TESR state and batching leak fixes (#2162)

* initial commit for enchant-glint-optimizations

* Fix spacing issues and remove GlintCompatibility.java

.editorconfig

@@ -22,6 +22,8 @@ indent_size = 2
 trim_trailing_whitespace = false
 
 [*.java]
+max_line_length = 240
+ij_java_wrap_long_lines = false
 ij_java_use_single_class_imports = true
 ij_java_class_count_to_use_import_on_demand = 999
 ij_java_names_count_to_use_import_on_demand = 999

.github/scripts/build-tracy-natives.sh

@@ -1,8 +1,8 @@
 #!/usr/bin/env bash
-# Builds the libTracyClient shared library for the tracy-client module.
+# Builds the libTracyClient and AngelicaTracyCapture shared libraries for the tracy-client module.
 set -euo pipefail
 
-TRACY_VERSION="${TRACY_VERSION:-v0.14.0}"
+TRACY_VERSION="${TRACY_VERSION:-v0.14.1}"
 TRACY_VERSION_BARE="${TRACY_VERSION#v}"
 OUT_DIR="${OUT_DIR:-dist/tracy-natives}"
 TRACY_REPO="https://github.com/wolfpld/tracy"
@@ -31,36 +31,95 @@ else
     git clone --depth 1 --branch "$TRACY_VERSION" "$TRACY_REPO" "$SRC_DIR"
 fi
 
-BUILD_DIR="$WORK_DIR/build"
 export MACOSX_DEPLOYMENT_TARGET="${MACOSX_DEPLOYMENT_TARGET:-11.0}"
 
-cmake -S "$REPO_ROOT/tracy-client/src/main/native" -B "$BUILD_DIR" \
+CLIENT_BUILD_DIR="$WORK_DIR/build-client"
+cmake -S "$REPO_ROOT/tracy-client/src/main/native" -B "$CLIENT_BUILD_DIR" \
     -DTRACY_SRC_DIR="$SRC_DIR" \
     -DCMAKE_BUILD_TYPE=Release \
     -DBUILD_SHARED_LIBS=ON \
     -DTRACY_STATIC=OFF \
     -DTRACY_ENABLE=ON \
     -DTRACY_ON_DEMAND=ON \
-    -DTRACY_DELAYED_INIT=ON \
     -DTRACY_MANUAL_LIFETIME=ON \
     -DTRACY_NO_SAMPLING=ON \
     -DTRACY_NO_SYSTEM_TRACING=ON \
     -DTRACY_NO_CRASH_HANDLER=ON \
     -DTRACY_LTO=OFF
-cmake --build "$BUILD_DIR" --config Release --parallel
+cmake --build "$CLIENT_BUILD_DIR" --config Release --parallel
 
-mkdir -p "$OUT_DIR"
+CPM_CACHE_DIR="$WORK_DIR/cpm"
+CAPTURE_BUILD_DIR="$WORK_DIR/build-capture"
+cmake -S "$REPO_ROOT/tracy-client/src/main/native-capture" -B "$CAPTURE_BUILD_DIR" \
+    -DTRACY_SRC_DIR="$SRC_DIR" \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DCPM_SOURCE_CACHE="$CPM_CACHE_DIR"
+cmake --build "$CAPTURE_BUILD_DIR" --config Release --parallel
+
+find_one() {
+    find "$1" -name "$2" 2>/dev/null | head -1
+}
+
+CLIENT_LIB_NAME=""
+CLIENT_LIB=""
 for NAME in libTracyClient.so libTracyClient.dylib TracyClient.dll; do
-    LIB="$(find "$BUILD_DIR" -name "$NAME" | head -1)"
+    LIB="$(find_one "$CLIENT_BUILD_DIR" "$NAME")"
     if [[ -n "$LIB" ]]; then
-        cp -L "$LIB" "$OUT_DIR/$NAME"
-        cp "$SRC_DIR/LICENSE" "$OUT_DIR/LICENSE"
-        mkdir -p "$RES_DIR"
-        cp -L "$LIB" "$RES_DIR/$NAME"
-        cp "$SRC_DIR/LICENSE" "$RES_DIR/LICENSE"
-        echo "built: $OUT_DIR/$NAME ($TRACY_VERSION), staged: $RES_DIR/$NAME"
-        exit 0
+        CLIENT_LIB="$LIB"
+        CLIENT_LIB_NAME="$NAME"
+        break
     fi
 done
-echo "error: built library not found under $BUILD_DIR" >&2
-exit 1
+if [[ -z "$CLIENT_LIB" ]]; then
+    echo "error: libTracyClient not found under $CLIENT_BUILD_DIR" >&2
+    exit 1
+fi
+
+CAPTURE_LIB_NAME=""
+CAPTURE_LIB=""
+for NAME in libAngelicaTracyCapture.so libAngelicaTracyCapture.dylib AngelicaTracyCapture.dll; do
+    LIB="$(find_one "$CAPTURE_BUILD_DIR" "$NAME")"
+    if [[ -n "$LIB" ]]; then
+        CAPTURE_LIB="$LIB"
+        CAPTURE_LIB_NAME="$NAME"
+        break
+    fi
+done
+if [[ -z "$CAPTURE_LIB" ]]; then
+    echo "error: AngelicaTracyCapture not found under $CAPTURE_BUILD_DIR" >&2
+    exit 1
+fi
+
+STRIPPED_CAPTURE_LIB="$WORK_DIR/$CAPTURE_LIB_NAME"
+cp -L "$CAPTURE_LIB" "$STRIPPED_CAPTURE_LIB"
+case "$PLAT_OS" in
+    macos) strip -x "$STRIPPED_CAPTURE_LIB" ;;
+    linux) strip --strip-unneeded "$STRIPPED_CAPTURE_LIB" ;;
+    *) ;;
+esac
+
+LICENSE_ZSTD="$(find_one "$CPM_CACHE_DIR/zstd" LICENSE)"
+LICENSE_CAPSTONE="$(find_one "$CPM_CACHE_DIR/capstone" LICENSE.TXT)"
+LICENSE_PPQSORT="$(find_one "$CPM_CACHE_DIR/ppqsort" LICENSE)"
+
+LICENSE_NAMES=(LICENSE LICENSE-zstd LICENSE-capstone LICENSE-ppqsort)
+LICENSE_SRCS=("$SRC_DIR/LICENSE" "$LICENSE_ZSTD" "$LICENSE_CAPSTONE" "$LICENSE_PPQSORT")
+
+for i in "${!LICENSE_NAMES[@]}"; do
+    if [[ -z "${LICENSE_SRCS[$i]}" || ! -f "${LICENSE_SRCS[$i]}" ]]; then
+        echo "error: ${LICENSE_NAMES[$i]} source not found under $CPM_CACHE_DIR" >&2
+        exit 1
+    fi
+done
+
+mkdir -p "$OUT_DIR" "$RES_DIR"
+for DEST in "$OUT_DIR" "$RES_DIR"; do
+    cp -L "$CLIENT_LIB" "$DEST/$CLIENT_LIB_NAME"
+    cp -L "$STRIPPED_CAPTURE_LIB" "$DEST/$CAPTURE_LIB_NAME"
+    for i in "${!LICENSE_NAMES[@]}"; do
+        cp "${LICENSE_SRCS[$i]}" "$DEST/${LICENSE_NAMES[$i]}"
+    done
+done
+
+echo "built: $OUT_DIR/$CLIENT_LIB_NAME, $OUT_DIR/$CAPTURE_LIB_NAME ($TRACY_VERSION)"
+echo "staged: $RES_DIR/$CLIENT_LIB_NAME, $RES_DIR/$CAPTURE_LIB_NAME"

.github/workflows/build-tracy-natives.yml

@@ -29,7 +29,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v5
-      - name: Build libTracyClient
+      - name: Build Tracy natives
         shell: bash
         env:
           OUT_DIR: dist/tracy-natives

.gitignore

@@ -44,5 +44,6 @@ tracy-client/src/main/resources/natives/
 tracy-client/angelica/
 dist/tracy-natives/
 *.tracy
+*.jfr
 
 tracy-client/angelica/

README.MD

@@ -101,3 +101,5 @@ Targets GL 3.3+ core profile
   * 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)
+* RGSS Terrain Texture Filtering
+  * Indiesoft for [defold-sharp-sprite](https://github.com/indiesoftby/defold-sharp-sprite), used as the reference implementation under the MIT license

dependencies.gradle.kts

@@ -93,6 +93,7 @@ DependencyHandlerScope.of(dependencies).apply {
     shadowImplementation(project(":lwjgl3-backend")) { isTransitive = false }
     shadowImplementation(project(":sdl-gpu")) { isTransitive = false }
     runtimeOnlyNonPublishable(project(":tracy-client")) { isTransitive = false }
+    devOnlyNonPublishable(libs.async.profiler)
     shadowImplementation(libs.eventbus)
 
     shadowImplementation(libs.jcpp) // Apache 2.0
@@ -161,6 +162,7 @@ DependencyHandlerScope.of(dependencies).apply {
     compileOnly(rfg.deobf("curse.maven:security-craft-64760:2818228"))
     compileOnly("ganymedes01.etfuturum:Et-Futurum-Requiem:2.6.49-GTNH:dev")
     compileOnly("com.github.GTNewHorizons:OpenBlocks:1.12.19-GTNH:dev")
+    compileOnly("com.github.GTNewHorizons:Draconic-Evolution:1.5.30-GTNH:dev")
     compileOnly("com.github.GTNewHorizons:Chisel:2.17.31-GTNH:dev")
     compileOnly(rfg.deobf("curse.maven:biomes-o-plenty-220318:2499612"))
 

glsm/build.gradle.kts

@@ -103,6 +103,11 @@ repositories {
     mavenLocal()
 }
 
+val spirvTestRuntime by configurations.creating {
+    isCanBeConsumed = false
+    isCanBeResolved = true
+}
+
 dependencies {
     // MC compile stubs
     compileOnly(sourceSets["stubs"].output)
@@ -133,6 +138,7 @@ dependencies {
     testRuntimeOnly(libs.lwjgl3.spvc) { artifact { classifier = lwjglNatives } }
     testRuntimeOnly(libs.lwjgl3)
     testRuntimeOnly(libs.lwjgl3) { artifact { classifier = lwjglNatives } }
+    spirvTestRuntime(libs.lwjgl3.opengl)
     // @Lwjgl3Aware annotation
     compileOnly(libs.lwjgl3ify) { artifact { classifier = "dev" }; isTransitive = false }
     compileOnly(libs.retrofuturabootstrap) { isTransitive = false }
@@ -309,7 +315,7 @@ val spirvTest by tasks.registering(Test::class) {
     classpath = sourceSets["test"].runtimeClasspath.filter { file ->
         // Strip the LWJGL2 jars - they collide with LWJGL3's sealed org.lwjgl package.
         !file.name.startsWith("lwjgl-2.") && !file.name.startsWith("lwjgl_util-") && !file.name.startsWith("lwjgl-platform-")
-    }
+    }.plus(spirvTestRuntime)
 
     filter {
         includeTestsMatching("com.gtnewhorizons.angelica.glsm.shader.SpirvShaderTranslator*Test")

glsm/src/main/java/com/gtnewhorizons/angelica/config/SystemProperties.java

@@ -37,12 +37,18 @@ public final class SystemProperties {
     public static final boolean SDL_VERIFY_PER_FRAME_UNIFORM_BLOCK = Boolean.getBoolean("angelica.sdlgpu.verifyPerFrameUniformBlock");
     public static final int SDL_FRAMES_IN_FLIGHT = Integer.getInteger("angelica.sdlgpu.framesInFlight", 2);
     public static final boolean DISABLE_SDL_PRESENTER_THREAD = Boolean.getBoolean("angelica.sdlgpu.disablePresenterThread");
+    public static final boolean SDL_DISABLE_IN_PASS_CLEAR = Boolean.getBoolean("angelica.sdlgpu.disableInPassClear");
 
     // Tracy
-    public static final boolean TRACY = Boolean.getBoolean("angelica.tracy");
-    public static final boolean TRACY_FINE_ZONES = Boolean.getBoolean("angelica.tracy.fineZones");
+    public static final Boolean TRACY_OVERRIDE = parseBooleanOverride("angelica.tracy");
+    public static final Boolean TRACY_FINE_ZONES_OVERRIDE = parseBooleanOverride("angelica.tracy.fineZones");
     public static final String TRACY_DIR = System.getProperty("angelica.tracy.dir", "angelica" + File.separator + "natives" + File.separator + "tracy");
-    public static final int TRACY_MAX_SRC_LOCS = Math.max(16, Integer.getInteger("angelica.tracy.maxSrcLocs", 4096));
+    public static final Integer TRACY_MAX_SRC_LOCS_OVERRIDE = Integer.getInteger("angelica.tracy.maxSrcLocs");
+
+    // Profiling
+    public static final String PROFILE_OPTS = System.getProperty("angelica.profile.opts", "event=wall,interval=5ms,alloc=512k,lock=10ms");
+    public static final String PROFILE_DIR = System.getProperty("angelica.profile.dir", "angelica" + File.separator + "profiles");
+    public static final String PROFILE_OUTPUT = System.getProperty("angelica.profile.output", "");
 
     // Flyby
     public static final String FLYBY_ROUTE = System.getProperty("angelica.flyby.route", "");
@@ -53,6 +59,11 @@ public final class SystemProperties {
     public static final double FLYBY_SPEED = parseDouble("angelica.flyby.speed"); // Travel speed in blocks per tick
     public static final boolean FLYBY_EXIT_WHEN_DONE = Boolean.getBoolean("angelica.flyby.exitWhenDone");
     public static final long FLYBY_TIME_OF_DAY = Math.floorMod(Long.getLong("angelica.flyby.timeOfDay", 6000L), 24000L);
+    public static final String FLYBY_COMMANDS = System.getProperty("angelica.flyby.commands", "");
+    public static final String FLYBY_ORIGIN = System.getProperty("angelica.flyby.origin", "");
+    public static final FlybyPacing FLYBY_PACING = parseEnum("angelica.flyby.pacing", FlybyPacing.UNCAPPED, FlybyPacing.UNCAPPED, FlybyPacing.class);
+    public static final FlybyWeather FLYBY_WEATHER = parseEnum("angelica.flyby.weather", FlybyWeather.CLEAR, FlybyWeather.CLEAR, FlybyWeather.class);
+    public static final boolean FLYBY_JFR = Boolean.getBoolean("angelica.flyby.jfr");
 
     // Debug
     public static final boolean LWJGL_DEBUG = Boolean.getBoolean("org.lwjgl.util.Debug");
@@ -61,11 +72,13 @@ public final class SystemProperties {
     public static final boolean ENABLE_TEST_BLOCKS = Boolean.getBoolean("angelica.debug.testBlocks");
     public static final boolean DUMP_CLASS = Boolean.getBoolean("angelica.debug.dumpClass");
     private static final boolean DUMP_SHADERS_PROP = Boolean.getBoolean("angelica.debug.dumpShaders");
+    private static final boolean DEBUG_TOOLING_PROP = Boolean.getBoolean("angelica.debug.tooling");
     public static final boolean REDIRECTOR_LOGSPAM = Boolean.getBoolean("angelica.debug.redirectorLogspam");
     public static final boolean DEBUG_DISPLAY_LISTS = Boolean.getBoolean("angelica.debug.displayLists");
     public static final boolean FFP_TRACE = Boolean.getBoolean("angelica.debug.ffpTrace");
     public static final boolean LOG_DISPLAY_LIST_COMPILATION = Boolean.getBoolean("angelica.debug.displayLists.compilation");
     public static final boolean FORCE_ORPHAN_STREAMING = Boolean.getBoolean("angelica.debug.forceOrphanStreaming");
+    public static final boolean WEATHER_REBUILD_ALWAYS = Boolean.getBoolean("angelica.debug.weatherRebuildAlways");
     public static final String SHADER_DUMP_ROOT = "angelica_dumps";
 
     // Set by us, read by celeritas
@@ -76,6 +89,10 @@ public final class SystemProperties {
         return DUMP_SHADERS_PROP || isDeobf();
     }
 
+    public static boolean debugTooling() {
+        return DEBUG_TOOLING_PROP || isDeobf();
+    }
+
     public static Path shaderDumpDir(String phase) {
         return dumpShaders() ? Paths.get(SHADER_DUMP_ROOT, phase) : null;
     }
@@ -105,6 +122,25 @@ public final class SystemProperties {
         FATAL
     }
 
+    public enum FlybyPacing {
+        UNCAPPED,
+        CONFIGURED
+    }
+
+    public enum FlybyWeather {
+        CLEAR,
+        RAIN,
+        THUNDER;
+
+        public boolean isRaining() {
+            return this != CLEAR;
+        }
+
+        public boolean isThundering() {
+            return this == THUNDER;
+        }
+    }
+
     private static <E extends Enum<E>> E parseEnum(String key, E whenAbsent, E whenInvalid, Class<E> type) {
         final String raw = System.getProperty(key);
         if (raw == null || raw.isEmpty()) return whenAbsent;
@@ -116,6 +152,11 @@ public final class SystemProperties {
         }
     }
 
+    private static Boolean parseBooleanOverride(String key) {
+        final String raw = System.getProperty(key);
+        return raw == null ? null : Boolean.parseBoolean(raw);
+    }
+
     private static double parseDouble(String key) {
         final String raw = System.getProperty(key);
         if (raw == null || raw.isEmpty()) return 0.0D;

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

@@ -0,0 +1,24 @@
+package com.gtnewhorizons.angelica.glsm;
+
+import com.gtnewhorizons.angelica.glsm.stacks.BooleanStateStack;
+
+public final class ClipPlaneBooleanState extends BooleanStateStack {
+
+    private final GLContextState owner;
+    private final int index;
+
+    ClipPlaneBooleanState(GLContextState owner, int index, int glCap) {
+        super(glCap);
+        this.owner = owner;
+        this.index = index;
+    }
+
+    @Override
+    protected void onEnabledChanged() {
+        if (isEnabled()) {
+            owner.clipPlaneEnabledMask |= (1 << index);
+        } else {
+            owner.clipPlaneEnabledMask &= ~(1 << index);
+        }
+    }
+}

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

@@ -117,6 +117,7 @@ public class CompatUniformManager {
 
     private static final class ProgramUniforms {
         final int[] locs;
+        GLContextState owner;
         int lastMvGen = -1, lastMvLinearGen = -1, lastProjGen = -1, lastTexMatGen = -1;
         int lastFragmentGen = -1, lastLightingGen = -1, lastClipPlaneGen = -1;
         ProgramUniforms(int[] locs) { this.locs = locs; }
@@ -161,7 +162,13 @@ public class CompatUniformManager {
         }
 
         if (hasAny) {
-            programUniforms.put(program, new ProgramUniforms(locs));
+            final ProgramUniforms uniforms = new ProgramUniforms(locs);
+            final boolean locked = GLStateManager.acquireDrawLock();
+            try {
+                programUniforms.put(program, uniforms);
+            } finally {
+                if (locked) GLStateManager.releaseDrawLock();
+            }
             GLStateManager.LOGGER.debug("CompatUniformManager: program {} has compat uniforms", program);
         }
     }
@@ -171,16 +178,21 @@ public class CompatUniformManager {
      *
      * @return Whether the program needs emulation (FFP or Iris Program)
      */
-    public static boolean refreshCompatUniforms(int program) {
+    public static boolean refreshCompatUniforms(int program, GLContextState glCtx) {
         final ProgramUniforms pu = programUniforms.get(program);
         if (pu == null) return false;
         final int[] locs = pu.locs;
+        if (pu.owner != glCtx) {
+            pu.owner = glCtx;
+            pu.lastMvGen = pu.lastMvLinearGen = pu.lastProjGen = pu.lastTexMatGen = -1;
+            pu.lastFragmentGen = pu.lastLightingGen = pu.lastClipPlaneGen = -1;
+        }
 
         // Matrix uniforms — skip if this program's storage already holds the current generation
-        final int mvGen = GLStateManager.getMvGeneration();
-        final int mvLinearGen = GLStateManager.getMvLinearGeneration();
-        final int projGen = GLStateManager.getProjGeneration();
-        final int texMatGen = GLStateManager.getTexMatrixGeneration();
+        final int mvGen = glCtx.mvGeneration;
+        final int mvLinearGen = glCtx.mvLinearGeneration;
+        final int projGen = glCtx.projGeneration;
+        final int texMatGen = glCtx.texMatrixGeneration;
         final boolean mvChanged = mvGen != pu.lastMvGen;
         final boolean mvLinearChanged = mvLinearGen != pu.lastMvLinearGen;
         final boolean projChanged = projGen != pu.lastProjGen;
@@ -194,14 +206,14 @@ public class CompatUniformManager {
         }
 
         // Fragment-category uniforms (fog, alpha) — skip if generation unchanged
-        final int fragGen = GLStateManager.getFragmentGeneration();
+        final int fragGen = glCtx.fragmentGeneration;
         if (fragGen != pu.lastFragmentGen) {
             pu.lastFragmentGen = fragGen;
             uploadFragmentUniforms(locs);
         }
 
         // Lighting-derived uniforms (scene color, light sources, material)
-        final int litGen = GLStateManager.getLightingGeneration();
+        final int litGen = glCtx.lightingGeneration;
         if (litGen != pu.lastLightingGen) {
             pu.lastLightingGen = litGen;
             if (locs[LOC_SCENE_COLOR] != -1) uploadSceneColor(locs);
@@ -211,7 +223,7 @@ public class CompatUniformManager {
 
         // 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.getClipPlaneGeneration();
+            final int cpGen = glCtx.clipPlaneGeneration;
             if (cpGen != pu.lastClipPlaneGen) {
                 pu.lastClipPlaneGen = cpGen;
                 uploadClipPlanes(locs);
@@ -438,7 +450,12 @@ public class CompatUniformManager {
     }
 
     public static void onDeleteProgram(int program) {
-        programUniforms.remove(program);
+        final boolean locked = GLStateManager.acquireDrawLock();
+        try {
+            programUniforms.remove(program);
+        } finally {
+            if (locked) GLStateManager.releaseDrawLock();
+        }
     }
 
     public static boolean hasProgram(int program) {

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

@@ -59,7 +59,7 @@ public class DisplayListIDAllocator {
         numSetElements = 1;
     }
 
-    public int allocRange(int count) {
+    public synchronized int allocRange(int count) {
         if (count <= 0) throw new IllegalArgumentException("count must be > 0");
         if (count == 1) return allocSingle();
         return allocMultiple(count);
@@ -132,7 +132,7 @@ public class DisplayListIDAllocator {
         return numElements;
     }
 
-    public void free(int id) {
+    public synchronized void free(int id) {
         if (id <= 0) return; // ID 0 is reserved
         int idx = id / 32;
         if (idx >= numElements) return;
@@ -147,7 +147,7 @@ public class DisplayListIDAllocator {
         }
     }
 
-    public void freeRange(int base, int count) {
+    public synchronized void freeRange(int base, int count) {
         if (count <= 0 || base <= 0) return;
 
         int startIdx = base / 32;
@@ -166,7 +166,7 @@ public class DisplayListIDAllocator {
         }
     }
 
-    public boolean isAllocated(int id) {
+    public synchronized boolean isAllocated(int id) {
         if (id <= 0) return false;
         int idx = id / 32;
         if (idx >= numSetElements) return false;

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

@@ -79,12 +79,13 @@ public class DisplayListManager {
     // Display list compilation state (current/active context)
     private static int glListMode = 0;
     private static int glListId = -1;
+    private static int recordedStatePushes;
+    private static final DisplayListCommand POP_STATE = GLStateManager::popState;
     private static CommandRecorder currentRecorder = null;  // Command recorder (null when not recording)
     private static volatile Thread recordingThread = null;  // Thread that started recording (for thread-safety)
     private static List<AccumulatedDraw> accumulatedDraws = null;  // Accumulates quad draws for batching
     private static AccumulatedDraw pendingDraw = null;
     private static DisplayListCallback transformCallback = null;
-    private static int relativeTransformType;
 
     private static final int TRANSFORM_SCALE = 0x1; // Can be extracted to a glScale easily
     private static final int TRANSFORM_TRANSLATE = 0x2; // Can be extracted to a glTranslate easily
@@ -93,7 +94,7 @@ public class DisplayListManager {
     private static StackTraceElement[] compilationStackTrace = null;  // For logging: captured at glNewList()
 
     // Debug logging: track sources of MULT_MATRIX commands and draw origins; only populated when LOG_DISPLAY_LIST_COMPILATION is true
-    private static List<String> pendingTransformOps = null;  // Ops accumulated since last flush
+    private static List<List<String>> pendingTransformOps = null;  // Ops per matrix slot since its last flush
     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
 
@@ -114,9 +115,10 @@ public class DisplayListManager {
         List<AccumulatedDraw> draws,
         DisplayListCallback callback,
         StackTraceElement[] stackTrace,
+        int recordedStatePushes,
 
         // Debug logging fields (only used when LOG_DISPLAY_LIST_COMPILATION)
-        List<String> pendingOps,
+        List<List<String>> pendingOps,
         List<List<String>> matrixSources,
         List<String> drawSources
     ) {}
@@ -141,7 +143,7 @@ public class DisplayListManager {
     }
 
     public static String describeCurrentCompilation() {
-        if (currentRecorder == null) {
+        if (!isRecording()) {
             return "(not compiling)";
         }
         final String mode = glListMode == GL11.GL_COMPILE_AND_EXECUTE ? "GL_COMPILE_AND_EXECUTE" : "GL_COMPILE";
@@ -150,16 +152,20 @@ public class DisplayListManager {
     }
 
     public static boolean isCompileAndExecute() {
-        return glListMode == GL11.GL_COMPILE_AND_EXECUTE;
+        return isRecording() && glListMode == GL11.GL_COMPILE_AND_EXECUTE;
     }
 
     public static CommandRecorder pauseRecording() {
+        if (Thread.currentThread() != recordingThread) return null;
         final CommandRecorder r = currentRecorder;
         currentRecorder = null;
         return r;
     }
 
     public static void resumeRecording(CommandRecorder r) {
+        if (Thread.currentThread() != recordingThread) {
+            throw new IllegalStateException("Cannot resume another thread's display list compilation");
+        }
         currentRecorder = r;
     }
 
@@ -168,7 +174,9 @@ public class DisplayListManager {
 
     static void flushAll() {
         drawBarrier();
-        flushMatrix();
+        for (int slot = 0; slot < DisplayListCallback.SLOT_COUNT; slot++) {
+            flushMatrix(slot);
+        }
     }
 
 
@@ -183,13 +191,21 @@ public class DisplayListManager {
     }
 
     /**
-     * Emit accumulated transform as MultMatrix if non-identity, then reset.
+     * Emit the current matrix target's accumulated transform as MultMatrix if non-identity, then reset.
      */
     static void flushMatrix() {
-        if (transformCallback.isIdentity()) {
+        flushMatrix(transformCallback.getCurrentSlot());
+    }
+
+    /**
+     * Emit one matrix target's accumulated transform as MultMatrix if non-identity, then reset.
+     */
+    private static void flushMatrix(int slot) {
+        if (transformCallback.isIdentity(slot)) {
             // Clear pending ops even if we don't emit - they were no-ops (identity)
+            transformCallback.reset(slot);
             if (pendingTransformOps != null) {
-                pendingTransformOps.clear();
+                pendingTransformOps.get(slot).clear();
             }
             return;
         }
@@ -197,44 +213,60 @@ public class DisplayListManager {
 
         // Save pending transform ops for logging (before we clear them)
         if (multMatrixSources != null && pendingTransformOps != null) {
-            if (pendingTransformOps.isEmpty()) {
+            final List<String> ops = pendingTransformOps.get(slot);
+            if (ops.isEmpty()) {
                 GLStateManager.LOGGER.warn("flushMatrix: non-identity transform with no tracked ops");
                 multMatrixSources.add(Collections.singletonList("(unknown source)"));
             } else {
-                multMatrixSources.add(new ArrayList<>(pendingTransformOps));
+                multMatrixSources.add(new ArrayList<>(ops));
             }
-            pendingTransformOps.clear();
+            ops.clear();
         }
 
         // Record the collapsed MultMatrix command (for playback)
         // Always put a draw barrier BEFORE flushing the matrix (the transforms are already baked into the current draw)
         drawBarrier();
-        if (relativeTransformType == TRANSFORM_SCALE) {
-            currentRecorder.writeScale(transformCallback.getScale(transformVector));
-        } else if (relativeTransformType == TRANSFORM_TRANSLATE) {
-            currentRecorder.writeTranslate(transformCallback.getTranslation(transformVector));
+        syncStreamMatrixMode(transformCallback.getSlotMatrixMode(slot));
+        final Matrix4f pending = transformCallback.getReadMatrix(slot);
+        final int type = transformCallback.getTransformType(slot);
+        if (type == TRANSFORM_SCALE) {
+            currentRecorder.writeScale(transformCallback.getScale(slot, transformVector));
+        } else if (type == TRANSFORM_TRANSLATE) {
+            currentRecorder.writeTranslate(transformCallback.getTranslation(slot, transformVector));
         } else {
-            currentRecorder.writeMultMatrix(transformCallback.getReadMatrix());
+            currentRecorder.writeMultMatrix(pending);
         }
         if (glListMode == GL11.GL_COMPILE_AND_EXECUTE) {
-            GLStateManager.applyMultMatrix(transformCallback.getReadMatrix());
+            GLStateManager.applyMultMatrix(pending);
         }
 
 
         // Reset to identity - we're now synchronized with GL
-        resetRelativeTransform();
+        transformCallback.reset(slot);
+    }
+
+    private static void syncStreamMatrixMode(int mode) {
+        if (transformCallback.getStreamMatrixMode() == 0 && !transformCallback.explicitMatrixMode) {
+            return;
+        }
+        if (transformCallback.getStreamMatrixMode() == mode) {
+            return;
+        }
+        drawBarrier();
+        transformCallback.setStreamMatrixMode(mode);
+        currentRecorder.writeMatrixMode(mode);
     }
 
     public static int getRecordingListId() {
-        return glListId;
+        return Thread.currentThread() == recordingThread ? glListId : -1;
     }
 
     public static int getListMode() {
-        return glListMode;
+        return Thread.currentThread() == recordingThread ? glListMode : 0;
     }
 
     public static void trackDrawRangeSource(String source) {
-        if (drawRangeSources != null) {
+        if (Thread.currentThread() == recordingThread && drawRangeSources != null) {
             drawRangeSources.add(source);
         }
     }
@@ -312,6 +344,11 @@ public class DisplayListManager {
         currentRecorder.writeSecondaryColor(r, g, b);
     }
 
+    public static void recordVertexAttrib(int index, float x, float y, float z, float w) {
+        drawBarrier();
+        currentRecorder.writeVertexAttrib(index, x, y, z, w);
+    }
+
     public static void recordColorMask(boolean r, boolean g, boolean b, boolean a) {
         drawBarrier();
         currentRecorder.writeColorMask(r, g, b, a);
@@ -368,14 +405,37 @@ public class DisplayListManager {
     }
 
     public static void recordMatrixMode(int mode) {
-        flushMatrix();  // Matrix barrier: flush and reset
+        final int previous = transformCallback.getMatrixMode();
+        if (!transformCallback.explicitMatrixMode) {
+            // Pending transforms still inherit the caller's target until this explicit selection.
+            flushMatrix();
+        }
+        transformCallback.explicitMatrixMode = true;
+        if (previous == mode) {
+            // The initial target and the target after a nested list are unknown at playback.
+            syncStreamMatrixMode(mode);
+            return;
+        }
+        if (glListMode == GL11.GL_COMPILE_AND_EXECUTE) {
+            // Live GL follows the app's matrix mode, so a pending delta can only be replayed onto GL
+            // while its own target is still current.
+            flushAll();
+        } else {
+            // MODELVIEW and PROJECTION share the vertex delta, so a delta belonging to one of them has to
+            // be flushed before the other starts adding to it.
+            final int slot = DisplayListCallback.slotOf(mode);
+            if (transformCallback.getSlotMatrixMode(slot) != mode) {
+                flushMatrix(slot);
+            }
+        }
         transformCallback.setMatrixMode(mode);
-        currentRecorder.writeMatrixMode(mode);
     }
 
     public static void recordPushMatrix() {
+        drawBarrier();
         // Flush any pending delta, then record push.
         flushMatrix();
+        syncStreamMatrixMode(transformCallback.getMatrixMode());
         currentRecorder.writePushMatrix();
     }
 
@@ -383,6 +443,7 @@ public class DisplayListManager {
         // Discard any transformations & flush any pending draw operations
         drawBarrier();
         resetRelativeTransform();
+        syncStreamMatrixMode(transformCallback.getMatrixMode());
         currentRecorder.writePopMatrix();
     }
 
@@ -432,6 +493,8 @@ public class DisplayListManager {
     }
 
     public static void recordActiveTexture(int texture) {
+        drawBarrier();
+        flushMatrix(DisplayListCallback.SLOT_TEXTURE);
         currentRecorder.writeActiveTexture(texture);
     }
 
@@ -440,15 +503,50 @@ public class DisplayListManager {
         currentRecorder.writeUseProgram(program);
     }
 
-    // PushAttrib saves state but doesn't change it - not a draw barrier
+    private record AttribState(int matrixMode, boolean restoresTexture) {}
+
     public static void recordPushAttrib(int mask) {
+        final boolean savesMode = (mask & GL11.GL_TRANSFORM_BIT) != 0;
+        if (savesMode) syncStreamMatrixMode(transformCallback.getMatrixMode());
+        transformCallback.attribStates.push(new AttribState(
+            savesMode ? transformCallback.getStreamMatrixMode() : -1, (mask & GL11.GL_TEXTURE_BIT) != 0));
         currentRecorder.writePushAttrib(mask);
     }
 
     // PopAttrib restores potentially any state - draw barrier
     public static void recordPopAttrib() {
-        drawBarrier();
+        final AttribState restored = transformCallback.attribStates.poll();
+        final int restoredMode = restored == null ? 0 : restored.matrixMode();
+        if (restoredMode != -1) flushAll();
+        else {
+            drawBarrier();
+            if (restored.restoresTexture()) flushMatrix(DisplayListCallback.SLOT_TEXTURE);
+        }
         currentRecorder.writePopAttrib();
+        if (restoredMode != -1) {
+            transformCallback.setMatrixMode(restoredMode == 0 ? GL11.GL_MODELVIEW : restoredMode);
+            transformCallback.setStreamMatrixMode(restoredMode);
+            transformCallback.explicitMatrixMode = restoredMode != 0;
+        }
+    }
+
+    public static int virtualStateDepth(RecordMode mode) {
+        return mode == RecordMode.COMPILE ? recordedStatePushes : 0;
+    }
+
+    public static void recordPushState(StateSet set) {
+        currentRecorder.writeComplexCommand(set.pushCommand);
+        recordedStatePushes++;
+    }
+
+    public static boolean recordPopStateIfPending() {
+        if (recordedStatePushes > 0) {
+            drawBarrier();
+            currentRecorder.writeComplexCommand(POP_STATE);
+            recordedStatePushes--;
+            return true;
+        }
+        return false;
     }
 
     public static void recordFogf(int pname, float param) {
@@ -549,7 +647,10 @@ public class DisplayListManager {
     public static void recordCallList(int listId) {
         // Flush all pending draws & transformations
         flushAll();
+        syncStreamMatrixMode(transformCallback.getMatrixMode());
         currentRecorder.writeCallList(listId);
+        transformCallback.setStreamMatrixMode(0);
+        transformCallback.explicitMatrixMode = false;
     }
 
     public static void recordDrawBuffer(int mode) {
@@ -572,6 +673,19 @@ public class DisplayListManager {
         currentRecorder.writeComplexCommand(cmd);
     }
 
+    public static void recordStateCommand(DisplayListCommand cmd) {
+        drawBarrier();
+        currentRecorder.writeComplexCommand(cmd);
+    }
+
+    public static void recordStateCommandIfChanged(DisplayListCommand cmd) {
+        if (!currentRecorder.isLastCommand(cmd)) recordStateCommand(cmd);
+    }
+
+    public static void recordStateCommandOnce(DisplayListCommand cmd) {
+        if (currentRecorder.markRecordedOnce(cmd)) recordStateCommand(cmd);
+    }
+
     public static void recordIndexedDrawCapture(IndexedDrawCapture capture) {
         flushAll(); //TODO
         currentRecorder.writeIndexedDrawCapture(capture);
@@ -580,12 +694,14 @@ public class DisplayListManager {
     public static void recordLoadMatrix(Matrix4f matrix) {
         drawBarrier();
         resetRelativeTransform();
+        syncStreamMatrixMode(transformCallback.getMatrixMode());
         currentRecorder.writeLoadMatrix(matrix);
     }
 
     public static void recordLoadIdentity() {
         drawBarrier();
         resetRelativeTransform();
+        syncStreamMatrixMode(transformCallback.getMatrixMode());
         currentRecorder.writeLoadIdentity();
 
