;
 
         for (int quadIdx = 0; quadIdx < numQuads; quadIdx++) {
             float uSum = 0, vSum = 0;
@@ -218,7 +219,17 @@ public class AngelicaChunkBuildContext extends ChunkBuildContext {
                 }
             }
 
-            final Material correctMaterial = selectMaterial(material, sprite, isShaderPackOverride);
+            final int faceBit = 1 << facing.ordinal();
+            final Material correctMaterial;
+            if ((facesAtBaseMaterial & faceBit) != 0) {
+                // Face already has a non-demoted quad — skip selectMaterial entirely
+                correctMaterial = material;
+            } else {
+                correctMaterial = selectMaterial(material, sprite, isShaderPackOverride);
+                if (correctMaterial == material) {
+                    facesAtBaseMaterial |= faceBit;
+                }
+            }
             final var builder = buffers.get(correctMaterial);
 
             if (correctMaterial != material && builder.getEncoder() instanceof IrisExtendedChunkVertexEncoder iris) {

src/main/java/com/gtnewhorizons/angelica/rendering/celeritas/AngelicaChunkBuilderMeshingTask.java

@@ -104,6 +104,7 @@ public abstract class AngelicaChunkBuilderMeshingTask extends ChunkBuilderTask<C
         onEnterExecute();
 
         final Tessellator tessellator = getTessellator();
+        ((StateAwareTessellator)tessellator).angelica$setCeleritasMeshing(true);
 
         try {
             tessellator.setTranslation(-minX, -minY, -minZ);
@@ -207,6 +208,7 @@ public abstract class AngelicaChunkBuilderMeshingTask extends ChunkBuilderTask<C
         } catch (Throwable ex) {
             throw fillCrashInfo(CrashReport.makeCrashReport(ex, "Encountered exception while building chunk meshes"), region, blockPos);
         } finally {
+            ((StateAwareTessellator)tessellator).angelica$setCeleritasMeshing(false);
             SmoothBiomeColorCache.clearActiveCache();
             onExitExecute();
         }
@@ -270,15 +272,19 @@ public abstract class AngelicaChunkBuilderMeshingTask extends ChunkBuilderTask<C
         final CompletableFuture<Void> future = CompletableFuture.runAsync(() -> {
             final RenderBlocks mainThreadRenderBlocks = new RenderBlocks(region);
             final Tessellator mainTessellator = Tessellator.instance;
+            ((StateAwareTessellator)mainTessellator).angelica$setCeleritasMeshing(true);
             mainTessellator.setTranslation(-minX, -minY, -minZ);
 
-            for (DeferredBlock deferred : deferredBlocks) {
-                renderBlock(deferred.block(), deferred.meta(), deferred.x(), deferred.y(), deferred.z(), deferred.pass(),
-                    mainTessellator, mainThreadRenderBlocks, buffers, buildContext,
-                    blockRenderContext, minX, minY, minZ, deferred.materialOverride(), deferred.isShaderPackOverride());
+            try {
+                for (DeferredBlock deferred : deferredBlocks) {
+                    renderBlock(deferred.block(), deferred.meta(), deferred.x(), deferred.y(), deferred.z(), deferred.pass(),
+                        mainTessellator, mainThreadRenderBlocks, buffers, buildContext,
+                        blockRenderContext, minX, minY, minZ, deferred.materialOverride(), deferred.isShaderPackOverride());
+                }
+            } finally {
+                ((StateAwareTessellator)mainTessellator).angelica$setCeleritasMeshing(false);
+                mainTessellator.setTranslation(0, 0, 0);
             }
-
-            mainTessellator.setTranslation(0, 0, 0);
         }, AngelicaRenderQueue.executor());
 
         if (Thread.currentThread().isInterrupted()) {

src/main/java/com/gtnewhorizons/angelica/rendering/celeritas/AngelicaChunkRenderer.java

@@ -4,9 +4,9 @@ import com.gtnewhorizons.angelica.AngelicaMod;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.rendering.celeritas.api.IrisShaderProvider;
 import com.gtnewhorizons.angelica.rendering.celeritas.api.IrisShaderProviderHolder;
+import me.jellysquid.mods.sodium.client.gui.options.named.MultiDrawMode;
 import org.embeddedt.embeddium.impl.gl.device.RenderDevice;
 import org.embeddedt.embeddium.impl.gl.shader.GlProgram;
-import me.jellysquid.mods.sodium.client.gui.options.named.MultiDrawMode;
 import org.embeddedt.embeddium.impl.render.chunk.DefaultChunkRenderer;
 import org.embeddedt.embeddium.impl.render.chunk.RenderPassConfiguration;
 import org.embeddedt.embeddium.impl.render.chunk.multidraw.DirectMultiDrawEmitter;

src/main/java/com/gtnewhorizons/angelica/rendering/celeritas/AngelicaRenderPassConfiguration.java

@@ -1,6 +1,7 @@
 package com.gtnewhorizons.angelica.rendering.celeritas;
 
 import com.google.common.collect.ImmutableListMultimap;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import it.unimi.dsi.fastutil.objects.Reference2ReferenceOpenHashMap;
 import org.embeddedt.embeddium.impl.render.chunk.RenderPassConfiguration;
 import org.embeddedt.embeddium.impl.render.chunk.compile.sorting.QuadPrimitiveType;
@@ -21,17 +22,17 @@ public class AngelicaRenderPassConfiguration {
         @Override
         public void setup() {
             if (pass == 0) {
-                GL11.glAlphaFunc(GL11.GL_GREATER, 0.1F);
+                GLStateManager.glAlphaFunc(GL11.GL_GREATER, 0.1F);
             }
             if (disableAlphaTest) {
-                GL11.glDisable(GL11.GL_ALPHA_TEST);
+                GLStateManager.disableAlphaTest();
             }
         }
 
         @Override
         public void clear() {
             if (disableAlphaTest) {
-                GL11.glEnable(GL11.GL_ALPHA_TEST);
+                GLStateManager.enableAlphaTest();
             }
         }
     }
@@ -40,7 +41,7 @@ public class AngelicaRenderPassConfiguration {
         return TerrainRenderPass.builder()
             .pipelineState(new AngelicaPipelineState(pass, disableAlphaTest))
             .vertexType(vertexType)
-            .primitiveType(QuadPrimitiveType.DIRECT);
+            .primitiveType(QuadPrimitiveType.TRIANGULATED);
     }
 
     public static RenderPassConfiguration<BlockRenderLayer> build(ChunkVertexType vertexType) {

src/main/java/com/gtnewhorizons/angelica/rendering/celeritas/CeleritasDebugScreenHandler.java

@@ -4,6 +4,8 @@ import com.gtnewhorizons.angelica.Tags;
 import com.gtnewhorizons.angelica.config.AngelicaConfig;
 import com.gtnewhorizons.angelica.dynamiclights.DynamicLights;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.ffp.ShaderManager;
+import com.gtnewhorizons.angelica.glsm.ffp.TessellatorStreamingDrawer;
 import com.gtnewhorizons.angelica.glsm.states.FogState;
 import cpw.mods.fml.common.eventhandler.EventPriority;
 import cpw.mods.fml.common.eventhandler.SubscribeEvent;
@@ -42,6 +44,11 @@ public class CeleritasDebugScreenHandler {
         event.right.add("");
         event.right.add(EnumChatFormatting.GREEN + "Angelica " + Tags.VERSION + " [Celeritas Renderer]");
         event.right.addAll(renderer.getDebugStrings());
+        final ShaderManager sm = ShaderManager.getInstance();
+        if (sm != null) {
+            event.right.add(sm.getDebugInfo());
+        }
+        event.right.add(TessellatorStreamingDrawer.getDebugInfo());
         event.right.add("");
     }
 

src/main/java/com/gtnewhorizons/angelica/rendering/celeritas/CeleritasWorldRenderer.java

@@ -230,6 +230,7 @@ public class CeleritasWorldRenderer extends SimpleWorldRenderer<WorldClient, Ang
 
     private int renderCulledTileEntities(TileEntityRenderContext renderContext) {
         int count = 0;
+        sortedTileEntities.clear();
         SortedRenderLists renderLists = renderSectionManager.getRenderLists();
         Iterator<ChunkRenderList> renderListIterator = renderLists.iterator();
 

src/main/java/com/gtnewhorizons/angelica/rendering/celeritas/threading/RenderPassHelper.java

@@ -4,19 +4,24 @@ import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import net.minecraftforge.client.ForgeHooksClient;
 
 public final class RenderPassHelper {
-    private static final ThreadLocal<Integer> threadLocalPass = ThreadLocal.withInitial(() -> -1);
+
+    private static final class PassIntHolder {
+        int pass = -1;
+    }
+
+    private static final ThreadLocal<PassIntHolder> threadLocalPass = ThreadLocal.withInitial(PassIntHolder::new);
 
     private RenderPassHelper() {}
 
     public static int getWorldRenderPass() {
-        return GLStateManager.isMainThread() ? ForgeHooksClient.worldRenderPass : threadLocalPass.get();
+        return GLStateManager.isMainThread() ? ForgeHooksClient.worldRenderPass : threadLocalPass.get().pass;
     }
 
     public static void setWorldRenderPass(int pass) {
         if (GLStateManager.isMainThread()) {
             ForgeHooksClient.worldRenderPass = pass;
         } else {
-            threadLocalPass.set(pass);
+            threadLocalPass.get().pass = pass;
         }
     }
 

src/main/java/com/prupe/mcpatcher/ctm/CTMUtils.java

@@ -7,8 +7,8 @@ import java.util.IdentityHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.StampedLock;
 
 import net.minecraft.block.Block;
 import net.minecraft.util.IIcon;
@@ -33,19 +33,36 @@ public class CTMUtils {
 
     private static final MCLogger logger = MCLogger.getLogger(MCLogger.Category.CONNECTED_TEXTURES, "CTM");
 
-    private static final List<TileOverride> allOverrides = new ArrayList<>();
-    private static final Map<Block, List<BlockStateMatcher>> blockOverrides = new IdentityHashMap<>();
-    private static final Map<String, List<TileOverride>> tileOverrides = new HashMap<>();
+    private static class Overrides {
+        private final List<TileOverride> all = new ArrayList<>();
+        private final Map<Block, List<BlockStateMatcher>> block = new IdentityHashMap<>();
+        private final Map<String, List<TileOverride>> tile = new HashMap<>();
+    }
+
+    private static Overrides overrides = new Overrides();
+    private static Overrides newOverrides = null;
     private static TileLoader tileLoader;
 
-    private static TileOverride lastOverride;
-    private static final Lock lock = new ReentrantLock();
+    private static final StampedLock lock = new StampedLock();
 
-    private static final TileOverrideIterator.IJK ijkIterator = newIJKIterator();
-    private static final TileOverrideIterator.Metadata metadataIterator = newMetadataIterator();
+    private static class StateAndIterator {
+        private final TileOverrideIterator.IJK ijkIterator = CTMUtils.newIJKIterator();
+        private final TileOverrideIterator.Metadata metadataIterator = CTMUtils.newMetadataIterator();
+        private final BlockOrientation renderBlockState = new BlockOrientation();
+        private final int texturePackChangeCounter;
 