     }
@@ -623,11 +739,10 @@ public class DisplayListManager {
     }
 
     public static void applyMatrixTranslation(float x, float y, float z) {
-        transformCallback.translate(x, y, z);
-        relativeTransformType |= TRANSFORM_TRANSLATE;
+        transformCallback.translate(x, y, z, TRANSFORM_TRANSLATE);
 
         if (pendingTransformOps != null) {
-            pendingTransformOps.add(String.format("glTranslatef(%.4f, %.4f, %.4f)", x, y, z));
+            pendingTransformOps.get(transformCallback.getCurrentSlot()).add(String.format("glTranslatef(%.4f, %.4f, %.4f)", x, y, z));
         }
 
         if (SystemProperties.DEBUG_DISPLAY_LISTS) {
@@ -636,11 +751,10 @@ public class DisplayListManager {
     }
 
     public static void applyMatrixScale(float x, float y, float z) {
-        transformCallback.scale(x, y, z);
-        relativeTransformType |= TRANSFORM_SCALE;
+        transformCallback.scale(x, y, z, TRANSFORM_SCALE);
 
         if (pendingTransformOps != null) {
-            pendingTransformOps.add(String.format("glScalef(%.4f, %.4f, %.4f)", x, y, z));
+            pendingTransformOps.get(transformCallback.getCurrentSlot()).add(String.format("glScalef(%.4f, %.4f, %.4f)", x, y, z));
         }
 
         if (SystemProperties.DEBUG_DISPLAY_LISTS) {
@@ -654,11 +768,10 @@ public class DisplayListManager {
      * Requires the angle to be in radians & the coordinates to be normalized.
      */
     public static void applyMatrixRotation(float rad, float x, float y, float z) {
-        transformCallback.rotate(rad, x, y, z);
-        relativeTransformType |= TRANSFORM_COMPLEX;
+        transformCallback.rotate(rad, x, y, z, TRANSFORM_COMPLEX);
 
         if (pendingTransformOps != null) {
-            pendingTransformOps.add(String.format("glRotatef(%.4f, %.4f, %.4f, %.4f)", Math.toDegrees(rad), x, y, z));
+            pendingTransformOps.get(transformCallback.getCurrentSlot()).add(String.format("glRotatef(%.4f, %.4f, %.4f, %.4f)", Math.toDegrees(rad), x, y, z));
         }
 
         if (SystemProperties.DEBUG_DISPLAY_LISTS) {
@@ -676,11 +789,10 @@ public class DisplayListManager {
      * @param matrix The matrix to multiply
      */
     public static void updateRelativeTransform(Matrix4f matrix) {
-        transformCallback.multMatrix(matrix);
-        relativeTransformType |= TRANSFORM_COMPLEX;
+        transformCallback.multMatrix(matrix, TRANSFORM_COMPLEX);
 
         if (pendingTransformOps != null) {
-            pendingTransformOps.add("glMultMatrixf(...)");
+            pendingTransformOps.get(transformCallback.getCurrentSlot()).add("glMultMatrixf(...)");
         }
 
         if (SystemProperties.DEBUG_DISPLAY_LISTS) {
@@ -694,11 +806,10 @@ public class DisplayListManager {
     public static void updateRelativeTransformOrtho(double left, double right, double bottom, double top, double zNear, double zFar) {
         orthoFrustumTemp.identity().ortho((float) left, (float) right, (float) bottom, (float) top, (float) zNear, (float) zFar);
 
-        transformCallback.multMatrix(orthoFrustumTemp);
-        relativeTransformType |= TRANSFORM_COMPLEX;
+        transformCallback.multMatrix(orthoFrustumTemp, TRANSFORM_COMPLEX);
 
         if (pendingTransformOps != null) {
-            pendingTransformOps.add(String.format("glOrtho(%.4f, %.4f, %.4f, %.4f, %.4f, %.4f)", left, right, bottom, top, zNear, zFar));
+            pendingTransformOps.get(transformCallback.getCurrentSlot()).add(String.format("glOrtho(%.4f, %.4f, %.4f, %.4f, %.4f, %.4f)", left, right, bottom, top, zNear, zFar));
         }
 
         if (SystemProperties.DEBUG_DISPLAY_LISTS) {
@@ -709,11 +820,10 @@ public class DisplayListManager {
     public static void updateRelativeTransformFrustum(double left, double right, double bottom, double top, double zNear, double zFar) {
         orthoFrustumTemp.identity().frustum((float) left, (float) right, (float) bottom, (float) top, (float) zNear, (float) zFar);
 
-        transformCallback.multMatrix(orthoFrustumTemp);
-        relativeTransformType |= TRANSFORM_COMPLEX;
+        transformCallback.multMatrix(orthoFrustumTemp, TRANSFORM_COMPLEX);
 
         if (pendingTransformOps != null) {
-            pendingTransformOps.add(String.format("glFrustum(%.4f, %.4f, %.4f, %.4f, %.4f, %.4f)", left, right, bottom, top, zNear, zFar));
+            pendingTransformOps.get(transformCallback.getCurrentSlot()).add(String.format("glFrustum(%.4f, %.4f, %.4f, %.4f, %.4f, %.4f)", left, right, bottom, top, zNear, zFar));
         }
 
         if (SystemProperties.DEBUG_DISPLAY_LISTS) {
@@ -727,8 +837,8 @@ public class DisplayListManager {
      * subsequent transforms are relative to that loaded matrix (i.e., start from identity).
      */
     static void resetRelativeTransform() {
-        transformCallback.setIdentity();
-        relativeTransformType = 0;
+        transformCallback.reset(transformCallback.getCurrentSlot());
+        if (pendingTransformOps != null) pendingTransformOps.get(transformCallback.getCurrentSlot()).clear();
     }
 
     /**
@@ -739,8 +849,11 @@ public class DisplayListManager {
      * @return true if the display list exists, false otherwise
      */
     public static boolean displayListExists(int list) {
-        if (displayListCache.containsKey(list)) {
-            return true;
+        final boolean locked = GLStateManager.acquireDrawLock();
+        try {
+            if (displayListCache.containsKey(list)) return true;
+        } finally {
+            if (locked) GLStateManager.releaseDrawLock();
         }
         // Check VBOManager for GTNHLib compatibility (negative IDs)
         if (list < -1) {
@@ -756,7 +869,12 @@ public class DisplayListManager {
      * @return The CompiledDisplayList, or null if not found
      */
     public static CompiledDisplayList getDisplayList(int list) {
-        return displayListCache.get(list);
+        final boolean locked = GLStateManager.acquireDrawLock();
+        try {
+            return displayListCache.get(list);
+        } finally {
+            if (locked) GLStateManager.releaseDrawLock();
+        }
     }
 
     /**
@@ -765,78 +883,113 @@ public class DisplayListManager {
      *   GL_COMPILE: Commands are recorded only (not executed), GLSM cache unchanged
      *   GL_COMPILE_AND_EXECUTE: Commands are recorded AND executed (GLSM cache updated)
      */
-    public static void glNewList(int list, int mode) {
-        // Handle nested compilation - push current context onto stack
+    public static synchronized void glNewList(int list, int mode) {
+        final Thread recorder = recordingThread;
+        if (recorder != null && recorder != Thread.currentThread()) {
+            throw new IllegalStateException("glNewList(" + list + ") on " + Thread.currentThread().getName() + " while " + recorder.getName() + " is compiling a display list");
+        }
         final boolean isNested = glListMode > 0;
+        final int captureDepth = TessellatorManager.getDirectCaptureDepth();
+        boolean pushed = false;
+        if (!isNested) recordingThread = Thread.currentThread();
+        try {
+            if (isNested) {
+                flushAll();
+                final CompilationContext parentContext = new CompilationContext(
+                    glListId, glListMode, currentRecorder, accumulatedDraws, transformCallback,
+                    compilationStackTrace, recordedStatePushes, pendingTransformOps, multMatrixSources, drawRangeSources
+                );
+                compilationStack.push(parentContext);
+                pushed = true;
+            }
 
-        if (isNested) {
-            flushAll();
-            // Nested display list compilation violates OpenGL spec, but some of our optimizations require it
-            // Save current compilation context and start fresh for nested list
-            final CompilationContext parentContext = new CompilationContext(
-                glListId, glListMode, currentRecorder, accumulatedDraws, transformCallback,
-                compilationStackTrace, pendingTransformOps, multMatrixSources, drawRangeSources
-            );
-            compilationStack.push(parentContext);
+            glListId = list;
+            glListMode = mode;
+            currentRecorder = new CommandRecorder();
+            accumulatedDraws = new ArrayList<>(8);
+            transformCallback = new DisplayListCallback();
+            recordedStatePushes = 0;
+            compilationStackTrace = SystemProperties.LOG_DISPLAY_LIST_COMPILATION ? Thread.currentThread().getStackTrace() : null;
+
+            if (SystemProperties.LOG_DISPLAY_LIST_COMPILATION) {
+                pendingTransformOps = new ArrayList<>();
+                for (int slot = 0; slot < DisplayListCallback.SLOT_COUNT; slot++) {
+                    pendingTransformOps.add(new ArrayList<>());
+                }
+                multMatrixSources = new ArrayList<>();
+                drawRangeSources = new ArrayList<>();
+            } else {
+                pendingTransformOps = null;
+                multMatrixSources = null;
+                drawRangeSources = null;
+            }
+
+            TessellatorManager.startCapturingDirect(transformCallback);
+        } catch (RuntimeException | Error failure) {
+            try {
+                if (TessellatorManager.getDirectCaptureDepth() > captureDepth) TessellatorManager.stopCapturingDirect();
+            } catch (RuntimeException | Error cleanup) {
+                failure.addSuppressed(cleanup);
+            }
+            try {
+                if (pushed) {
+                    final CommandRecorder parent = compilationStack.peek().recorder();
+                    try {
+                        if (currentRecorder != null && currentRecorder != parent) currentRecorder.delete();
+                    } finally {
+                        popCompilationContext();
+                    }
+                } else if (!isNested) {
+                    try {
+                        if (currentRecorder != null) currentRecorder.delete();
+                    } finally {
+                        resetCompilationState();
+                    }
+                }
+            } catch (RuntimeException | Error cleanup) {
+                failure.addSuppressed(cleanup);
+            }
+            throw failure;
         }
-
-        // Initialize fresh context for this (possibly nested) list
-        glListId = list;
-        glListMode = mode;
-        recordingThread = Thread.currentThread();  // Track which thread is recording
-        currentRecorder = new CommandRecorder();  // Create command recorder
-        accumulatedDraws = new ArrayList<>(8);   // Fewer draws than commands typically
-        transformCallback = new DisplayListCallback();
-        compilationStackTrace = SystemProperties.LOG_DISPLAY_LIST_COMPILATION ? Thread.currentThread().getStackTrace() : null;
-
-        // Initialize debug logging fields (only when logging enabled)
-        if (SystemProperties.LOG_DISPLAY_LIST_COMPILATION) {
-            pendingTransformOps = new ArrayList<>();
-            multMatrixSources = new ArrayList<>();
-            drawRangeSources = new ArrayList<>();
-        } else {
-            pendingTransformOps = null;
-            multMatrixSources = null;
-            drawRangeSources = null;
-        }
-
-        TessellatorManager.startCapturingDirect(transformCallback);
     }
 
     /**
      * End display list compilation and build optimized/unoptimized versions.
      */
-    public static void glEndList() {
+    public static synchronized void glEndList() {
+        final Thread recorder = recordingThread;
+        if (recorder != null && recorder != Thread.currentThread()) {
+            throw new IllegalStateException("glEndList on " + Thread.currentThread().getName() + " while " + recorder.getName() + " is compiling a display list");
+        }
         if (glListMode == 0) {
             GLStateManager.warnOnce("endlist-outside", "glEndList called outside of a display list!");
             return;
         }
         if (Tracy.ENABLED) Tracy.beginZone(Z_GL_LIST_COMPILE);
         try {
+            TessellatorManager.stopCapturingDirect();
             finishCurrentList();
         } finally {
             if (Tracy.ENABLED) Tracy.endZone();
-            // Non-null here means finishCurrentList threw before transferring or releasing
-            // ownership of the recorder.
-            if (currentRecorder != null) {
-                currentRecorder.delete();
+            try {
+                if (currentRecorder != null) currentRecorder.delete();
+            } finally {
+                popCompilationContext();
             }
-            // Must always run, even when compilation fails - a leaked context leaves
-            // isRecording() true forever and every guarded GL call throws afterward.
-            popCompilationContext();
         }
     }
 
     private static void finishCurrentList() {
-        // Stop compiling mode (works for both root and nested lists now)
-        TessellatorManager.stopCapturingDirect();
+        boolean unbalancedStatePush = false;
+        while (recordPopStateIfPending()) unbalancedStatePush = true;
+        if (unbalancedStatePush) {
+            GLStateManager.warnOnce("unbalanced-state-push", "Display list {} ended with unpopped internal state pushes - closing them", glListId);
+        }
 
         flushAll();
 
-        // Reset back to MODELVIEW (default state)
-        if (transformCallback.getMatrixMode() != GL11.GL_MODELVIEW) {
-            recordMatrixMode(GL11.GL_MODELVIEW);
-        }
+        transformCallback.setMatrixMode(GL11.GL_MODELVIEW);
+        syncStreamMatrixMode(GL11.GL_MODELVIEW);
 
         final CompiledDisplayList compiled;
         // Create CompiledDisplayList with both unoptimized and optimized versions
@@ -921,6 +1074,7 @@ public class DisplayListManager {
             accumulatedDraws = parentContext.draws;
             transformCallback = parentContext.callback;
             compilationStackTrace = parentContext.stackTrace;
+            recordedStatePushes = parentContext.recordedStatePushes;
             pendingTransformOps = parentContext.pendingOps;
             multMatrixSources = parentContext.matrixSources;
             drawRangeSources = parentContext.drawSources;
@@ -936,7 +1090,6 @@ public class DisplayListManager {
     /** Clear all root-level compilation state back to "not recording". */
     private static void resetCompilationState() {
         currentRecorder = null;
-        recordingThread = null;
         accumulatedDraws = null;
         pendingDraw = null;
         transformCallback = null;
@@ -946,9 +1099,14 @@ public class DisplayListManager {
         drawRangeSources = null;
         glListId = -1;
         glListMode = 0;
+        recordedStatePushes = 0;
+        recordingThread = null;
     }
 
-    public static void abortCompilation() {
+    public static synchronized void abortCompilation() {
+        if (recordingThread != null && recordingThread != Thread.currentThread()) {
+            throw new IllegalStateException("Cannot abort another thread's display list compilation");
+        }
         if (glListMode == 0 && compilationStack.isEmpty()) {
             return;
         }
@@ -976,7 +1134,7 @@ public class DisplayListManager {
     }
 
     public static void abortIfLeaked() {
-        if (glListMode != 0 || !compilationStack.isEmpty()) {
+        if (Thread.currentThread() == recordingThread && (glListMode != 0 || !compilationStack.isEmpty())) {
             GLStateManager.warnOnce("frame-leak", "Display list {} left open across a frame boundary - aborting to recover", glListId);
             abortCompilation();
         }
@@ -1012,7 +1170,7 @@ public class DisplayListManager {
      * Execute a compiled display list.
      */
     public static void glCallList(int list) {
-        if (currentRecorder != null) {
+        if (isRecording()) {
             recordCallList(list);
 
             if (getListMode() != GL11.GL_COMPILE) {
@@ -1326,12 +1484,32 @@ public class DisplayListManager {
 
     private static final class DisplayListCallback extends VertexTransformCallback {
 
+        static final int SLOT_VERTEX = 0;   // GL_MODELVIEW + GL_PROJECTION, feeds into gl_Position
+        static final int SLOT_TEXTURE = 1;
+        static final int SLOT_COLOR = 2;
+        static final int SLOT_OTHER = 3;
+        static final int SLOT_COUNT = 4;
+
+        static int slotOf(int mode) {
+            return switch (mode) {
+                case GL11.GL_MODELVIEW, GL11.GL_PROJECTION -> SLOT_VERTEX;
+                case GL11.GL_TEXTURE -> SLOT_TEXTURE;
+                case GL11.GL_COLOR -> SLOT_COLOR;
+                default -> SLOT_OTHER;
+            };
+        }
 
         private int matrixMode = GL11.GL_MODELVIEW;
 
+        private int streamMatrixMode;
+        private boolean explicitMatrixMode;
+        private final Deque<AttribState> attribStates = new ArrayDeque<>();
+
         private final Matrix3f normalMatrix = new Matrix3f();
 
-        private final Matrix4f transformMatrix = new Matrix4f();
+        private final Matrix4f[] transformMatrices = { new Matrix4f(), new Matrix4f(), new Matrix4f(), new Matrix4f() };
+        private final int[] transformTypes = new int[SLOT_COUNT];
+        private final int[] slotModes = { GL11.GL_MODELVIEW, GL11.GL_TEXTURE, GL11.GL_COLOR, 0 };
 
         private DirectTessellator bakedOwner;
         private int bakedVertices;
@@ -1343,49 +1521,69 @@ public class DisplayListManager {
             }
         }
 
-        public void scale(float x, float y, float z) {
-            transformMatrix.scale(x, y, z);
+        private Matrix4f begin(int typeBits) {
+            final int slot = getCurrentSlot();
+            transformTypes[slot] |= typeBits;
+            slotModes[slot] = matrixMode;
+            return transformMatrices[slot];
+        }
+
+        public void scale(float x, float y, float z, int typeBits) {
+            begin(typeBits).scale(x, y, z);
             markDirty();
         }
 
-        public void translate(float x, float y, float z) {
-            transformMatrix.translate(x, y, z);
+        public void translate(float x, float y, float z, int typeBits) {
+            begin(typeBits).translate(x, y, z);
             markDirty();
         }
 
-        public void rotate(float rad, float x, float y, float z) {
-            transformMatrix.rotate(rad, x, y, z);
+        public void rotate(float rad, float x, float y, float z, int typeBits) {
+            begin(typeBits).rotate(rad, x, y, z);
             markDirty();
         }
 
-        public void multMatrix(Matrix4f matrix4f) {
-            transformMatrix.mul(matrix4f);
+        public void multMatrix(Matrix4f matrix4f, int typeBits) {
+            begin(typeBits).mul(matrix4f);
             markDirty();
         }
 
-        public void setIdentity() {
-            transformMatrix.identity();
-            markDirty();
+        public void reset(int slot) {
+            transformMatrices[slot].identity();
+            transformTypes[slot] = 0;
+            if (slot == SLOT_VERTEX) {
+                markDirty();
+            }
         }
 
-        public Vector3f getScale(Vector3f dest) {
-            return transformMatrix.getScale(dest);
+        public Vector3f getScale(int slot, Vector3f dest) {
+            final Matrix4f matrix = transformMatrices[slot];
+            return dest.set(matrix.m00(), matrix.m11(), matrix.m22());
         }
 
-        public Vector3f getTranslation(Vector3f dest) {
-            return transformMatrix.getTranslation(dest);
+        public Vector3f getTranslation(int slot, Vector3f dest) {
+            return transformMatrices[slot].getTranslation(dest);
         }
 
         /**
          * WARNING: If you apply transformations to this matrix, make sure to call markDirty() afterward!
          */
-        public Matrix4f getReadMatrix() {
-            return transformMatrix;
+        public Matrix4f getReadMatrix(int slot) {
+            return transformMatrices[slot];
+        }
+
+        public int getTransformType(int slot) {
+            return transformTypes[slot];
+        }
+
+        /** The GL matrix target a slot's pending delta belongs to. */
+        public int getSlotMatrixMode(int slot) {
+            return slotModes[slot];
         }
 
         public void markDirty() {
             if (matrixMode == GL11.GL_MODELVIEW) {
-                NormalHelper.getNormalMatrix(transformMatrix, normalMatrix);
+                NormalHelper.getNormalMatrix(transformMatrices[SLOT_VERTEX], normalMatrix);
             }
         }
 
@@ -1394,15 +1592,26 @@ public class DisplayListManager {
          */
         public void setMatrixMode(int mode) {
             this.matrixMode = mode;
-            markDirty();
         }
 
         public int getMatrixMode() {
             return this.matrixMode;
         }
 
-        public boolean isIdentity() {
-            return MatrixHelper.isIdentity(transformMatrix);
+        public int getCurrentSlot() {
+            return slotOf(matrixMode);
+        }
+
+        public int getStreamMatrixMode() {
+            return this.streamMatrixMode;
+        }
+
+        public void setStreamMatrixMode(int mode) {
+            this.streamMatrixMode = mode;
+        }
+
+        public boolean isIdentity(int slot) {
+            return MatrixHelper.isIdentity(transformMatrices[slot]);
         }
 
         @Override
@@ -1415,10 +1624,12 @@ public class DisplayListManager {
         @Override
         public boolean onDraw(CallbackTessellator tessellator) {
             if (!tessellator.isEmpty()) {
-                if (!isIdentity()) {
+                if (!isIdentity(SLOT_VERTEX) || !isIdentity(SLOT_TEXTURE) || !isIdentity(SLOT_COLOR)) {
                     final int baked = bakedOwner == tessellator ? bakedVertices : 0;
                     if (bakedVertices == 0) {
-                        flushMatrix();
+                        flushMatrix(SLOT_VERTEX);
+                        flushMatrix(SLOT_TEXTURE);
+                        flushMatrix(SLOT_COLOR);
                     } else if (baked != tessellator.vertexCount) {
                         GLStateManager.warnOnce("dl-mixed-baked-raw", "Display list {}: draw of {} vertices carries {} transformed ones - the rest lose the pending transform", glListId, tessellator.vertexCount, baked);
                     }
@@ -1442,22 +1653,22 @@ public class DisplayListManager {
 
         @Override
         protected Matrix4f getMVPMatrix() {
-            return matrixMode <= GL11.GL_PROJECTION ? transformMatrix : null;
+            return transformTypes[SLOT_VERTEX] != 0 ? transformMatrices[SLOT_VERTEX] : null;
         }
 
         @Override
         protected Matrix4f getTextureMatrix() {
-            return matrixMode == GL11.GL_TEXTURE ? transformMatrix : null;
+            return transformTypes[SLOT_TEXTURE] != 0 ? transformMatrices[SLOT_TEXTURE] : null;
         }
 
         @Override
         protected Matrix4f getColorMatrix() {
-            return matrixMode == GL11.GL_COLOR ? transformMatrix : null;
+            return transformTypes[SLOT_COLOR] != 0 ? transformMatrices[SLOT_COLOR] : null;
         }
 
         @Override
         protected Matrix3f getNormalMatrix() {
-            return matrixMode == GL11.GL_MODELVIEW ? normalMatrix : null; // GL_PROJECTION doesn't transform normals
+            return transformTypes[SLOT_VERTEX] != 0 && slotModes[SLOT_VERTEX] == GL11.GL_MODELVIEW ? normalMatrix : null;
         }
     }
 }

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

@@ -3,18 +3,13 @@ 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 com.gtnewhorizons.angelica.glsm.stacks.CowStateStack;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 import org.lwjgl.opengl.GL11;
 import org.lwjgl.opengl.GL13;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
 import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
 import java.util.Set;
 
 public class Feature {
@@ -23,52 +18,49 @@ public class Feature {
         GL13.GL_MULTISAMPLE_BIT, GL11.GL_PIXEL_MODE_BIT, GL11.GL_POINT_BIT, GL11.GL_POLYGON_BIT, GL11.GL_POLYGON_STIPPLE_BIT, GL11.GL_SCISSOR_BIT,
         GL11.GL_STENCIL_BUFFER_BIT, GL11.GL_TEXTURE_BIT, GL11.GL_TRANSFORM_BIT, GL11.GL_VIEWPORT_BIT };
 
-    static final Int2ObjectMap<List<IStateStack<?>>> maskToFeaturesMap = new Int2ObjectOpenHashMap<>();
-    static final Int2ObjectMap<IStateStack<?>[]> maskToNonBooleanStacksMap = new Int2ObjectOpenHashMap<>();
+    private static final long[] NO_MEMBERS = new long[0];
 
-    static List<IStateStack<?>> maskToFeatures(int mask) {
-        if(maskToFeaturesMap.containsKey(mask)) {
-            return maskToFeaturesMap.get(mask);
-        }
+    private static final Int2ObjectMap<long[]> maskToMembersMap = new Int2ObjectOpenHashMap<>();
 
-        final Set<IStateStack<?>> features = new HashSet<>();
-
-        for(int attrib : Feature.supportedAttribs) {
-            if((mask & attrib) == attrib) {
-                features.addAll(getFeatures(attrib));
-            }
-        }
-
-        final List<IStateStack<?>> asList = new ArrayList<>(features);
-
-        maskToFeaturesMap.put(mask, asList);
-        return asList;
-    }
-
-    /**
-     * Returns only non-BooleanStateStack instances for the given mask.
-     * These use traditional push/pop without global depth tracking.
-     */
-    static IStateStack<?>[] maskToNonBooleanStacks(int mask) {
-        IStateStack<?>[] cached = maskToNonBooleanStacksMap.get(mask);
+    static long[] maskToMembers(int mask) {
+        final long[] cached = maskToMembersMap.get(mask);
         if (cached != null) {
             return cached;
         }
 
-        final List<IStateStack<?>> all = maskToFeatures(mask);
-        final List<IStateStack<?>> nonBooleans = new ArrayList<>();
-        for (int i = 0; i < all.size(); i++) {
-            final IStateStack<?> stack = all.get(i);
-            if (!(stack instanceof BooleanStateStack)) {
-                nonBooleans.add(stack);
+        long[] result = NO_MEMBERS;
+        for (int attrib : Feature.supportedAttribs) {
+            if ((mask & attrib) == attrib) {
+                result = union(result, attribToMembers.get(attrib));
             }
         }
-        cached = nonBooleans.toArray(new IStateStack<?>[0]);
-        maskToNonBooleanStacksMap.put(mask, cached);
-        return cached;
+
+        maskToMembersMap.put(mask, result);
+        return result;
     }
 
-    private static final Map<Integer, Set<IStateStack<?>>> attribToFeatures = new HashMap<>();
+    private static long[] union(long[] a, long[] b) {
+        if (b == null || b.length == 0) return a;
+        if (a.length == 0) return b.clone();
+        final long[] result = new long[Math.max(a.length, b.length)];
+        System.arraycopy(a, 0, result, 0, a.length);
+        for (int i = 0; i < b.length; i++) result[i] |= b[i];
+        return result;
+    }
+
+    private static long[] toMembers(Set<IStateStack<?>> stacks) {
+        if (stacks.isEmpty()) return NO_MEMBERS;
+        int max = 0;
+        for (IStateStack<?> s : stacks) max = Math.max(max, ((CowStateStack<?>) s).stackId());
+        final long[] bits = new long[(max >> 6) + 1];
+        for (IStateStack<?> s : stacks) {
+            final int id = ((CowStateStack<?>) s).stackId();
+            bits[id >> 6] |= 1L << id;
+        }
+        return bits;
+    }
+
+    private static final Int2ObjectMap<long[]> attribToMembers = new Int2ObjectOpenHashMap<>();
 
     /**
      * Helper method to add all texture gen states (S, T, R, Q) for all texture units to a collection.
@@ -84,6 +76,8 @@ public class Feature {
     }
 
     static {
+        final Int2ObjectMap<Set<IStateStack<?>>> attribToFeatures = new Int2ObjectOpenHashMap<>();
+
         attribToFeatures.put(GL11.GL_COLOR_BUFFER_BIT, ImmutableSet.of(
               GLStateManager.getAlphaTest()
             , GLStateManager.getAlphaState()
@@ -191,11 +185,25 @@ public class Feature {
 
         attribToFeatures.put(GL11.GL_ENABLE_BIT, enableBits);
         attribToFeatures.put(GL11.GL_EVAL_BIT, ImmutableSet.of(
-            // GL_MAP1_x enable bits, where x is a map type
-            // GL_MAP2_x enable bits, where x is a map type
-            // 1D grid endpoints and divisions
-            // 2D grid endpoints and divisions
-            // GL_AUTO_NORMAL enable bit
+              GLStateManager.getAutoNormalState()
+            , GLStateManager.getMap1Color4State()
+            , GLStateManager.getMap1IndexState()
+            , GLStateManager.getMap1NormalState()
+            , GLStateManager.getMap1TextureCoord1State()
+            , GLStateManager.getMap1TextureCoord2State()
+            , GLStateManager.getMap1TextureCoord3State()
+            , GLStateManager.getMap1TextureCoord4State()
+            , GLStateManager.getMap1Vertex3State()
+            , GLStateManager.getMap1Vertex4State()
+            , GLStateManager.getMap2Color4State()
+            , GLStateManager.getMap2IndexState()
+            , GLStateManager.getMap2NormalState()
+            , GLStateManager.getMap2TextureCoord1State()
+            , GLStateManager.getMap2TextureCoord2State()
+            , GLStateManager.getMap2TextureCoord3State()
+            , GLStateManager.getMap2TextureCoord4State()
+            , GLStateManager.getMap2Vertex3State()
+            , GLStateManager.getMap2Vertex4State()
         ));
         attribToFeatures.put(GL11.GL_FOG_BIT, ImmutableSet.of(
               GLStateManager.getFogMode()
@@ -258,10 +266,10 @@ public class Feature {
             // GL_LIST_BASE setting
         ));
         attribToFeatures.put(GL13.GL_MULTISAMPLE_BIT, ImmutableSet.of(
-            // GL_MULTISAMPLE enable bit
-            // GL_SAMPLE_ALPHA_TO_COVERAGE flag
-            // GL_SAMPLE_ALPHA_TO_ONE flag
-            // GL_SAMPLE_COVERAGE flag
+              GLStateManager.getMultisampleState()
+            , GLStateManager.getSampleAlphaToCoverageState()
+            , GLStateManager.getSampleAlphaToOneState()
+            , GLStateManager.getSampleCoverageState()
             // GL_SAMPLE_COVERAGE_VALUE value
             // GL_SAMPLE_COVERAGE_INVERT value
         ));
@@ -294,7 +302,7 @@ public class Feature {
         ));
         attribToFeatures.put(GL11.GL_SCISSOR_BIT, ImmutableSet.of(
               GLStateManager.getScissorTest()
-            // Scissor box
+            , GLStateManager.getScissorState()
         ));
         attribToFeatures.put(GL11.GL_STENCIL_BUFFER_BIT, ImmutableSet.of(
               GLStateManager.getStencilTest()
@@ -327,22 +335,24 @@ public class Feature {
 
         attribToFeatures.put(GL11.GL_TEXTURE_BIT, textureAttribs);
 
-        attribToFeatures.put(GL11.GL_TRANSFORM_BIT, ImmutableSet.of(
+        final Set<IStateStack<?>> transformAttribs = new HashSet<>(ImmutableSet.of(
             // Coefficients of the six clipping planes
-            
+
               GLStateManager.getMatrixMode()
             , GLStateManager.getNormalizeState()
             , GLStateManager.getRescaleNormalState()
         ));
+        for(int i = 0; i < GLStateManager.getClipPlaneStates().length; i++) {
+            transformAttribs.add(GLStateManager.getClipPlaneStates()[i]);
+        }
+        attribToFeatures.put(GL11.GL_TRANSFORM_BIT, transformAttribs);
         attribToFeatures.put(GL11.GL_VIEWPORT_BIT, ImmutableSet.of(
-            
+
             GLStateManager.getViewportState()
         ));
+
+        for (Int2ObjectMap.Entry<Set<IStateStack<?>>> entry : attribToFeatures.int2ObjectEntrySet()) {
+            attribToMembers.put(entry.getIntKey(), toMembers(entry.getValue()));
+        }
     }
-
-    public static Set<IStateStack<?>> getFeatures(int attrib) {
-        return attribToFeatures.getOrDefault(attrib, Collections.emptySet());
-    }
-
-
 }

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

@@ -1,6 +1,5 @@
 package com.gtnewhorizons.angelica.glsm;
 
-import com.gtnewhorizons.angelica.glsm.ffp.VAOManager;
 import com.gtnewhorizons.angelica.glsm.recording.ImmediateModeRecorder;
 import com.gtnewhorizons.angelica.glsm.states.ViewportState;
 import org.joml.Matrix4f;
@@ -48,6 +47,10 @@ public class FeedbackManager {
         return renderMode == GL11.GL_FEEDBACK;
     }
 
+    public static int getRenderMode() {
+        return renderMode;
+    }
+
     public static void glFeedbackBuffer(int type, FloatBuffer buffer) {
         if (renderMode == GL11.GL_FEEDBACK) {
             GLStateManager.LOGGER.error("glFeedbackBuffer called while already in feedback mode");
@@ -126,30 +129,32 @@ public class FeedbackManager {
         feedbackVertex(winX, winY, winZ, winW);
     }
 
-    private static int positionStride() {
-        final int s = VAOManager.getAttribEffectiveStride(0);
+    private static int positionStride(GLContextState glCtx) {
+        final int s = glCtx.vaos.attribEffectiveStride(0);
         return (s != 0) ? s : 12;
     }
 
-    private static long positionOffset() {
-        return VAOManager.getAttribOffset(0);
+    private static long positionOffset(GLContextState glCtx) {
+        return glCtx.vaos.attribOffset(0);
     }
 
     public static void processDrawArrays(int mode, int first, int count) {
         computeMVP();
-        final int stride = positionStride();
-        final long posOffset = positionOffset();
+        final GLContextState glCtx = GLStateManager.ctx();
+        final int stride = positionStride(glCtx);
+        final long posOffset = positionOffset(glCtx);
         final int byteCount = count * stride;
         ensureReadbackCapacity(byteCount);
         readbackBuf.clear().limit(byteCount);
-        readPositionBuffer((long) first * stride + posOffset, readbackBuf);
+        readPositionBuffer((long) first * stride + posOffset, readbackBuf, glCtx);
 
         emitAllPrimitives(mode, count, i -> i, stride);
     }
 
     public static void processDrawElements(int mode, int indexCount, int type, long eboOffset) {
         computeMVP();
-        final int stride = positionStride();
+        final GLContextState glCtx = GLStateManager.ctx();
+        final int stride = positionStride(glCtx);
 
         final int elementSize = GLTypes.sizeBytes(type);
         final int indexByteCount = indexCount * elementSize;
@@ -165,12 +170,12 @@ public class FeedbackManager {
             if (idx > maxIdx) maxIdx = idx;
         }
 
-        final long posOffset = positionOffset();
+        final long posOffset = positionOffset(glCtx);
         final int vertexCount = maxIdx - minIdx + 1;
         final int byteCount = vertexCount * stride;
         ensureReadbackCapacity(byteCount);
         readbackBuf.clear().limit(byteCount);
-        readPositionBuffer((long) minIdx * stride + posOffset, readbackBuf);
+        readPositionBuffer((long) minIdx * stride + posOffset, readbackBuf, glCtx);
 
         final int base = minIdx;
         emitAllPrimitives(mode, indexCount, i -> ImmediateModeRecorder.readIndex(indexBuf, type, 0, i) - base, stride);
@@ -204,7 +209,8 @@ public class FeedbackManager {
 
     private static void processDrawElementsImpl(int mode, int count, IndexReader reader) {
         computeMVP();
-        final int stride = positionStride();
+        final GLContextState glCtx = GLStateManager.ctx();
+        final int stride = positionStride(glCtx);
 
         int minIdx = Integer.MAX_VALUE, maxIdx = Integer.MIN_VALUE;
         for (int i = 0; i < count; i++) {
@@ -213,7 +219,7 @@ public class FeedbackManager {
             if (idx > maxIdx) maxIdx = idx;
         }
 
-        readVerticesFromVBO(minIdx, maxIdx, stride);
+        readVerticesFromVBO(minIdx, maxIdx, stride, glCtx);
         final int base = minIdx;
         emitAllPrimitives(mode, count, i -> reader.read(i) - base, stride);
     }
@@ -245,18 +251,18 @@ public class FeedbackManager {
         }
     }
 
-    private static void readVerticesFromVBO(int minIdx, int maxIdx, int stride) {
-        final long posOffset = positionOffset();
+    private static void readVerticesFromVBO(int minIdx, int maxIdx, int stride, GLContextState glCtx) {
+        final long posOffset = positionOffset(glCtx);
         final int vertexCount = maxIdx - minIdx + 1;
         final int byteCount = vertexCount * stride;
         ensureReadbackCapacity(byteCount);
         readbackBuf.clear().limit(byteCount);
-        readPositionBuffer((long) minIdx * stride + posOffset, readbackBuf);
+        readPositionBuffer((long) minIdx * stride + posOffset, readbackBuf, glCtx);
     }
 
-    private static void readPositionBuffer(long offset, ByteBuffer destination) {
-        final int positionVbo = VAOManager.getAttribVBO(0);
-        final int previousVbo = GLStateManager.getBoundVBO();
+    private static void readPositionBuffer(long offset, ByteBuffer destination, GLContextState glCtx) {
+        final int positionVbo = glCtx.vaos.attribVBO(0);
+        final int previousVbo = glCtx.boundVBO;
 
         if (positionVbo != 0 && positionVbo != previousVbo) {
             GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, positionVbo);

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

@@ -3,13 +3,14 @@ package com.gtnewhorizons.angelica.glsm;
 import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import it.unimi.dsi.fastutil.ints.Int2IntMap;
 import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
-import it.unimi.dsi.fastutil.ints.IntOpenHashSet;
-import it.unimi.dsi.fastutil.ints.IntSet;
 import com.gtnewhorizons.angelica.glsm.stacks.AlphaStateStack;
 import com.gtnewhorizons.angelica.glsm.stacks.BlendStateStack;
 import com.gtnewhorizons.angelica.glsm.stacks.BooleanStateStack;
 import com.gtnewhorizons.angelica.glsm.stacks.Color4Stack;
 import com.gtnewhorizons.angelica.glsm.stacks.ColorMaskStack;
+import com.gtnewhorizons.angelica.glsm.stacks.CowDepths;
+import com.gtnewhorizons.angelica.glsm.stacks.CowDispatch;
+import com.gtnewhorizons.angelica.glsm.stacks.CowStateStack;
 import com.gtnewhorizons.angelica.glsm.stacks.DepthStateStack;
 import com.gtnewhorizons.angelica.glsm.stacks.FogStateStack;
 import com.gtnewhorizons.angelica.glsm.stacks.IntegerStateStack;
@@ -20,33 +21,53 @@ import com.gtnewhorizons.angelica.glsm.stacks.MaterialStateStack;
 import com.gtnewhorizons.angelica.glsm.stacks.MatrixModeStack;
 import com.gtnewhorizons.angelica.glsm.stacks.PointStateStack;
 import com.gtnewhorizons.angelica.glsm.stacks.PolygonStateStack;
+import com.gtnewhorizons.angelica.glsm.stacks.ScissorStateStack;
+import com.gtnewhorizons.angelica.glsm.stacks.StackIdAllocator;
 import com.gtnewhorizons.angelica.glsm.stacks.StencilStateStack;
 import com.gtnewhorizons.angelica.glsm.stacks.ViewPortStateStack;
+import com.gtnewhorizons.angelica.glsm.states.AlphaState;
 import com.gtnewhorizons.angelica.glsm.states.BlendState;
 import com.gtnewhorizons.angelica.glsm.states.ClipPlaneState;
 import com.gtnewhorizons.angelica.glsm.states.Color4;
 import com.gtnewhorizons.angelica.glsm.states.PixelUnpackState;
 import com.gtnewhorizons.angelica.glsm.states.ImageUnitArray;
+import com.gtnewhorizons.angelica.glsm.states.SamplerUnitArray;
 import com.gtnewhorizons.angelica.glsm.states.TextureUnitArray;
-import it.unimi.dsi.fastutil.ints.IntArrayList;
-import it.unimi.dsi.fastutil.ints.IntStack;
+import com.gtnewhorizons.angelica.glsm.ffp.Instancing;
+import com.gtnewhorizons.angelica.glsm.ffp.ShaderManager;
+import com.gtnewhorizons.angelica.glsm.ffp.VAOManager;
+import com.gtnewhorizons.angelica.glsm.streaming.StreamingVaos;
+import org.joml.Matrix4d;
+import org.joml.Matrix4f;
 import org.joml.Matrix4fStack;
+import org.joml.Vector4f;
 import org.lwjgl.BufferUtils;
 import org.lwjgl.opengl.GL11;
 import org.lwjgl.opengl.GL12;
 import org.lwjgl.opengl.GL13;
 import org.lwjgl.opengl.GL14;
+import org.lwjgl.opengl.GL30;
 
 import java.nio.DoubleBuffer;
 import java.nio.FloatBuffer;
+import java.nio.IntBuffer;
 import java.util.ArrayList;
 import java.util.List;
 
-class GLContextState {
+public class GLContextState {
+    private final List<IStateStack<?>> allStacksBuilder = new ArrayList<>();
+    public IStateStack<?>[] allStacks;
     final List<BooleanStateStack> allBooleanStates = new ArrayList<>();
 
     private BooleanStateStack track(BooleanStateStack s) {
+        s.setStackId(StackIdAllocator.nextId());
         allBooleanStates.add(s);
+        allStacksBuilder.add(s);
+        return s;
+    }
+
+    private <T extends IStateStack<?>> T member(T s) {
+        allStacksBuilder.add(s);
         return s;
     }
 
@@ -67,6 +88,7 @@ class GLContextState {
     public int colorGeneration;
     // clip plane equation changes
     public int clipPlaneGeneration;
+    public int clipPlaneEnabledMask;
     public float overlayR = 0.0f;
     public float overlayG = 0.0f;
     public float overlayB = 0.0f;
@@ -83,10 +105,17 @@ class GLContextState {
     public boolean unit23TexCoordSetDuringDraw = false;
     public int maxBoundTextureUnit = 0;
     public int maxBoundImageUnit = 0;
-    public final IntStack attribs = new IntArrayList(GLStateManager.MAX_ATTRIB_STACK_DEPTH);
+    public final StateSet[] attribSets = new StateSet[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
     public int attribDepth = 0;
-    @SuppressWarnings("unchecked")
-    public final List<IStateStack<?>>[] modifiedAtDepth = new List[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
+    public int batchStateGeneration;
+    public final int[] savedBatchStateGen = new int[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
+    public CowStateStack<?>[] stackById;
+    public CowDepths[] depthsById;
+    public int[] restoreBitById;
+    public int[] restoreUnitById;
+    public byte[] kindById;
+    public int[][] modifiedIds;
+    public int[] modifiedCount;
     public final int[] savedMvGen = new int[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
     public final int[] savedMvLinearGen = new int[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
     public final int[] savedProjGen = new int[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
@@ -96,28 +125,31 @@ class GLContextState {
     public final int[] savedColorGen = new int[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
     public final int[] savedNormalGen = new int[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
     public final int[] savedTexCoordGen = new int[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
-    public final IntegerStateStack activeTextureUnit = new IntegerStateStack(0);
+    public final IntegerStateStack activeTextureUnit = member(new IntegerStateStack(0, StackIdAllocator.nextId()).restoreBit(StateSet.R_ACTIVE_UNIT));
     public int clientActiveTextureUnit = 0;
-    public final IntegerStateStack shadeModelState = new IntegerStateStack(GL11.GL_SMOOTH);
+    public final IntegerStateStack shadeModelState = member(new IntegerStateStack(GL11.GL_SMOOTH, StackIdAllocator.nextId()));
     public final TextureUnitArray textures = new TextureUnitArray();
     public final ImageUnitArray imageUnits = new ImageUnitArray();
-    public final BlendStateStack blendState = new BlendStateStack();
+    public final SamplerUnitArray samplerUnits = new SamplerUnitArray();
+    public final BlendStateStack blendState = member(new BlendStateStack(StackIdAllocator.nextId()));
     public final BooleanStateStack blendMode = track(new BooleanStateStack(GL11.GL_BLEND));
     public final BooleanStateStack scissorTest = track(new BooleanStateStack(GL11.GL_SCISSOR_TEST));
-    public final DepthStateStack depthState = new DepthStateStack();
+    public final BooleanStateStack rasterizerDiscard = track(new BooleanStateStack(GL30.GL_RASTERIZER_DISCARD));
+    public final DepthStateStack depthState = member(new DepthStateStack(StackIdAllocator.nextId()));
     public final BooleanStateStack depthTest = track(new BooleanStateStack(GL11.GL_DEPTH_TEST));
-    public final FogStateStack fogState = new FogStateStack();
+    public final FogStateStack fogState = member(new FogStateStack(StackIdAllocator.nextId()));
     public final BooleanStateStack fogMode = track(new BooleanStateStack(GL11.GL_FOG, false, true));
-    public final Color4Stack color = new Color4Stack();
+    public final Color4Stack color = member(new Color4Stack(StackIdAllocator.nextId()));
     // GL_CURRENT_SECONDARY_COLOR - alpha is always 1 and unused, the color sum only adds RGB
-    public final Color4Stack secondaryColor = new Color4Stack(new Color4(0.0F, 0.0F, 0.0F, 1.0F));
+    public final Color4Stack secondaryColor = member(new Color4Stack(StackIdAllocator.nextId(), new Color4(0.0F, 0.0F, 0.0F, 1.0F)).restoreBit(StateSet.R_SECONDARY_COLOR));
     public final BooleanStateStack colorSumState = track(new BooleanStateStack(GL14.GL_COLOR_SUM, false, true));
-    public final Color4Stack clearColor = new Color4Stack(new Color4(0.0F, 0.0F, 0.0F, 0.0F));
-    public final ColorMaskStack colorMask = new ColorMaskStack();
-    public final IntegerStateStack drawBuffer = new IntegerStateStack(GLStateManager.DEFAULT_DRAW_BUFFER);
-    public final IntegerStateStack logicOpMode = new IntegerStateStack(GL11.GL_COPY);
+    public final Color4Stack clearColor = member(new Color4Stack(StackIdAllocator.nextId(), new Color4(0.0F, 0.0F, 0.0F, 0.0F)).restoreBit(StateSet.R_CLEAR_COLOR));
+    public final ColorMaskStack colorMask = member(new ColorMaskStack(StackIdAllocator.nextId()));
+    public final IntegerStateStack drawBuffer = member(new IntegerStateStack(GLStateManager.DEFAULT_DRAW_BUFFER, StackIdAllocator.nextId()).restoreBit(StateSet.R_DRAW_BUFFER));
+    public final IntegerStateStack logicOpMode = member(new IntegerStateStack(GL11.GL_COPY, StackIdAllocator.nextId()).restoreBit(StateSet.R_LOGIC_OP));
     public final BooleanStateStack cullState = track(new BooleanStateStack(GL11.GL_CULL_FACE));
-    public final AlphaStateStack alphaState = new AlphaStateStack();
+    public final AlphaState restoredAlphaScratch = new AlphaState();
+    public final AlphaStateStack alphaState = member(new AlphaStateStack(StackIdAllocator.nextId()));
     public final BooleanStateStack alphaTest = track(new BooleanStateStack(GL11.GL_ALPHA_TEST, false, true));
     public final BooleanStateStack lightingState = track(new BooleanStateStack(GL11.GL_LIGHTING, false, true));
     public final BooleanStateStack rescaleNormalState = track(new BooleanStateStack(GL12.GL_RESCALE_NORMAL, false, true));
@@ -138,10 +170,10 @@ class GLContextState {
     public final BooleanStateStack polygonOffsetPointState = track(new BooleanStateStack(GL11.GL_POLYGON_OFFSET_POINT));
     public final BooleanStateStack polygonOffsetLineState = track(new BooleanStateStack(GL11.GL_POLYGON_OFFSET_LINE));
     public final BooleanStateStack polygonOffsetFillState = track(new BooleanStateStack(GL11.GL_POLYGON_OFFSET_FILL));
-    public final LineStateStack lineState = new LineStateStack();
-    public final PointStateStack pointState = new PointStateStack();
-    public final PolygonStateStack polygonState = new PolygonStateStack();
-    public final StencilStateStack stencilState = new StencilStateStack();
+    public final LineStateStack lineState = member(new LineStateStack(StackIdAllocator.nextId()));
+    public final PointStateStack pointState = member(new PointStateStack(StackIdAllocator.nextId()));
+    public final PolygonStateStack polygonState = member(new PolygonStateStack(StackIdAllocator.nextId()));
+    public final StencilStateStack stencilState = member(new StencilStateStack(StackIdAllocator.nextId()));
     public int stencilBitMask = 0xFFFFFFFF;
     public final BooleanStateStack autoNormalState = track(new BooleanStateStack(GL11.GL_AUTO_NORMAL, false, true));
     public final BooleanStateStack map1Color4State = track(new BooleanStateStack(GL11.GL_MAP1_COLOR_4, false, true));
@@ -166,19 +198,21 @@ class GLContextState {
     public final ClipPlaneState clipPlaneState = new ClipPlaneState();
     public final FloatBuffer queryScratch = BufferUtils.createFloatBuffer(16);
     public final DoubleBuffer queryScratchDouble = BufferUtils.createDoubleBuffer(16);
-    public final MatrixModeStack matrixMode = new MatrixModeStack();
+    public final MatrixModeStack matrixMode = member(new MatrixModeStack(StackIdAllocator.nextId()));
     public final Matrix4fStack modelViewMatrix = new Matrix4fStack(GLStateManager.MAX_MODELVIEW_STACK_DEPTH);
     public final Matrix4fStack projectionMatrix = new Matrix4fStack(GLStateManager.MAX_PROJECTION_STACK_DEPTH);
     public final BooleanStateStack[] lightStates = new BooleanStateStack[8];
     public final LightStateStack[] lightDataStates = new LightStateStack[8];
     public final BooleanStateStack colorMaterial = track(new BooleanStateStack(GL11.GL_COLOR_MATERIAL, false, true));
-    public final IntegerStateStack colorMaterialFace = new IntegerStateStack(GL11.GL_FRONT_AND_BACK);
-    public final IntegerStateStack colorMaterialParameter = new IntegerStateStack(GL11.GL_AMBIENT_AND_DIFFUSE);
-    public final LightModelStateStack lightModel = new LightModelStateStack();
-    public final MaterialStateStack frontMaterial = new MaterialStateStack(GL11.GL_FRONT);
-    public final MaterialStateStack backMaterial = new MaterialStateStack(GL11.GL_BACK);
-    public final ViewPortStateStack viewportState = new ViewPortStateStack();
+    public final IntegerStateStack colorMaterialFace = member(new IntegerStateStack(GL11.GL_FRONT_AND_BACK, StackIdAllocator.nextId()));
+    public final IntegerStateStack colorMaterialParameter = member(new IntegerStateStack(GL11.GL_AMBIENT_AND_DIFFUSE, StackIdAllocator.nextId()));
+    public final LightModelStateStack lightModel = member(new LightModelStateStack(StackIdAllocator.nextId()));
+    public final MaterialStateStack frontMaterial = member(new MaterialStateStack(GL11.GL_FRONT, StackIdAllocator.nextId()));
+    public final MaterialStateStack backMaterial = member(new MaterialStateStack(GL11.GL_BACK, StackIdAllocator.nextId()));
+    public final ViewPortStateStack viewportState = member(new ViewPortStateStack(StackIdAllocator.nextId()));
+    public final ScissorStateStack scissorState = member(new ScissorStateStack(StackIdAllocator.nextId()));
     public int activeProgram = 0;
+    public final IntegerStateStack programStack = member(new IntegerStateStack(0, StackIdAllocator.nextId()));
     public int listBase = 0;
     public int boundVBO;
     public int boundVAO;
@@ -187,33 +221,83 @@ class GLContextState {
     public int boundCopyReadBuffer;
     public int boundCopyWriteBuffer;
     public final Int2IntMap boundOtherBuffers = new Int2IntOpenHashMap();
-    public final IntSet writeMappedBuffers = new IntOpenHashSet();
     public PixelUnpackState pixelUnpackState = PixelUnpackState.DEFAULT;
     public final int[] clientAttribSavedTextureUnit = new int[GLStateManager.CLIENT_ATTRIB_STACK_DEPTH];
     public final int[] clientAttribSavedVertexFlags = new int[GLStateManager.CLIENT_ATTRIB_STACK_DEPTH];
     public int clientAttribStackPointer = 0;
-    public final boolean[] restoreUnitChanged = new boolean[GLStateManager.MAX_TEXTURE_UNITS];
-    public boolean restoreDepthChanged, restoreBlendChanged, restoreColorMaskChanged, restoreClearColorChanged, restoreDrawBufferChanged, restoreLogicOpChanged, restoreStencilChanged, restoreViewportChanged, restoreLineChanged, restorePointChanged, restorePolygonChanged, restoreActiveUnitChanged, restoreSecondaryColorChanged;
+    public int restoreChangedMask;
+    public long restoreUnitChangedMask;
     public final BlendState vanillaBlendBefore = new BlendState();
     public final BlendState vanillaBlendAfter = new BlendState();
     public boolean vanillaBlendEnabledBefore;
     public int drawFramebuffer = 0;
     public int readFramebuffer = 0;
     public int texGenGeneration;
+    public int defaultVAO;
+    public final VAOManager vaos = new VAOManager();
+    public final StreamingVaos streamingVaos = new StreamingVaos();
+    public int fontVao;
+    public boolean lockBindCallback;
+    public int foreignDrawDepth;
+    public int internalGlDepth;
+    public int internalDrawDepth;
+    public int savedFilterTextureId;
+    public int savedFilterMin = -1;
+    public int savedFilterMag = -1;
+    public float savedFilterAniso = -1.0f;
+    public boolean wideLineEmulationActive = false;
+    public boolean lineStippleActive = false;
+    public Instancing ffpInstancing = Instancing.NONE;
+    public float lastBrightnessX;
+    public float lastBrightnessY;
+    public final Matrix4f multMatrix = new Matrix4f();
+    public final Matrix4d conversionMatrix4d = new Matrix4d();
+    public final Matrix4f conversionMatrix4f = new Matrix4f();
+    public final Matrix4f gluMatrix = new Matrix4f();
+    public final Matrix4f gluMatrix2 = new Matrix4f();
+    public final Vector4f gluVec4 = new Vector4f();
+    public final FloatBuffer gluBuffer = BufferUtils.createFloatBuffer(16);
+    public final float[] texGenTempPlane = new float[4];
+    public final IntBuffer shaderBuf = BufferUtils.createIntBuffer(8);
+    public final FloatBuffer projectionMatrixBuffer = BufferUtils.createFloatBuffer(16);
+    public final ShaderManager ffp = new ShaderManager();
 
     GLContextState() {
-        for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) modifiedAtDepth[i] = new ArrayList<>();
+        allStacksBuilder.addAll(textures.idStacks());
         for (int i = 0; i < lightStates.length; i++) {
             lightStates[i] = track(new BooleanStateStack(GL11.GL_LIGHT0 + i, false, true));
         }
         for (int i = 0; i < GLStateManager.MAX_CLIP_PLANES; i++) {
-            clipPlaneStates[i] = track(new BooleanStateStack(GL11.GL_CLIP_PLANE0 + i));
+            clipPlaneStates[i] = track(new ClipPlaneBooleanState(this, i, GL11.GL_CLIP_PLANE0 + i));
         }
     }
 
     void init() {
         for (int i = 0; i < lightDataStates.length; i++) {
-            lightDataStates[i] = new LightStateStack(GL11.GL_LIGHT0 + i);
+            lightDataStates[i] = member(new LightStateStack(GL11.GL_LIGHT0 + i, StackIdAllocator.nextId()));
         }
+        allStacksBuilder.add(ffp.normalStack);
+        allStacksBuilder.add(ffp.texCoordStack);
+        allStacks = allStacksBuilder.toArray(new IStateStack<?>[0]);
+
+        final int capacity = StackIdAllocator.allocated();
+        stackById = new CowStateStack<?>[capacity];
+        depthsById = new CowDepths[capacity];
+        restoreBitById = new int[capacity];
+        restoreUnitById = new int[capacity];
+        kindById = new byte[capacity];
+        for (final IStateStack<?> stack : allStacks) {
+            final CowStateStack<?> s = (CowStateStack<?>) stack;
+            final int id = s.stackId();
+            stackById[id] = s;
+            depthsById[id] = s.cowDepths();
+            depthsById[id].owner = this;
+            restoreBitById[id] = s.restoreBit();
+            restoreUnitById[id] = s.restoreUnit();
+            kindById[id] = CowDispatch.kindOf(s);
+        }
+
+        modifiedIds = new int[GLStateManager.MAX_ATTRIB_STACK_DEPTH][allStacks.length];
+        modifiedCount = new int[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
     }
 }

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

@@ -19,6 +19,7 @@ import org.lwjgl.opengl.GL43;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
+import java.util.Arrays;
 
 public final class GLDebug {
 
@@ -586,6 +587,13 @@ public final class GLDebug {
         }
     }
 
+    public static void resetGroupStack() {
+        if (debugState instanceof KHRDebugState khr) {
+            khr.depth = 0;
+            Arrays.fill(khr.groupStack, null);
+        }
+    }
+
     public static void debugMessage(String message) {
         if (debugState != null && Thread.currentThread() == GLStateManager.getMainThread()) {
             debugState.debugMessage(message);

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

@@ -0,0 +1,12 @@
+package com.gtnewhorizons.angelica.glsm;
+
+import org.lwjgl.opengl.OpenGLException;
+
+final class GLErrorReporter {
+
+    private GLErrorReporter() {}
+
+    static void reportError(int error) {
+        throw new OpenGLException(error);
+    }
+}

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

@@ -0,0 +1,26 @@
+package com.gtnewhorizons.angelica.glsm;
+
+import com.gtnewhorizons.angelica.glsm.ffp.VertexKey;
+import com.gtnewhorizons.angelica.glsm.states.LightModelState;
+import com.gtnewhorizons.angelica.glsm.states.LightState;
+import com.gtnewhorizons.angelica.glsm.states.MaterialState;
+import org.lwjgl.opengl.GL11;
+
+public final class LightingSnapshot {
+    final boolean[] lightEnabled = new boolean[VertexKey.FFP_LIGHT_COUNT];
+    final LightState[] lights = new LightState[VertexKey.FFP_LIGHT_COUNT];
+    final LightModelState lightModel = new LightModelState();
+    final MaterialState frontMaterial = new MaterialState(GL11.GL_FRONT);
+    final MaterialState backMaterial = new MaterialState(GL11.GL_BACK);
+    boolean colorMaterial;
+    int colorMaterialFace;
+    int colorMaterialParameter;
+    boolean normalize;
+    boolean rescaleNormal;
+
+    public LightingSnapshot() {
+        for (int i = 0; i < lights.length; i++) {
+            lights[i] = new LightState(GL11.GL_LIGHT0 + i);
+        }
+    }
+}

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

@@ -82,17 +82,17 @@ public final class QuadConverter {
      * @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) {
-        drawSharedQuadEbo(first, vertexCount, 1, false);
+    public static void drawQuadsAsTriangles(GLContextState glCtx, int first, int vertexCount) {
+        drawSharedQuadEbo(glCtx, first, vertexCount, 1, false);
     }
 
-    public static void drawQuadsAsTrianglesInstanced(int first, int vertexCount, int primcount) {
-        drawSharedQuadEbo(first, vertexCount, primcount, true);
+    public static void drawQuadsAsTrianglesInstanced(GLContextState glCtx, int first, int vertexCount, int primcount) {
+        drawSharedQuadEbo(glCtx, first, vertexCount, primcount, true);
     }
 
     private static int misalignedDraws;
 
-    private static void drawSharedQuadEbo(int first, int vertexCount, int primcount, boolean instanced) {
+    private static void drawSharedQuadEbo(GLContextState glCtx, int first, int vertexCount, int primcount, boolean instanced) {
         final int quadCount = vertexCount / 4;
         if ((first & 3) != 0) {
             misalignedDraws++;
@@ -111,26 +111,21 @@ public final class QuadConverter {
                 memPutInt(ptr + 20, base + 3);
                 ptr += 24;
             }
-            uploadAndDraw(dst, quadCount * 6, GL11.GL_UNSIGNED_INT, 4, primcount, instanced);
+            uploadAndDraw(glCtx, dst, quadCount * 6, GL11.GL_UNSIGNED_INT, 4, primcount, instanced);
             return;
         }
-        final boolean locked = GLStateManager.acquireDrawLock();
-        try {
-            GLStateManager.preDraw();
-            final int prevEbo = GLStateManager.getBoundEBO();
-            ensureCapacity(first / 4 + quadCount);
-            RENDER_BACKEND.bindBuffer(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;
-            if (instanced) {
-                RENDER_BACKEND.drawElementsInstanced(GL11.GL_TRIANGLES, quadCount * 6, INDEX_TYPE, indexOffset, primcount);
-            } else {
-                RENDER_BACKEND.drawElements(GL11.GL_TRIANGLES, quadCount * 6, INDEX_TYPE, indexOffset);
-            }
-            RENDER_BACKEND.bindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, prevEbo);
-        } finally {
-            if (locked) GLStateManager.releaseDrawLock();
+        GLStateManager.preDraw(glCtx, GL11.GL_TRIANGLES);
+        final int prevEbo = glCtx.vaos.boundEBO;
+        ensureCapacity(first / 4 + quadCount);
+        RENDER_BACKEND.bindBuffer(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;
+        if (instanced) {
+            RENDER_BACKEND.drawElementsInstanced(GL11.GL_TRIANGLES, quadCount * 6, INDEX_TYPE, indexOffset, primcount);
+        } else {
+            RENDER_BACKEND.drawElements(GL11.GL_TRIANGLES, quadCount * 6, INDEX_TYPE, indexOffset);
         }
+        RENDER_BACKEND.bindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, prevEbo);
     }
 
     /**
@@ -143,42 +138,37 @@ public final class QuadConverter {
      * @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) {
-        uploadAndDraw(dst, triIndexCount, indexType, bytesPerIndex, 1, false);
+    private static void uploadAndDraw(GLContextState glCtx, ByteBuffer dst, int triIndexCount, int indexType, int bytesPerIndex) {
+        uploadAndDraw(glCtx, dst, triIndexCount, indexType, bytesPerIndex, 1, false);
     }
 
-    private static void uploadAndDraw(ByteBuffer dst, int triIndexCount, int indexType, int bytesPerIndex, int primcount, boolean instanced) {
-        final boolean locked = GLStateManager.acquireDrawLock();
-        try {
-            GLStateManager.preDraw();
-            final int needed = triIndexCount * bytesPerIndex;
-            final int prevEbo = GLStateManager.getBoundEBO();
+    private static void uploadAndDraw(GLContextState glCtx, ByteBuffer dst, int triIndexCount, int indexType, int bytesPerIndex, int primcount, boolean instanced) {
+        GLStateManager.preDraw(glCtx, GL11.GL_TRIANGLES);
+        final int needed = triIndexCount * bytesPerIndex;
+        final int prevEbo = glCtx.vaos.boundEBO;
 
-            if (scratchEboId == 0) {
-                scratchEboId = RENDER_BACKEND.genBuffers();
-            }
-
-            RENDER_BACKEND.bindBuffer(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;
-                RENDER_BACKEND.bufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, newCap, GL15.GL_STREAM_DRAW);
-                scratchEboCapacity = newCap;
-            }
-            RENDER_BACKEND.bufferSubData(GL15.GL_ELEMENT_ARRAY_BUFFER, 0, dst);
-
-            if (instanced) {
-                RENDER_BACKEND.drawElementsInstanced(GL11.GL_TRIANGLES, triIndexCount, indexType, 0L, primcount);
-            } else {
-                RENDER_BACKEND.drawElements(GL11.GL_TRIANGLES, triIndexCount, indexType, 0L);
-            }
-
-            RENDER_BACKEND.bindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, prevEbo);
-        } finally {
-            if (locked) GLStateManager.releaseDrawLock();
+        if (scratchEboId == 0) {
+            scratchEboId = RENDER_BACKEND.genBuffers();
         }
+
+        RENDER_BACKEND.bindBuffer(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;
+            RENDER_BACKEND.bufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, newCap, GL15.GL_STREAM_DRAW);
+            scratchEboCapacity = newCap;
+        }
+        RENDER_BACKEND.bufferSubData(GL15.GL_ELEMENT_ARRAY_BUFFER, 0, dst);
+
+        if (instanced) {
+            RENDER_BACKEND.drawElementsInstanced(GL11.GL_TRIANGLES, triIndexCount, indexType, 0L, primcount);
+        } else {
+            RENDER_BACKEND.drawElements(GL11.GL_TRIANGLES, triIndexCount, indexType, 0L);
+        }
+
+        RENDER_BACKEND.bindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, prevEbo);
         memFree(dst);
     }
 
@@ -190,15 +180,15 @@ public final class QuadConverter {
      * @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) {
-        drawQuadElementsFromEbo(indexCount, type, offset, 1, false);
+    public static void drawQuadElementsAsTriangles(GLContextState glCtx, int indexCount, int type, long offset) {
+        drawQuadElementsFromEbo(glCtx, indexCount, type, offset, 1, false);
     }
 
-    public static void drawQuadElementsAsTrianglesInstanced(int indexCount, int type, long offset, int primcount) {
-        drawQuadElementsFromEbo(indexCount, type, offset, primcount, true);
+    public static void drawQuadElementsAsTrianglesInstanced(GLContextState glCtx, int indexCount, int type, long offset, int primcount) {
+        drawQuadElementsFromEbo(glCtx, indexCount, type, offset, primcount, true);
     }
 
-    private static void drawQuadElementsFromEbo(int indexCount, int type, long offset, int primcount, boolean instanced) {
+    private static void drawQuadElementsFromEbo(GLContextState glCtx, int indexCount, int type, long offset, int primcount, boolean instanced) {
         if (indexCount == 0) return;
         assert indexCount % 4 == 0 : "QuadConverter: indexCount must be multiple of 4";
         final int quadCount = indexCount / 4;
@@ -213,13 +203,13 @@ public final class QuadConverter {
         triangulateQuads(memAddress0(src), type, memAddress0(dst), GL11.GL_UNSIGNED_INT, quadCount);
 
         memFree(src);
-        uploadAndDraw(dst, triIndexCount, GL11.GL_UNSIGNED_INT, 4, primcount, instanced);
+        uploadAndDraw(glCtx, dst, triIndexCount, GL11.GL_UNSIGNED_INT, 4, primcount, instanced);
     }
 
     /**
      * Convert a client-side IntBuffer of quad indices to triangles.
      */
-    public static void drawQuadElementsAsTriangles(IntBuffer indices) {
+    public static void drawQuadElementsAsTriangles(GLContextState glCtx, IntBuffer indices) {
         final int indexCount = indices.remaining();
         if (indexCount == 0) return;
         assert indexCount % 4 == 0;
@@ -230,13 +220,13 @@ public final class QuadConverter {
         final long srcAddr = memAddress0(indices) + (long) indices.position() * 4;
         triangulateQuads(srcAddr, GL11.GL_UNSIGNED_INT, memAddress0(dst), GL11.GL_UNSIGNED_INT, quadCount);
 
-        uploadAndDraw(dst, triIndexCount, GL11.GL_UNSIGNED_INT, 4);
+        uploadAndDraw(glCtx, dst, triIndexCount, GL11.GL_UNSIGNED_INT, 4);
     }
 
     /**
      * Convert a client-side ShortBuffer of quad indices to triangles.
      */
-    public static void drawQuadElementsAsTriangles(ShortBuffer indices) {
+    public static void drawQuadElementsAsTriangles(GLContextState glCtx, ShortBuffer indices) {
         final int indexCount = indices.remaining();
         if (indexCount == 0) return;
         assert indexCount % 4 == 0;
@@ -247,13 +237,13 @@ public final class QuadConverter {
         final long srcAddr = memAddress0(indices) + (long) indices.position() * 2;
         triangulateQuads(srcAddr, GL11.GL_UNSIGNED_SHORT, memAddress0(dst), GL11.GL_UNSIGNED_SHORT, quadCount);
 
-        uploadAndDraw(dst, triIndexCount, GL11.GL_UNSIGNED_SHORT, 2);
+        uploadAndDraw(glCtx, 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) {
+    public static void drawQuadElementsAsTriangles(GLContextState glCtx, int count, int type, ByteBuffer indices) {
         if (count == 0) return;
         assert count % 4 == 0;
         final int quadCount = count / 4;
@@ -263,23 +253,7 @@ public final class QuadConverter {
         final ByteBuffer dst = memAlloc(triIndexCount * 4);
         triangulateQuads(srcAddr, type, memAddress0(dst), GL11.GL_UNSIGNED_INT, quadCount);
 
-        uploadAndDraw(dst, triIndexCount, GL11.GL_UNSIGNED_INT, 4);
-    }
-
-    /**
-     * Clean up the shared EBO.
-     */
-    public static void destroy() {
-        if (eboId != 0) {
-            GLStateManager.glDeleteBuffers(eboId);
-            eboId = 0;
-            maxQuads = 0;
-        }
-        if (scratchEboId != 0) {
-            GLStateManager.glDeleteBuffers(scratchEboId);
-            scratchEboId = 0;
-            scratchEboCapacity = 0;
-        }
+        uploadAndDraw(glCtx, dst, triIndexCount, GL11.GL_UNSIGNED_INT, 4);
     }
 
     /**

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

@@ -49,6 +49,7 @@ public class RenderSystem {
     private static boolean supportsTesselation;
     private static boolean supportsSamplerObjects;
     private static int maxImageUnits;
+    @Getter private static int maxCombinedTextureImageUnits;
     private static int maxSSBOBindings;
     private static int maxGlslVersion;
     private static boolean supportsGpuShader4;
@@ -64,9 +65,6 @@ public class RenderSystem {
     private static volatile boolean isLTW;
     private static volatile boolean ltwDetected;
 
-    // Sampler object state tracking (null if unsupported)
-    private static int[] samplers;
-
     private static final Pattern SEMVER_PATTERN = Pattern.compile("(?<major>\\d+)\\.(?<minor>\\d+)\\.*(?<bugfix>\\d*)(.*)");
 
     private RenderSystem() {}
@@ -158,7 +156,7 @@ public class RenderSystem {
         // Check for sampler objects support (GL 3.3+ or ARB extension)
         supportsSamplerObjects = GLStateManager.capabilities.OpenGL33 || GLStateManager.capabilities.GL_ARB_sampler_objects;
         if (supportsSamplerObjects) {
-            samplers = new int[RENDER_BACKEND.getInteger(GL20.GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS)];
+            maxCombinedTextureImageUnits = RENDER_BACKEND.getInteger(GL20.GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS);
         }
 
         maxGlslVersion = Integer.parseInt(parseGlVersionString(RENDER_BACKEND.getString(GL20.GL_SHADING_LANGUAGE_VERSION)));
@@ -171,13 +169,13 @@ public class RenderSystem {
 
         if (isGLES) {
             GLStateManager.LOGGER.info("GL ES context detected, enabling shader transformer.");
-            ShaderManager.getInstance().enable();
+            ShaderManager.enable();
         } else if (GLStateManager.capabilities.OpenGL32) {
             final int profileMask = RENDER_BACKEND.getInteger(GL32.GL_CONTEXT_PROFILE_MASK);
             if ((profileMask & GL32.GL_CONTEXT_CORE_PROFILE_BIT) != 0) {
                 coreProfile = true;
                 GLStateManager.LOGGER.info("GL 3.3 core profile detected, enabling FFP shader emulation.");
-                ShaderManager.getInstance().enable();
+                ShaderManager.enable();
             } else {
                 throw new IllegalStateException("Non-core GL context (profile mask 0x" + Integer.toHexString(profileMask)
                     + "); FFP emulation requires a core profile and nothing would render. Context creation should have rejected this.");
@@ -486,34 +484,33 @@ public class RenderSystem {
     }
 
     public static void disableBufferBlend(int buffer) {
-        RENDER_BACKEND.disablei(GL11.GL_BLEND, buffer);
-        GLStateManager.getBlendMode().setUnknownState();
+        GLStateManager.glDisablei(GL11.GL_BLEND, buffer);
     }
 
     public static void enableBufferBlend(int buffer) {
-        RENDER_BACKEND.enablei(GL11.GL_BLEND, buffer);
-        GLStateManager.getBlendMode().setUnknownState();
+        GLStateManager.glEnablei(GL11.GL_BLEND, buffer);
     }
 
     public static void blendFuncSeparatei(int buffer, int srcRGB, int dstRGB, int srcAlpha, int dstAlpha) {
-        RENDER_BACKEND.blendFuncSeparatei(buffer, srcRGB, dstRGB, srcAlpha, dstAlpha);
+        GLStateManager.glBlendFuncSeparatei(buffer, srcRGB, dstRGB, srcAlpha, dstAlpha);
     }
 
     public static void bindTextureToUnit(int unit, int texture) {
+        if (unit != 0 && GLStateManager.getBoundTextureForServerState(unit) != texture) GLStateManager.beforeUncapturedStateChange();
         dsaState.bindTextureToUnit(unit, texture);
     }
 
     public static void bindTextureToUnit(int target, int unit, int texture) {
+        if (unit != 0 && GLStateManager.getBoundTextureForServerState(unit) != texture) GLStateManager.beforeUncapturedStateChange();
         dsaState.bindTextureToUnit(target, unit, texture);
     }
 
-    public static final FloatBuffer PROJECTION_MATRIX_BUFFER = BufferUtils.createFloatBuffer(16);
-
     public static void setupProjectionMatrix(Matrix4f matrix) {
+        final FloatBuffer projectionMatrixBuffer = GLStateManager.ctx().projectionMatrixBuffer;
         GLStateManager.glMatrixMode(GL11.GL_PROJECTION);
         GLStateManager.glPushMatrix();
-        matrix.get(0, PROJECTION_MATRIX_BUFFER);
-        GLStateManager.glLoadMatrix(PROJECTION_MATRIX_BUFFER);
+        matrix.get(0, projectionMatrixBuffer);
+        GLStateManager.glLoadMatrix(projectionMatrixBuffer);
         GLStateManager.glMatrixMode(GL11.GL_MODELVIEW);
     }
 
@@ -628,7 +625,7 @@ public class RenderSystem {
 
     public static int genSampler() {
         if (!supportsSamplerObjects) return 0;
-        return RENDER_BACKEND.genSamplers();
+        return GLStateManager.glGenSamplers();
     }
 
     public static void destroySampler(int sampler) {
@@ -638,22 +635,25 @@ public class RenderSystem {
 
     public static void samplerParameteri(int sampler, int pname, int param) {
         if (!supportsSamplerObjects || sampler == 0) return;
-        RENDER_BACKEND.samplerParameteri(sampler, pname, param);
+        GLStateManager.glSamplerParameteri(sampler, pname, param);
+    }
+
+    public static void samplerParameterf(int sampler, int pname, float param) {
+        if (!supportsSamplerObjects || sampler == 0) return;
+        GLStateManager.glSamplerParameterf(sampler, pname, param);
     }
 
     public static void bindSamplerToUnit(int unit, int sampler) {
         if (!supportsSamplerObjects) return;
-        if (samplers[unit] == sampler) return;
-        RENDER_BACKEND.bindSampler(unit, sampler);
-        samplers[unit] = sampler;
+        GLStateManager.glBindSampler(unit, sampler);
     }
 
     public static void unbindAllSamplers() {
         if (!supportsSamplerObjects) return;
-        for (int i = 0; i < samplers.length; i++) {
-            if (samplers[i] != 0) {
-                RENDER_BACKEND.bindSampler(i, 0);
-                samplers[i] = 0;
+        final int count = GLStateManager.getSamplerUnitCount();
+        for (int i = 0; i < count; i++) {
+            if (GLStateManager.getSamplerBinding(i) != 0) {
+                GLStateManager.glBindSampler(i, 0);
             }
         }
     }