-    private static boolean haveBlockFace;
-    private static final BlockOrientation renderBlockState = new BlockOrientation();
+        public StateAndIterator() {
+            this.texturePackChangeCounter = 0;
+        }
+
+        public StateAndIterator(int texturePackChangeCounter) {
+            this.texturePackChangeCounter = texturePackChangeCounter;
+        }
+    }
+
+    private static final ThreadLocal<StateAndIterator> stateAndIterator = ThreadLocal.withInitial(StateAndIterator::new);
+
+    private static final AtomicInteger texturePackChangeCounter = new AtomicInteger(0);
 
     static {
         try {
@@ -61,7 +78,7 @@ public class CTMUtils {
 
             @Override
             public void beforeChange() {
-                lock.lock();
+                long stamp = lock.writeLock();
                 try {
                     RenderPassAPI.instance.clear();
                     try {
@@ -71,39 +88,39 @@ public class CTMUtils {
                     } catch (Exception e) {
                         e.printStackTrace();
                     }
-                    renderBlockState.clear();
-                    ijkIterator.clear();
-                    metadataIterator.clear();
-                    allOverrides.clear();
-                    blockOverrides.clear();
-                    tileOverrides.clear();
-                    lastOverride = null;
                     RenderBlocksUtils.blankIcon = null;
                     tileLoader = new TileLoader("textures/blocks", logger);
                     RenderPassAPI.instance.refreshBlendingOptions();
 
+                    logger.info("loading CTM overrides");
+                    newOverrides = new Overrides();
                     if (MCPatcherForgeConfig.ConnectedTextures.standard || MCPatcherForgeConfig.ConnectedTextures.nonStandard) {
                         for (ResourceLocation resource : ResourceList.getInstance()
                             .listResources(TexturePackAPI.MCPATCHER_SUBDIR + "ctm", ".properties", true)) {
-                            registerOverride(TileOverride.create(resource, tileLoader));
+                            registerOverrideWithoutLock(newOverrides, TileOverride.create(resource, tileLoader));
                         }
                     }
                     for (ResourceLocation resource : BlendMethod.getAllBlankResources()) {
                         tileLoader.preloadTile(resource, false);
                     }
                 } finally {
-                    lock.unlock();
+                    lock.unlockWrite(stamp);
                 }
             }
 
             @Override
             public void afterChange() {
-                lock.lock();
+                if (newOverrides == null) {
+                    logger.error("CTM overrides were not initialized during texture pack change");
+                    logger.error("Maybe beforeChange was not called, or threw an exception?");
+                    return;
+                }
+                long stamp = lock.writeLock();
                 try {
-                    for (TileOverride override : allOverrides) {
+                    for (TileOverride override : newOverrides.all) {
                         override.registerIcons();
                     }
-                    for (Map.Entry<Block, List<BlockStateMatcher>> entry : blockOverrides.entrySet()) {
+                    for (Map.Entry<Block, List<BlockStateMatcher>> entry : newOverrides.block.entrySet()) {
                         for (BlockStateMatcher matcher : entry.getValue()) {
                             TileOverride override = (TileOverride) matcher.getData();
                             if (override.getRenderPass() >= 0) {
@@ -111,67 +128,90 @@ public class CTMUtils {
                             }
                         }
                     }
-                    for (List<BlockStateMatcher> overrides : blockOverrides.values()) {
+                    for (List<BlockStateMatcher> overrides : newOverrides.block.values()) {
                         overrides.sort((m1, m2) -> {
                             TileOverride o1 = (TileOverride) m1.getData();
                             TileOverride o2 = (TileOverride) m2.getData();
                             return o1.compareTo(o2);
                         });
                     }
-                    for (List<TileOverride> overrides : tileOverrides.values()) {
+                    for (List<TileOverride> overrides : newOverrides.tile.values()) {
                         Collections.sort(overrides);
                     }
-                    setBlankResource();
+                    setBlankResourceWithoutLock();
+                    overrides = newOverrides;
+                    newOverrides = null;
+                    texturePackChangeCounter.getAndIncrement();
                 } finally {
-                    lock.unlock();
+                    lock.unlockWrite(stamp);
                 }
             }
         });
     }
 
-    private static void clearBlockFace() {
-        haveBlockFace = false;
+    private static StateAndIterator getStateAndIterator() {
+        int globalTexturePackChangeCounter = texturePackChangeCounter.get();
+        StateAndIterator local = stateAndIterator.get();
+        if (local.texturePackChangeCounter < globalTexturePackChangeCounter) {
+            local = new StateAndIterator(globalTexturePackChangeCounter);
+            stateAndIterator.set(local);
+        }
+        return local;
+    }
+
+    private static IIcon getBlockIconWithoutLock(IIcon icon, Block block, IBlockAccess blockAccess,
+                                                 int x, int y, int z, int face) {
+        StateAndIterator local = getStateAndIterator();
+        if (blockAccess != null && checkFace(face)) {
+            local.renderBlockState.setBlock(block, blockAccess, x, y, z);
+            local.renderBlockState.setFace(face);
+            TileOverride lastOverride = local.ijkIterator.go(local.renderBlockState, icon);
+            if (lastOverride != null) {
+                return skipDefaultRendering(block) ? RenderBlocksUtils.blankIcon : local.ijkIterator.getIcon();
+            }
+        }
+        return skipDefaultRendering(block) ? RenderBlocksUtils.blankIcon : icon;
+    }
+
+    private static IIcon getBlockIconWithoutLock(IIcon icon, Block block, int face, int metadata) {
+        StateAndIterator local = getStateAndIterator();
+        if (checkFace(face) && checkRenderType(block)) {
+            local.renderBlockState.setBlockMetadata(block, metadata, face);
+            TileOverride lastOverride = local.metadataIterator.go(local.renderBlockState, icon);
+            if (lastOverride != null) {
+                return local.metadataIterator.getIcon();
+            }
+        }
+        return icon;
     }
 