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

@@ -0,0 +1,244 @@
+package com.gtnewhorizons.angelica.glsm;
+
+import com.gtnewhorizons.angelica.glsm.recording.commands.DisplayListCommand;
+import com.gtnewhorizons.angelica.glsm.stacks.CowStateStack;
+import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
+import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+import org.lwjgl.opengl.GL11;
+
+public final class StateSet {
+
+    public static final int R_DEPTH = 1;
+    public static final int R_BLEND = 1 << 1;
+    public static final int R_COLOR_MASK = 1 << 2;
+    public static final int R_CLEAR_COLOR = 1 << 3;
+    public static final int R_DRAW_BUFFER = 1 << 4;
+    public static final int R_LOGIC_OP = 1 << 5;
+    public static final int R_SECONDARY_COLOR = 1 << 6;
+    public static final int R_STENCIL = 1 << 7;
+    public static final int R_VIEWPORT = 1 << 8;
+    public static final int R_LINE = 1 << 9;
+    public static final int R_POINT = 1 << 10;
+    public static final int R_POLYGON = 1 << 11;
+    public static final int R_TEXTURE = 1 << 12;
+    public static final int R_ACTIVE_UNIT = 1 << 13;
+    public static final int R_PROGRAM = 1 << 14;
+    public static final int R_SCISSOR = 1 << 15;
+
+    public static final int B_FRAG_COLORBUF = 1;
+    public static final int B_FRAG_TEXTURE = 1 << 1;
+    public static final int B_FRAG_FOG = 1 << 2;
+    public static final int B_CURRENT = 1 << 3;
+    public static final int B_LIGHTING = 1 << 4;
+    public static final int B_TRANSFORM = 1 << 5;
+
+    private static final long[] NO_MEMBERS = new long[0];
+    private static final Int2ObjectMap<StateSet> maskToStateSetMap = new Int2ObjectOpenHashMap<>();
+
+    public final int glMask;
+    public final long[] members;
+    public final int restore;
+    public final int bump;
+    public final boolean blendSnapshot;
+    public final DisplayListCommand pushCommand;
+
+    StateSet(int glMask, long[] members, int restore, int bump, boolean blendSnapshot) {
+        this.glMask = glMask;
+        this.members = members;
+        this.restore = restore;
+        this.bump = bump;
+        this.blendSnapshot = blendSnapshot;
+        this.pushCommand = () -> GLStateManager.pushStateLive(this);
+    }
+
+    public boolean contains(int id) {
+        if (id < 0) return false;
+        final int word = id >> 6;
+        return word < members.length && (members[word] & (1L << id)) != 0;
+    }
+
+    private static long[] ids(CowStateStack<?>... stacks) {
+        if (stacks.length == 0) return NO_MEMBERS;
+        int max = 0;
+        for (CowStateStack<?> s : stacks) max = Math.max(max, s.stackId());
+        final long[] bits = new long[(max >> 6) + 1];
+        for (CowStateStack<?> s : stacks) {
+            final int id = s.stackId();
+            bits[id >> 6] |= 1L << id;
+        }
+        return bits;
+    }
+
+    public static final StateSet BATCH = buildBatch();
+    public static final StateSet FONT = buildFont();
+    public static final StateSet FONT_PIPELINE = buildFontPipeline();
+    public static final StateSet HAND = buildHand();
+    public static final StateSet BLEND = buildBlend();
+    public static final StateSet ALPHA = buildAlpha();
+    public static final StateSet CUTOUT = buildCutout();
+    public static final StateSet MASKS = buildMasks();
+    public static final StateSet CULL = buildCull();
+
+    private static StateSet buildBatch() {
+        return new StateSet(0,
+            ids(
+                GLStateManager.getBlendState(), GLStateManager.getAlphaState(), GLStateManager.getDepthState(),
+                GLStateManager.getColorMask(), GLStateManager.getPolygonState(),
+                GLStateManager.getTextures().getTextureUnitBindings(0), GLStateManager.getTextures().getTextureUnitBindings(1),
+                GLStateManager.getActiveTextureUnitStack(),
+                GLStateManager.getBlendMode(), GLStateManager.getAlphaTest(), GLStateManager.getDepthTest(),
+                GLStateManager.getLightingState(), GLStateManager.getCullState(), GLStateManager.getPolygonOffsetFillState(),
+                GLStateManager.getTextures().getTextureUnitStates(0), GLStateManager.getTextures().getTextureUnitStates(1),
+                GLStateManager.getLightStates()[0], GLStateManager.getLightStates()[1],
+                GLStateManager.getLightDataStates()[0], GLStateManager.getLightDataStates()[1],
+                GLStateManager.getColorMaterial(), GLStateManager.getColorMaterialFace(), GLStateManager.getColorMaterialParameter(),
+                GLStateManager.getLightModel(), GLStateManager.getFrontMaterial(), GLStateManager.getBackMaterial(),
+                GLStateManager.getNormalizeState(), GLStateManager.getRescaleNormalState()
+            ),
+            R_BLEND | R_DEPTH | R_COLOR_MASK | R_POLYGON | R_TEXTURE | R_ACTIVE_UNIT,
+            B_FRAG_COLORBUF | B_LIGHTING,
+            true);
+    }
+
+    private static StateSet buildFont() {
+        return new StateSet(0,
+            ids(
+                GLStateManager.getBlendState(), GLStateManager.getDepthState(), GLStateManager.getShadeModelState(),
+                GLStateManager.getTextures().getTextureUnitBindings(0), GLStateManager.getTextures().getTextureUnitBindings(1),
+                GLStateManager.getActiveTextureUnitStack(), GLStateManager.getProgramStack(),
+                GLStateManager.getBlendMode(), GLStateManager.getAlphaTest(), GLStateManager.getDepthTest(),
+                GLStateManager.getTextures().getTextureUnitStates(0)
+            ),
+            R_BLEND | R_DEPTH | R_TEXTURE | R_ACTIVE_UNIT | R_PROGRAM,
+            0,
+            true);
+    }
+
+    private static StateSet buildFontPipeline() {
+        return new StateSet(0,
+            ids(
+                GLStateManager.getBlendState(), GLStateManager.getDepthState(),
+                GLStateManager.getTextures().getTextureUnitBindings(0), GLStateManager.getTextures().getTextureUnitBindings(1),
+                GLStateManager.getActiveTextureUnitStack(),
+                GLStateManager.getBlendMode(), GLStateManager.getAlphaTest(), GLStateManager.getDepthTest(),
+                GLStateManager.getTextures().getTextureUnitStates(0)
+            ),
+            R_BLEND | R_DEPTH | R_TEXTURE | R_ACTIVE_UNIT,
+            0,
+            true);
+    }
+
+    private static StateSet buildHand() {
+        return new StateSet(0,
+            ids(
+                GLStateManager.getBlendState(), GLStateManager.getAlphaState(), GLStateManager.getDepthState(),
+                GLStateManager.getBlendMode(), GLStateManager.getAlphaTest(), GLStateManager.getTextures().getTextureUnitStates(1)
+            ),
+            R_BLEND | R_DEPTH,
+            B_FRAG_COLORBUF,
+            true);
+    }
+
+    private static StateSet buildBlend() {
+        return new StateSet(0,
+            ids(GLStateManager.getBlendState(), GLStateManager.getBlendMode()),
+            R_BLEND,
+            0,
+            true);
+    }
+
+    private static StateSet buildAlpha() {
+        return new StateSet(0,
+            ids(GLStateManager.getAlphaState(), GLStateManager.getAlphaTest()),
+            0,
+            B_FRAG_COLORBUF,
+            false);
+    }
+
+    private static StateSet buildCutout() {
+        return new StateSet(0,
+            ids(GLStateManager.getAlphaState(), GLStateManager.getAlphaTest(), GLStateManager.getTextures().getTextureUnitStates(1)),
+            0,
+            B_FRAG_COLORBUF,
+            false);
+    }
+
+    private static StateSet buildMasks() {
+        return new StateSet(0,
+            ids(GLStateManager.getDepthState(), GLStateManager.getColorMask()),
+            R_DEPTH | R_COLOR_MASK,
+            0,
+            false);
+    }
+
+    private static StateSet buildCull() {
+        return new StateSet(0,
+            ids(GLStateManager.getPolygonState(), GLStateManager.getCullState()),
+            R_POLYGON,
+            0,
+            false);
+    }
+
+    public static StateSet forMask(int mask) {
+        StateSet cached = maskToStateSetMap.get(mask);
+        if (cached != null) {
+            return cached;
+        }
+        cached = buildForMask(mask);
+        maskToStateSetMap.put(mask, cached);
+        return cached;
+    }
+
+    private static StateSet buildForMask(int mask) {
+        int restore = 0;
+        int bump = 0;
+        final boolean blendSnapshot = (mask & (GL11.GL_COLOR_BUFFER_BIT | GL11.GL_ENABLE_BIT)) != 0;
+
+        if ((mask & GL11.GL_DEPTH_BUFFER_BIT) != 0) {
+            restore |= R_DEPTH;
+        }
+        if ((mask & GL11.GL_COLOR_BUFFER_BIT) != 0) {
+            restore |= R_BLEND | R_COLOR_MASK | R_CLEAR_COLOR | R_DRAW_BUFFER | R_LOGIC_OP;
+            bump |= B_FRAG_COLORBUF;
+        }
+        if ((mask & GL11.GL_CURRENT_BIT) != 0) {
+            restore |= R_SECONDARY_COLOR;
+            bump |= B_CURRENT;
+        }
+        if ((mask & GL11.GL_STENCIL_BUFFER_BIT) != 0) {
+            restore |= R_STENCIL;
+        }
+        if ((mask & GL11.GL_VIEWPORT_BIT) != 0) {
+            restore |= R_VIEWPORT;
+        }
+        if ((mask & GL11.GL_SCISSOR_BIT) != 0) {
+            restore |= R_SCISSOR;
+        }
+        if ((mask & GL11.GL_LINE_BIT) != 0) {
+            restore |= R_LINE;
+        }
+        if ((mask & GL11.GL_POINT_BIT) != 0) {
+            restore |= R_POINT;
+        }
+        if ((mask & GL11.GL_POLYGON_BIT) != 0) {
+            restore |= R_POLYGON;
+        }
+        if ((mask & GL11.GL_TEXTURE_BIT) != 0) {
+            restore |= R_TEXTURE | R_ACTIVE_UNIT;
+            bump |= B_FRAG_TEXTURE;
+        }
+        if ((mask & GL11.GL_LIGHTING_BIT) != 0) {
+            bump |= B_LIGHTING;
+        }
+        if ((mask & GL11.GL_FOG_BIT) != 0) {
+            bump |= B_FRAG_FOG;
+        }
+        if ((mask & GL11.GL_TRANSFORM_BIT) != 0) {
+            bump |= B_TRANSFORM;
+        }
+
+        final long[] members = Feature.maskToMembers(mask);
+
+        return new StateSet(mask, members, restore, bump, blendSnapshot);
+    }
+}

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/backend/Lwjgl2GLRenderBackend.java

@@ -134,6 +134,12 @@ public final class Lwjgl2GLRenderBackend extends RenderBackend {
         return caps != null && caps.GL_EXT_texture_filter_anisotropic;
     }
 
+    @Override
+    public void updateDisplayFromWorkerThread(boolean processMessages) {
+        if (processMessages) pumpDisplayMessages();
+        Display.update(false);
+    }
+
     @Override
     public void flush() {GL11.glFlush();}
 
@@ -646,6 +652,11 @@ public final class Lwjgl2GLRenderBackend extends RenderBackend {
         GL11.glReadPixels(x, y, width, height, format, type, pixels);
     }
 
+    @Override
+    public void readPixels(int x, int y, int width, int height, int format, int type, long pixelBufferOffset) {
+        GL11.glReadPixels(x, y, width, height, format, type, pixelBufferOffset);
+    }
+
     @Override
     public void getTexImage(int target, int level, int format, int type, ByteBuffer pixels) {
         GL11.glGetTexImage(target, level, format, type, pixels);

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/backend/RenderBackend.java

@@ -3,6 +3,7 @@ package com.gtnewhorizons.angelica.glsm.backend;
 import com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.RenderSystem;
+import org.lwjgl.LWJGLException;
 import org.lwjgl.opengl.Display;
 import org.lwjgl.opengl.GL20;
 
@@ -241,6 +242,8 @@ public abstract class RenderBackend {
         }
     }
 
+    public void invalidateStateMirror() {}
+
     public void onFrameEnd() {}
 
     /** Fired by lwjgl3ify Display before a mutation that recreates the swapchain. */
@@ -251,9 +254,16 @@ public abstract class RenderBackend {
     public boolean handleSwapBuffers() { return false; }
     public void onRenderThreadReleased(Thread thread) {}
 
+    public void updateDisplayFromWorkerThread(boolean processMessages) throws LWJGLException {
+        GLStateManager.swapBuffers();
+        if (processMessages) {
+            pumpDisplayMessages();
+        }
+    }
+
     public String getTransferDebugInfo() { return null; }
 
-    public boolean bindVoxelizationRegion(int ssboBinding, int vertexBufferGlId, long openPass, float x, float y, float z) { return false; }
+    public boolean bindVoxelizationRegion(int ssboBinding, long openPass, float x, float y, float z) { return false; }
     public long beginVoxelizationBatch(int ssboBinding) { return 0L; }
     public void voxelizeRange(long pass, int vertexOffset, int vertexCount) {}
     public void endVoxelizationBatch(long pass) {}
@@ -383,6 +393,7 @@ public abstract class RenderBackend {
     public abstract void readPixels(int x, int y, int width, int height, int format, int type, ByteBuffer pixels);
     public abstract void readPixels(int x, int y, int width, int height, int format, int type, FloatBuffer pixels);
     public abstract void readPixels(int x, int y, int width, int height, int format, int type, IntBuffer pixels);
+    public abstract void readPixels(int x, int y, int width, int height, int format, int type, long pixelBufferOffset);
     public abstract void getTexImage(int target, int level, int format, int type, ByteBuffer pixels);
     public abstract void getTexImage(int target, int level, int format, int type, IntBuffer pixels);
     public abstract void getTexImage(int target, int level, int format, int type, long pixelBufferOffset);

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

@@ -104,7 +104,9 @@ public class DSAARB extends DSAUnsupported {
             super.bindTextureToUnit(target != 0 ? target : GL11.GL_TEXTURE_2D, unit, texture);
         } else {
             RENDER_BACKEND.bindTextureUnit(unit, texture);
-            GLStateManager.getTextures().getTextureUnitBindings(unit).setBinding(texture, target);
+            final var binding = GLStateManager.getTextures().getTextureUnitBindings(unit);
+            binding.beforeModify();
+            binding.setBinding(texture, target);
             GLStateManager.trackMaxBoundTextureUnit(unit);
         }
     }

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

@@ -0,0 +1,55 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import org.joml.Matrix4f;
+import org.joml.Matrix4fc;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL14;
+
+public final class CombinedGlint {
+    private static final Matrix4f savedMatrix = new Matrix4f();
+    private static final Matrix4f inverse = new Matrix4f();
+    private static final Matrix4f relative = new Matrix4f();
+    private static boolean active;
+    private static boolean replaceAlpha;
+
+    private CombinedGlint() {}
+
+    public static boolean isActive() {
+        return active;
+    }
+
+    public static boolean replacesAlpha() {
+        return active && replaceAlpha;
+    }
+
+    public static boolean begin(Matrix4fc secondTextureMatrix) {
+        if (active || GLStateManager.getActiveProgram() != 0 || GLStateManager.getLightingState().isEnabled() || GLStateManager.getColorSumState().isEnabled() || !GLStateManager.glIsEnabled(GL11.GL_BLEND)) return false;
+        final var blend = GLStateManager.getBlendState();
+        final boolean lastAlpha = blend.getSrcAlpha() == GL11.GL_ONE && blend.getDstAlpha() == GL11.GL_ZERO && blend.getEquationAlpha() == GL14.GL_FUNC_ADD;
+        final boolean preserveAlpha = blend.getSrcAlpha() == GL11.GL_ZERO && blend.getDstAlpha() == GL11.GL_ONE && (blend.getEquationAlpha() == GL14.GL_FUNC_ADD || blend.getEquationAlpha() == GL14.GL_FUNC_REVERSE_SUBTRACT);
+        if (blend.getSrcRgb() != GL11.GL_SRC_COLOR || blend.getDstRgb() != GL11.GL_ONE
+            || (!lastAlpha && !preserveAlpha && (blend.getSrcAlpha() != GL11.GL_SRC_COLOR || blend.getDstAlpha() != GL11.GL_ONE || blend.getEquationAlpha() != blend.getEquationRgb()))
+            || (blend.getEquationRgb() != GL14.GL_FUNC_ADD && blend.getEquationRgb() != GL14.GL_FUNC_REVERSE_SUBTRACT)) return false;
+        final var textures = GLStateManager.getTextures();
+        if (!textures.getTextureUnitStates(0).isEnabled() || textures.getTextureUnitBindings(0).getBinding() == 0 || textures.getTexEnvState(0).mode != GL11.GL_MODULATE) return false;
+        if (textures.getTextureUnitStates(1).isEnabled() && textures.getTextureUnitBindings(1).getBinding() != 0 && textures.getTexEnvState(1).mode != GL11.GL_MODULATE) return false;
+        for (int unit = 2; unit < 4; unit++) {
+            if (textures.getTextureUnitStates(unit).isEnabled() && textures.getTextureUnitBindings(unit).getBinding() != 0) return false;
+        }
+        inverse.set(textures.getTextureUnitMatrix(0)).invert();
+        relative.set(secondTextureMatrix).mul(inverse);
+        if (!relative.isFinite()) return false;
+        savedMatrix.set(textures.getTextureUnitMatrix(3));
+        GLStateManager.setTextureMatrix(3, relative);
+        replaceAlpha = lastAlpha;
+        active = true;
+        return true;
+    }
+
+    public static void end() {
+        if (!active) return;
+        active = false;
+        GLStateManager.setTextureMatrix(3, savedMatrix);
+    }
+}

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

@@ -0,0 +1,27 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import org.lwjgl.opengl.GL11;
+
+public final class CubeInstancedAttribs {
+
+    public static final int LOC_LIGHTMAP_SCALE = InstancedAttribs.LOC_LIGHTMAP;
+    public static final int LOC_CUBE_TEX = 15;
+
+    public static final int OFFSET_LIGHTMAP_SCALE = InstancedAttribs.HEAD_SIZE;
+    public static final int OFFSET_CUBE_TEX = OFFSET_LIGHTMAP_SCALE + 16;
+    public static final int STRIDE = OFFSET_CUBE_TEX + 16;
+
+    public static void pointInstanceAttribs(long base) {
+        InstancedAttribs.pointHead(base, STRIDE);
+        GLStateManager.glVertexAttribPointer(LOC_LIGHTMAP_SCALE, 4, GL11.GL_FLOAT, false, STRIDE, base + OFFSET_LIGHTMAP_SCALE);
+        GLStateManager.glVertexAttribPointer(LOC_CUBE_TEX, 4, GL11.GL_FLOAT, false, STRIDE, base + OFFSET_CUBE_TEX);
+    }
+
+    static void enableInstanceArrays() {
+        InstancedAttribs.enableHeadArrays();
+        InstancedAttribs.enableInstanced(LOC_CUBE_TEX);
+    }
+
+    private CubeInstancedAttribs() {}
+}

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

@@ -0,0 +1,54 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutFloat;
+
+public record CubeParams(float minX, float minY, float minZ, float spanX, float spanY, float spanZ, float u0, float v0, float uScaleX, float vScaleY, float uScaleZ, float vScaleZ) {
+
+    private static final float MIN_SPAN = 1.0e-4f;
+
+    public CubeParams {
+        if (!(spanX > MIN_SPAN && spanY > MIN_SPAN && spanZ > MIN_SPAN)) throw new IllegalArgumentException("degenerate cube span");
+    }
+
+    public static CubeParams of(float texWidth, float texHeight, boolean mirror, int texU, int texV, float x, float y, float z, int sizeX, int sizeY, int sizeZ, float inflate) {
+        if (texWidth <= 0.0f || texHeight <= 0.0f) return null;
+        if (sizeX < 0 || sizeY < 0 || sizeZ < 0) return null;
+        if (mirror && sizeX == 0) return null;
+        final float minX = x - inflate;
+        final float minY = y - inflate;
+        final float minZ = z - inflate;
+        final float spanX = ((x + sizeX) + inflate) - minX;
+        final float spanY = ((y + sizeY) + inflate) - minY;
+        final float spanZ = ((z + sizeZ) + inflate) - minZ;
+        if (spanX <= MIN_SPAN || spanY <= MIN_SPAN || spanZ <= MIN_SPAN) return null;
+        return new CubeParams(minX, minY, minZ, spanX, spanY, spanZ, texU / texWidth, texV / texHeight, (mirror ? -sizeX : sizeX) / texWidth, sizeY / texHeight, sizeZ / texWidth, sizeZ / texHeight);
+    }
+
+    public void writeRows(long ptr, float[] mv, int off, float scale) {
+        final float tx = minX * scale;
+        final float ty = minY * scale;
+        final float tz = minZ * scale;
+        final float sx = spanX * scale;
+        final float sy = spanY * scale;
+        final float sz = spanZ * scale;
+        for (int r = 0; r < 3; r++) {
+            final float c0 = mv[off + r];
+            final float c1 = mv[off + 4 + r];
+            final float c2 = mv[off + 8 + r];
+            final long row = ptr + InstancedAttribs.OFFSET_ROWS + r * 16L;
+            memPutFloat(row, c0 * sx);
+            memPutFloat(row + 4, c1 * sy);
+            memPutFloat(row + 8, c2 * sz);
+            memPutFloat(row + 12, mv[off + 12 + r] + c0 * tx + c1 * ty + c2 * tz);
+        }
+    }
+
+    public void writeTexture(long ptr) {
+        memPutFloat(ptr + CubeInstancedAttribs.OFFSET_LIGHTMAP_SCALE + 8, uScaleZ);
+        memPutFloat(ptr + CubeInstancedAttribs.OFFSET_LIGHTMAP_SCALE + 12, vScaleZ);
+        memPutFloat(ptr + CubeInstancedAttribs.OFFSET_CUBE_TEX, u0);
+        memPutFloat(ptr + CubeInstancedAttribs.OFFSET_CUBE_TEX + 4, v0);
+        memPutFloat(ptr + CubeInstancedAttribs.OFFSET_CUBE_TEX + 8, uScaleX);
+        memPutFloat(ptr + CubeInstancedAttribs.OFFSET_CUBE_TEX + 12, vScaleY);
+    }
+}

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

@@ -107,6 +107,12 @@ public final class FFPUniformBlock {
     public static final int FOG_PARAMS = vec4("u_FogParams");
     public static final int FOG_COLOR = vec4("u_FogColor");
 
+    // Rain and snow, for Instancing.WEATHER. 0 = (translate.xyz, 1/radius),
+    // 1 = (cameraFrac.xy, partialTicks, age), 2 = (rainScroll, snowScroll, rainStrength, unused).
+    public static final int WEATHER_PARAMS_0 = vec4("u_WeatherParams0");
+    public static final int WEATHER_PARAMS_1 = vec4("u_WeatherParams1");
+    public static final int WEATHER_PARAMS_2 = vec4("u_WeatherParams2");
+
     public static final int SIZE;
     public static final String GLSL_DECL;
 

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

@@ -2,7 +2,9 @@ package com.gtnewhorizons.angelica.glsm.ffp;
 
 import com.gtnewhorizon.gtnhlib.client.renderer.cel.api.util.NormI8;
 import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFormatElement.Usage;
+import com.gtnewhorizons.angelica.glsm.GLContextState;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.hooks.BatchStateGuard;
 import com.gtnewhorizons.angelica.glsm.hooks.GLSMHooks;
 import com.gtnewhorizons.angelica.glsm.hooks.ImmediateExtendedAttribHandler;
 import it.unimi.dsi.fastutil.ints.Int2IntMap;
@@ -59,7 +61,6 @@ public final class FfpExtendedAttribs {
 
     private static final HashMap<Key, ExtBuffer> cache = new HashMap<>();
     private static final Key lookup = new Key();
-    private static int internalGlDepth = 0;
 
     private static final HashMap<EboKey, Boolean> eboPatternCache = new HashMap<>();
     private static final EboKey eboLookup = new EboKey();
@@ -79,15 +80,19 @@ public final class FfpExtendedAttribs {
         return cache.isEmpty() && eboPatternCache.isEmpty();
     }
 
-    private static int internalDrawDepth = 0;
+    public static void beginInternalDraw() { GLStateManager.ctx().internalDrawDepth++; }
 
-    public static void beginInternalDraw() { internalDrawDepth++; }
+    public static void endInternalDraw() {
+        final GLContextState glCtx = GLStateManager.ctx();
+        if (glCtx.internalDrawDepth > 0) glCtx.internalDrawDepth--;
+    }
 
-    public static void endInternalDraw() { if (internalDrawDepth > 0) internalDrawDepth--; }
+    private static void beginInternalGl() { GLStateManager.ctx().internalGlDepth++; }
 
-    private static void beginInternalGl() { internalGlDepth++; }
-
-    private static void endInternalGl() { if (internalGlDepth > 0) internalGlDepth--; }
+    private static void endInternalGl() {
+        final GLContextState glCtx = GLStateManager.ctx();
+        if (glCtx.internalGlDepth > 0) glCtx.internalGlDepth--;
+    }
 
     private static boolean isNotConventionalTexturedArray(VAOManager.Attrib a) {
         return a == null || !a.enabled || a.genericPointer || a.vboId == 0 || a.size < 2;
@@ -104,20 +109,20 @@ public final class FfpExtendedAttribs {
         return true;
     }
 
-    public static boolean maybeBind(int mode, int first, int count) {
+    public static boolean maybeBind(GLContextState glCtx, int mode, int first, int count) {
         final ImmediateExtendedAttribHandler h = GLSMHooks.immediateExtendedHandler;
         if (h == null) return false;
-        if (internalDrawDepth > 0) return false;
+        if (glCtx.internalDrawDepth > 0) return false;
         final int extPrim = ImmediateExtendedAttribHandler.extPrimVerts(mode, count);
         if (extPrim == 0 || first < 0) return false;
         if (!h.wantsExtended()) return false;
 
-        final VAOManager.Attrib pos = VAOManager.get(POSITION_LOC);
-        final VAOManager.Attrib uv = VAOManager.get(UV_LOC);
+        final VAOManager.Attrib pos = glCtx.vaos.attrib(POSITION_LOC);
+        final VAOManager.Attrib uv = glCtx.vaos.attrib(UV_LOC);
         if (isNotConventionalTexturedArray(pos) || isNotConventionalTexturedArray(uv)) return false;
         if (isStreaming(pos.vboId) || isStreaming(uv.vboId)) return false;
 
-        VAOManager.Attrib normal = extPrim == 3 ? VAOManager.get(NORMAL_LOC) : null;
+        VAOManager.Attrib normal = extPrim == 3 ? glCtx.vaos.attrib(NORMAL_LOC) : null;
         if (normal != null && (!normal.enabled || normal.genericPointer || normal.vboId == 0 || normal.size < 3
             || isStreaming(normal.vboId))) {
             normal = null;
@@ -126,17 +131,17 @@ public final class FfpExtendedAttribs {
         return bindExt(h, mode, first, count, extPrim, pos, uv, normal);
     }
 
-    public static boolean maybeBindIndexed(int mode, int indexCount, int indexType, long indicesOffset) {
+    public static boolean maybeBindIndexed(GLContextState glCtx, int mode, int indexCount, int indexType, long indicesOffset) {
         final ImmediateExtendedAttribHandler h = GLSMHooks.immediateExtendedHandler;
         if (h == null) return false;
-        if (internalDrawDepth > 0) return false;
+        if (glCtx.internalDrawDepth > 0) return false;
         if (mode != GL11.GL_TRIANGLES || indexCount <= 0 || indexCount % 6 != 0) return false;
         if (!h.wantsExtended()) return false;
 
-        final VAOManager.Attrib pos = VAOManager.get(POSITION_LOC);
-        final VAOManager.Attrib uv = VAOManager.get(UV_LOC);
+        final VAOManager.Attrib pos = glCtx.vaos.attrib(POSITION_LOC);
+        final VAOManager.Attrib uv = glCtx.vaos.attrib(UV_LOC);
         if (isNotConventionalTexturedArray(pos) || isNotConventionalTexturedArray(uv)) return false;
-        if (isStreaming(pos.vboId) || isStreaming(uv.vboId) || isStreaming(VAOManager.boundEBO)) return false;
+        if (isStreaming(pos.vboId) || isStreaming(uv.vboId) || isStreaming(glCtx.vaos.boundEBO)) return false;
 
         final int indexSize = indexTypeBytes(indexType);
         if (indexSize == 0) return false;
@@ -144,7 +149,7 @@ public final class FfpExtendedAttribs {
         final int first = (int) (indicesOffset / indexSize) / 6 * 4;
         final int count = indexCount / 6 * 4;
 
-        if (!isQuadPatternEbo(VAOManager.boundEBO, indicesOffset, indexCount, indexType, indexSize, first)) return false;
+        if (!isQuadPatternEbo(glCtx.vaos.boundEBO, indicesOffset, indexCount, indexType, indexSize, first)) return false;
 
         // Build/bind as GL_QUADS (the real primitive): face-normal tangents, 4-vertex tiles, no per-vertex normal.
         return bindExt(h, GL11.GL_QUADS, first, count, 4, pos, uv, null);
@@ -222,12 +227,17 @@ public final class FfpExtendedAttribs {
     }
 
     public static void setNeutralCurrentValues() {
-        GLStateManager.glVertexAttrib2f(ImmediateExtendedAttribHandler.LOC_MID_TEX, 0.5f, 0.5f);
-        GLStateManager.glVertexAttrib4f(ImmediateExtendedAttribHandler.LOC_TANGENT, 1.0f, 0.0f, 0.0f, 1.0f);
+        BatchStateGuard.suspend();
+        try {
+            GLStateManager.glVertexAttrib2f(ImmediateExtendedAttribHandler.LOC_MID_TEX, 0.5f, 0.5f);
+            GLStateManager.glVertexAttrib4f(ImmediateExtendedAttribHandler.LOC_TANGENT, 1.0f, 0.0f, 0.0f, 1.0f);
+        } finally {
+            BatchStateGuard.resume();
+        }
     }
 
-    public static void onDeleteBuffer(int vboId) {
-        if (internalGlDepth > 0 || vboId == 0) return;
+    public static void onDeleteBuffer(GLContextState glCtx, int vboId) {
+        if (glCtx.internalGlDepth > 0 || vboId == 0) return;
         dropDerivedFrom(vboId);
         respecCounts.remove(vboId);
         respecFrames.remove(vboId);
@@ -236,8 +246,8 @@ public final class FfpExtendedAttribs {
         persistentSources.remove(vboId);
     }
 
-    public static void onBufferRespecified(int vboId) {
-        if (internalGlDepth > 0 || vboId == 0) return;
+    public static void onBufferRespecified(GLContextState glCtx, int vboId) {
+        if (glCtx.internalGlDepth > 0 || vboId == 0) return;
         if (streamingSources.contains(vboId)) {
             respecFrames.put(vboId, frame);
             return;
@@ -268,16 +278,15 @@ public final class FfpExtendedAttribs {
         respecFrames.put(vboId, frame);
     }
 
-    public static void markStreaming(int vboId) {
-        if (internalGlDepth > 0 || vboId == 0) return;
+    private static void markStreaming(int vboId) {
         respecCounts.remove(vboId);
         respecRunStart.remove(vboId);
         respecFrames.put(vboId, frame);
         if (streamingSources.add(vboId)) dropDerivedFrom(vboId);
     }
 
-    public static void markPersistent(int vboId) {
-        if (internalGlDepth > 0 || vboId == 0) return;
+    public static void markPersistent(GLContextState glCtx, int vboId) {
+        if (glCtx.internalGlDepth > 0 || vboId == 0) return;
         markStreaming(vboId);
         persistentSources.add(vboId);
     }

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

@@ -2,8 +2,10 @@ package com.gtnewhorizons.angelica.glsm.ffp;
 
 import java.util.Arrays;
 
+import com.gtnewhorizons.angelica.glsm.GLContextState;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.TexEnvState;
+import com.gtnewhorizons.angelica.glsm.states.TextureUnitArray;
 import org.lwjgl.opengl.GL11;
 import org.lwjgl.opengl.GL12;
 import org.lwjgl.opengl.GL13;
@@ -12,7 +14,7 @@ import org.lwjgl.opengl.GL13;
  * Packed-long fragment shader permutation key for FFP emulation.
  *
  * Layout:
- *   long[0]: global bits (13) + unit 0 (47 bits at offset 13)
+ *   long[0]: global bits (14) + unit 0 (47 bits at offset 14)
  *   long[1..3]: unit 1..3 (47 bits each, low-aligned)
  * Only max(1, nrEnabledUnits) longs are significant.
  *
@@ -63,7 +65,9 @@ public final class FragmentKey {
     public static final int FOG_EXP    = 2;
     public static final int FOG_EXP2   = 3;
 
-    private static final int GLOBAL_BITS = 13;
+    private static final int GLOBAL_BITS = 14;
+    private static final int BIT_COMBINED_GLINT = 61;
+    private static final int BIT_GLINT_REPLACE_ALPHA = 62;
     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
@@ -72,6 +76,7 @@ public final class FragmentKey {
     private static final int BIT_OVERLAY_ENABLED   = 10; // 1 bit
     private static final int BIT_LINE_STIPPLE      = 11; // 1 bit
     private static final int BIT_COLOR_SUM         = 12; // 1 bit
+    private static final int BIT_OVERLAY_INSTANCED = 13;
 
     private static final int U_ENABLED         = 0;
     private static final int U_MODE            = 1;   // 3 bits
@@ -103,11 +108,17 @@ public final class FragmentKey {
      * @return number of significant longs (1..4)
      */
     public static int packFromState(long[] out) {
+        return packFromState(out, GLStateManager.ctx());
+    }
+
+    public static int packFromState(long[] out, GLContextState glCtx) {
         long global = 0;
+        if (CombinedGlint.isActive()) global |= 1L << BIT_COMBINED_GLINT;
+        if (CombinedGlint.replacesAlpha()) global |= 1L << BIT_GLINT_REPLACE_ALPHA;
 
         // Fog
-        if (GLStateManager.getFogMode().isEnabled()) {
-            final int fogMode = switch (GLStateManager.getFogState().getFogMode()) {
+        if (glCtx.fogMode.isEnabled()) {
+            final int fogMode = switch (glCtx.fogState.getFogMode()) {
                 case GL11.GL_LINEAR -> FOG_LINEAR;
                 case GL11.GL_EXP    -> FOG_EXP;
                 case GL11.GL_EXP2   -> FOG_EXP2;
@@ -117,37 +128,40 @@ public final class FragmentKey {
         }
 
         // Alpha test
-        if (GLStateManager.getAlphaTest().isEnabled()) {
+        if (glCtx.alphaTest.isEnabled()) {
             global |= (1L << BIT_ALPHA_TEST);
-            global |= ((long) (encodeAlphaFunc(GLStateManager.getAlphaState().getFunction()) & 0x7)) << BIT_ALPHA_FUNC;
+            global |= ((long) (encodeAlphaFunc(glCtx.alphaState.getFunction()) & 0x7)) << BIT_ALPHA_FUNC;
         }
 
         // Damage overlay
-        if (GLStateManager.getOverlayA() != 0.0f) {
+        if (glCtx.ffpInstancing.hasInstanceHead()) {
+            global |= (1L << BIT_OVERLAY_INSTANCED);
+        } else if (glCtx.overlayA != 0.0f) {
             global |= (1L << BIT_OVERLAY_ENABLED);
         }
 
-        if (GLStateManager.lineStippleActive) {
+        if (glCtx.lineStippleActive) {
             global |= (1L << BIT_LINE_STIPPLE);
         }
 
         // Separate specular / color sum
-        if (GLStateManager.getLightingState().isEnabled()
-            && GLStateManager.getLightModel().colorControl == GL12.GL_SEPARATE_SPECULAR_COLOR) {
+        if (glCtx.lightingState.isEnabled()
+            && glCtx.lightModel.colorControl == GL12.GL_SEPARATE_SPECULAR_COLOR) {
             global |= (1L << BIT_SEPARATE_SPECULAR);
-        } else if (GLStateManager.getColorSumState().isEnabled()) {
+        } else if (glCtx.colorSumState.isEnabled()) {
             global |= (1L << BIT_COLOR_SUM);
         }
 
         // Per-unit state
+        final TextureUnitArray textures = glCtx.textures;
         int highestEnabled = -1;
         long unit0Bits = 0;
         for (int i = 0; i < MAX_UNITS; i++) {
             // Per Mesa - an enabled unit with no complete texture bound counts as disabled.
-            final boolean texEnabled = GLStateManager.getTextures().getTextureUnitStates(i).isEnabled() && GLStateManager.getTextures().getTextureUnitBindings(i).getBinding() != 0;
+            final boolean texEnabled = textures.getTextureUnitStates(i).isEnabled() && textures.getTextureUnitBindings(i).getBinding() != 0;
             if (texEnabled) highestEnabled = i;
 
-            final long unitBits = packUnit(i, texEnabled);
+            final long unitBits = packUnit(i, texEnabled, textures);
             if (i == 0) {
                 unit0Bits = unitBits;
             } else {
@@ -163,10 +177,10 @@ public final class FragmentKey {
         return Math.max(1, nrEnabled);
     }
 
-    private static long packUnit(int unitIndex, boolean texEnabled) {
+    private static long packUnit(int unitIndex, boolean texEnabled, TextureUnitArray textures) {
         if (!texEnabled) return 0;
 
-        final TexEnvState envState = GLStateManager.getTextures().getTexEnvState(unitIndex);
+        final TexEnvState envState = textures.getTexEnvState(unitIndex);
         final int mode = encodeTexEnvMode(envState.mode);
 
         long bits = 1L; // enabled
@@ -238,6 +252,8 @@ public final class FragmentKey {
     }
 
     public int fogMode()              { return (int) (packed[0] & 0x3); }
+    public boolean combinedGlint()    { return (packed[0] & (1L << BIT_COMBINED_GLINT)) != 0; }
+    public boolean glintReplaceAlpha() { return (packed[0] & (1L << BIT_GLINT_REPLACE_ALPHA)) != 0; }
     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; }
@@ -245,6 +261,7 @@ public final class FragmentKey {
     public boolean lineStipple()      { return ((packed[0] >> BIT_LINE_STIPPLE) & 1) != 0; }
     public int nrEnabledUnits()       { return (int) ((packed[0] >> BIT_NR_ENABLED_UNITS) & 0x7); }
     public boolean overlayEnabled()   { return ((packed[0] >> BIT_OVERLAY_ENABLED) & 1) != 0; }
+    public boolean overlayInstanced() { return ((packed[0] >> BIT_OVERLAY_INSTANCED) & 1) != 0; }
 
     private long unitBits(int i) {
         return (i == 0) ? (packed[0] >>> GLOBAL_BITS) : packed[i];
@@ -378,10 +395,9 @@ public final class FragmentKey {
             default -> "?";
         };
         final StringBuilder sb = new StringBuilder();
-        sb.append(String.format("FFPFragmentKey[fog=%s alpha=%b(%s) specSep=%b colorSum=%b overlay=%b units=%d",
-            fogName, alphaTestEnabled(),
-            alphaTestEnabled() ? String.format("0x%04X", decodeAlphaFunc(alphaTestFunc())) : "-",
-            separateSpecular(), colorSum(), overlayEnabled(), nrEnabledUnits()));
+        sb.append(String.format("FFPFragmentKey[fog=%s alpha=%b(%s) specSep=%b colorSum=%b overlay=%b units=%d", fogName, alphaTestEnabled(),
+            alphaTestEnabled() ? String.format("0x%04X", decodeAlphaFunc(alphaTestFunc())) : "-", separateSpecular(), colorSum(),
+            overlayEnabled() || overlayInstanced(), nrEnabledUnits()));
         for (int i = 0; i < nrEnabledUnits(); i++) {
             if (!unitEnabled(i)) {
                 sb.append(String.format(" u%d=OFF", i));