     public static IIcon getBlockIcon(IIcon icon, Block block, IBlockAccess blockAccess,
                                      int x, int y, int z, int face) {
-        lock.lock();
-        try {
-            lastOverride = null;
-            if (blockAccess != null && checkFace(face)) {
-                if (!haveBlockFace) {
-                    renderBlockState.setBlock(block, blockAccess, x, y, z);
-                    renderBlockState.setFace(face);
-                }
-                lastOverride = ijkIterator.go(renderBlockState, icon);
-                if (lastOverride != null) {
-                    icon = ijkIterator.getIcon();
-                }
+        long stamp = lock.tryOptimisticRead();
+        IIcon value = getBlockIconWithoutLock(icon, block, blockAccess, x, y, z, face);
+        if (!lock.validate(stamp)) {
+            stamp = lock.readLock();
+            try {
+                value = getBlockIconWithoutLock(icon, block, blockAccess, x, y, z, face);
+            } finally {
+                lock.unlockRead(stamp);
             }
-            clearBlockFace();
-            IIcon result = lastOverride == null && skipDefaultRendering(block) ? RenderBlocksUtils.blankIcon : icon;
-            return result;
-        } finally {
-            lock.unlock();
         }
+        return value;
     }
 
     public static IIcon getBlockIcon(IIcon icon, Block block, int face, int metadata) {
-        lock.lock();
-        try {
-            lastOverride = null;
-            if (checkFace(face) && checkRenderType(block)) {
-                renderBlockState.setBlockMetadata(block, metadata, face);
-                lastOverride = metadataIterator.go(renderBlockState, icon);
-                if (lastOverride != null) {
-                    icon = metadataIterator.getIcon();
-                }
+        long stamp = lock.tryOptimisticRead();
+        IIcon value = getBlockIconWithoutLock(icon, block, face, metadata);
+        if (!lock.validate(stamp)) {
+            stamp = lock.readLock();
+            try {
+                value = getBlockIconWithoutLock(icon, block, face, metadata);
+            } finally {
+                lock.unlockRead(stamp);
             }
-            return icon;
-
-        } finally {
-            lock.unlock();
         }
+        return value;
     }
 
     public static IIcon getBlockIcon(IIcon icon, Block block, int face) {
@@ -197,56 +237,55 @@ public class CTMUtils {
         return RenderPassAPI.instance.skipDefaultRendering(block);
     }
 
-    private static void registerOverride(TileOverride override) {
-        lock.lock();
-        try {
-            if (override != null && !override.isDisabled()) {
-                boolean registered = false;
-                List<BlockStateMatcher> matchingBlocks = override.getMatchingBlocks();
-                if (!MCPatcherUtils.isNullOrEmpty(matchingBlocks)) {
-                    for (BlockStateMatcher matcher : matchingBlocks) {
-                        if (matcher == null) {
-                            continue;
-                        }
-                        Block block = matcher.getBlock();
-                        List<BlockStateMatcher> list = blockOverrides.computeIfAbsent(block, k -> new ArrayList<>());
-                        list.add(matcher);
-                        logger.fine("using %s for block %s", override, BlockAPI.getBlockName(block));
-                        registered = true;
+    private static void registerOverrideWithoutLock(Overrides overrides, TileOverride override) {
+        if (override != null && !override.isDisabled()) {
+            boolean registered = false;
+            List<BlockStateMatcher> matchingBlocks = override.getMatchingBlocks();
+            if (!MCPatcherUtils.isNullOrEmpty(matchingBlocks)) {
+                for (BlockStateMatcher matcher : matchingBlocks) {
+                    if (matcher == null) {
+                        continue;
                     }
-                }
-                Set<String> matchingTiles = override.getMatchingTiles();
-                if (!MCPatcherUtils.isNullOrEmpty(matchingTiles)) {
-                    for (String name : matchingTiles) {
-                        List<TileOverride> list = tileOverrides.computeIfAbsent(name, k -> new ArrayList<>());
-                        list.add(override);
-                        logger.fine("using %s for tile %s", override, name);
-                        registered = true;
-                    }
-                }
-                if (registered) {
-                    allOverrides.add(override);
+                    Block block = matcher.getBlock();
+                    List<BlockStateMatcher> list = overrides.block.computeIfAbsent(block, k -> new ArrayList<>());
+                    list.add(matcher);
+                    logger.fine("using %s for block %s", override, BlockAPI.getBlockName(block));
+                    registered = true;
                 }
             }
-        } finally {
-            lock.unlock();
+            Set<String> matchingTiles = override.getMatchingTiles();
+            if (!MCPatcherUtils.isNullOrEmpty(matchingTiles)) {
+                for (String name : matchingTiles) {
+                    List<TileOverride> list = overrides.tile.computeIfAbsent(name, k -> new ArrayList<>());
+                    list.add(override);
+                    logger.fine("using %s for tile %s", override, name);
+                    registered = true;
+                }
+            }
+            if (registered) {
+                overrides.all.add(override);
+            }
         }
     }
 