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

@@ -1,6 +1,7 @@
 package com.gtnewhorizons.angelica.glsm.ffp;
 
 import org.lwjgl.opengl.GL11;
+import org.embeddedt.embeddium.impl.render.shader.ShaderLoader;
 
 /**
  * Generates GLSL 330 core fragment shaders for FFP emulation.
@@ -17,6 +18,15 @@ public final class FragmentShaderGenerator {
 
         emitInputs(sb, key);
         emitUniforms(sb, key);
+        if (key.combinedGlint()) {
+            sb.append("#define GLINT_REPLACE_ALPHA ").append(key.glintReplaceAlpha() ? 1 : 0).append('\n');
+            sb.append("#define GLINT_FOG_MODE ").append(key.fogMode()).append('\n');
+            sb.append("#define GLINT_ALPHA_FUNC ").append(key.alphaTestEnabled() ? key.alphaTestFunc() : 7).append('\n');
+            sb.append("#define GLINT_OVERLAY ").append(key.overlayInstanced() ? 2 : key.overlayEnabled() ? 1 : 0).append('\n');
+            sb.append("#define GLINT_LIGHTMAP ").append(key.nrEnabledUnits() > 1 && key.unitEnabled(1) ? 1 : 0).append('\n');
+            sb.append(ShaderLoader.getShaderSource("angelica:combined_glint.frag.glsl"));
+            return sb.toString();
+        }
         sb.append("out vec4 fragColor;\n\n");
 
         sb.append("void main() {\n");
@@ -35,6 +45,9 @@ public final class FragmentShaderGenerator {
     private static void emitInputs(StringBuilder sb, FragmentKey key) {
         sb.append("// Inputs from vertex shader\n");
         sb.append("in vec4 v_Color;\n");
+        if (key.overlayInstanced()) {
+            sb.append("in vec4 v_Overlay;\n");
+        }
         if (key.separateSpecular()) {
             sb.append("in vec3 v_SpecularColor;\n");
         }
@@ -116,8 +129,11 @@ public final class FragmentShaderGenerator {
      * Emit the modern-style damage overlay mix.
      */
     private static void emitOverlay(StringBuilder sb, FragmentKey key) {
-        if (!key.overlayEnabled()) return;
-        sb.append("  color.rgb = mix(color.rgb, u_OverlayColor.rgb, u_OverlayColor.a);\n");
+        if (key.overlayInstanced()) {
+            sb.append("  color.rgb = mix(color.rgb, v_Overlay.rgb, v_Overlay.a);\n");
+        } else if (key.overlayEnabled()) {
+            sb.append("  color.rgb = mix(color.rgb, u_OverlayColor.rgb, u_OverlayColor.a);\n");
+        }
     }
 
     private static void emitSimpleUnit(StringBuilder sb, FragmentKey key, int unit, String texVar, String envColorVar, String prevVar, String assign) {

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

@@ -1,18 +1,89 @@
 package com.gtnewhorizons.angelica.glsm.ffp;
 
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import org.lwjgl.opengl.GL11;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutFloat;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutInt;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutLong;
+
 public final class InstancedAttribs {
 
-    public static final int LOC_MATRIX_COL0 = 5;
-    public static final int LOC_MATRIX_COL1 = 6;
-    public static final int LOC_MATRIX_COL2 = 7;
-    public static final int LOC_MATRIX_COL3 = 8;
-    public static final int LOC_COLOR = 9;
+    public static final int LOC_ROW0 = 5;
+    public static final int LOC_ROW1 = 6;
+    public static final int LOC_ROW2 = 7;
+    public static final int LOC_COLOR = 8;
+    public static final int LOC_OVERLAY = 9;
     public static final int LOC_LIGHTMAP = 10;
+    public static final int LOC_ENTITY = 11;
 
-    public static final int OFFSET_MATRIX = 0;
-    public static final int OFFSET_COLOR = 64;
-    public static final int OFFSET_LIGHTMAP = 68;
-    public static final int STRIDE = 80;
+    public static final int OFFSET_ROWS = 0;
+    public static final int OFFSET_COLOR = 48;
+    public static final int OFFSET_OVERLAY = 52;
+    public static final int OFFSET_ENTITY = 56;
+    public static final int HEAD_SIZE = 64;
+    public static final int OFFSET_LIGHTMAP = HEAD_SIZE;
+    public static final int STRIDE = 72;
+
+    public static void writeHead(long ptr, float[] colMajor, int off, int colorABGR, int overlayABGR, long entityInfo) {
+        writeRows(ptr, colMajor, off);
+        writeTail(ptr, colorABGR, overlayABGR, entityInfo);
+    }
+
+    private static void writeRows(long ptr, float[] colMajor, int off) {
+        for (int r = 0; r < 3; r++) {
+            final long row = ptr + OFFSET_ROWS + r * 16L;
+            memPutFloat(row, colMajor[off + r]);
+            memPutFloat(row + 4, colMajor[off + 4 + r]);
+            memPutFloat(row + 8, colMajor[off + 8 + r]);
+            memPutFloat(row + 12, colMajor[off + 12 + r]);
+        }
+    }
+
+    public static void writeTail(long ptr, int colorABGR, int overlayABGR, long entityInfo) {
+        memPutInt(ptr + OFFSET_COLOR, colorABGR);
+        memPutInt(ptr + OFFSET_OVERLAY, overlayABGR);
+        memPutLong(ptr + OFFSET_ENTITY, entityInfo);
+    }
+
+    public static void writeLightmap(long ptr, int packedLight) {
+        memPutFloat(ptr, packedLight & 0xFFFF);
+        memPutFloat(ptr + 4, (packedLight >>> 16) & 0xFFFF);
+    }
+
+    public static long packEntityInfo(int entity, int blockEntity, int item) {
+        return (entity & 0xFFFFL) | ((blockEntity & 0xFFFFL) << 16) | ((item & 0xFFFFL) << 32);
+    }
+
+    public static int unpackId(long info, int shift) {
+        final int id = (int) (info >>> shift) & 0xFFFF;
+        return id == 0xFFFF ? -1 : id;
+    }
+
+    public static void pointHead(long base, int stride) {
+        for (int r = 0; r < 3; r++) {
+            GLStateManager.glVertexAttribPointer(LOC_ROW0 + r, 4, GL11.GL_FLOAT, false, stride, base + OFFSET_ROWS + r * 16L);
+        }
+        GLStateManager.glVertexAttribPointer(LOC_COLOR, 4, GL11.GL_UNSIGNED_BYTE, true, stride, base + OFFSET_COLOR);
+        GLStateManager.glVertexAttribPointer(LOC_OVERLAY, 4, GL11.GL_UNSIGNED_BYTE, true, stride, base + OFFSET_OVERLAY);
+        GLStateManager.glVertexAttribIPointer(LOC_ENTITY, 4, GL11.GL_UNSIGNED_SHORT, stride, base + OFFSET_ENTITY);
+    }
+
+    public static void pointTemplate(long base) {
+        pointHead(base, STRIDE);
+        GLStateManager.glVertexAttribPointer(LOC_LIGHTMAP, 2, GL11.GL_FLOAT, false, STRIDE, base + OFFSET_LIGHTMAP);
+    }
+
+    public static void enableHeadArrays() {
+        for (int loc = LOC_ROW0; loc <= LOC_ENTITY; loc++) {
+            enableInstanced(loc);
+        }
+    }
+
+    static void enableInstanced(int loc) {
+        GLStateManager.glEnableVertexAttribArray(loc);
+        GLStateManager.glVertexAttribDivisor(loc, 1);
+    }
 
     private InstancedAttribs() {}
 }

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

@@ -0,0 +1,145 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFormatElement;
+
+import java.util.ArrayList;
+
+public final class InstancedGlslHelpers {
+
+    private InstancedGlslHelpers() {}
+
+    public static String mat4FromRows(String row0, String row1, String row2) {
+        return "mat4("
+            + "vec4(" + row0 + ".x, " + row1 + ".x, " + row2 + ".x, 0.0), "
+            + "vec4(" + row0 + ".y, " + row1 + ".y, " + row2 + ".y, 0.0), "
+            + "vec4(" + row0 + ".z, " + row1 + ".z, " + row2 + ".z, 0.0), "
+            + "vec4(" + row0 + ".w, " + row1 + ".w, " + row2 + ".w, 1.0))";
+    }
+
+    public static String mat3FromRows(String row0, String row1, String row2) {
+        return "mat3("
+            + "normalize(vec3(" + row0 + ".x, " + row1 + ".x, " + row2 + ".x)), "
+            + "normalize(vec3(" + row0 + ".y, " + row1 + ".y, " + row2 + ".y)), "
+            + "normalize(vec3(" + row0 + ".z, " + row1 + ".z, " + row2 + ".z)))";
+    }
+
+    public static String particlePos(String centerHalf, String offset) {
+        return "vec4(" + centerHalf + ".xyz + " + offset + " * " + centerHalf + ".w, 1.0)";
+    }
+
+    public static String particleUv(String uv, String corner) {
+        return "vec4("
+            + "mix(" + uv + ".x, " + uv + ".z, " + corner + ".x), "
+            + "mix(" + uv + ".y, " + uv + ".w, " + corner + ".y), "
+            + "0.0, 1.0)";
+    }
+
+    // wHalfWidth is vanilla's rainXCoords table.
+    private static final String WEATHER_PROLOGUE = """
+        vec2 {p}wColumn = {span}.xy;
+        float {p}wBottom = {span}.z;
+        float {p}wTop = {span}.w;
+        vec2 {p}wLightmap = {params}.xy;
+        float {p}wHash = {params}.z;
+        bool {p}wSnow = {params}.w > 0.5;
+        vec3 {p}wTranslate = {p}WeatherParams0.xyz;
+        float {p}wInvRadius = {p}WeatherParams0.w;
+        vec2 {p}wCameraFrac = {p}WeatherParams1.xy;
+        float {p}wPartialTicks = {p}WeatherParams1.z;
+        float {p}wAge = {p}WeatherParams1.w;
+        float {p}wRainScroll = {p}WeatherParams2.x;
+        float {p}wSnowScroll = {p}WeatherParams2.y;
+        float {p}wStrength = {p}WeatherParams2.z;
+
+        vec2 {p}wHalfWidth = vec2(-{p}wColumn.y, {p}wColumn.x) * (0.5 / sqrt(dot({p}wColumn, {p}wColumn)));
+        vec2 {p}wCornerXZ = {p}wColumn + vec2(0.5) + ({corner}.x * 2.0 - 1.0) * {p}wHalfWidth;
+        float {p}wCornerY = mix({p}wBottom, {p}wTop, {corner}.y);
+        {vertex} = vec4(vec3({p}wCornerXZ.x, {p}wCornerY, {p}wCornerXZ.y) + {p}wTranslate, 1.0);
+
+        float {p}wDistance = length({p}wColumn + vec2(0.5) - {p}wCameraFrac) * {p}wInvRadius;
+        float {p}wFade = 1.0 - {p}wDistance * {p}wDistance;
+        float {p}wScroll;
+        vec2 {p}wDrift;
+        float {p}wAlpha;
+        if ({p}wSnow) {
+            {p}wScroll = ({p}wSnowScroll + {p}wPartialTicks) / 512.0;
+            {p}wDrift = vec2({jitter}.x + {p}wAge * 0.01 * {jitter}.y, {jitter}.z + {p}wAge * {jitter}.w * 0.001);
+            {p}wAlpha = {p}wFade * 0.3 + 0.5;
+        } else {
+            {p}wScroll = (mod({p}wRainScroll + {p}wHash, 32.0) + {p}wPartialTicks) / 32.0 * (3.0 + {jitter}.x);
+            {p}wDrift = vec2(0.0);
+            {p}wAlpha = {p}wFade * 0.5 + 0.5;
+        }
+
+        {tex0} = vec4({corner}.x + {p}wDrift.x, {p}wCornerY * 0.25 + {p}wScroll + {p}wDrift.y, 0.0, 1.0);
+        {tex1} = vec4({p}wLightmap, 0.0, 1.0);
+        {color} = vec4(1.0, 1.0, 1.0, {p}wAlpha * {p}wStrength);""";
+
+    public static String weatherPrologue(String uniformPrefix, String attribPrefix, String corner,
+        String vertex, String color, String tex0, String tex1, String sep) {
+        return WEATHER_PROLOGUE
+            .replace("{p}", uniformPrefix)
+            .replace("{span}", attribPrefix + "InstColumnSpan")
+            .replace("{jitter}", attribPrefix + "InstJitter")
+            .replace("{params}", attribPrefix + "InstWeatherParams")
+            .replace("{corner}", corner)
+            .replace("{vertex}", vertex)
+            .replace("{color}", color)
+            .replace("{tex0}", tex0)
+            .replace("{tex1}", tex1)
+            .replace("\n", sep);
+    }
+
+    public static String cubePrelude(String prefix, String mid, String delta, String normal, String tex, String sep) {
+        return "float " + prefix + "cubeMirror = " + tex + ".z < 0.0 ? 1.0 : 0.0;" + sep
+            + "vec2 " + prefix + "cubeMidU = " + mid + ".xy - " + prefix + "cubeMirror * " + normal + ".x;" + sep
+            + "vec2 " + prefix + "cubeU = " + prefix + "cubeMidU + (1.0 - 2.0 * " + prefix + "cubeMirror) * " + delta + ".xy;" + sep
+            + "vec2 " + prefix + "cubeV = " + mid + ".zw + " + delta + ".zw;";
+    }
+
+    public static String cubeUv(String tex, String lightScale, String uA, String uZ, String vA, String vZ) {
+        return "vec4("
+            + tex + ".x + " + uA + " * abs(" + tex + ".z) + " + uZ + " * " + lightScale + ".z, "
+            + tex + ".y + " + vA + " * " + tex + ".w + " + vZ + " * " + lightScale + ".w, "
+            + "0.0, 1.0)";
+    }
+
+    public static String[] attributeDecls(String prefix, Instancing kind) {
+        final ArrayList<String> decls = new ArrayList<>(9);
+        switch (kind) {
+            case NONE -> {}
+            case TEMPLATE -> addHead(decls, prefix, "vec2", "InstLightmap");
+            case CUBE -> {
+                decls.add(decl(VertexFormatElement.Usage.PRIMARY_UV.getAttributeLocation(), "vec4", prefix + "CubeMid"));
+                decls.add(decl(VertexFormatElement.Usage.SECONDARY_UV.getAttributeLocation(), "vec4", prefix + "CubeDelta"));
+                addHead(decls, prefix, "vec4", "InstLightmapScale");
+                decls.add(decl(CubeInstancedAttribs.LOC_CUBE_TEX, "vec4", prefix + "CubeTex"));
+            }
+            case PARTICLE -> {
+                decls.add(decl(ParticleInstancedAttribs.LOC_CENTER_HALF, "vec4", prefix + "InstCenterHalf"));
+                decls.add(decl(ParticleInstancedAttribs.LOC_UV, "vec4", prefix + "InstUv"));
+                decls.add(decl(ParticleInstancedAttribs.LOC_COLOR, "vec4", prefix + "InstColor"));
+                decls.add(decl(ParticleInstancedAttribs.LOC_LIGHTMAP, "vec2", prefix + "InstLightmap"));
+            }
+            case WEATHER -> {
+                decls.add(decl(WeatherInstancedAttribs.LOC_COLUMN_SPAN, "vec4", prefix + "InstColumnSpan"));
+                decls.add(decl(WeatherInstancedAttribs.LOC_JITTER, "vec4", prefix + "InstJitter"));
+                decls.add(decl(WeatherInstancedAttribs.LOC_PARAMS, "vec4", prefix + "InstWeatherParams"));
+            }
+        }
+        return decls.toArray(String[]::new);
+    }
+
+    private static void addHead(ArrayList<String> decls, String prefix, String lightmapType, String lightmapName) {
+        decls.add(decl(InstancedAttribs.LOC_ROW0, "vec4", prefix + "InstRow0"));
+        decls.add(decl(InstancedAttribs.LOC_ROW1, "vec4", prefix + "InstRow1"));
+        decls.add(decl(InstancedAttribs.LOC_ROW2, "vec4", prefix + "InstRow2"));
+        decls.add(decl(InstancedAttribs.LOC_COLOR, "vec4", prefix + "InstColor"));
+        decls.add(decl(InstancedAttribs.LOC_OVERLAY, "vec4", prefix + "InstOverlay"));
+        decls.add(decl(InstancedAttribs.LOC_LIGHTMAP, lightmapType, prefix + lightmapName));
+    }
+
+    private static String decl(int loc, String type, String name) {
+        return "layout(location = " + loc + ") in " + type + " " + name + ";";
+    }
+}

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

@@ -0,0 +1,21 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+public enum Instancing {
+    NONE(""),
+    TEMPLATE("_instanced"),
+    CUBE("_cubeinstanced"),
+    PARTICLE("_particleinstanced"),
+    WEATHER("_weatherinstanced");
+
+    public static final Instancing[] VALUES = values();
+
+    public final String variantSuffix;
+
+    Instancing(String variantSuffix) {
+        this.variantSuffix = variantSuffix;
+    }
+
+    public boolean hasInstanceHead() {
+        return this == TEMPLATE || this == CUBE;
+    }
+}

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

@@ -0,0 +1,50 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import org.lwjgl.opengl.GL11;
+
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutFloat;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutInt;
+
+public final class ParticleInstancedAttribs {
+
+    public static final int LOC_CENTER_HALF = 5;
+    public static final int LOC_UV = 6;
+    public static final int LOC_COLOR = InstancedAttribs.LOC_COLOR;
+    public static final int LOC_LIGHTMAP = InstancedAttribs.LOC_LIGHTMAP;
+
+    public static final int OFFSET_CENTER_HALF = 0;
+    public static final int OFFSET_UV = 16;
+    public static final int OFFSET_COLOR = 32;
+    public static final int OFFSET_LIGHTMAP = 36;
+    public static final int STRIDE = 48;
+
+    public static void pointInstanceAttribs(long base) {
+        GLStateManager.glVertexAttribPointer(LOC_CENTER_HALF, 4, GL11.GL_FLOAT, false, STRIDE, base + OFFSET_CENTER_HALF);
+        GLStateManager.glVertexAttribPointer(LOC_UV, 4, GL11.GL_FLOAT, false, STRIDE, base + OFFSET_UV);
+        GLStateManager.glVertexAttribPointer(LOC_COLOR, 4, GL11.GL_UNSIGNED_BYTE, true, STRIDE, base + OFFSET_COLOR);
+        GLStateManager.glVertexAttribPointer(LOC_LIGHTMAP, 2, GL11.GL_FLOAT, false, STRIDE, base + OFFSET_LIGHTMAP);
+    }
+
+    static void enableInstanceArrays() {
+        InstancedAttribs.enableInstanced(LOC_CENTER_HALF);
+        InstancedAttribs.enableInstanced(LOC_UV);
+        InstancedAttribs.enableInstanced(LOC_COLOR);
+        InstancedAttribs.enableInstanced(LOC_LIGHTMAP);
+    }
+
+    public static void writeInstance(long ptr, float cx, float cy, float cz, float half, float u0, float v0, float u1, float v1, int colorABGR, int packedLight) {
+        memPutFloat(ptr + OFFSET_CENTER_HALF, cx);
+        memPutFloat(ptr + OFFSET_CENTER_HALF + 4, cy);
+        memPutFloat(ptr + OFFSET_CENTER_HALF + 8, cz);
+        memPutFloat(ptr + OFFSET_CENTER_HALF + 12, half);
+        memPutFloat(ptr + OFFSET_UV, u0);
+        memPutFloat(ptr + OFFSET_UV + 4, v0);
+        memPutFloat(ptr + OFFSET_UV + 8, u1);
+        memPutFloat(ptr + OFFSET_UV + 12, v1);
+        memPutInt(ptr + OFFSET_COLOR, colorABGR);
+        InstancedAttribs.writeLightmap(ptr + OFFSET_LIGHTMAP, packedLight);
+    }
+
+    private ParticleInstancedAttribs() {}
+}

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

@@ -0,0 +1,160 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.cel.api.util.NormI8;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFlags;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFormatElement;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.hooks.ImmediateExtendedAttribHandler;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL15;
+
+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;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutFloat;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutInt;
+
+public final class ParticleQuadMesh {
+
+    public static final int VERTEX_FLAGS = VertexFlags.TEXTURE_BIT;
+
+    public static final int VERTEX_COUNT = 4;
+    private static final int VERTEX_STRIDE = 24;
+
+    private static final int OFFSET_OFFSET = 0;
+    private static final int OFFSET_CORNER = 12;
+    private static final int OFFSET_TANGENT = 20;
+
+    private static final float[] CORNER_A = { -1.0f, -1.0f, 1.0f, 1.0f };
+    private static final float[] CORNER_B = { -1.0f, 1.0f, 1.0f, -1.0f };
+
+    private static int vao;
+    private static int vbo;
+    private static ByteBuffer staging;
+    private static boolean written;
+    private static float lastRotX, lastRotXZ, lastRotZ, lastRotYZ, lastRotXY;
+
+    private ParticleQuadMesh() {}
+
+    public static float cornerA(int corner) {
+        return CORNER_A[corner];
+    }
+
+    public static float cornerB(int corner) {
+        return CORNER_B[corner];
+    }
+
+    public static float offsetX(float a, float b, float rotX, float rotYZ) {
+        return a * rotX + b * rotYZ;
+    }
+
+    public static float offsetY(float b, float rotXZ) {
+        return b * rotXZ;
+    }
+
+    public static float offsetZ(float a, float b, float rotZ, float rotXY) {
+        return a * rotZ + b * rotXY;
+    }
+
+    public static int vao() {
+        if (vao == 0) build();
+        return vao;
+    }
+
+    public static void update(float rotX, float rotXZ, float rotZ, float rotYZ, float rotXY) {
+        if (vao == 0) build();
+        if (written && rotX == lastRotX && rotXZ == lastRotXZ && rotZ == lastRotZ && rotYZ == lastRotYZ && rotXY == lastRotXY) {
+            return;
+        }
+        lastRotX = rotX;
+        lastRotXZ = rotXZ;
+        lastRotZ = rotZ;
+        lastRotYZ = rotYZ;
+        lastRotXY = rotXY;
+        written = true;
+
+        write(memAddress0(staging), rotX, rotXZ, rotZ, rotYZ, rotXY);
+        final int savedVBO = GLStateManager.getBoundVBO();
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo);
+        staging.position(0).limit(VERTEX_COUNT * VERTEX_STRIDE);
+        GLStateManager.glBufferSubData(GL15.GL_ARRAY_BUFFER, 0L, staging);
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, savedVBO);
+    }
+
+    private static void write(long dst, float rotX, float rotXZ, float rotZ, float rotYZ, float rotXY) {
+        final int tangent = packTangent(rotX, 0.0f, rotZ);
+        long ptr = dst;
+        for (int i = 0; i < VERTEX_COUNT; i++) {
+            final float a = cornerA(i);
+            final float b = cornerB(i);
+            memPutFloat(ptr + OFFSET_OFFSET, offsetX(a, b, rotX, rotYZ));
+            memPutFloat(ptr + OFFSET_OFFSET + 4, offsetY(b, rotXZ));
+            memPutFloat(ptr + OFFSET_OFFSET + 8, offsetZ(a, b, rotZ, rotXY));
+            memPutFloat(ptr + OFFSET_CORNER, (a + 1.0f) * 0.5f);
+            memPutFloat(ptr + OFFSET_CORNER + 4, (b + 1.0f) * 0.5f);
+            memPutInt(ptr + OFFSET_TANGENT, tangent);
+            ptr += VERTEX_STRIDE;
+        }
+    }
+
+    private static int packTangent(float x, float y, float z) {
+        final float lenSq = x * x + y * y + z * z;
+        final float nx, ny, nz;
+        if (lenSq < 1.0e-12f) {
+            nx = 1.0f;
+            ny = 0.0f;
+            nz = 0.0f;
+        } else {
+            final float inv = (float) (1.0 / Math.sqrt(lenSq));
+            nx = x * inv;
+            ny = y * inv;
+            nz = z * inv;
+        }
+        return NormI8.pack(nx, ny, nz) | (127 << 24);
+    }
+
+    private static void build() {
+        final int savedVAO = GLStateManager.getBoundVAO();
+        final int savedVBO = GLStateManager.getBoundVBO();
+        vao = GLStateManager.glGenVertexArrays();
+        GLStateManager.glBindVertexArray(vao);
+        vbo = GLStateManager.glGenBuffers();
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo);
+        GLStateManager.glBufferData(GL15.GL_ARRAY_BUFFER, (long) VERTEX_COUNT * VERTEX_STRIDE, GL15.GL_DYNAMIC_DRAW);
+
+        attrib(VertexFormatElement.Usage.POSITION.getAttributeLocation(), 3, GL11.GL_FLOAT, false, OFFSET_OFFSET);
+        attrib(VertexFormatElement.Usage.PRIMARY_UV.getAttributeLocation(), 2, GL11.GL_FLOAT, false, OFFSET_CORNER);
+        attrib(ImmediateExtendedAttribHandler.LOC_TANGENT, 4, GL11.GL_BYTE, true, OFFSET_TANGENT);
+
+        ParticleInstancedAttribs.enableInstanceArrays();
+
+        GLStateManager.glBindVertexArray(savedVAO);
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, savedVBO);
+
+        if (staging == null) staging = memAlloc(VERTEX_COUNT * VERTEX_STRIDE);
+        written = false;
+    }
+
+    private static void attrib(int loc, int size, int type, boolean normalized, int offset) {
+        GLStateManager.glEnableVertexAttribArray(loc);
+        GLStateManager.glVertexAttribPointer(loc, size, type, normalized, VERTEX_STRIDE, offset);
+    }
+
+    public static void delete() {
+        if (vbo != 0) {
+            GLStateManager.glDeleteBuffers(vbo);
+            vbo = 0;
+        }
+        if (vao != 0) {
+            GLStateManager.glDeleteVertexArrays(vao);
+            vao = 0;
+        }
+        if (staging != null) {
+            memFree(staging);
+            staging = null;
+        }
+        written = false;
+    }
+}

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

@@ -102,7 +102,11 @@ public class Program {
             for (int i = 0; i < 4; i++) {
                 if (ffpProgram.locSampler[i] != -1) backend.uniform1i(ffpProgram.locSampler[i], i);
             }
-            backend.useProgram(previousProgram);
+            if (previousProgram != 0) {
+                backend.useProgram(previousProgram);
+            } else {
+                ShaderManager.getInstance().invalidateProgram();
+            }
 
             return ffpProgram;
         } catch (RuntimeException e) {

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

@@ -9,7 +9,6 @@ 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;
 
 
@@ -271,25 +270,6 @@ public class ShaderCache {
         }
     }
 
-    /** 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();
-        geometrySourceCache.clear();
-        lastProgram = null;
-        lastVK = Long.MIN_VALUE;
-        GLStateManager.LOGGER.debug("FFP shader cache cleared");
-    }
-
     public int getProgramCount() {
         return count;
     }

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

@@ -4,12 +4,13 @@ import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFlags;
 import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFormat;
 import com.gtnewhorizons.angelica.config.SystemProperties;
 import com.gtnewhorizons.angelica.glsm.CompatUniformManager;
+import com.gtnewhorizons.angelica.glsm.GLContextState;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.hooks.DeferredBlendHandler;
 import com.gtnewhorizons.angelica.glsm.hooks.GLSMHooks;
-import com.gtnewhorizons.angelica.glsm.hooks.GLSMInitConfig;
 import com.gtnewhorizons.angelica.glsm.QuadConverter;
 import com.gtnewhorizons.angelica.glsm.profiling.Tracy;
+import com.gtnewhorizons.angelica.glsm.stacks.StackIdAllocator;
 import com.gtnewhorizons.angelica.glsm.stacks.Vec3fStack;
 import com.gtnewhorizons.angelica.glsm.stacks.Vec4fStack;
 import com.gtnewhorizons.angelica.glsm.streaming.TessellatorStreamingDrawer;
@@ -26,45 +27,42 @@ import static com.gtnewhorizons.angelica.glsm.backend.BackendManager.RENDER_BACK
  */
 public final class ShaderManager {
 
-    private static final class Holder {
-
-        static final ShaderManager INSTANCE = new ShaderManager();
-    }
-
-    private final ShaderCache cache = new ShaderCache();
+    private static final ShaderCache cache = new ShaderCache();
     private final Uniforms uniforms = new Uniforms();
 
     @Getter
-    private boolean active = false;
+    private boolean active;
     private Program currentProgram = null;
-    private int lastBoundProgramId = -1;
+    private int lastBoundProgramId;
     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);
-    private static final Vector4f[] currentTexCoords = {
+    public final Vector3f currentNormal = new Vector3f(0.0f, 0.0f, 1.0f);
+    public final Vector4f[] currentTexCoords = {
         new Vector4f(0.0f, 0.0f, 0.0f, 1.0f),
         new Vector4f(0.0f, 0.0f, 0.0f, 1.0f),
         new Vector4f(0.0f, 0.0f, 0.0f, 1.0f),
         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(currentTexCoords[0]);
-    @Getter private static int normalGeneration;
-    @Getter private static int texCoordGeneration;
+    public final Vec3fStack normalStack = new Vec3fStack(currentNormal, StackIdAllocator.nextId());
+    public final Vec4fStack texCoordStack = new Vec4fStack(currentTexCoords[0], StackIdAllocator.nextId());
+    public int normalGeneration;
+    public int texCoordGeneration;
 
     private int preDrawCalls;
     private int lastFramePreDrawCalls;
 
     public static long variantSwitches;
 
-    public static Vector4f getCurrentTexCoord() { return currentTexCoords[0]; }
-    public static Vector4f getCurrentTexCoord(int unit) { return currentTexCoords[unit]; }
-    @Getter private boolean enabled = false;
+    public static Vector3f getCurrentNormal() { return GLStateManager.ctx().ffp.currentNormal; }
+    public static Vector4f getCurrentTexCoord() { return GLStateManager.ctx().ffp.currentTexCoords[0]; }
+    public static Vec3fStack getNormalStack() { return GLStateManager.ctx().ffp.normalStack; }
+    public static Vec4fStack getTexCoordStack() { return GLStateManager.ctx().ffp.texCoordStack; }
+    @Getter private static boolean enabled = false;
 
-    private ShaderManager() {
+    static {
         cache.setDumpDir(SystemProperties.shaderDumpDir("ffp"));
         VertexFormat.registerSetupBufferStateOverride((format, offset) -> {
             VAOManager.setCurrentVertexFlags(format.getVertexFlags());
@@ -72,18 +70,20 @@ public final class ShaderManager {
         });
     }
 
-    public static ShaderManager getInstance() {
-        return Holder.INSTANCE;
+    public ShaderManager() {
+        active = enabled;
+        lastBoundProgramId = enabled ? 0 : -1;
     }
 
-    public void enable() {
+    public static ShaderManager getInstance() {
+        return GLStateManager.ctx().ffp;
+    }
+
+    public static void enable() {
         warmUp();
         enabled = true;
-
-        if (GLStateManager.getActiveProgram() == 0) {
-            activate();
-        }
-
+        final GLContextState glCtx = GLStateManager.ctx();
+        if (glCtx.activeProgram == 0) glCtx.ffp.activate();
         GLStateManager.LOGGER.info("FFP shader emulation enabled");
     }
 
@@ -97,6 +97,8 @@ public final class ShaderManager {
             final long vkPacked = VertexKey.packFromState(true, true, true, true, fragMask);
             final VertexKey vk = VertexKey.fromPacked(vkPacked);
             VertexShaderGenerator.generate(vk);
+            VertexShaderGenerator.generate(VertexKey.fromPacked(VertexKey.withInstancing(vkPacked, Instancing.CUBE)));
+            VertexShaderGenerator.generate(VertexKey.fromPacked(VertexKey.withInstancing(vkPacked, Instancing.PARTICLE)));
             FragmentShaderGenerator.generate(FragmentKey.fromPacked(fkScratch, fkLen));
             GeometryShaderGenerator.generate(vk);
             final Class<?>[] touched = { Program.class, ShaderCache.class, TessellatorStreamingDrawer.class, QuadConverter.class };
@@ -108,13 +110,21 @@ public final class ShaderManager {
         }
     }
 
-    public void disable() {
+    public static void disable() {
         enabled = false;
     }
 
     public void activate() {
         active = true;
-        lastBoundProgramId = GLStateManager.getActiveProgram();
+        invalidateProgram();
+    }
+
+    /** Invalidate both binding and state key so the next draw selects and binds an FFP variant. */
+    public void invalidateProgram() {
+        lastBoundProgramId = -1;
+        currentProgram = null;
+        currentVertexKeyPacked = Long.MIN_VALUE;
+        uniforms.invalidateBinding();
     }
 
     public void deactivate() {
@@ -126,44 +136,46 @@ public final class ShaderManager {
         GLStateManager.forceAttribDefaultsDirty();
     }
 
-    public void preDraw() {
+    public void preDraw(GLContextState glCtx) {
+        GLSMHooks.resolvePendingProgram();
         final DeferredBlendHandler bh = GLSMHooks.blendHandler;
         if (bh != null) bh.flushDeferredBlend();
 
         // Handle FFP & Iris uniforms
-        final int currentProgramId = GLStateManager.getActiveProgram();
+        final int currentProgramId = glCtx.activeProgram;
         if (currentProgramId != 0) {
-            if (!CompatUniformManager.refreshCompatUniforms(currentProgramId)) {
+            if (!CompatUniformManager.refreshCompatUniforms(currentProgramId, glCtx)) {
                 return; // Don't emulate FFP on non-iris core shaders
             }
         }
 
-        final int vertexFlags = VAOManager.getCurrentVertexFlags();
+        final int vertexFlags = glCtx.vaos.getVertexFlags();
         final boolean hasColor = (vertexFlags & VertexFlags.COLOR_BIT) != 0;
         final boolean hasNormal =   (vertexFlags & VertexFlags.NORMAL_BIT) != 0;
         final boolean hasTexCoord = (vertexFlags & VertexFlags.TEXTURE_BIT) != 0;
         final boolean hasLightmap = (vertexFlags & VertexFlags.BRIGHTNESS_BIT) != 0;
-        GLStateManager.flushDeferredVertexAttribs(hasColor, hasNormal, hasTexCoord, hasLightmap);
+        GLStateManager.flushDeferredVertexAttribs(glCtx, hasColor, hasNormal, hasTexCoord, hasLightmap);
 
         if (!active) return;
 
         preDrawCalls++;
-        final int fkLen = FragmentKey.packFromState(currentFKScratch);
+        final int fkLen = FragmentKey.packFromState(currentFKScratch, glCtx);
         final int fragMask = FragmentKey.unitMaskFromPacked(currentFKScratch, fkLen);
-        final long vkPacked = VertexKey.packFromState(hasColor, hasNormal, hasTexCoord, hasLightmap, fragMask);
+        final long vkPacked = VertexKey.packFromState(hasColor, hasNormal, hasTexCoord, hasLightmap, fragMask, glCtx);
 
         if (vkPacked != currentVertexKeyPacked || !Arrays.equals(currentFKScratch, 0, fkLen, currentFKPacked, 0, currentFKLen)) {
             commitVariant(vkPacked, fkLen);
         }
 
-        uploadUniforms();
+        uploadUniforms(glCtx);
     }
 
     private void commitVariant(long vkPacked, int fkLen) {
-        currentVertexKeyPacked = vkPacked;
         System.arraycopy(currentFKScratch, 0, currentFKPacked, 0, fkLen);
         currentFKLen = fkLen;
         currentProgram = cache.getOrCreate(vkPacked, currentFKPacked, currentFKLen);
+        // Building a variant can invalidate the previous binding and key.
+        currentVertexKeyPacked = vkPacked;
         final int programId = currentProgram.getProgramId();
         if (programId != lastBoundProgramId) {
             if (Tracy.ENABLED) variantSwitches++;
@@ -172,48 +184,38 @@ public final class ShaderManager {
         }
     }
 
-    private void uploadUniforms() {
+    private void uploadUniforms(GLContextState glCtx) {
         if (currentProgram != null) {
-            uniforms.upload();
+            uniforms.upload(glCtx);
         }
     }
 
     public static void endFrame() {
-        final ShaderManager sm = Holder.INSTANCE;
+        final ShaderManager sm = GLStateManager.ctx().ffp;
         sm.lastFramePreDrawCalls = sm.preDrawCalls;
         sm.preDrawCalls = 0;
         sm.uniforms.endFrame();
         FfpExtendedAttribs.endFrame();
     }
 
-    public static void setCurrentNormal(float x, float y, float z) {
+    public void setNormal(float x, float y, float z) {
+        normalStack.beforeModify();
         currentNormal.set(x, y, z);
         normalGeneration++;
     }
 
-    public static void setCurrentTexCoord(float s, float t, float r, float q) {
+    public void setTexCoord(float s, float t, float r, float q) {
+        texCoordStack.beforeModify();
         currentTexCoords[0].set(s, t, r, q);
         texCoordGeneration++;
     }
 
-    public static void setCurrentTexCoord(int unit, float s, float t, float r, float q) {
+    public void setTexCoord(int unit, float s, float t, float r, float q) {
+        if (unit == 0) texCoordStack.beforeModify();
         currentTexCoords[unit].set(s, t, r, q);
         texCoordGeneration++;
     }
 
-    public static void bumpNormalGeneration() { normalGeneration++; }
-    public static void bumpTexCoordGeneration() { texCoordGeneration++; }
-
-    public void destroy() {
-        cache.destroy();
-        uniforms.destroy();
-        final GLSMInitConfig config = GLStateManager.getInitConfig();
-        if (config != null && config.getStreamingDrawerDestroy() != null) config.getStreamingDrawerDestroy().run();
-        QuadConverter.destroy();
-        active = false;
-        currentProgram = null;
-    }
-
     public String getDebugInfo() {
         return String.format("FFP: %d programs (%d vert, %d frag variants) | UBO: %d/%d draws wrote (mat %d, light %d, frag %d, misc %d)",
             cache.getProgramCount(), cache.getVertexVariantCount(), cache.getFragmentVariantCount(),

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

@@ -1,5 +1,6 @@
 package com.gtnewhorizons.angelica.glsm.ffp;
 
+import com.gtnewhorizons.angelica.glsm.GLContextState;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.ClipPlaneState;
 import com.gtnewhorizons.angelica.glsm.states.FogState;
@@ -7,9 +8,9 @@ import com.gtnewhorizons.angelica.glsm.states.LightState;
 import com.gtnewhorizons.angelica.glsm.states.LineState;
 import com.gtnewhorizons.angelica.glsm.states.MaterialState;
 import com.gtnewhorizons.angelica.glsm.states.TexGenState;
+import com.gtnewhorizons.angelica.glsm.states.TextureUnitArray;
 import com.gtnewhorizons.angelica.glsm.states.ViewportState;
 import com.gtnewhorizons.angelica.glsm.streaming.UniformRingBuffer;
-import com.gtnewhorizons.angelica.glsm.hooks.GLSMConfig;
 import org.joml.Math;
 import org.joml.Matrix3f;
 import org.joml.Matrix4f;
@@ -47,6 +48,7 @@ public class Uniforms {
     private float lightmapX = Float.NaN, lightmapY = Float.NaN, lineWidth = Float.NaN;
     private int viewportX = Integer.MIN_VALUE, viewportY = Integer.MIN_VALUE, viewportWidth = -1, viewportHeight = -1;
     private int lineStipple = -1;
+    private int weatherGen = -1;
 
     int blockWrites;
     int blockSkips;
@@ -81,66 +83,67 @@ public class Uniforms {
     private static final double LN2 = java.lang.Math.log(2.0);
     private static final double SQRT_LN2 = java.lang.Math.sqrt(LN2);
 
-    public void upload() {
+    public void upload(GLContextState glCtx) {
         boolean dirty = false;
         contentChanged = false;
 
-        final int mvG = GLStateManager.getMvGeneration();
-        final int projG = GLStateManager.getProjGeneration();
+        final int mvG = glCtx.mvGeneration;
+        final int projG = glCtx.projGeneration;
         final boolean mvChanged = mvG != mvGen;
         final boolean projChanged = projG != projGen;
         if (mvChanged || projChanged) {
-            stageMatrices(mvChanged, projChanged);
+            stageMatrices(mvChanged, projChanged, glCtx);
             mvGen = mvG;
             projGen = projG;
             stagedMatrices++;
             dirty = true;
         }
-        final int mvLinG = GLStateManager.getMvLinearGeneration();
+        final int mvLinG = glCtx.mvLinearGeneration;
         if (mvLinG != mvLinearGen) {
-            stageNormalMatrix();
+            stageNormalMatrix(glCtx);
             mvLinearGen = mvLinG;
             dirty = true;
         }
-        final int texMatG = GLStateManager.getTexMatrixGeneration();
+        final int texMatG = glCtx.texMatrixGeneration;
         if (texMatG != texMatGen) {
-            stageTextureMatrices();
+            stageTextureMatrices(glCtx);
             texMatGen = texMatG;
             dirty = true;
         }
-        final int litG = GLStateManager.getLightingGeneration();
+        final int litG = glCtx.lightingGeneration;
         if (litG != lightingGen) {
-            stageLighting();
+            stageLighting(glCtx);
             lightingGen = litG;
             stagedLighting++;
             dirty = true;
         }
-        final int colG = GLStateManager.getColorGeneration();
+        final int colG = glCtx.colorGeneration;
         if (colG != colorGen) {
-            stageCurrentColor();
+            stageCurrentColor(glCtx);
             colorGen = colG;
             stagedColor++;
             dirty = true;
         }
-        final int normG = ShaderManager.getNormalGeneration();
+        final ShaderManager ffp = glCtx.ffp;
+        final int normG = ffp.normalGeneration;
         if (normG != normalGen) {
-            final Vector3f normal = ShaderManager.getCurrentNormal();
+            final Vector3f normal = ffp.currentNormal;
             putVec3(FFPUniformBlock.CURRENT_NORMAL, normal.x, normal.y, normal.z);
             normalGen = normG;
             stagedNormal++;
             dirty = true;
         }
-        final int tcG = ShaderManager.getTexCoordGeneration();
+        final int tcG = ffp.texCoordGeneration;
         if (tcG != texCoordGen) {
-            putVec4(FFPUniformBlock.CURRENT_TEX_COORD_0, ShaderManager.getCurrentTexCoord(0));
-            putVec4(FFPUniformBlock.CURRENT_TEX_COORD_2, ShaderManager.getCurrentTexCoord(2));
-            putVec4(FFPUniformBlock.CURRENT_TEX_COORD_3, ShaderManager.getCurrentTexCoord(3));
+            putVec4(FFPUniformBlock.CURRENT_TEX_COORD_0, ffp.currentTexCoords[0]);
+            putVec4(FFPUniformBlock.CURRENT_TEX_COORD_2, ffp.currentTexCoords[2]);
+            putVec4(FFPUniformBlock.CURRENT_TEX_COORD_3, ffp.currentTexCoords[3]);
             texCoordGen = tcG;
             stagedTexCoord++;
             dirty = true;
         }
-        final float brightX = GLSMConfig.lastBrightnessX;
-        final float brightY = GLSMConfig.lastBrightnessY;
+        final float brightX = glCtx.lastBrightnessX;
+        final float brightY = glCtx.lastBrightnessY;
         if (brightX != lightmapX || brightY != lightmapY) {
             putFloat(FFPUniformBlock.CURRENT_LIGHTMAP_COORD, brightX);
             putFloat(FFPUniformBlock.CURRENT_LIGHTMAP_COORD + 4, brightY);
@@ -149,35 +152,36 @@ public class Uniforms {
             stagedLightmap++;
             dirty = true;
         }
-        final int tgG = GLStateManager.getTexGenGeneration();
+        final int tgG = glCtx.texGenGeneration;
         if (tgG != texGenGen) {
-            stageTexGen();
+            stageTexGen(glCtx);
             texGenGen = tgG;
             stagedTexGen++;
             dirty = true;
         }
-        final int cpG = GLStateManager.getClipPlaneGeneration();
+        final int cpG = glCtx.clipPlaneGeneration;
         if (cpG != clipPlaneGen) {
-            stageClipPlanes();
+            stageClipPlanes(glCtx);
             clipPlaneGen = cpG;
             stagedClipPlanes++;
             dirty = true;
         }
-        final int fragG = GLStateManager.getFragmentGeneration();
+        final int fragG = glCtx.fragmentGeneration;
         if (fragG != fragmentGen) {
-            stageFragment();
+            stageFragment(glCtx);
             fragmentGen = fragG;
             stagedFragment++;
             dirty = true;
         }
-        final float lw = GLStateManager.getLineState().getWidth();
+        final LineState line = glCtx.lineState;
+        final float lw = line.getWidth();
         if (lw != lineWidth) {
             putFloat(FFPUniformBlock.LINE_WIDTH, lw);
             lineWidth = lw;
             stagedMisc++;
             dirty = true;
         }
-        final ViewportState vp = GLStateManager.getViewportState();
+        final ViewportState vp = glCtx.viewportState;
         if (vp.x != viewportX || vp.y != viewportY || vp.width != viewportWidth || vp.height != viewportHeight) {
             putFloat(FFPUniformBlock.VIEWPORT_SIZE, vp.width);
             putFloat(FFPUniformBlock.VIEWPORT_SIZE + 4, vp.height);
@@ -189,8 +193,13 @@ public class Uniforms {
             stagedMisc++;
             dirty = true;
         }
-        final LineState line = GLStateManager.getLineState();
-        final int stippleFactor = line.getStippleFactor() < 1 ? 1 : line.getStippleFactor();
+        if (WeatherParams.generation != weatherGen) {
+            stageWeatherParams();
+            weatherGen = WeatherParams.generation;
+            stagedMisc++;
+            dirty = true;
+        }
+        final int stippleFactor = Math.max(line.getStippleFactor(), 1);
         final int stipplePacked = (line.getStipplePattern() & 0xFFFF) | (stippleFactor << 16);
         if (stipplePacked != lineStipple) {
             putInt(FFPUniformBlock.LINE_STIPPLE, stipplePacked);
@@ -215,9 +224,9 @@ public class Uniforms {
         }
     }
 
-    private void stageMatrices(boolean mvChanged, boolean projChanged) {
-        final Matrix4f mv = GLStateManager.getModelViewMatrix();
-        final Matrix4f proj = GLStateManager.getProjectionMatrix();
+    private void stageMatrices(boolean mvChanged, boolean projChanged, GLContextState glCtx) {
+        final Matrix4f mv = glCtx.modelViewMatrix;
+        final Matrix4f proj = glCtx.projectionMatrix;
         if (mvChanged) {
             putMat4(FFPUniformBlock.MODEL_VIEW_MATRIX, mv);
         }
@@ -228,8 +237,8 @@ public class Uniforms {
         putMat4(FFPUniformBlock.MVP_MATRIX, mvpMatrix);
     }
 
-    private void stageNormalMatrix() {
-        GLStateManager.getModelViewMatrix().normal(normalMatrix);
+    private void stageNormalMatrix(GLContextState glCtx) {
+        glCtx.modelViewMatrix.normal(normalMatrix);
         putMat3(FFPUniformBlock.NORMAL_MATRIX, normalMatrix);
         putFloat(FFPUniformBlock.NORMAL_SCALE, rescaleFactor(normalMatrix, tempVec3));
     }
@@ -239,18 +248,19 @@ public class Uniforms {
         return f > 1.0e-12f ? 1.0f / (float) Math.sqrt(f) : 1.0f;
     }
 
-    private void stageTextureMatrices() {
-        putMat4(FFPUniformBlock.TEXTURE_MATRIX_0, GLStateManager.getTextures().getTextureUnitMatrix(0));
-        putMat4(FFPUniformBlock.TEXTURE_MATRIX_2, GLStateManager.getTextures().getTextureUnitMatrix(2));
-        putMat4(FFPUniformBlock.TEXTURE_MATRIX_3, GLStateManager.getTextures().getTextureUnitMatrix(3));
-        putMat4(FFPUniformBlock.LIGHTMAP_TEXTURE_MATRIX, GLStateManager.getTextures().getTextureUnitMatrix(1));
+    private void stageTextureMatrices(GLContextState glCtx) {
+        final TextureUnitArray textures = glCtx.textures;
+        putMat4(FFPUniformBlock.TEXTURE_MATRIX_0, textures.getTextureUnitMatrix(0));
+        putMat4(FFPUniformBlock.TEXTURE_MATRIX_2, textures.getTextureUnitMatrix(2));
+        putMat4(FFPUniformBlock.TEXTURE_MATRIX_3, textures.getTextureUnitMatrix(3));
+        putMat4(FFPUniformBlock.LIGHTMAP_TEXTURE_MATRIX, textures.getTextureUnitMatrix(1));
     }
 
-    private void stageLighting() {
-        final MaterialState mat = GLStateManager.getFrontMaterial();
-        final Vector4f lmAmbient = GLStateManager.getLightModel().ambient;
-        final LightState light0 = GLStateManager.getLightDataStates()[0];
-        final LightState light1 = GLStateManager.getLightDataStates()[1];
+    private void stageLighting(GLContextState glCtx) {
+        final MaterialState mat = glCtx.frontMaterial;
+        final Vector4f lmAmbient = glCtx.lightModel.ambient;
+        final LightState light0 = glCtx.lightDataStates[0];
+        final LightState light1 = glCtx.lightDataStates[1];
 
         putVec4(FFPUniformBlock.LIGHT_MODEL_AMBIENT, lmAmbient);
         putVec4(FFPUniformBlock.MATERIAL_EMISSION, mat.emission);
@@ -284,8 +294,8 @@ public class Uniforms {
         putVec3(offset, lightVal.x * materialVal.x, lightVal.y * materialVal.y, lightVal.z * materialVal.z);
     }
 
-    private void stageCurrentColor() {
-        final var color = GLStateManager.getColor();
+    private void stageCurrentColor(GLContextState glCtx) {
+        final var color = glCtx.color;
         putVec4(FFPUniformBlock.CURRENT_COLOR,
             Math.clamp(0f, 1f, color.getRed()),
             Math.clamp(0f, 1f, color.getGreen()),
@@ -293,8 +303,8 @@ public class Uniforms {
             Math.clamp(0f, 1f, color.getAlpha()));
     }
 
-    private void stageTexGen() {
-        final TexGenState tg = GLStateManager.getTextures().getTexGenState(0);
+    private void stageTexGen(GLContextState glCtx) {
+        final TexGenState tg = glCtx.textures.getTexGenState(0);
         putPlane(FFPUniformBlock.TEX_GEN_OBJ_PLANE_S, tg.getObjectPlane(GL11.GL_S));
         putPlane(FFPUniformBlock.TEX_GEN_OBJ_PLANE_T, tg.getObjectPlane(GL11.GL_T));
         putPlane(FFPUniformBlock.TEX_GEN_OBJ_PLANE_R, tg.getObjectPlane(GL11.GL_R));
@@ -305,8 +315,8 @@ public class Uniforms {
         putPlane(FFPUniformBlock.TEX_GEN_EYE_PLANE_Q, tg.getEyePlane(GL11.GL_Q));
     }
 
-    private void stageClipPlanes() {
-        final ClipPlaneState cps = GLStateManager.getClipPlaneState();
+    private void stageClipPlanes(GLContextState glCtx) {
+        final ClipPlaneState cps = glCtx.clipPlaneState;
         clipPlaneBuf.clear();
         for (int i = 0; i < GLStateManager.MAX_CLIP_PLANES; i++) {
             cps.putEyePlane(i, clipPlaneBuf);
@@ -317,24 +327,24 @@ public class Uniforms {
         }
     }
 
-    private void stageFragment() {
-        putFloat(FFPUniformBlock.ALPHA_REF, GLStateManager.getAlphaState().getReference());
+    private void stageFragment(GLContextState glCtx) {
+        putFloat(FFPUniformBlock.ALPHA_REF, glCtx.alphaState.getReference());
 
         for (int i = 0; i < 4; i++) {
-            final var envState = GLStateManager.getTextures().getTexEnvState(i);
+            final var envState = glCtx.textures.getTexEnvState(i);
             putVec4(FFPUniformBlock.TEX_ENV_COLOR_0 + i * 16,
                 envState.envColorR, envState.envColorG, envState.envColorB, envState.envColorA);
         }
 
         putVec4(FFPUniformBlock.OVERLAY_COLOR,
-            GLStateManager.getOverlayR(), GLStateManager.getOverlayG(),
-            GLStateManager.getOverlayB(), GLStateManager.getOverlayA());
+            glCtx.overlayR, glCtx.overlayG,
+            glCtx.overlayB, glCtx.overlayA);
 
-        final var secondary = GLStateManager.getSecondaryColor();
+        final var secondary = glCtx.secondaryColor;
         putVec3(FFPUniformBlock.SECONDARY_COLOR, secondary.getRed(), secondary.getGreen(), secondary.getBlue());
 
         // Mesa STATE_FOG_PARAMS_OPTIMIZED
-        final FogState fog = GLStateManager.getFogState();
+        final FogState fog = glCtx.fogState;
         final float start = fog.getStart();
         final float end = fog.getEnd();
         final float density = fog.getDensity();
@@ -376,6 +386,15 @@ public class Uniforms {
         putVec3(offset + 32, m.m20(), m.m21(), m.m22());
     }
 
+    private void stageWeatherParams() {
+        putVec4(FFPUniformBlock.WEATHER_PARAMS_0, WeatherParams.translateX, WeatherParams.translateY,
+            WeatherParams.translateZ, WeatherParams.invRadius);
+        putVec4(FFPUniformBlock.WEATHER_PARAMS_1, WeatherParams.cameraFracX, WeatherParams.cameraFracZ,
+            WeatherParams.partialTicks, WeatherParams.age);
+        putVec4(FFPUniformBlock.WEATHER_PARAMS_2, WeatherParams.rainScroll, WeatherParams.snowScroll,
+            WeatherParams.rainStrength, 0.0f);
+    }
+
     private void putVec4(int offset, Vector4f v) {
         putVec4(offset, v.x, v.y, v.z, v.w);
     }
@@ -427,6 +446,10 @@ public class Uniforms {
         stagedMisc = 0;
     }
 
+    void invalidateBinding() {
+        bound = false;
+    }
+
     UniformRingBuffer getRing() {
         return ring;
     }

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

@@ -0,0 +1,161 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.cel.api.util.NormI8;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFlags;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFormatElement;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.hooks.ImmediateExtendedAttribHandler;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL15;
+
+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;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutFloat;
+import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memPutInt;
+
+public final class UnitCubeMesh {
+
+    public static final int VERTEX_FLAGS = VertexFlags.COLOR_BIT | VertexFlags.TEXTURE_BIT | VertexFlags.NORMAL_BIT;
+
+    public static final int FACE_COUNT = 6;
+    public static final int VERTEX_COUNT = 24;
+    public static final int VERTEX_STRIDE = 64;
+
+    public static final int OFFSET_POSITION = 0;
+    private static final int OFFSET_COLOR = 12;
+    public static final int OFFSET_MID = 16;
+    public static final int OFFSET_DELTA = 32;
+    public static final int OFFSET_NORMAL = 48;
+    public static final int OFFSET_TANGENT = 60;
+
+    public static final float[][] CORNERS = {
+        { 0, 0, 0 }, { 1, 0, 0 }, { 1, 1, 0 }, { 0, 1, 0 },
+        { 0, 0, 1 }, { 1, 0, 1 }, { 1, 1, 1 }, { 0, 1, 1 },
+    };
+
+    public record Span(int a, int z) {
+        public int texels(int sizeA, int sizeZ) {
+            return a * sizeA + z * sizeZ;
+        }
+    }
+
+    public record Net(Span uLow, Span uHigh, Span vLow, Span vHigh) {
+        public Span u(int vertex) {
+            return vertex == 0 || vertex == 3 ? uHigh : uLow;
+        }
+
+        public Span v(int vertex) {
+            return vertex >= 2 ? vHigh : vLow;
+        }
+    }
+
+    public record Face(int[] corners, float[] normal, float[] tangent, Net net) {}
+
+    public static final Face[] FACES = {
+        new Face(new int[] { 5, 1, 2, 6 }, new float[] { 1, 0, 0 }, new float[] { 0, 0, 1, 1 }, new Net(new Span(1, 1), new Span(1, 2), new Span(0, 1), new Span(1, 1))),
+        new Face(new int[] { 0, 4, 7, 3 }, new float[] { -1, 0, 0 }, new float[] { 0, 0, -1, 1 }, new Net(new Span(0, 0), new Span(0, 1), new Span(0, 1), new Span(1, 1))),
+        new Face(new int[] { 5, 4, 0, 1 }, new float[] { 0, -1, 0 }, new float[] { 1, 0, 0, 1 }, new Net(new Span(0, 1), new Span(1, 1), new Span(0, 0), new Span(0, 1))),
+        new Face(new int[] { 2, 3, 7, 6 }, new float[] { 0, 1, 0 }, new float[] { 1, 0, 0, -1 }, new Net(new Span(1, 1), new Span(2, 1), new Span(0, 1), new Span(0, 0))),
+        new Face(new int[] { 1, 0, 3, 2 }, new float[] { 0, 0, -1 }, new float[] { 1, 0, 0, 1 }, new Net(new Span(0, 1), new Span(1, 1), new Span(0, 1), new Span(1, 1))),
+        new Face(new int[] { 4, 5, 6, 7 }, new float[] { 0, 0, 1 }, new float[] { -1, 0, 0, 1 }, new Net(new Span(1, 2), new Span(2, 2), new Span(0, 1), new Span(1, 1))),
+    };
+
+    private static int vao;
+    private static int vbo;
+
+    private UnitCubeMesh() {}
+
+    public static void write(long dst) {
+        long ptr = dst;
+        for (int f = 0; f < FACE_COUNT; f++) {
+            final Face face = FACES[f];
+            final Net net = face.net();
+            final float midUA = (net.uLow().a() + net.uHigh().a()) * 0.5f;
+            final float midUZ = (net.uLow().z() + net.uHigh().z()) * 0.5f;
+            final float midVA = (net.vLow().a() + net.vHigh().a()) * 0.5f;
+            final float midVZ = (net.vLow().z() + net.vHigh().z()) * 0.5f;
+            for (int c = 0; c < 4; c++) {
+                final float[] corner = CORNERS[face.corners()[c]];
+                final Span u = net.u(c);
+                final Span v = net.v(c);
+                memPutFloat(ptr + OFFSET_POSITION, corner[0]);
+                memPutFloat(ptr + OFFSET_POSITION + 4, corner[1]);
+                memPutFloat(ptr + OFFSET_POSITION + 8, corner[2]);
+                memPutInt(ptr + OFFSET_COLOR, 0xFFFFFFFF);
+                memPutFloat(ptr + OFFSET_MID, midUA);
+                memPutFloat(ptr + OFFSET_MID + 4, midUZ);
+                memPutFloat(ptr + OFFSET_MID + 8, midVA);
+                memPutFloat(ptr + OFFSET_MID + 12, midVZ);
+                memPutFloat(ptr + OFFSET_DELTA, u.a() - midUA);
+                memPutFloat(ptr + OFFSET_DELTA + 4, u.z() - midUZ);
+                memPutFloat(ptr + OFFSET_DELTA + 8, v.a() - midVA);
+                memPutFloat(ptr + OFFSET_DELTA + 12, v.z() - midVZ);
+                memPutFloat(ptr + OFFSET_NORMAL, face.normal()[0]);
+                memPutFloat(ptr + OFFSET_NORMAL + 4, face.normal()[1]);
+                memPutFloat(ptr + OFFSET_NORMAL + 8, face.normal()[2]);
+                final float[] tangent = face.tangent();
+                memPutInt(ptr + OFFSET_TANGENT, packTangent(tangent[0], tangent[1], tangent[2], tangent[3]));
+                ptr += VERTEX_STRIDE;
+            }
+        }
+    }
+
+    private static int packTangent(float x, float y, float z, float w) {
+        return NormI8.pack(x, y, z) | (((int) (w * 127.0f) & 0xFF) << 24);
+    }
+
+    public static int vao() {
+        if (vao == 0) build();
+        return vao;
+    }
+
+    private static void build() {
+        final int savedVAO = GLStateManager.getBoundVAO();
+        final int savedVBO = GLStateManager.getBoundVBO();
+        vao = GLStateManager.glGenVertexArrays();
+        GLStateManager.glBindVertexArray(vao);
+        vbo = GLStateManager.glGenBuffers();
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo);
+
+        final int bytes = VERTEX_COUNT * VERTEX_STRIDE;
+        final ByteBuffer data = memAlloc(bytes);
+        try {
+            write(memAddress0(data));
+            data.position(0).limit(bytes);
+            GLStateManager.glBufferData(GL15.GL_ARRAY_BUFFER, data, GL15.GL_STATIC_DRAW);
+        } finally {
+            memFree(data);
+        }
+
+        attrib(VertexFormatElement.Usage.POSITION.getAttributeLocation(), 3, GL11.GL_FLOAT, false, OFFSET_POSITION);
+        attrib(VertexFormatElement.Usage.COLOR.getAttributeLocation(), 4, GL11.GL_UNSIGNED_BYTE, true, OFFSET_COLOR);
+        attrib(VertexFormatElement.Usage.PRIMARY_UV.getAttributeLocation(), 4, GL11.GL_FLOAT, false, OFFSET_MID);
+        attrib(VertexFormatElement.Usage.SECONDARY_UV.getAttributeLocation(), 4, GL11.GL_FLOAT, false, OFFSET_DELTA);
+        attrib(VertexFormatElement.Usage.NORMAL.getAttributeLocation(), 3, GL11.GL_FLOAT, false, OFFSET_NORMAL);
+        attrib(ImmediateExtendedAttribHandler.LOC_TANGENT, 4, GL11.GL_BYTE, true, OFFSET_TANGENT);
+
+        CubeInstancedAttribs.enableInstanceArrays();
+
+        GLStateManager.glBindVertexArray(savedVAO);
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, savedVBO);
+    }
+
+    private static void attrib(int loc, int size, int type, boolean normalized, int offset) {
+        GLStateManager.glEnableVertexAttribArray(loc);
+        GLStateManager.glVertexAttribPointer(loc, size, type, normalized, VERTEX_STRIDE, offset);
+    }
+
+    public static void delete() {
+        if (vbo != 0) {
+            GLStateManager.glDeleteBuffers(vbo);
+            vbo = 0;
+        }
+        if (vao != 0) {
+            GLStateManager.glDeleteVertexArrays(vao);
+            vao = 0;
+        }
+    }
+}

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

@@ -14,30 +14,34 @@ import static com.gtnewhorizons.angelica.glsm.backend.BackendManager.RENDER_BACK
 public final class VAOManager {
     public static final int MAX_ATTRIBS = 16;
 
-    public static final Int2ObjectOpenHashMap<VAOData> vaoMap = new Int2ObjectOpenHashMap<>();
+    public final Int2ObjectOpenHashMap<VAOData> vaoMap = new Int2ObjectOpenHashMap<>();
 
-    static final Int2ObjectOpenHashMap<VAOData> eboOwners = new Int2ObjectOpenHashMap<>();
+    final Int2ObjectOpenHashMap<VAOData> eboOwners = new Int2ObjectOpenHashMap<>();
 
-    private static VAOData current = null;
-    private static int currentVertexFlags = 0;
-    private static Attrib[] currentAttribs = null;
-    public static int boundEBO = 0;
+    private VAOData current = null;
+    private int currentVertexFlags = 0;
+    private Attrib[] currentAttribs = null;
+    public int boundEBO = 0;
 
-    private static int clientSideEnabledCount = 0;
+    private int clientSideEnabledCount = 0;
 
 
-    public static void init(int defaultVAO) {
+    public void init(int defaultVAO) {
         final VAOData data = new VAOData();
         current = data;
         currentAttribs = data.attribs;
         vaoMap.put(defaultVAO, data);
     }
 
-    public static void onBindEBO(int ebo) {
+    public boolean isInitialized() {
+        return current != null;
+    }
+
+    public void onBindEBO(int ebo) {
         boundEBO = ebo;
     }
 
-    public static void onBindVertexArrayPre(int vaoId) {
+    public void onBindVertexArrayPre(int vaoId) {
         // Save old VAO data
         if (current != null) {
             current.vertexFlags = currentVertexFlags;
@@ -62,14 +66,14 @@ public final class VAOManager {
         clientSideEnabledCount = data.clientSideEnabledCount;
     }
 
-    public static void onDeleteVertexArray(int vaoId) {
+    public void onDeleteVertexArray(int vaoId) {
         final VAOData data = vaoMap.remove(vaoId);
         if (data == null) return;
         removeEboOwner(data.ebo, data);
         if (data == current) current = null;
     }
 
-    public static void onDeleteBuffer(int buffer) {
+    public void onDeleteBuffer(int buffer) {
         if (buffer == 0) return;
         VAOData owner = eboOwners.remove(buffer);
         while (owner != null) {
@@ -80,12 +84,12 @@ public final class VAOManager {
         }
     }
 
-    private static void addEboOwner(int ebo, VAOData data) {
+    private void addEboOwner(int ebo, VAOData data) {
         if (ebo == 0) return;
         data.nextEboOwner = eboOwners.put(ebo, data);
     }
 
-    private static void removeEboOwner(int ebo, VAOData data) {
+    private void removeEboOwner(int ebo, VAOData data) {
         if (ebo == 0) return;
         VAOData node = eboOwners.get(ebo);
         if (node == data) {
@@ -105,10 +109,11 @@ public final class VAOManager {
         }
     }
 
-    public static void enableClientVertexFlag(int flag) { currentVertexFlags |= flag; }
-    public static void disableClientVertexFlag(int flag) { currentVertexFlags &= ~flag; }
-    public static int getCurrentVertexFlags() { return currentVertexFlags; }
-    public static void setCurrentVertexFlags(int flags) { currentVertexFlags = flags; }
+    public void enableClientVertexFlag(int flag) { currentVertexFlags |= flag; }
+    public void disableClientVertexFlag(int flag) { currentVertexFlags &= ~flag; }
+    public int getVertexFlags() { return currentVertexFlags; }
+    public void setVertexFlags(int flags) { currentVertexFlags = flags; }
+    public static void setCurrentVertexFlags(int flags) { GLStateManager.ctx().vaos.currentVertexFlags = flags; }
 
     public static final class VAOData {
         public Attrib[] attribs;
@@ -122,7 +127,7 @@ public final class VAOManager {
         }
     }
 
-    public static void setAttribute(int index, int size, int type, boolean normalized, int stride, long offset, int vboId) {
+    public void setAttribute(int index, int size, int type, boolean normalized, int stride, long offset, int vboId) {
         if (index < 0 || index >= MAX_ATTRIBS) return;
         final Attrib a = getAttrib(index);
         final boolean wasClient = a.clientPointer != null;
@@ -139,7 +144,7 @@ public final class VAOManager {
         }
     }
 
-    public static void setAttribute(int index, int size, int type, boolean normalized, int stride, ByteBuffer pointer) {
+    public void setAttribute(int index, int size, int type, boolean normalized, int stride, ByteBuffer pointer) {
         if (index < 0 || index >= MAX_ATTRIBS) return;
         final Attrib a = getAttrib(index);
         final boolean wasClient = a.clientPointer != null;
@@ -156,19 +161,19 @@ public final class VAOManager {
         }
     }
 
-    public static boolean isGenericPointerEnabled(int index) {
+    public boolean isGenericPointerEnabled(int index) {
         if (index < 0 || index >= MAX_ATTRIBS) return false;
         final Attrib a = currentAttribs[index];
         return a != null && a.genericPointer && a.enabled;
     }
 
-    public static void markConventional(int index) {
+    public void markConventional(int index) {
         if (index < 0 || index >= MAX_ATTRIBS) return;
         final Attrib a = currentAttribs[index];
         if (a != null) a.genericPointer = false;
     }
 
-    public static void setEnabled(int index, boolean enabled) {
+    public void setEnabled(int index, boolean enabled) {
         if (index < 0 || index >= MAX_ATTRIBS) return;
         final Attrib a = getAttrib(index);
         if (a.clientPointer != null && a.enabled != enabled) {
@@ -177,7 +182,7 @@ public final class VAOManager {
         a.enabled = enabled;
     }
 
-    public static void enableAttribute(int index) {
+    public void enableAttribute(int index) {
         if (index < 0 || index >= MAX_ATTRIBS) return;
         final Attrib a = getAttrib(index);
         if (a.clientPointer != null && !a.enabled) {
@@ -186,7 +191,7 @@ public final class VAOManager {
         a.enabled = true;
     }
 
-    public static void disableAttribute(int index) {
+    public void disableAttribute(int index) {
         if (index < 0 || index >= MAX_ATTRIBS) return;
         final Attrib a = getAttrib(index);
         if (a.clientPointer != null && a.enabled) {
@@ -196,7 +201,7 @@ public final class VAOManager {
     }
 
     // Lazily allocate each attrib. Most VAOs don't even have 4 attribs, let alone 16.
-    private static Attrib getAttrib(int index) {
+    private Attrib getAttrib(int index) {
         Attrib a = currentAttribs[index];
         if (a == null) {
             a = new Attrib();
@@ -205,28 +210,32 @@ public final class VAOManager {
         return a;
     }
 
-    public static boolean isClientSideAttrib(int index) {
+    public boolean isClientSideAttrib(int index) {
         final Attrib attrib = currentAttribs[index];
         return attrib != null && attrib.isClientSide();
     }
 
-    public static int getAttribEffectiveStride(int index) {
+    public Attrib attrib(int index) {
+        return currentAttribs[index];
+    }
+
+    public int attribEffectiveStride(int index) {
         final Attrib attrib = currentAttribs[index];
         return attrib != null ? attrib.effectiveStride() : 0;
     }
 
-    public static long getAttribOffset(int index) {
+    public long attribOffset(int index) {
         final Attrib attrib = currentAttribs[index];
         return attrib != null ? attrib.offset : 0;
     }
 
-    public static int getAttribVBO(int index) {
+    public int attribVBO(int index) {
         final Attrib attrib = currentAttribs[index];
         return attrib != null ? attrib.vboId : 0;
     }
 
     public static @Nullable Attrib get(int index) {
-        return currentAttribs[index];
+        return GLStateManager.ctx().vaos.attrib(index);
     }
 
 
@@ -236,7 +245,7 @@ public final class VAOManager {
      * (i.e. as a client-side pointer). In core profile, such attribs are treated as null
      * offsets into a non-existent buffer, causing a native crash at draw time.
      */
-    public static boolean hasAnyClientSideEnabledAttrib() {
+    public boolean hasAnyClientSideEnabledAttrib() {
         return clientSideEnabledCount > 0;
     }
 
@@ -244,15 +253,15 @@ public final class VAOManager {
      * If any enabled vertex attribute uses a client-side pointer (no VBO), upload all such
      * attribs into a shared stream VBO so the draw succeeds under core profile.
      */
-    private static int clientArraysVBO = 0;
-    private static int clientArraysVBOCapacity = 0;
-    private static final int[] clientArraysVBOOffsets = new int[VAOManager.MAX_ATTRIBS];
+    private int clientArraysVBO = 0;
+    private int clientArraysVBOCapacity = 0;
+    private final int[] clientArraysVBOOffsets = new int[VAOManager.MAX_ATTRIBS];
 
-    public static void uploadClientArraysToVBO() {
+    public void uploadClientArraysToVBO() {
         int totalBytes = 0;
         for (int i = 0; i < VAOManager.MAX_ATTRIBS; i++) {
             clientArraysVBOOffsets[i] = -1;
-            final VAOManager.Attrib a = VAOManager.get(i);
+            final VAOManager.Attrib a = currentAttribs[i];
             if (a == null || !a.enabled || a.clientPointer == null) continue;
             clientArraysVBOOffsets[i] = totalBytes;
             totalBytes += a.clientPointer.remaining();
@@ -275,7 +284,7 @@ public final class VAOManager {
 
         for (int i = 0; i < VAOManager.MAX_ATTRIBS; i++) {
             if (clientArraysVBOOffsets[i] < 0) continue;
-            final VAOManager.Attrib a = VAOManager.get(i);
+            final VAOManager.Attrib a = currentAttribs[i];
             RENDER_BACKEND.bufferSubData(GL15.GL_ARRAY_BUFFER, clientArraysVBOOffsets[i], a.clientPointer.duplicate());
             RENDER_BACKEND.vertexAttribPointer(i, a.size, a.type, a.normalized, a.stride, (long) clientArraysVBOOffsets[i]);
         }

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

@@ -2,6 +2,7 @@ package com.gtnewhorizons.angelica.glsm.ffp;
 
 import com.gtnewhorizon.gtnhlib.client.renderer.MatrixHelper;
 import com.gtnewhorizons.angelica.glsm.DisplayListManager;
+import com.gtnewhorizons.angelica.glsm.GLContextState;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.TexGenState;
 import com.gtnewhorizons.angelica.glsm.states.TextureUnitArray;
@@ -49,7 +50,14 @@ public final class VertexKey {
     private static final int BIT_UNIT_TEXMAT_BASE    = BIT_WIDE_LINE + 1;
     private static final int BIT_UNIT23_UV_FROM_UNIT0 = BIT_UNIT_TEXMAT_BASE + MAX_UNITS;
     private static final int BIT_LINE_STIPPLE        = BIT_UNIT23_UV_FROM_UNIT0 + 1;
-    private static final int BIT_INSTANCED           = BIT_LINE_STIPPLE + 1;
+    private static final int BIT_INSTANCING          = BIT_LINE_STIPPLE + 1;
+    private static final long INSTANCING_MASK        = 0x7L;
+
+    static {
+        if (Instancing.VALUES.length > INSTANCING_MASK + 1) {
+            throw new IllegalStateException("Instancing has outgrown the VertexKey field; widen INSTANCING_MASK");
+        }
+    }
 
     public static final int TG_NONE                  = 0;
     public static final int TG_OBJ_LINEAR            = 1;
@@ -97,7 +105,7 @@ public final class VertexKey {
     public boolean clipPlanesEnabled()    { return bit(BIT_CLIP_PLANES); }
     public boolean wideLineEmulation()   { return bit(BIT_WIDE_LINE); }
     public boolean lineStipple()          { return bit(BIT_LINE_STIPPLE); }
-    public boolean instancedDraw()       { return bit(BIT_INSTANCED); }
+    public Instancing instancing()         { return Instancing.VALUES[(int) ((packed >> BIT_INSTANCING) & INSTANCING_MASK)]; }
 
     public boolean cmReplacesAmbient()    { final int m = colorMaterialMode(); return m == CM_AMBIENT || m == CM_AMBIENT_AND_DIFFUSE; }
     public boolean cmReplacesDiffuse()    { final int m = colorMaterialMode(); return m == CM_DIFFUSE || m == CM_AMBIENT_AND_DIFFUSE; }
@@ -126,54 +134,66 @@ public final class VertexKey {
     }
 
     public static long packFromState(boolean hasColor, boolean hasNormal, boolean hasTexCoord, boolean hasLightmap, int fragUnitMask) {
+        return packFromState(hasColor, hasNormal, hasTexCoord, hasLightmap, fragUnitMask, GLStateManager.ctx());
+    }
+
+    public static long packFromState(boolean hasColor, boolean hasNormal, boolean hasTexCoord, boolean hasLightmap, int fragUnitMask, GLContextState glCtx) {
         long bits = 0;
 