+    private static void setBlankResourceWithoutLock() {
+        RenderBlocksUtils.blankIcon = tileLoader.getIcon(RenderPassAPI.instance.getBlankResource());
+    }
+
     public static void setBlankResource() {
-        lock.lock();
+        long stamp = lock.writeLock();
         try {
-            RenderBlocksUtils.blankIcon = tileLoader.getIcon(RenderPassAPI.instance.getBlankResource());
+            setBlankResourceWithoutLock();
         } finally {
-            lock.unlock();
+            lock.unlockWrite(stamp);
         }
     }
 
     private static TileOverrideIterator.IJK newIJKIterator() {
-        return new TileOverrideIterator.IJK(blockOverrides, tileOverrides);
+        return new TileOverrideIterator.IJK(overrides.block, overrides.tile);
     }
 
     private static TileOverrideIterator.Metadata newMetadataIterator() {
-        return new TileOverrideIterator.Metadata(blockOverrides, tileOverrides);
+        return new TileOverrideIterator.Metadata(overrides.block, overrides.tile);
     }
 }

src/main/java/com/prupe/mcpatcher/hd/MipmapHelper.java

@@ -71,13 +71,13 @@ public class MipmapHelper {
     }
 
     static void setupTexture(int width, int height, boolean blur, boolean clamp, String textureName) {
-        int mipmaps = useMipmapsForTexture(textureName) ? getMipmapLevels(width, height, 1) : 0;
+        final int mipmaps = useMipmapsForTexture(textureName) ? getMipmapLevels(width, height, 1) : 0;
         logger.finer("setupTexture(%s) %dx%d %d mipmaps", textureName, width, height, mipmaps);
-        int magFilter = blur ? GL11.GL_LINEAR : GL11.GL_NEAREST;
-        int minFilter = mipmaps > 0 ? GL11.GL_LINEAR_MIPMAP_LINEAR : magFilter;
-        int wrap = clamp ? GL11.GL_CLAMP : GL11.GL_REPEAT;
+        final int magFilter = blur ? GL11.GL_LINEAR : GL11.GL_NEAREST;
+        final int minFilter = mipmaps > 0 ? GL11.GL_LINEAR_MIPMAP_LINEAR : magFilter;
+        final int wrap = clamp ? GL11.GL_CLAMP : GL11.GL_REPEAT;
+        GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL12.GL_TEXTURE_MAX_LEVEL, mipmaps);
         if (mipmaps > 0) {
-            GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL12.GL_TEXTURE_MAX_LEVEL, mipmaps);
             checkGLError("%s: set GL_TEXTURE_MAX_LEVEL = %d", textureName, mipmaps);
             if (anisoSupported && anisoLevel > 1) {
                 GL11.glTexParameterf(
@@ -125,12 +125,12 @@ public class MipmapHelper {
         mipmapType.clear();
         mipmapType.put("terrain", true);
         mipmapType.put("items", false);
-        PropertiesFile properties = PropertiesFile.get(logger, MIPMAP_PROPERTIES);
+        final PropertiesFile properties = PropertiesFile.get(logger, MIPMAP_PROPERTIES);
         if (properties != null) {
             for (Map.Entry<String, String> entry : properties.entrySet()) {
-                String key = entry.getKey()
+                final String key = entry.getKey()
                     .trim();
-                boolean value = Boolean.parseBoolean(
+                final boolean value = Boolean.parseBoolean(
                     entry.getValue()
                         .trim()
                         .toLowerCase());
@@ -172,7 +172,7 @@ public class MipmapHelper {
     }
 
     static int getMipmapLevelsForCurrentTexture() {
-        int filter = GL11.glGetTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER);
+        final int filter = GL11.glGetTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER);
         if (filter != GL11.GL_NEAREST_MIPMAP_LINEAR && filter != GL11.GL_NEAREST_MIPMAP_NEAREST) {
             return 0;
         }
@@ -195,7 +195,7 @@ public class MipmapHelper {
     static void scaleHalf(IntBuffer in, int w, int h, IntBuffer out, int rotate) {
         for (int i = 0; i < w / 2; i++) {
             for (int j = 0; j < h / 2; j++) {
-                int k = w * 2 * j + 2 * i;
+                final int k = w * 2 * j + 2 * i;
                 int pixel00 = in.get(k);
                 int pixel01 = in.get(k + 1);
                 int pixel10 = in.get(k + w);
@@ -216,10 +216,10 @@ public class MipmapHelper {
     }
 
     private static int average4RGBA(int pixel00, int pixel01, int pixel10, int pixel11) {
-        int a00 = pixel00 & 0xff;
-        int a01 = pixel01 & 0xff;
-        int a10 = pixel10 & 0xff;
-        int a11 = pixel11 & 0xff;
+        final int a00 = pixel00 & 0xff;
+        final int a01 = pixel01 & 0xff;
+        final int a10 = pixel10 & 0xff;
+        final int a11 = pixel11 & 0xff;
         switch ((a00 << 24) | (a01 << 16) | (a10 << 8) | a11) {
             case 0xff000000:
                 return pixel00;
@@ -256,10 +256,10 @@ public class MipmapHelper {
                 return average2RGBA(average2RGBA(pixel00, pixel11), average2RGBA(pixel01, pixel10));
 
             default:
-                int a = a00 + a01 + a10 + a11;
+                final int a = a00 + a01 + a10 + a11;
                 int pixel = a >> 2;
                 for (int i = 8; i < 32; i += 8) {
-                    int average = (a00 * ((pixel00 >> i) & 0xff) + a01 * ((pixel01 >> i) & 0xff)
+                    final int average = (a00 * ((pixel00 >> i) & 0xff) + a01 * ((pixel01 >> i) & 0xff)
                         + a10 * ((pixel10 >> i) & 0xff)
                         + a11 * ((pixel11 >> i) & 0xff)) / a;
                     pixel |= (average << i);
@@ -273,9 +273,9 @@ public class MipmapHelper {
     }
 
     private static void checkGLError(String format, Object... params) {
-        int error = GL11.glGetError();
+        final int error = GL11.glGetError();
         if (error != 0) {
-            String message = GLU.gluErrorString(error) + ": " + String.format(format, params);
+            final String message = GLU.gluErrorString(error) + ": " + String.format(format, params);
             new RuntimeException(message).printStackTrace();
         }
     }

src/main/java/jss/notfine/core/Settings.java

@@ -50,6 +50,7 @@ public enum Settings {
         }
     },
     DYNAMIC_FOV(new NotFineOptionTickBox(true, null)),
+    HURT_SHAKE(new NotFineOptionSliderPercentage(100, 0, 300, 5, OptionImpact.LOW)),
     DYNAMIC_LIGHTS(new NotFineOptionCycling<>(DynamicLightsMode.FANCY, OptionImpact.VARIES)){
         @Override
         public void applyChanges() {

src/main/java/me/jellysquid/mods/sodium/client/gui/SodiumGameOptionPages.java

@@ -152,6 +152,7 @@ public class SodiumGameOptionPages {
                     .setBinding((opts, value) -> opts.viewBobbing = value, opts -> opts.viewBobbing)
                         .build())
                 .add(Settings.DYNAMIC_FOV.option)
+                .add(Settings.HURT_SHAKE.option)
                 .add(Settings.MODE_WATER.option)
                 .add(Settings.MODE_DROPPED_ITEMS.option)
                 .build());
@@ -280,6 +281,21 @@ public class SodiumGameOptionPages {
                         .setImpact(OptionImpact.VARIES)
                         .setEnabled(GLStateManager.capabilities != null)
                         .build())
+                .add(OptionImpl.createBuilder(boolean.class, sodiumOpts)
+                        .setName(I18n.format("sodium.options.use_map_buffer_range.name"))
+                        .setTooltip(I18n.format("sodium.options.use_map_buffer_range.tooltip"))
+                        .setControl(TickBoxControl::new)
+                        .setBinding((opts, value) -> opts.advanced.useMapBufferRange = value, opts -> opts.advanced.useMapBufferRange)
+                        .setFlags(OptionFlag.REQUIRES_RENDERER_RELOAD)
+                        .setImpact(OptionImpact.VARIES)
+                        .build())
+                .add(OptionImpl.createBuilder(boolean.class, sodiumOpts)
+                        .setName(I18n.format("sodium.options.enable_deferred_batching.name"))
+                        .setTooltip(I18n.format("sodium.options.enable_deferred_batching.tooltip"))
+                        .setControl(TickBoxControl::new)
+                        .setBinding((opts, value) -> opts.advanced.enableDeferredBatching = value, opts -> opts.advanced.enableDeferredBatching)
+                        .setImpact(OptionImpact.MEDIUM)
+                        .build())
                 .build());
 
         groups.add(OptionGroup.createBuilder()

src/main/java/me/jellysquid/mods/sodium/client/gui/SodiumGameOptions.java

@@ -33,6 +33,8 @@ public class SodiumGameOptions {
         public boolean useParticleCulling = true;
         public boolean allowDirectMemoryAccess = true;
         public boolean ignoreDriverBlacklist = false;
+        public boolean useMapBufferRange = false;
+        public boolean enableDeferredBatching = true;
     }
 
     public static class PerformanceSettings {
@@ -89,6 +91,10 @@ public class SodiumGameOptions {
             }
         } else {
             config = new SodiumGameOptions();
+            // Lwjgl2 doesn't expose multidraw and actually does individual, so try indirect if available
+            if (isLwjgl2() && !isMacOS()) {
+                config.advanced.multiDrawMode = MultiDrawMode.INDIRECT;
+            }
         }
 
         config.configPath = path;
@@ -98,6 +104,7 @@ public class SodiumGameOptions {
             config.performance.cpuRenderAheadLimit = 0;
         }
 
+        // Downgrade INDIRECT if hardware doesn't support it
         if (config.advanced.multiDrawMode == MultiDrawMode.INDIRECT && (GLStateManager.capabilities == null || (!GLStateManager.capabilities.OpenGL43 && !GLStateManager.capabilities.GL_ARB_multi_draw_indirect))) {
             config.advanced.multiDrawMode = MultiDrawMode.DIRECT;
         }
@@ -112,6 +119,14 @@ public class SodiumGameOptions {
         return config;
     }
 