-        final boolean lighting = GLStateManager.getLightingState().isEnabled();
+        final boolean lighting = glCtx.lightingState.isEnabled();
         if (lighting) {
             bits |= (1L << BIT_LIGHTING);
 
             for (int i = 0; i < FFP_LIGHT_COUNT; i++) {
-                if (!GLStateManager.getLightStates()[i].isEnabled()) continue;
+                if (!glCtx.lightStates[i].isEnabled()) continue;
                 bits |= (1L << (BIT_LIGHT_BASE + i));
                 // position.w == 0 means directional
-                if (GLStateManager.getLightDataStates()[i].position.w == 0.0f) {
+                if (glCtx.lightDataStates[i].position.w == 0.0f) {
                     bits |= (1L << (BIT_LIGHT_DIR_BASE + i));
                 }
             }
 
-            if (GLStateManager.getColorMaterial().isEnabled()) {
+            if (glCtx.colorMaterial.isEnabled()) {
                 bits |= (1L << BIT_COLOR_MATERIAL);
-                final int cmMode = encodeColorMaterialMode(GLStateManager.getColorMaterialParameter().getValue());
+                final int cmMode = encodeColorMaterialMode(glCtx.colorMaterialParameter.getValue());
                 bits |= ((long) cmMode & 0x7) << BIT_COLOR_MAT_MODE;
             }
 
-            if (GLStateManager.getLightModel().colorControl == GL12.GL_SEPARATE_SPECULAR_COLOR) {
+            if (glCtx.lightModel.colorControl == GL12.GL_SEPARATE_SPECULAR_COLOR) {
                 bits |= (1L << BIT_SEPARATE_SPECULAR);
             }
         }
 
-        if (GLStateManager.getFogMode().isEnabled()) {
+        if (glCtx.fogMode.isEnabled()) {
             bits |= (1L << BIT_FOG);
-            final int fogDistMode = GLStateManager.getFogState().getFogDistanceMode();
+            final int fogDistMode = glCtx.fogState.getFogDistanceMode();
             bits |= ((long) fogDistMode & 0x3) << BIT_FOG_DIST_MODE;
         }
 
-        if (GLStateManager.getNormalizeState().isEnabled()) {
+        if (glCtx.normalizeState.isEnabled()) {
             bits |= (1L << BIT_NORMALIZE);
         }
-        if (GLStateManager.getRescaleNormalState().isEnabled()) {
+        if (glCtx.rescaleNormalState.isEnabled()) {
             bits |= (1L << BIT_RESCALE_NORMAL);
         }
 
-        final TextureUnitArray texUnit = GLStateManager.getTextures();
+        final TextureUnitArray texUnit = glCtx.textures;
         for (int i = 0; i < MAX_UNITS; i++) {
             if ((fragUnitMask & (1 << i)) != 0) {
                 bits |= (1L << (BIT_UNIT_TEX_BASE + i));
             }
-            if (!MatrixHelper.isIdentity(texUnit.getTextureUnitMatrix(i))) {
-                bits |= (1L << (BIT_UNIT_TEXMAT_BASE + i));
-            }
         }
+        if (texUnit.texMatIdentityGen != glCtx.texMatrixGeneration) {
+            int mask = 0;
+            for (int i = 0; i < MAX_UNITS; i++) {
+                if (!MatrixHelper.isIdentity(texUnit.getTextureUnitMatrix(i))) {
+                    mask |= 1 << i;
+                }
+            }
+            texUnit.texMatIdentityMask = mask;
+            texUnit.texMatIdentityGen = glCtx.texMatrixGeneration;
+        }
+        bits |= ((long) texUnit.texMatIdentityMask) << BIT_UNIT_TEXMAT_BASE;
 
         // TexGen (unit 0 only) - per-coordinate mode if enabled.
         // TODO: per-unit texgen for units 2/3. Deferred - no MC code path uses glTexGen on those.
@@ -210,29 +230,31 @@ public final class VertexKey {
         if (hasTexCoord) bits |= (1L << BIT_HAS_VERTEX_TEX);
         if (hasLightmap) bits |= (1L << BIT_HAS_VERTEX_LIGHTMAP);
 
-        if (GLStateManager.consumeUnit23TexCoordSetDuringDraw() && hasTexCoord) {
+        if (GLStateManager.consumeUnit23TexCoordSetDuringDraw(glCtx) && hasTexCoord) {
             bits |= (1L << BIT_UNIT23_UV_FROM_UNIT0);
         }
 
-        if (GLStateManager.anyClipPlaneEnabled()) {
+        if (GLStateManager.anyClipPlaneEnabled(glCtx)) {
             bits |= (1L << BIT_CLIP_PLANES);
         }
 
-        if (GLStateManager.wideLineEmulationActive) {
+        if (glCtx.wideLineEmulationActive) {
             bits |= (1L << BIT_WIDE_LINE);
         }
 
-        if (GLStateManager.lineStippleActive) {
+        if (glCtx.lineStippleActive) {
             bits |= (1L << BIT_LINE_STIPPLE);
         }
 
-        if (GLStateManager.instancedFfpDrawActive) {
-            bits |= (1L << BIT_INSTANCED);
-        }
+        bits |= (long) glCtx.ffpInstancing.ordinal() << BIT_INSTANCING;
 
         return bits;
     }
 
+    static long withInstancing(long packed, Instancing kind) {
+        return (packed & ~(INSTANCING_MASK << BIT_INSTANCING)) | ((long) kind.ordinal() << BIT_INSTANCING);
+    }
+
     public static VertexKey fromState(boolean hasColor, boolean hasNormal, boolean hasTexCoord, boolean hasLightmap, int fragUnitMask) {
         return new VertexKey(packFromState(hasColor, hasNormal, hasTexCoord, hasLightmap, fragUnitMask));
     }
@@ -255,12 +277,6 @@ public final class VertexKey {
 
     @Override
     public String toString() {
-        return String.format("FFPVertexKey[0x%011X: lit=%b l0=%b l1=%b cm=%b fog=%b tex=%d%d%d%d texmat=%d%d%d%d col=%b nrm=%b vtex=%b vlm=%b tg=%d/%d/%d/%d clip=%b wline=%b inst=%b]",
-            packed, lightingEnabled(), lightEnabled(0), lightEnabled(1),
-            colorMaterialEnabled(), fogEnabled(),
-            unitTexCoordEnabled(0)?1:0, unitTexCoordEnabled(1)?1:0, unitTexCoordEnabled(2)?1:0, unitTexCoordEnabled(3)?1:0,
-            unitTexMatEnabled(0)?1:0, unitTexMatEnabled(1)?1:0, unitTexMatEnabled(2)?1:0, unitTexMatEnabled(3)?1:0,
-            hasVertexColor(), hasVertexNormal(), hasVertexTexCoord(), hasVertexLightmap(),
-            texGenModeS(), texGenModeT(), texGenModeR(), texGenModeQ(), clipPlanesEnabled(), wideLineEmulation(), instancedDraw());
+        return String.format("FFPVertexKey[0x%011X: lit=%b l0=%b l1=%b cm=%b fog=%b tex=%d%d%d%d texmat=%d%d%d%d col=%b nrm=%b vtex=%b vlm=%b tg=%d/%d/%d/%d clip=%b wline=%b inst=%s]", packed,lightingEnabled(), lightEnabled(0), lightEnabled(1), colorMaterialEnabled(), fogEnabled(), unitTexCoordEnabled(0)?1:0, unitTexCoordEnabled(1)?1:0, unitTexCoordEnabled(2)?1:0, unitTexCoordEnabled(3)?1:0, unitTexMatEnabled(0)?1:0, unitTexMatEnabled(1)?1:0, unitTexMatEnabled(2)?1:0, unitTexMatEnabled(3)?1:0, hasVertexColor(), hasVertexNormal(), hasVertexTexCoord(), hasVertexLightmap(), texGenModeS(), texGenModeT(), texGenModeR(), texGenModeQ(), clipPlanesEnabled(), wideLineEmulation(), instancing());
     }
 }

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

@@ -21,6 +21,10 @@ public final class VertexShaderGenerator {
         emitOutputs(sb, key);
 
         sb.append("void main() {\n");
+        if (key.instancing() == Instancing.WEATHER) {
+            sb.append("  ").append(InstancedGlslHelpers.weatherPrologue("u_", "a_", "a_TexCoord0",
+                "vec4 weatherVertex", "vec4 weatherColor", "vec4 weatherTex0", "vec4 weatherTex1", "\n  ")).append('\n');
+        }
         emitPositionTransform(sb, key);
         if (key.lightingEnabled()) {
             emitNormalTransform(sb, key);
@@ -55,31 +59,44 @@ public final class VertexShaderGenerator {
     }
 
     private static void emitAttributes(StringBuilder sb, VertexKey key) {
+        final Instancing kind = key.instancing();
         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()) {
+        if (kind == Instancing.PARTICLE || kind == Instancing.WEATHER) {
             sb.append("layout(location = ").append(VertexFormatElement.Usage.PRIMARY_UV.getAttributeLocation()).append(") in vec2 a_TexCoord0;\n");
+        } else {
+            if (key.hasVertexColor()) {
+                sb.append("layout(location = ").append(VertexFormatElement.Usage.COLOR.getAttributeLocation()).append(") in vec4 a_Color;\n");
+            }
+            if (kind != Instancing.CUBE) {
+                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() || kind == Instancing.CUBE) {
+                sb.append("layout(location = ").append(VertexFormatElement.Usage.NORMAL.getAttributeLocation()).append(") in vec3 a_Normal;\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");
-        }
-        if (key.instancedDraw()) {
-            sb.append("layout(location = ").append(InstancedAttribs.LOC_MATRIX_COL0).append(") in vec4 a_InstCol0;\n");
-            sb.append("layout(location = ").append(InstancedAttribs.LOC_MATRIX_COL1).append(") in vec4 a_InstCol1;\n");
-            sb.append("layout(location = ").append(InstancedAttribs.LOC_MATRIX_COL2).append(") in vec4 a_InstCol2;\n");
-            sb.append("layout(location = ").append(InstancedAttribs.LOC_MATRIX_COL3).append(") in vec4 a_InstCol3;\n");
-            sb.append("layout(location = ").append(InstancedAttribs.LOC_COLOR).append(") in vec4 a_InstColor;\n");
-            sb.append("layout(location = ").append(InstancedAttribs.LOC_LIGHTMAP).append(") in vec2 a_InstLightmap;\n");
+        for (String d : InstancedGlslHelpers.attributeDecls("a_", kind)) {
+            sb.append(d).append('\n');
         }
         sb.append('\n');
     }
 
+    private static final String PARTICLE_UV = InstancedGlslHelpers.particleUv("a_InstUv", "a_TexCoord0");
+
+    private static String unit0Source(VertexKey key) {
+        return switch (key.instancing()) {
+            case CUBE -> "cubeUv";
+            case PARTICLE -> PARTICLE_UV;
+            case WEATHER -> "weatherTex0";
+            case NONE, TEMPLATE -> key.hasVertexTexCoord() ? "vec4(a_TexCoord0, 0.0, 1.0)" : "u_CurrentTexCoord0";
+        };
+    }
+
     private static void emitLineStart(StringBuilder sb) {
         sb.append("  vec2 ndc = gl_Position.xy / gl_Position.w;\n");
         sb.append("  v_LineStart = u_Viewport.xy + (ndc * 0.5 + 0.5) * u_Viewport.zw;\n\n");
@@ -93,6 +110,10 @@ public final class VertexShaderGenerator {
     private static void emitOutputs(StringBuilder sb, VertexKey key) {
         sb.append("// Outputs\n");
         sb.append("out vec4 v_Color;\n");
+        if (key.instancing().hasInstanceHead()) {
+            sb.append("out vec4 v_Overlay;\n");
+            sb.append("invariant gl_Position;\n");
+        }
         if (key.lineStipple()) {
             sb.append("flat out vec2 v_LineStart;\n");
         }
@@ -116,11 +137,18 @@ public final class VertexShaderGenerator {
 
     private static void emitPositionTransform(StringBuilder sb, VertexKey key) {
         sb.append("  // Position transform\n");
-        sb.append("  vec4 pos4 = vec4(a_Position, 1.0);\n");
-        if (key.instancedDraw()) {
-            sb.append("  mat4 instMV = mat4(a_InstCol0, a_InstCol1, a_InstCol2, a_InstCol3);\n");
+        if (key.instancing() == Instancing.PARTICLE) {
+            sb.append("  vec4 pos4 = ").append(InstancedGlslHelpers.particlePos("a_InstCenterHalf", "a_Position")).append(";\n");
+        } else if (key.instancing() == Instancing.WEATHER) {
+            sb.append("  vec4 pos4 = weatherVertex;\n");
+        } else {
+            sb.append("  vec4 pos4 = vec4(a_Position, 1.0);\n");
+        }
+        if (key.instancing().hasInstanceHead()) {
+            sb.append("  mat4 instMV = ").append(InstancedGlslHelpers.mat4FromRows("a_InstRow0", "a_InstRow1", "a_InstRow2")).append(";\n");
             sb.append("  vec4 eyePos = instMV * pos4;\n");
             sb.append("  gl_Position = u_ProjectionMatrix * eyePos;\n");
+            sb.append("  v_Overlay = a_InstOverlay;\n");
         } else {
             sb.append("  gl_Position = u_MVPMatrix * pos4;\n");
 
@@ -134,8 +162,8 @@ public final class VertexShaderGenerator {
 
     private static void emitNormalTransform(StringBuilder sb, VertexKey key) {
         sb.append("  // Normal transform\n");
-        final String srcNormal = key.hasVertexNormal() ? "a_Normal" : "u_CurrentNormal";
-        if (key.instancedDraw()) {
+        final String srcNormal = key.hasVertexNormal() && key.instancing() != Instancing.PARTICLE ? "a_Normal" : "u_CurrentNormal";
+        if (key.instancing().hasInstanceHead()) {
             sb.append("  vec3 normal = normalize(mat3(instMV) * ").append(srcNormal).append(");\n");
             sb.append('\n');
             return;
@@ -156,9 +184,13 @@ public final class VertexShaderGenerator {
         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");
-            if (key.instancedDraw()) {
-                sb.append(" * a_InstColor");
+            if (key.instancing() == Instancing.PARTICLE) {
+                sb.append("a_InstColor");
+            } else {
+                sb.append(key.hasVertexColor() ? "a_Color" : "u_CurrentColor");
+                if (key.instancing().hasInstanceHead()) {
+                    sb.append(" * a_InstColor");
+                }
             }
             sb.append(";\n");
 
@@ -255,22 +287,28 @@ public final class VertexShaderGenerator {
     private static void emitColorPassthrough(StringBuilder sb, VertexKey key) {
         sb.append("  // Color passthrough (no lighting)\n");
         final String src = key.hasVertexColor() ? "a_Color" : "u_CurrentColor";
-        if (key.instancedDraw()) {
-            sb.append("  v_Color = ").append(src).append(" * a_InstColor;\n");
-        } else {
-            sb.append("  v_Color = ").append(src).append(";\n");
+        switch (key.instancing()) {
+            case PARTICLE -> sb.append("  v_Color = a_InstColor;\n");
+            case WEATHER -> sb.append("  v_Color = weatherColor;\n");
+            case TEMPLATE, CUBE -> sb.append("  v_Color = ").append(src).append(" * a_InstColor;\n");
+            case NONE -> sb.append("  v_Color = ").append(src).append(";\n");
         }
         sb.append('\n');
     }
 
     private static void emitTexCoordPassthrough(StringBuilder sb, VertexKey key) {
+        final boolean cube = key.instancing() == Instancing.CUBE;
+        final boolean unit0FromCube = cube && key.unitTexCoordEnabled(0) && !key.texGenEnabled();
+        final boolean unit23FromCube = cube && key.unit23UvFromUnit0() && (key.unitTexCoordEnabled(2) || key.unitTexCoordEnabled(3));
+        if (unit0FromCube || unit23FromCube) {
+            emitCubeTexCoord(sb);
+        }
+
         if (key.texGenEnabled()) {
             emitTexGenCoordGeneration(sb, key);
         } else if (key.unitTexCoordEnabled(0)) {
             sb.append("  // Texture coordinates - unit 0\n");
-            final String src = key.hasVertexTexCoord()
-                ? "vec4(a_TexCoord0, 0.0, 1.0)"
-                : "u_CurrentTexCoord0";
+            final String src = unit0Source(key);
             if (key.unitTexMatEnabled(0)) {
                 sb.append("  v_TexCoord0 = u_TextureMatrix0 * ").append(src).append(";\n");
             } else {
@@ -279,20 +317,18 @@ public final class VertexShaderGenerator {
         }
 
         if (key.lightmapEnabled()) {
-            if (key.instancedDraw()) {
-                sb.append("  v_TexCoord1 = u_LightmapTextureMatrix * vec4(a_InstLightmap, 0.0, 1.0);\n");
-            } else 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");
-            }
+            final String lightmap = switch (key.instancing()) {
+                case PARTICLE, TEMPLATE -> "a_InstLightmap";
+                case CUBE -> "a_InstLightmapScale.xy";
+                case WEATHER -> "weatherTex1.xy";
+                case NONE -> key.hasVertexLightmap() ? "a_TexCoord1" : "u_CurrentLightmapCoord";
+            };
+            sb.append("  v_TexCoord1 = u_LightmapTextureMatrix * vec4(").append(lightmap).append(", 0.0, 1.0);\n");
         }
 
         for (int i = 2; i < VertexKey.MAX_UNITS; i++) {
             if (!key.unitTexCoordEnabled(i)) continue;
-            final String src = key.unit23UvFromUnit0()
-                ? "vec4(a_TexCoord0, 0.0, 1.0)"
-                : "u_CurrentTexCoord" + i;
+            final String src = key.unit23UvFromUnit0() ? unit0Source(key) : "u_CurrentTexCoord" + i;
             if (!key.unit23UvFromUnit0() && key.unitTexMatEnabled(i)) {
                 sb.append("  v_TexCoord").append(i).append(" = u_TextureMatrix").append(i).append(" * ").append(src).append(";\n");
             } else {
@@ -301,6 +337,12 @@ public final class VertexShaderGenerator {
         }
     }
 
+    private static void emitCubeTexCoord(StringBuilder sb) {
+        sb.append("  // Cube texture net\n");
+        sb.append("  ").append(InstancedGlslHelpers.cubePrelude("", "a_CubeMid", "a_CubeDelta", "a_Normal", "a_CubeTex", "\n  ")).append('\n');
+        sb.append("  vec4 cubeUv = ").append(InstancedGlslHelpers.cubeUv("a_CubeTex", "a_InstLightmapScale", "cubeU.x", "cubeU.y", "cubeV.x", "cubeV.y")).append(";\n\n");
+    }
+
     /**
      * Emit per-coordinate texgen code following Mesa's ffvertex_prog.c build order.
      * OBJ_LINEAR: dot(pos4, objPlane), EYE_LINEAR: dot(eyePos, eyePlane).

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

@@ -0,0 +1,34 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import org.lwjgl.opengl.GL11;
+
+
+/**
+ * One rain or snow column per instance.
+ */
+public final class WeatherInstancedAttribs {
+
+    public static final int LOC_COLUMN_SPAN = ParticleInstancedAttribs.LOC_CENTER_HALF;
+    public static final int LOC_JITTER = ParticleInstancedAttribs.LOC_UV;
+    public static final int LOC_PARAMS = InstancedAttribs.LOC_COLOR;
+
+    public static final int OFFSET_COLUMN_SPAN = 0;
+    public static final int OFFSET_JITTER = 16;
+    public static final int OFFSET_PARAMS = 32;
+    public static final int STRIDE = 48;
+
+    public static void pointInstanceAttribs(long base) {
+        GLStateManager.glVertexAttribPointer(LOC_COLUMN_SPAN, 4, GL11.GL_FLOAT, false, STRIDE, base + OFFSET_COLUMN_SPAN);
+        GLStateManager.glVertexAttribPointer(LOC_JITTER, 4, GL11.GL_FLOAT, false, STRIDE, base + OFFSET_JITTER);
+        GLStateManager.glVertexAttribPointer(LOC_PARAMS, 4, GL11.GL_FLOAT, false, STRIDE, base + OFFSET_PARAMS);
+    }
+
+    static void enableInstanceArrays() {
+        InstancedAttribs.enableInstanced(LOC_COLUMN_SPAN);
+        InstancedAttribs.enableInstanced(LOC_JITTER);
+        InstancedAttribs.enableInstanced(LOC_PARAMS);
+    }
+
+    private WeatherInstancedAttribs() {}
+}

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

@@ -0,0 +1,42 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+/**
+ * The per-frame half of the rain and snow instancing, set once per weather draw.
+ */
+public final class WeatherParams {
+
+    public static float translateX;
+    public static float translateY;
+    public static float translateZ;
+    public static float invRadius;
+
+    public static float cameraFracX;
+    public static float cameraFracZ;
+    public static float partialTicks;
+    public static float age;
+
+    public static float rainScroll;
+    public static float snowScroll;
+    public static float rainStrength;
+
+    public static int generation;
+
+    private WeatherParams() {}
+
+    public static void set(float translateX, float translateY, float translateZ, float invRadius,
+        float cameraFracX, float cameraFracZ, float partialTicks, float age,
+        float rainScroll, float snowScroll, float rainStrength) {
+        WeatherParams.translateX = translateX;
+        WeatherParams.translateY = translateY;
+        WeatherParams.translateZ = translateZ;
+        WeatherParams.invRadius = invRadius;
+        WeatherParams.cameraFracX = cameraFracX;
+        WeatherParams.cameraFracZ = cameraFracZ;
+        WeatherParams.partialTicks = partialTicks;
+        WeatherParams.age = age;
+        WeatherParams.rainScroll = rainScroll;
+        WeatherParams.snowScroll = snowScroll;
+        WeatherParams.rainStrength = rainStrength;
+        generation++;
+    }
+}

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

@@ -0,0 +1,69 @@
+package com.gtnewhorizons.angelica.glsm.ffp;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFlags;
+import com.gtnewhorizon.gtnhlib.client.renderer.vertex.VertexFormatElement;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import org.lwjgl.opengl.GL11;
+import org.lwjgl.opengl.GL15;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+/**
+ * The four corners every rain and snow column is expanded from. x picks the end of the billboard, y picks
+ * the bottom or top edge.
+ */
+public final class WeatherQuadMesh {
+
+    public static final int VERTEX_FLAGS = VertexFlags.TEXTURE_BIT;
+    public static final int VERTEX_COUNT = 4;
+
+    private static final float[] CORNERS = { 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f };
+
+    private static int vao;
+    private static int vbo;
+
+    private WeatherQuadMesh() {}
+
+    public static int vao() {
+        if (vao != 0) return vao;
+
+        final ByteBuffer data = ByteBuffer.allocateDirect(CORNERS.length * Float.BYTES).order(ByteOrder.nativeOrder());
+        for (float corner : CORNERS) data.putFloat(corner);
+        data.flip();
+
+        vao = GLStateManager.glGenVertexArrays();
+        GLStateManager.glBindVertexArray(vao);
+        vbo = GLStateManager.glGenBuffers();
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, vbo);
+        GLStateManager.glBufferData(GL15.GL_ARRAY_BUFFER, data, GL15.GL_STATIC_DRAW);
+
+        final int corner = VertexFormatElement.Usage.PRIMARY_UV.getAttributeLocation();
+        GLStateManager.glEnableVertexAttribArray(corner);
+        GLStateManager.glVertexAttribPointer(corner, 2, GL11.GL_FLOAT, false, 2 * Float.BYTES, 0L);
+        WeatherInstancedAttribs.enableInstanceArrays();
+
+        GLStateManager.glBindVertexArray(0);
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
+        return vao;
+    }
+
+    public static void bindInstanceBuffer(int bufferId) {
+        GLStateManager.glBindVertexArray(vao());
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, bufferId);
+        WeatherInstancedAttribs.pointInstanceAttribs(0L);
+        GLStateManager.glBindVertexArray(0);
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
+    }
+
+    public static void delete() {
+        if (vbo != 0) {
+            GLStateManager.glDeleteBuffers(vbo);
+            vbo = 0;
+        }
+        if (vao != 0) {
+            GLStateManager.glDeleteVertexArrays(vao);
+            vao = 0;
+        }
+    }
+}

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/hooks/BatchStateGuard.java

@@ -0,0 +1,30 @@
+package com.gtnewhorizons.angelica.glsm.hooks;
+
+import com.gtnewhorizons.angelica.glsm.DisplayListManager;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.recording.CommandRecorder;
+
+/** Drains deferred geometry before changing state that is not stored with each batch. */
+public final class BatchStateGuard {
+    public static Runnable flush;
+    private static int suspended;
+
+    private BatchStateGuard() {}
+
+    public static void suspend() { suspended++; }
+    public static void resume() { suspended--; }
+    public static boolean isSuspended() { return suspended != 0; }
+
+    public static void beforeChange() {
+        if (flush == null || suspended != 0 || !GLStateManager.isMainThread()
+            || DisplayListManager.getRecordMode() == DisplayListManager.RecordMode.COMPILE) return;
+        final CommandRecorder recorder = DisplayListManager.isRecording() ? DisplayListManager.pauseRecording() : null;
+        suspend();
+        try {
+            flush.run();
+        } finally {
+            resume();
+            if (recorder != null) DisplayListManager.resumeRecording(recorder);
+        }
+    }
+}

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/hooks/DeferredAlphaHandler.java

@@ -2,6 +2,6 @@ package com.gtnewhorizons.angelica.glsm.hooks;
 
 public interface DeferredAlphaHandler {
     boolean isAlphaTestLocked();
-    void deferAlphaTestToggle(boolean enabled);
-    void deferAlphaFunc(int function, float reference);
+    boolean deferAlphaTestToggle(boolean enabled);
+    boolean deferAlphaFunc(int function, float reference);
 }

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/hooks/FrameHooks.java

@@ -41,10 +41,6 @@ public final class FrameHooks {
         BackendManager.shutdown();
     }
 
-    public static void bindSplashVao() {
-        GLStateManager.glBindVertexArray(GLStateManager.glGenVertexArrays());
-    }
-
     public static void splashFinished() {
         GLStateManager.markSplashComplete("SplashProgress.finish");
     }

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/hooks/GLSMConfig.java

@@ -1,17 +1,17 @@
 package com.gtnewhorizons.angelica.glsm.hooks;
 
-public final class GLSMConfig {
+import com.gtnewhorizons.angelica.glsm.GLContextState;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
 
-    // Lightmap (replaces OpenGlHelper.lastBrightnessX/Y)
-    public static float lastBrightnessX;
-    public static float lastBrightnessY;
+public final class GLSMConfig {
 
     public static int packBrightness(float x, float y) {
         return ((int) y << 16) | ((int) x & 0xFFFF);
     }
 
     public static int packedLastBrightness() {
-        return packBrightness(lastBrightnessX, lastBrightnessY);
+        final GLContextState glCtx = GLStateManager.ctx();
+        return packBrightness(glCtx.lastBrightnessX, glCtx.lastBrightnessY);
     }
 
     public static boolean hudCacheOverride;

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/hooks/GLSMHooks.java

@@ -1,5 +1,6 @@
 package com.gtnewhorizons.angelica.glsm.hooks;
 
+import com.gtnewhorizons.angelica.glsm.DisplayListManager;
 import com.gtnewhorizons.angelica.glsm.hooks.events.*;
 import net.minecraftforge.eventbus.api.bus.EventBus;
 
@@ -14,6 +15,12 @@ public final class GLSMHooks {
     public static ShaderTransformPostProcessor postTransformProcessor;
     public static PerFrameUniformBlock perFrameUniformBlock;
     public static PerFrameUniformBlock perPassUniformBlock;
+    public static PendingProgramSelection pendingProgramSelection;
+
+    public static void resolvePendingProgram() {
+        final PendingProgramSelection p = pendingProgramSelection;
+        if (p != null && !DisplayListManager.isRecording()) p.resolvePendingProgram();
+    }
 
     // EventBus instances
     public static final EventBus<TextureBindEvent> TEXTURE_BIND = EventBus.create(TextureBindEvent.class);

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/hooks/GLSMInitConfig.java

@@ -12,7 +12,6 @@ public final class GLSMInitConfig {
     @Getter private final boolean lwjglDebug;
     @Getter private final StreamingUploader.UploadStrategy streamingUploadStrategy;
     @Getter private final Consumer<DirectTessellator> directDrawer;
-    @Getter private final Runnable streamingDrawerDestroy;
     @Getter private final int displayWidth;
     @Getter private final int displayHeight;
     @Getter private final Runnable postInitCallback;
@@ -24,7 +23,6 @@ public final class GLSMInitConfig {
         this.streamingUploadStrategy = builder.streamingUploadStrategy;
         this.noErrorChecks = builder.noErrorChecks;
         this.directDrawer = builder.directDrawer;
-        this.streamingDrawerDestroy = builder.streamingDrawerDestroy;
         this.displayWidth = builder.displayWidth;
         this.displayHeight = builder.displayHeight;
         this.postInitCallback = builder.postInitCallback;
@@ -43,7 +41,6 @@ public final class GLSMInitConfig {
         private boolean lwjglDebug = SystemProperties.LWJGL_DEBUG;
         private StreamingUploader.UploadStrategy streamingUploadStrategy = StreamingUploader.UploadStrategy.BUFFER_DATA;
         private Consumer<DirectTessellator> directDrawer = TessellatorStreamingDrawer::drawDirect;
-        private Runnable streamingDrawerDestroy = TessellatorStreamingDrawer::destroy;
         private int displayWidth = 0;
         private int displayHeight = 0;
         private Runnable postInitCallback = null;
@@ -72,11 +69,6 @@ public final class GLSMInitConfig {
             return this;
         }
 
-        public Builder streamingDrawerDestroy(Runnable streamingDrawerDestroy) {
-            this.streamingDrawerDestroy = streamingDrawerDestroy;
-            return this;
-        }
-
         public Builder displaySize(int width, int height) {
             this.displayWidth = width;
             this.displayHeight = height;

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/hooks/PendingProgramSelection.java

@@ -0,0 +1,5 @@
+package com.gtnewhorizons.angelica.glsm.hooks;
+
+public interface PendingProgramSelection {
+    void resolvePendingProgram();
+}

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/hooks/TextureUtilHooks.java

@@ -1,32 +1,54 @@
 package com.gtnewhorizons.angelica.glsm.hooks;
 
 import com.gtnewhorizons.angelica.glsm.DisplayListManager;
+import com.gtnewhorizons.angelica.glsm.GLContextState;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.RenderSystem;
+import com.gtnewhorizons.angelica.glsm.backend.BackendManager;
+import com.gtnewhorizons.angelica.glsm.texture.TextureInfo;
+import com.gtnewhorizons.angelica.glsm.texture.TextureInfoCache;
 import org.lwjgl.opengl.EXTTextureFilterAnisotropic;
 import org.lwjgl.opengl.GL11;
 import org.lwjgl.opengl.GL12;
 
 public final class TextureUtilHooks {
 
-    private TextureUtilHooks() {}
+    private static int pausedTexture;
+    private static int pausedMin;
+    private static int pausedMag;
+    private static float pausedAniso;
 
-    private static int savedFilterTextureId;
+    private static int nearestTexture;
+    private static int nearestMin;
+    private static int nearestMag;
+    private static float nearestAniso;
+
+    private TextureUtilHooks() {}
 
     public static void setMaxLevel(int mipmapLevels) {
         GLStateManager.glTexParameteri(GL11.GL_TEXTURE_2D, GL12.GL_TEXTURE_MAX_LEVEL, mipmapLevels);
     }
 
     public static void captureBoundFilterTexture() {
-        savedFilterTextureId = GLStateManager.getBoundTextureForServerState();
+        final GLContextState ctx = GLStateManager.ctx();
+        final int id = GLStateManager.getBoundTextureForServerState();
+        ctx.savedFilterTextureId = id;
+        final TextureInfo info = TextureInfoCache.INSTANCE.getInfo(id);
+        if (info != null) {
+            ctx.savedFilterMin = info.getMinFilter();
+            ctx.savedFilterMag = info.getMagFilter();
+            ctx.savedFilterAniso = info.getMaxAnisotropy();
+        } else {
+            ctx.savedFilterMin = -1;
+        }
     }
 
     public static void clearSavedFilterTexture() {
-        savedFilterTextureId = 0;
+        GLStateManager.ctx().savedFilterTextureId = 0;
     }
 
     public static void restoreFilter(int min, int mag) {
-        final int id = savedFilterTextureId;
+        final int id = GLStateManager.ctx().savedFilterTextureId;
         if (id != 0 && DisplayListManager.getRecordMode() == DisplayListManager.RecordMode.NONE) {
             RenderSystem.texParameteri(id, GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, min);
             RenderSystem.texParameteri(id, GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, mag);
@@ -37,11 +59,68 @@ public final class TextureUtilHooks {
     }
 
     public static void restoreAniso(float aniso) {
-        final int id = savedFilterTextureId;
+        final int id = GLStateManager.ctx().savedFilterTextureId;
         if (id != 0 && DisplayListManager.getRecordMode() == DisplayListManager.RecordMode.NONE) {
             RenderSystem.texParameterf(id, GL11.GL_TEXTURE_2D, EXTTextureFilterAnisotropic.GL_TEXTURE_MAX_ANISOTROPY_EXT, aniso);
         } else {
             GLStateManager.glTexParameterf(GL11.GL_TEXTURE_2D, EXTTextureFilterAnisotropic.GL_TEXTURE_MAX_ANISOTROPY_EXT, aniso);
         }
     }
+
+    public static boolean pauseTemporaryFilter() {
+        final GLContextState ctx = GLStateManager.ctx();
+        final int id = ctx.savedFilterTextureId;
+        if (id == 0 || pausedTexture != 0 || ctx.savedFilterMin < 0
+            || DisplayListManager.getRecordMode() != DisplayListManager.RecordMode.NONE) return false;
+        final TextureInfo info = TextureInfoCache.INSTANCE.getInfo(id);
+        if (info == null) return false;
+        pausedTexture = id;
+        pausedMin = info.getMinFilter();
+        pausedMag = info.getMagFilter();
+        pausedAniso = info.getMaxAnisotropy();
+        setFilter(id, ctx.savedFilterMin, ctx.savedFilterMag, ctx.savedFilterAniso);
+        return true;
+    }
+
+    public static void resumeTemporaryFilter() {
+        if (pausedTexture == 0) return;
+        final int id = pausedTexture;
+        pausedTexture = 0;
+        setFilter(id, pausedMin, pausedMag, pausedAniso);
+    }
+
+    /** TextureUtil.func_152777_a(false, false, 1) without using vanilla's single save slot, which the caller may hold. */
+    public static void forceNearestFilter() {
+        final int id = GLStateManager.getBoundTextureForServerState();
+        final TextureInfo info = id != 0 ? TextureInfoCache.INSTANCE.getInfo(id) : null;
+        if (info == null) {
+            nearestTexture = 0;
+            return;
+        }
+        nearestTexture = id;
+        nearestMin = info.getMinFilter();
+        nearestMag = info.getMagFilter();
+        nearestAniso = info.getMaxAnisotropy();
+        setFilter(id, GL11.GL_NEAREST, GL11.GL_NEAREST, 1.0f);
+    }
+
+    public static void restoreFilterAfterNearest() {
+        if (nearestTexture == 0) return;
+        final int id = nearestTexture;
+        nearestTexture = 0;
+        setFilter(id, nearestMin, nearestMag, nearestAniso);
+    }
+
+    private static void setFilter(int id, int min, int mag, float aniso) {
+        final boolean anisotropic = BackendManager.RENDER_BACKEND.isAnisotropicSupported();
+        if (DisplayListManager.getRecordMode() == DisplayListManager.RecordMode.NONE) {
+            RenderSystem.texParameteri(id, GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, min);
+            RenderSystem.texParameteri(id, GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, mag);
+            if (anisotropic) RenderSystem.texParameterf(id, GL11.GL_TEXTURE_2D, EXTTextureFilterAnisotropic.GL_TEXTURE_MAX_ANISOTROPY_EXT, aniso);
+        } else {
+            GLStateManager.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, min);
+            GLStateManager.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, mag);
+            if (anisotropic) GLStateManager.glTexParameterf(GL11.GL_TEXTURE_2D, EXTTextureFilterAnisotropic.GL_TEXTURE_MAX_ANISOTROPY_EXT, aniso);
+        }
+    }
 }

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/loading/ClassDump.java

@@ -21,6 +21,7 @@ public final class ClassDump {
 
     public void dumpRFBClass(String className, ClassNodeHandle classNode, Object transformer) {
         if (!enabled) return;
+        classNode.markDirty();
         dumpClass(className, classNode.getOriginalBytes(), classNode.computeBytes(), transformer);
     }
 }

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/loading/DependencyVerifier.java