+    private static boolean isLwjgl2() {
+        return SodiumGameOptions.class.getClassLoader().getResource("org/lwjgl/Sys.class") != null;
+    }
+
+    private static boolean isMacOS() {
+        return System.getProperty("os.name", "").toLowerCase().contains("mac");
+    }
+
     public void writeChanges() throws IOException {
         final Path dir = this.configPath.getParent();
 

src/main/java/net/coderbot/iris/celeritas/CeleritasTerrainPipeline.java

@@ -1,11 +1,14 @@
 package net.coderbot.iris.celeritas;
 
 import com.google.common.collect.ImmutableSet;
+import com.google.common.primitives.Ints;
 import lombok.Getter;
 import lombok.experimental.Accessors;
 import net.coderbot.iris.Iris;
 import net.coderbot.iris.gl.blending.BlendModeOverride;
+import net.coderbot.iris.gl.blending.BufferBlendOverride;
 import net.coderbot.iris.gl.framebuffer.GlFramebuffer;
+import net.coderbot.iris.shaderpack.loading.ProgramId;
 import net.coderbot.iris.gl.program.ProgramImages;
 import net.coderbot.iris.gl.program.ProgramSamplers;
 import net.coderbot.iris.gl.program.ProgramUniforms;
@@ -19,7 +22,10 @@ import net.coderbot.iris.shaderpack.ProgramSource;
 import net.coderbot.iris.uniforms.custom.CustomUniforms;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.EnumMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
@@ -43,6 +49,7 @@ public class CeleritasTerrainPipeline {
         private final EnumMap<PatchShaderType, Optional<String>> sources = new EnumMap<>(PatchShaderType.class);
         private GlFramebuffer framebuffer;
         private BlendModeOverride blendModeOverride;
+        private List<BufferBlendOverride> bufferBlendOverrides;
         private float alphaReference;
 
         private PassInfo() {
@@ -91,21 +98,41 @@ public class CeleritasTerrainPipeline {
             PassInfo passInfo = new PassInfo();
             passInfoMap.put(pass, passInfo);
 
-            // Set up framebuffer
+            // Set up framebuffer, blend mode, and buffer blend overrides
+            final ProgramId programId = switch (pass) {
+                case GBUFFER_TRANSLUCENT -> ProgramId.Water;
+                case SHADOW, SHADOW_CUTOUT -> ProgramId.Shadow;
+                default -> ProgramId.Terrain;
+            };
+
             if (pass == IrisTerrainPass.SHADOW || pass == IrisTerrainPass.SHADOW_CUTOUT) {
                 passInfo.framebuffer = shadowFramebuffer;
+                passInfo.blendModeOverride = programId.getBlendModeOverride();
+                passInfo.bufferBlendOverrides = Collections.emptyList();
             } else if (renderTargets != null) {
                 ImmutableSet<Integer> flipped = pass == IrisTerrainPass.GBUFFER_TRANSLUCENT ? flippedAfterTranslucent : flippedAfterPrepare;
 
                 Optional<ProgramSource> programSource = gbufferProgramSource.get(pass);
-                programSource.ifPresentOrElse(source -> passInfo.framebuffer = renderTargets.createGbufferFramebuffer(flipped, source.getDirectives().getDrawBuffers()), () -> passInfo.framebuffer = renderTargets.createGbufferFramebuffer(flipped, new int[] {0}));
-            }
+                programSource.ifPresentOrElse(source -> {
+                    passInfo.framebuffer = renderTargets.createGbufferFramebuffer(flipped, source.getDirectives().getDrawBuffers());
+                    passInfo.blendModeOverride = source.getDirectives().getBlendModeOverride().orElse(programId.getBlendModeOverride());
 
-            // Set blend mode override
-            passInfo.blendModeOverride = switch (pass) {
-                case GBUFFER_TRANSLUCENT -> null; // Default blending
-                default -> BlendModeOverride.OFF;
-            };
+                    passInfo.bufferBlendOverrides = new ArrayList<>();
+                    source.getDirectives().getBufferBlendOverrides().forEach(information -> {
+                        int index = Ints.indexOf(source.getDirectives().getDrawBuffers(), information.getIndex());
+                        if (index > -1) {
+                            passInfo.bufferBlendOverrides.add(new BufferBlendOverride(index, information.getBlendMode()));
+                        }
+                    });
+                }, () -> {
+                    passInfo.framebuffer = renderTargets.createGbufferFramebuffer(flipped, new int[] {0});
+                    passInfo.blendModeOverride = programId.getBlendModeOverride();
+                    passInfo.bufferBlendOverrides = Collections.emptyList();
+                });
+            } else {
+                passInfo.blendModeOverride = programId.getBlendModeOverride();
+                passInfo.bufferBlendOverrides = Collections.emptyList();
+            }
 
             // Set alpha reference
             passInfo.alphaReference = switch (pass) {

src/main/java/net/coderbot/iris/celeritas/IrisCeleritasChunkProgramOverrides.java

@@ -2,6 +2,7 @@ package net.coderbot.iris.celeritas;
 
 import net.coderbot.iris.Iris;
 import net.coderbot.iris.gl.blending.BlendModeOverride;
+import net.coderbot.iris.gl.blending.BufferBlendOverride;
 import net.coderbot.iris.pipeline.WorldRenderingPipeline;
 import net.coderbot.iris.pipeline.transform.PatchShaderType;
 import net.coderbot.iris.shadows.ShadowRenderingState;
@@ -15,6 +16,7 @@ import org.embeddedt.embeddium.impl.render.chunk.terrain.TerrainRenderPass;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.EnumMap;
+import java.util.List;
 import java.util.Locale;
 import java.util.Optional;
 
@@ -82,11 +84,11 @@ public class IrisCeleritasChunkProgramOverrides {
                 builder.bindAttribute(attr.getName(), attrIndex++);
             }
 
-            // Get blend from PassInfo
             final CeleritasTerrainPipeline.PassInfo passInfo = pipeline.getPassInfo(pass);
             final BlendModeOverride blendOverride = passInfo.blendModeOverride();
+            final List<BufferBlendOverride> bufferOverrides = passInfo.bufferBlendOverrides();
 
-            return builder.link(context -> new IrisCeleritasChunkShaderInterface(((GlObject) context).handle(), context, pipeline, pass.isShadow(), blendOverride, pipeline.getCustomUniforms()));
+            return builder.link(context -> new IrisCeleritasChunkShaderInterface(((GlObject) context).handle(), context, pipeline, pass.isShadow(), blendOverride, bufferOverrides, pipeline.getCustomUniforms()));
         } finally {
             vertShader.delete();
             if (geomShader != null) geomShader.delete();

src/main/java/net/coderbot/iris/celeritas/IrisCeleritasChunkShaderInterface.java

@@ -4,18 +4,17 @@ import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.mixins.interfaces.EntityRendererAccessor;
 import net.coderbot.iris.Iris;
 import net.coderbot.iris.gl.blending.BlendModeOverride;
+import net.coderbot.iris.gl.blending.BufferBlendOverride;
 import net.coderbot.iris.gl.framebuffer.GlFramebuffer;
-import net.coderbot.iris.pipeline.WorldRenderingPipeline;
-import net.coderbot.iris.samplers.IrisSamplers;
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.texture.DynamicTexture;
-import org.lwjgl.opengl.GL11;
-import org.lwjgl.opengl.GL13;
 import net.coderbot.iris.gl.program.ProgramImages;
 import net.coderbot.iris.gl.program.ProgramSamplers;
 import net.coderbot.iris.gl.program.ProgramUniforms;
+import net.coderbot.iris.pipeline.WorldRenderingPipeline;
+import net.coderbot.iris.samplers.IrisSamplers;
 import net.coderbot.iris.shadows.ShadowRenderingState;
 import net.coderbot.iris.uniforms.custom.CustomUniforms;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.texture.DynamicTexture;
 import org.embeddedt.embeddium.impl.gl.shader.ShaderBindingContext;
 import org.embeddedt.embeddium.impl.gl.shader.uniform.GlUniformFloat3v;
 import org.embeddedt.embeddium.impl.gl.shader.uniform.GlUniformMatrix3f;
@@ -28,6 +27,10 @@ import org.jetbrains.annotations.Nullable;
 import org.joml.Matrix3f;
 import org.joml.Matrix4f;
 import org.joml.Matrix4fc;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL13;
+
+import java.util.List;
 
 public class IrisCeleritasChunkShaderInterface implements ChunkShaderInterface {
     @Nullable
@@ -51,13 +54,15 @@ public class IrisCeleritasChunkShaderInterface implements ChunkShaderInterface {
 
     // Rendering state
     private final BlendModeOverride blendModeOverride;
+    private final List<BufferBlendOverride> bufferBlendOverrides;
+    private final boolean hasOverrides;
 
     // Stored matrices for inverse and normal matrix computation
     private final Matrix4f projectionMatrixInverse = new Matrix4f();
     private final Matrix4f modelViewMatrixInverse = new Matrix4f();
     private final Matrix3f normalMatrix = new Matrix3f();
 
-    public IrisCeleritasChunkShaderInterface(int handle, ShaderBindingContext context, CeleritasTerrainPipeline pipeline, boolean isShadowPass, BlendModeOverride blendModeOverride, CustomUniforms customUniforms) {
+    public IrisCeleritasChunkShaderInterface(int handle, ShaderBindingContext context, CeleritasTerrainPipeline pipeline, boolean isShadowPass, BlendModeOverride blendModeOverride, List<BufferBlendOverride> bufferBlendOverrides, CustomUniforms customUniforms) {
         this.uniformModelViewMatrix = context.bindUniformIfPresent("iris_ModelViewMatrix", GlUniformMatrix4f::new);
         this.uniformModelViewMatrixInverse = context.bindUniformIfPresent("iris_ModelViewMatrixInverse", GlUniformMatrix4f::new);
         this.uniformProjectionMatrix = context.bindUniformIfPresent("iris_ProjectionMatrix", GlUniformMatrix4f::new);
@@ -66,6 +71,8 @@ public class IrisCeleritasChunkShaderInterface implements ChunkShaderInterface {
         this.uniformRegionOffset = context.bindUniformIfPresent("u_RegionOffset", GlUniformFloat3v::new);
 
         this.blendModeOverride = blendModeOverride;
+        this.bufferBlendOverrides = bufferBlendOverrides;
+        this.hasOverrides = bufferBlendOverrides != null && !bufferBlendOverrides.isEmpty();
         this.customUniforms = customUniforms;
 
         final ProgramUniforms.Builder builder = pipeline.initUniforms(handle);
@@ -94,6 +101,10 @@ public class IrisCeleritasChunkShaderInterface implements ChunkShaderInterface {
             blendModeOverride.apply();
         }
 
+        if (hasOverrides) {
+            bufferBlendOverrides.forEach(BufferBlendOverride::apply);
+        }
+
         if (irisProgramUniforms != null) {
             irisProgramUniforms.update();
         }
@@ -109,7 +120,7 @@ public class IrisCeleritasChunkShaderInterface implements ChunkShaderInterface {
 
     @Override
     public void restoreState() {
-        if (blendModeOverride != null) {
+        if (blendModeOverride != null || hasOverrides) {
             BlendModeOverride.restore();
         }
 
@@ -119,7 +130,7 @@ public class IrisCeleritasChunkShaderInterface implements ChunkShaderInterface {
 
     @Override
     public GlPrimitiveType getPrimitiveType() {
-        return GlPrimitiveType.QUADS;
+        return GlPrimitiveType.TRIANGLES;
     }
 
     @Override