@@ -30,11 +30,20 @@ public final class DependencyVerifier {
      * @param checks  Dependency checks to run
      */
     public static void verify(Class<?> anchor, List<Check> checks) {
+        final Check missing = firstMissing(anchor, checks);
+        if (missing != null) {
+            throw new RuntimeException(missing.errorMessage());
+        }
+    }
+
+    /** @return the first check whose resource is absent, or null when all pass. */
+    public static Check firstMissing(Class<?> anchor, List<Check> checks) {
         for (Check check : checks) {
             if (anchor.getResource(check.resourcePath()) == null) {
-                throw new RuntimeException(check.errorMessage());
+                return check;
             }
         }
+        return null;
     }
 
     public static List<Check> gtnhLibChecks(String productName) {

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/profiling/Tracy.java

@@ -1,6 +1,5 @@
 package com.gtnewhorizons.angelica.glsm.profiling;
 
-import com.gtnewhorizons.angelica.config.SystemProperties;
 import com.gtnewhorizons.angelica.glsm.CaptureGate;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.sun.management.ThreadMXBean;
@@ -66,12 +65,12 @@ public final class Tracy {
 
     static {
         TracyBackend backend = null;
-        if (SystemProperties.TRACY) {
+        if (TracyOptions.enabled()) {
             backend = loadAndInit();
         }
         BACKEND = backend;
         ENABLED = backend != null;
-        FINE_ZONES = ENABLED && SystemProperties.TRACY_FINE_ZONES;
+        FINE_ZONES = ENABLED && TracyOptions.fineZones();
         if (ENABLED) {
             Runtime.getRuntime().addShutdownHook(new Thread(Tracy::shutdown, "Tracy-Shutdown"));
             SECTIONS.registerCategory(SECTION_WORLD, "World");
@@ -86,6 +85,18 @@ public final class Tracy {
 
     private static void shutdown() {
         SHUTTING_DOWN = true;
+        if (isCaptureActive(BACKEND.captureState())) {
+            BACKEND.captureStop();
+            final long deadline = System.nanoTime() + TimeUnit.SECONDS.toNanos(10);
+            while (isCaptureActive(BACKEND.captureState()) && System.nanoTime() < deadline) {
+                try {
+                    Thread.sleep(50);
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                    break;
+                }
+            }
+        }
         final Thread worker = new Thread(BACKEND::shutdown, "Tracy-Shutdown-Worker");
         worker.setDaemon(true);
         worker.start();
@@ -96,6 +107,10 @@ public final class Tracy {
         }
     }
 
+    private static boolean isCaptureActive(int state) {
+        return state == TracyBackend.CAPTURE_CONNECTING || state == TracyBackend.CAPTURE_RECORDING || state == TracyBackend.CAPTURE_SAVING;
+    }
+
     private static TracyBackend loadAndInit() {
         TracyBackend found = null;
         try {
@@ -104,11 +119,11 @@ public final class Tracy {
                 found = it.next();
             }
         } catch (ServiceConfigurationError | LinkageError e) {
-            LOGGER.warn("Tracy requested (-Dangelica.tracy=true) but backend unavailable: {}", e.getMessage());
+            LOGGER.warn("Tracy: backend unavailable: {}", e.getMessage());
             return null;
         }
         if (found == null) {
-            LOGGER.warn("Tracy requested (-Dangelica.tracy=true) but no TracyBackend service present");
+            LOGGER.warn("Tracy: enabled but the angelica-tracy jar is not installed");
             return null;
         }
         if (!implementsCurrentAbi(found)) return null;
@@ -120,7 +135,7 @@ public final class Tracy {
         init.start();
         try {
             if (!done.await(15, TimeUnit.SECONDS) && result.compareAndSet(null, Boolean.FALSE)) {
-                LOGGER.warn("Tracy requested (-Dangelica.tracy=true) but init timed out; profiling disabled");
+                LOGGER.warn("Tracy: init timed out; profiling disabled");
                 return null;
             }
         } catch (InterruptedException e) {
@@ -131,7 +146,7 @@ public final class Tracy {
             return null;
         }
         if (!Boolean.TRUE.equals(result.get())) {
-            LOGGER.warn("Tracy requested (-Dangelica.tracy=true) but native init failed; profiling disabled");
+            LOGGER.warn("Tracy: native init failed; profiling disabled");
             return null;
         }
         return backend;
@@ -388,6 +403,31 @@ public final class Tracy {
         return ENABLED && BACKEND.isConnected();
     }
 
+    public static String captureStart(String path, int seconds) {
+        if (!ENABLED) return "Tracy not enabled";
+        return BACKEND.captureStart(path, seconds);
+    }
+
+    public static void captureStop() {
+        if (!ENABLED) return;
+        BACKEND.captureStop();
+    }
+
+    public static int captureState() {
+        if (!ENABLED) return 0;
+        return BACKEND.captureState();
+    }
+
+    public static long captureElapsedMs() {
+        if (!ENABLED) return 0;
+        return BACKEND.captureElapsedMs();
+    }
+
+    public static String captureError() {
+        if (!ENABLED) return "";
+        return BACKEND.captureError();
+    }
+
     private static boolean gpuInitAttempted;
     private static boolean gpuReady;
     @Setter private static boolean gpuZonesEnabled = true;

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/profiling/TracyBackend.java

@@ -12,6 +12,13 @@ public interface TracyBackend {
     int SEVERITY_ERROR = 4;
     int SEVERITY_FATAL = 5;
 
+    int CAPTURE_IDLE = 0;
+    int CAPTURE_CONNECTING = 1;
+    int CAPTURE_RECORDING = 2;
+    int CAPTURE_SAVING = 3;
+    int CAPTURE_DONE = 4;
+    int CAPTURE_FAILED = 5;
+
     boolean init();
 
     long internSrcLoc(String name, int color);
@@ -47,4 +54,12 @@ public interface TracyBackend {
     boolean gpuBeginZone(long srcLoc);
     void gpuEndZone();
     void gpuCollect();
+
+    default String captureStart(String path, int seconds) {
+        return "Tracy capture unsupported by this angelica-tracy build";
+    }
+    default void captureStop() {}
+    default int captureState() { return CAPTURE_IDLE; }
+    default long captureElapsedMs() { return 0; }
+    default String captureError() { return ""; }
 }

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/profiling/TracyOptions.java

@@ -0,0 +1,64 @@
+package com.gtnewhorizons.angelica.glsm.profiling;
+
+import com.gtnewhorizons.angelica.config.SystemProperties;
+
+public final class TracyOptions {
+
+    private static boolean configEnabled;
+    private static boolean configRemote;
+    private static boolean configFineZones;
+    private static int configMaxSrcLocs = 4096;
+
+    private TracyOptions() {}
+
+    public static void latch(boolean enabled, boolean allowRemote, boolean fineZones, int maxSrcLocs) {
+        configEnabled = enabled;
+        configRemote = allowRemote;
+        configFineZones = fineZones;
+        configMaxSrcLocs = maxSrcLocs;
+    }
+
+    public static boolean enabled() {
+        return resolveBoolean(SystemProperties.TRACY_OVERRIDE, configEnabled);
+    }
+
+    public static boolean allowRemote() {
+        return configRemote;
+    }
+
+    public static boolean fineZones() {
+        return resolveBoolean(SystemProperties.TRACY_FINE_ZONES_OVERRIDE, configFineZones);
+    }
+
+    public static int maxSrcLocs() {
+        return resolveMaxSrcLocs(SystemProperties.TRACY_MAX_SRC_LOCS_OVERRIDE, configMaxSrcLocs);
+    }
+
+    public static boolean configEnabled() {
+        return configEnabled;
+    }
+
+    public static boolean configRemote() {
+        return configRemote;
+    }
+
+    public static boolean configFineZones() {
+        return configFineZones;
+    }
+
+    public static int configMaxSrcLocs() {
+        return configMaxSrcLocs;
+    }
+
+    public static boolean backendPresent() {
+        return TracyOptions.class.getResource("/com/gtnewhorizons/angelica/tracy/TracyClientBackend.class") != null;
+    }
+
+    static boolean resolveBoolean(Boolean override, boolean config) {
+        return override != null ? override : config;
+    }
+
+    static int resolveMaxSrcLocs(Integer override, int config) {
+        return Math.max(16, override != null ? override : config);
+    }
+}

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

@@ -68,6 +68,7 @@ public final class AttribSnapshot {
         final AttribDesc[] out = new AttribDesc[VAOManager.MAX_ATTRIBS];
         final List<ByteBuffer> allocated = new ArrayList<>();
         final int prevVBO = GLStateManager.getBoundVBO();
+        final VAOManager vaos = GLStateManager.ctx().vaos;
         boolean success = false;
 
         // Pass 1 — unioned [start,end] per vboId. Hot path: one source VBO, zero allocations.
@@ -78,7 +79,7 @@ public final class AttribSnapshot {
 
         final long lastVtx = (long) firstVertex + vertexCount - 1;
         for (int i = 0; i < VAOManager.MAX_ATTRIBS; i++) {
-            final VAOManager.Attrib a = VAOManager.get(i);
+            final VAOManager.Attrib a = vaos.attrib(i);
             if (a == null || !a.enabled || a.vboId == 0) continue;
             final int stride = a.effectiveStride();
             final long typeBytes = (long) a.size * GLTypes.sizeBytes(a.type);
@@ -114,7 +115,7 @@ public final class AttribSnapshot {
 
         try {
             for (int i = 0; i < VAOManager.MAX_ATTRIBS; i++) {
-                final VAOManager.Attrib a = VAOManager.get(i);
+                final VAOManager.Attrib a = vaos.attrib(i);
                 if (a == null || !a.enabled) continue;
 
                 if (a.vboId != 0) {

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

@@ -97,7 +97,8 @@ public final class CommandBufferExecutor {
                     ptr += 4;
                 }
                 case GLCommand.USE_PROGRAM -> {
-                    GLStateManager.glUseProgram(memGetInt(ptr));
+                    final int recordedProgram = memGetInt(ptr);
+                    GLStateManager.glUseProgram(compiledDisplayList.resolveProgram(recordedProgram));
                     ptr += 4;
                 }
                 case GLCommand.PUSH_ATTRIB -> {
@@ -252,6 +253,11 @@ public final class CommandBufferExecutor {
                 }
 
                 // === Float commands ===
+                case GLCommand.VERTEX_ATTRIB -> {
+                    GLStateManager.glVertexAttrib4f(memGetInt(ptr), memGetFloat(ptr + 4), memGetFloat(ptr + 8),
+                        memGetFloat(ptr + 12), memGetFloat(ptr + 16));
+                    ptr += 20;
+                }
                 case GLCommand.POINT_SIZE -> {
                     GLStateManager.glPointSize(memGetFloat(ptr));
                     ptr += 4;

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

@@ -10,6 +10,8 @@ import java.nio.ByteBuffer;
 import java.nio.FloatBuffer;
 import java.nio.IntBuffer;
 import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
 
 import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.*;
 
@@ -21,6 +23,13 @@ public final class CommandRecorder {
     private long writePointer;
     private final ArrayList<DisplayListCommand> complexObjects = new ArrayList<>();
     private final IndexedDrawBatchBuilder indexedDraws = new IndexedDrawBatchBuilder();
+    private Set<DisplayListCommand> onceCommands;
+    private DisplayListCommand lastComplexCommand;
+    private int lastComplexCommandEnd = -1;
+
+    public boolean isLastCommand(DisplayListCommand command) {
+        return size() == lastComplexCommandEnd && command.equals(lastComplexCommand);
+    }
 
     public CommandRecorder() {
         this(DEFAULT_CAPACITY);
@@ -32,6 +41,11 @@ public final class CommandRecorder {
         this.writePointer = basePointer;
     }
 
+    public boolean markRecordedOnce(DisplayListCommand command) {
+        if (onceCommands == null) onceCommands = new HashSet<>();
+        return onceCommands.add(command);
+    }
+
     // === Low-level write operations ===
 
     private void writeInt(int value) {
@@ -364,6 +378,16 @@ public final class CommandRecorder {
         writeFloat(b);
     }
 
+    public void writeVertexAttrib(int index, float x, float y, float z, float w) {
+        ensureCapacity(24);
+        writeInt(GLCommand.VERTEX_ATTRIB);
+        writeInt(index);
+        writeFloat(x);
+        writeFloat(y);
+        writeFloat(z);
+        writeFloat(w);
+    }
+
     public void writeClearColor(float r, float g, float b, float a) {
         ensureCapacity(20);
         writeInt(GLCommand.CLEAR_COLOR);
@@ -649,6 +673,8 @@ public final class CommandRecorder {
         complexObjects.add(cmd);
         writeInt(GLCommand.COMPLEX_REF);
         writeInt(index);
+        lastComplexCommand = cmd;
+        lastComplexCommandEnd = size();
     }
 
     // === Lifecycle ===

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

@@ -1,6 +1,7 @@
 package com.gtnewhorizons.angelica.glsm.recording;
 
 import com.gtnewhorizons.angelica.glsm.DisplayListManager;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.recording.commands.DisplayListCommand;
 import com.gtnewhorizons.angelica.glsm.recording.commands.IndexedDrawBatch;
 import it.unimi.dsi.fastutil.ints.Int2IntMap;
@@ -35,6 +36,24 @@ public final class CompiledDisplayList {
     private final DisplayListCommand[] complexObjects;      // Complex commands (TexImage2D, etc.)
     private final DisplayListVBO ownedVbos;     // GPU resources referenced by index
     private final List<IndexedDrawBatch> indexedBatches; // Shared VAO/VBO/EBO triples per layout group
+    private Int2IntMap replayPrograms;
+    private long programLifetimeGeneration = -1;
+
+    int resolveProgram(int program) {
+        if (program == 0) return 0;
+        final long generation = GLStateManager.getProgramLifetimeGeneration();
+        if (replayPrograms == null) replayPrograms = new Int2IntOpenHashMap();
+        if (programLifetimeGeneration != generation) {
+            replayPrograms.clear();
+            programLifetimeGeneration = generation;
+        }
+        if (replayPrograms.containsKey(program)) return replayPrograms.get(program);
+        final boolean valid = GLStateManager.glIsProgram(program);
+        if (!valid || !GLStateManager.isProgramPendingDeletion(program)) {
+            replayPrograms.put(program, valid ? program : 0);
+        }
+        return valid ? program : 0;
+    }
 
     public CompiledDisplayList(ByteBuffer commandBuffer, DisplayListCommand[] complexObjects, DisplayListVBO ownedVbos, List<IndexedDrawBatch> indexedBatches) {
         this.commandBuffer = commandBuffer;

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

@@ -24,9 +24,9 @@ public final class GLCommand {
     public static final int USE_PROGRAM = 11;        // [cmd:4][program:4]
     public static final int PUSH_ATTRIB = 12;        // [cmd:4][mask:4]
     public static final int POP_ATTRIB = 13;         // [cmd:4][unused:4]
-    public static final int LOAD_IDENTITY = 14;      // [cmd:4][matrixMode:4]
-    public static final int PUSH_MATRIX = 15;        // [cmd:4][matrixMode:4]
-    public static final int POP_MATRIX = 16;         // [cmd:4][matrixMode:4]
+    public static final int LOAD_IDENTITY = 14;      // [cmd:4]
+    public static final int PUSH_MATRIX = 15;        // [cmd:4]
+    public static final int POP_MATRIX = 16;         // [cmd:4]
     public static final int STENCIL_MASK = 17;       // [cmd:4][mask:4]
     public static final int DEPTH_MASK = 18;         // [cmd:4][flag:4] (0 or 1)
     public static final int FRONT_FACE = 19;         // [cmd:4][mode:4]
@@ -62,6 +62,7 @@ public final class GLCommand {
     public static final int CLEAR_COLOR = 55;        // [cmd:4][r:4f][g:4f][b:4f][a:4f]
     public static final int BLEND_COLOR = 56;        // [cmd:4][r:4f][g:4f][b:4f][a:4f]
     public static final int SECONDARY_COLOR = 57;    // [cmd:4][r:4f][g:4f][b:4f]
+    public static final int VERTEX_ATTRIB = 58;      // [cmd:4][index:4][x:4f][y:4f][z:4f][w:4f]
 
     // === Mixed int+float commands ===
     public static final int ALPHA_FUNC = 60;         // [cmd:4][func:4][ref:4f]
@@ -73,14 +74,13 @@ public final class GLCommand {
     public static final int MATERIALF = 66;          // [cmd:4][face:4][pname:4][param:4f]
     public static final int TEX_PARAMETERF = 67;     // [cmd:4][target:4][pname:4][param:4f]
 
-    // === Double commands ===
-    public static final int TRANSLATE = 70;          // [cmd:4][mode:4][x:8d][y:8d][z:8d] = 32 bytes
-    public static final int SCALE = 72;              // [cmd:4][mode:4][x:8d][y:8d][z:8d] = 32 bytes
+    public static final int TRANSLATE = 70;          // [cmd:4][x:4f][y:4f][z:4f] = 16 bytes
+    public static final int SCALE = 72;              // [cmd:4][x:4f][y:4f][z:4f] = 16 bytes
     public static final int CLEAR_DEPTH = 75;        // [cmd:4][depth:8d] = 12 bytes
 
-    // === Matrix commands (72 bytes) ===
-    public static final int MULT_MATRIX = 80;        // [cmd:4][mode:4][m00-m33:64f] = 72 bytes
-    public static final int LOAD_MATRIX = 81;        // [cmd:4][mode:4][m00-m33:64f] = 72 bytes
+    // === Matrix commands (68 bytes) ===
+    public static final int MULT_MATRIX = 80;        // [cmd:4][m00-m33:64f] = 68 bytes
+    public static final int LOAD_MATRIX = 81;        // [cmd:4][m00-m33:64f] = 68 bytes
 
     // === Buffer commands (inline 4 floats max) ===
     public static final int FOG = 90;                // [cmd:4][pname:4][count:4][params:16f] = 28 bytes
@@ -157,6 +157,7 @@ public final class GLCommand {
             case CLEAR_COLOR -> "CLEAR_COLOR";
             case BLEND_COLOR -> "BLEND_COLOR";
             case SECONDARY_COLOR -> "SECONDARY_COLOR";
+            case VERTEX_ATTRIB -> "VERTEX_ATTRIB";
             case ALPHA_FUNC -> "ALPHA_FUNC";
             case FOGF -> "FOGF";
             case LIGHTF -> "LIGHTF";
@@ -221,6 +222,8 @@ public final class GLCommand {
                  GLCommand.SCISSOR,
                  GLCommand.COLOR, GLCommand.CLEAR_COLOR, GLCommand.BLEND_COLOR -> 20;
 
+            case GLCommand.VERTEX_ATTRIB -> 24;
+
             // DRAW_RANGE_RESTORE: 28 bytes
             case GLCommand.DRAW_RANGE_RESTORE -> 28;
 

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/redirect/GLSMRedirector.java

@@ -164,6 +164,8 @@ public class GLSMRedirector {
     private static final String EXTGPUShader4 = "org/lwjgl/opengl/EXTGPUShader4";
     private static final String ARBTimerQuery = "org/lwjgl/opengl/ARBTimerQuery";
     private static final String EXTTimerQuery = "org/lwjgl/opengl/EXTTimerQuery";
+    private static final String ARBSamplerObjects = "org/lwjgl/opengl/ARBSamplerObjects";
+    private static final String ARBMultiBind = "org/lwjgl/opengl/ARBMultiBind";
 
     // Redirect VAO related calls from NHLib
     private static final String UniversalVAO = "com/gtnewhorizon/gtnhlib/client/opengl/UniversalVAO";
@@ -555,6 +557,7 @@ public class GLSMRedirector {
             .add("glMultiDrawElementsIndirect");
         final var gl44 = RedirectMap.newMap()
             .add("glBufferStorage")
+            .add("glBindSamplers")
             .add("glClearTexImage");
         final var gl45 = RedirectMap.newMap()
             .add("glCreateBuffers")
@@ -767,6 +770,17 @@ public class GLSMRedirector {
             .add("glMapBufferRange")
             .add("glFlushMappedBufferRange")
         );
+        methodRedirects.put(ARBSamplerObjects, RedirectMap.newMap()
+            .add("glGenSamplers")
+            .add("glDeleteSamplers")
+            .add("glIsSampler")
+            .add("glBindSampler")
+            .add("glSamplerParameteri")
+            .add("glSamplerParameterf")
+        );
+        methodRedirects.put(ARBMultiBind, RedirectMap.newMap()
+            .add("glBindSamplers")
+        );
 
         // APPLE
         methodRedirects.put(APPLEVertexArrayObject, RedirectMap.newMap()
@@ -796,6 +810,8 @@ public class GLSMRedirector {
             .add("gluBuild2DMipmaps")
             .add("gluErrorString")
         );
+        // Must honor disableErrorChecks like glGetError, or it throws on errors those checks left latched
+        methodRedirects.put("org/lwjgl/opengl/Util", RedirectMap.newMap().add("checkGLError"));
 
         // Quadric type replacements
         typeRedirects.put("org/lwjgl/util/glu/Sphere", "com/gtnewhorizons/angelica/glsm/compat/lwjgl/AngelicaSphere");

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

@@ -1,45 +1,46 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.hooks.VanillaStateLayer;
 import com.gtnewhorizons.angelica.glsm.states.AlphaState;
 import lombok.Setter;
 
-public class AlphaStateStack extends AlphaState implements IStateStack<AlphaState> {
+public final class AlphaStateStack extends AlphaState implements CowStateStack<AlphaStateStack> {
 
     protected final AlphaState[] stack;
-
-    protected int pointer;
+    private final CowDepths cow = new CowDepths();
 
     @Setter private VanillaStateLayer<AlphaState> vanillaLayer;
 
-    public AlphaStateStack() {
+    public AlphaStateStack(int id) {
+        cow.id = id;
         stack = new AlphaState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new AlphaState();
         }
     }
 
-    public AlphaStateStack push() {
-        if(pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        VanillaStateLayer.capture(vanillaLayer, stack[pointer++].set(this));
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public AlphaStateStack pop() {
-        if(pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
+    @Override
+    public void captureSlot(int s) {
+        VanillaStateLayer.capture(vanillaLayer, stack[s].set(this));
+    }
 
-        final AlphaState saved = stack[--pointer];
+    @Override
+    public void restoreSlot(int s) {
+        final AlphaState saved = stack[s];
         if (!VanillaStateLayer.restore(vanillaLayer, saved)) {
             set(saved);
         }
-        return this;
+    }
+
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
     }
 
     public AlphaState readEffective(AlphaState out) {
@@ -48,7 +49,8 @@ public class AlphaStateStack extends AlphaState implements IStateStack<AlphaStat
         return out;
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,47 +1,63 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.StateSet;
 import com.gtnewhorizons.angelica.glsm.hooks.VanillaStateLayer;
 import com.gtnewhorizons.angelica.glsm.states.BlendState;
 import lombok.Setter;
 
-public class BlendStateStack extends BlendState implements IStateStack<BlendStateStack> {
+public final class BlendStateStack extends BlendState implements CowStateStack<BlendStateStack> {
 
     protected final BlendState[] stack;
+    private final CowDepths cow = new CowDepths(StateSet.R_BLEND);
 
-    protected int pointer;
+    private boolean funcUnknown;
 
     @Setter private VanillaStateLayer<BlendState> vanillaLayer;
 
-    public BlendStateStack() {
+    public BlendStateStack(int id) {
+        cow.id = id;
         stack = new BlendState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new BlendState();
         }
     }
 
-    public BlendStateStack push() {
-        if(pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        VanillaStateLayer.capture(vanillaLayer, stack[pointer++].set(this));
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public BlendStateStack pop() {
-        if(pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
+    @Override
+    public void captureSlot(int s) {
+        VanillaStateLayer.capture(vanillaLayer, stack[s].set(this));
+    }
 
-        final BlendState saved = stack[--pointer];
+    @Override
+    public void restoreSlot(int s) {
+        final BlendState saved = stack[s];
         if (VanillaStateLayer.restore(vanillaLayer, saved)) {
             setExceptFunc(saved);
         } else {
             set(saved);
         }
-        return this;
+    }
+
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
+    }
+
+    public void setFuncUnknownState() {
+        funcUnknown = true;
+    }
+
+    public boolean isFuncUnknown() {
+        return funcUnknown;
+    }
+
+    public void clearFuncUnknownState() {
+        funcUnknown = false;
     }
 
     public BlendState readEffective(BlendState out) {
@@ -50,11 +66,8 @@ public class BlendStateStack extends BlendState implements IStateStack<BlendStat
         return out;
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
-    }
-
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,6 +1,6 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
+import com.gtnewhorizons.angelica.glsm.GLContextState;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.hooks.VanillaBooleanLayer;
 import com.gtnewhorizons.angelica.glsm.states.BooleanState;
@@ -13,17 +13,12 @@ import lombok.Setter;
  * saved when actually modified, dramatically reducing overhead when most states
  * don't change (e.g., GL_ENABLE_BIT saves ~270 states but typically only 3-4 change).
  */
-public class BooleanStateStack extends BooleanState implements IStateStack<BooleanStateStack> {
+public class BooleanStateStack extends BooleanState implements CowStateStack<BooleanStateStack> {
 
     protected final boolean[] stack;
+    private final CowDepths cow = new CowDepths();
     @Setter private VanillaBooleanLayer vanillaLayer;
 
-    /**
-     * The depth at which state has been saved. Compared against GLStateManager.getAttribDepth()
-     * to determine if we need to save before modification or restore on pop.
-     */
-    protected int savedDepth;
-
     public BooleanStateStack(int glCap) {
         this(glCap, false, false);
     }
@@ -52,24 +47,24 @@ public class BooleanStateStack extends BooleanState implements IStateStack<Boole
         stack = new boolean[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
     }
 
-    // ==================== Traditional Stack Operations ====================
-
     @Override
-    public BooleanStateStack push() {
-        if (savedDepth >= stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (savedDepth + 1) + " reached");
-        }
-        stack[savedDepth++] = vanillaValue();
-        return this;
+    public CowDepths cowDepths() {
+        return cow;
     }
 
     @Override
-    public BooleanStateStack pop() {
-        if (savedDepth == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-        restore(stack[--savedDepth]);
-        return this;
+    public void captureSlot(int slot) {
+        stack[slot] = vanillaValue();
+    }
+
+    @Override
+    public void restoreSlot(int slot) {
+        restore(stack[slot]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 
     public boolean isEffectivelyEnabled() {
@@ -88,45 +83,6 @@ public class BooleanStateStack extends BooleanState implements IStateStack<Boole
         }
     }
 
-    @Override
-    public boolean isEmpty() {
-        return savedDepth == 0;
-    }
-
-    // ==================== Lazy Copy-on-Write Operations ====================
-
-    @Override
-    public int pushDepth() {
-        // No-op: global depth is managed by GLStateManager
-        return GLStateManager.getAttribDepth();
-    }
-
-    /**
-     * Restore state if it was modified at the current depth.
-     * Only called by GLStateManager.popState() for states that registered as modified.
-     */
-    @Override
-    public BooleanStateStack popDepth() {
-        // We're only called if we were modified, so savedDepth should match
-        if (savedDepth > 0) {
-            restore(stack[--savedDepth]);
-        }
-        return this;
-    }
-
-    /**
-     * Called before modifying state. If we haven't saved at the current depth yet,
-     * save the current value and register with GLStateManager for restoration.
-     */
-    @Override
-    public void beforeModify() {
-        final int globalDepth = GLStateManager.getAttribDepth();
-        if (savedDepth < globalDepth) {
-            stack[savedDepth++] = vanillaValue();
-            GLStateManager.registerModifiedState(this);
-        }
-    }
-
     @Override
     public int getDepth() {
         return GLStateManager.getAttribDepth();
@@ -134,7 +90,11 @@ public class BooleanStateStack extends BooleanState implements IStateStack<Boole
 
     @Override
     public void setEnabled(boolean enabled) {
-        beforeModify();
+        final GLContextState o = cow.owner;
+        if (o != null && o.attribDepth > 0
+            && (stateUnknown || !GLStateManager.isCachingEnabled() || enabled != vanillaValue())) {
+            beforeModify();
+        }
         super.setEnabled(enabled);
     }
 

glsm/src/main/java/com/gtnewhorizons/angelica/glsm/stacks/Color4Stack.java

@@ -1,50 +1,55 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.Color4;
 
-public class Color4Stack extends Color4 implements IStateStack<Color4Stack> {
+public final class Color4Stack extends Color4 implements CowStateStack<Color4Stack> {
 
     protected final Color4[] stack;
+    private CowDepths cow = new CowDepths();
 
-    protected int pointer;
-
-    public Color4Stack() {
+    public Color4Stack(int id) {
+        cow.id = id;
         stack = new Color4[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new Color4();
         }
     }
 
-    public Color4Stack(Color4 color4) {
-        this();
+    public Color4Stack(int id, Color4 color4) {
+        this(id);
         set(color4);
     }
 
-    public Color4Stack push() {
-        if(pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        stack[pointer++].set(this);
+    public Color4Stack restoreBit(int bit) {
+        final int id = cow.id;
+        cow = new CowDepths(bit);
+        cow.id = id;
         return this;
     }
 
-    public Color4Stack pop() {
-        if(pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
+    }
+
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,52 +1,51 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.StateSet;
 import com.gtnewhorizons.angelica.glsm.hooks.VanillaStateLayer;
 import com.gtnewhorizons.angelica.glsm.states.ColorMask;
 import lombok.Setter;
 
-public class ColorMaskStack extends ColorMask implements IStateStack<ColorMaskStack> {
+public final class ColorMaskStack extends ColorMask implements CowStateStack<ColorMaskStack> {
 
     protected final ColorMask[] stack;
-
-    protected int pointer;
+    private final CowDepths cow = new CowDepths(StateSet.R_COLOR_MASK);
 
     @Setter private VanillaStateLayer<ColorMask> vanillaLayer;
 
-    public ColorMaskStack() {
+    public ColorMaskStack(int id) {
+        cow.id = id;
         stack = new ColorMask[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new ColorMask();
         }
     }
 
-    public ColorMaskStack push() {
-        if(pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        VanillaStateLayer.capture(vanillaLayer, stack[pointer++].set(this));
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public ColorMaskStack pop() {
-        if(pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
+    @Override
+    public void captureSlot(int s) {
+        VanillaStateLayer.capture(vanillaLayer, stack[s].set(this));
+    }
 
-        final ColorMask saved = stack[--pointer];
+    @Override
+    public void restoreSlot(int s) {
+        final ColorMask saved = stack[s];
         if (!VanillaStateLayer.restore(vanillaLayer, saved)) {
             set(saved);
         }
-        return this;
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
     }
 
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -0,0 +1,71 @@
+package com.gtnewhorizons.angelica.glsm.stacks;
+
+import com.gtnewhorizons.angelica.glsm.GLContextState;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+
+/**
+ *            __n__n__
+ *     .------`-\00/-'
+ *    /  ##  ## (oo)
+ *   / \## __   ./
+ *      |//YY \|/
+ *      |||   |||
+ *    Copy On Write Depths
+ */
+
+public final class CowDepths {
+    public int id = -1;
+    public GLContextState owner;
+    public final int restoreBit;
+    public final int restoreUnit;
+    private final int[] slotDepth = new int[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
+    private int pointer;
+
+    public CowDepths() {
+        this(0, -1);
+    }
+
+    public CowDepths(int restoreBit) {
+        this(restoreBit, -1);
+    }
+
+    public CowDepths(int restoreBit, int restoreUnit) {
+        this.restoreBit = restoreBit;
+        this.restoreUnit = restoreUnit;
+    }
+
+    public int claim(int depth) {
+        if (depth <= 0) return -1;
+        if (pointer > 0 && slotDepth[pointer - 1] == depth) return -1;
+        slotDepth[pointer] = depth;
+        return pointer++;
+    }
+
+    public int claimUnconditional() {
+        slotDepth[pointer] = -1;
+        return pointer++;
+    }
+
+    public int pop() {
+        return pointer > 0 ? --pointer : -1;
+    }
+
+    public int discard(int poppedDepth) {
+        if (pointer == 0) return -1;
+        final int parent = poppedDepth - 1;
+        if (parent > 0 && (pointer < 2 || slotDepth[pointer - 2] != parent)) {
+            slotDepth[pointer - 1] = parent;
+            return pointer - 1;
+        }
+        pointer--;
+        return -1;
+    }
+
+    public int top() {
+        return pointer - 1;
+    }
+
+    public boolean isEmpty() {
+        return pointer == 0;
+    }
+}

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

@@ -0,0 +1,133 @@
+package com.gtnewhorizons.angelica.glsm.stacks;
+
+import com.gtnewhorizons.angelica.glsm.ClipPlaneBooleanState;
+import com.gtnewhorizons.angelica.glsm.states.TexEnvState;
+
+/**
+ *            __n__n__
+ *     .------`-\00/-'
+ *    /  ##  ## (oo)    Casts look redundant, they aren't. Casting to the
+ *   / \## __   ./      final class avoids an interface lookup on every
+ *      |//YY \|/       call. 74-85% faster push/pops in JMH testing.
+ *      |||   |||
+ *    Copy On Write Dispatch
+ */
+@SuppressWarnings("RedundantCast")
+public final class CowDispatch {
+
+    private CowDispatch() {}
+
+    public static final byte BLEND = 0;
+    public static final byte BOOLEAN = 1;
+    public static final byte CLIP_PLANE_BOOLEAN = 2;
+    public static final byte TEXTURE_UNIT_BOOLEAN = 3;
+    public static final byte COLOR_MASK = 4;
+    public static final byte LIGHT_STATE = 5;
+    public static final byte MATERIAL = 6;
+    public static final byte STENCIL = 7;
+    public static final byte MATRIX_MODE = 8;
+    public static final byte LIGHT_MODEL = 9;
+    public static final byte ALPHA = 10;
+    public static final byte POINT = 11;
+    public static final byte FOG = 12;
+    public static final byte VEC4F = 13;
+    public static final byte VEC3F = 14;
+    public static final byte INTEGER = 15;
+    public static final byte DEPTH = 16;
+    public static final byte VIEWPORT = 17;
+    public static final byte POLYGON = 18;
+    public static final byte COLOR4 = 19;
+    public static final byte LINE = 20;
+    public static final byte TEXTURE_BINDING = 21;
+    public static final byte TEX_ENV = 22;
+    public static final byte SCISSOR = 23;
+
+    public static byte kindOf(CowStateStack<?> s) {
+        final Class<?> c = s.getClass();
+        if (c == TextureUnitBooleanStateStack.class) return TEXTURE_UNIT_BOOLEAN;
+        if (c == ClipPlaneBooleanState.class) return CLIP_PLANE_BOOLEAN;
+        if (c == BooleanStateStack.class) return BOOLEAN;
+        if (c == BlendStateStack.class) return BLEND;
+        if (c == ColorMaskStack.class) return COLOR_MASK;
+        if (c == LightStateStack.class) return LIGHT_STATE;
+        if (c == MaterialStateStack.class) return MATERIAL;
+        if (c == StencilStateStack.class) return STENCIL;
+        if (c == MatrixModeStack.class) return MATRIX_MODE;
+        if (c == LightModelStateStack.class) return LIGHT_MODEL;
+        if (c == AlphaStateStack.class) return ALPHA;
+        if (c == PointStateStack.class) return POINT;
+        if (c == FogStateStack.class) return FOG;
+        if (c == Vec4fStack.class) return VEC4F;
+        if (c == Vec3fStack.class) return VEC3F;
+        if (c == IntegerStateStack.class) return INTEGER;
+        if (c == DepthStateStack.class) return DEPTH;
+        if (c == ViewPortStateStack.class) return VIEWPORT;
+        if (c == PolygonStateStack.class) return POLYGON;
+        if (c == Color4Stack.class) return COLOR4;
+        if (c == LineStateStack.class) return LINE;
+        if (c == TextureBindingStack.class) return TEXTURE_BINDING;
+        if (c == TexEnvState.class) return TEX_ENV;
+        if (c == ScissorStateStack.class) return SCISSOR;
+        throw new IllegalStateException("Unknown CowStateStack class: " + c.getName());
+    }
+
+    public static boolean topSlotChanged(byte kind, CowStateStack<?> s) {
+        return switch (kind) {
+            case BLEND -> ((BlendStateStack) s).topSlotChanged();
+            case BOOLEAN -> ((BooleanStateStack) s).topSlotChanged();
+            case CLIP_PLANE_BOOLEAN -> ((ClipPlaneBooleanState) s).topSlotChanged();
+            case TEXTURE_UNIT_BOOLEAN -> ((TextureUnitBooleanStateStack) s).topSlotChanged();
+            case COLOR_MASK -> ((ColorMaskStack) s).topSlotChanged();
+            case LIGHT_STATE -> ((LightStateStack) s).topSlotChanged();
+            case MATERIAL -> ((MaterialStateStack) s).topSlotChanged();
+            case STENCIL -> ((StencilStateStack) s).topSlotChanged();
+            case MATRIX_MODE -> ((MatrixModeStack) s).topSlotChanged();
+            case LIGHT_MODEL -> ((LightModelStateStack) s).topSlotChanged();
+            case ALPHA -> ((AlphaStateStack) s).topSlotChanged();
+            case POINT -> ((PointStateStack) s).topSlotChanged();
+            case FOG -> ((FogStateStack) s).topSlotChanged();
+            case VEC4F -> ((Vec4fStack) s).topSlotChanged();
+            case VEC3F -> ((Vec3fStack) s).topSlotChanged();
+            case INTEGER -> ((IntegerStateStack) s).topSlotChanged();
+            case DEPTH -> ((DepthStateStack) s).topSlotChanged();
+            case VIEWPORT -> ((ViewPortStateStack) s).topSlotChanged();
+            case POLYGON -> ((PolygonStateStack) s).topSlotChanged();
+            case COLOR4 -> ((Color4Stack) s).topSlotChanged();
+            case LINE -> ((LineStateStack) s).topSlotChanged();
+            case TEXTURE_BINDING -> ((TextureBindingStack) s).topSlotChanged();
+            case TEX_ENV -> ((TexEnvState) s).topSlotChanged();
+            case SCISSOR -> ((ScissorStateStack) s).topSlotChanged();
+            default -> throw new IllegalStateException("Unknown kind: " + kind);
+        };
+    }
+
+    public static void restoreSlot(byte kind, CowStateStack<?> s, int slot) {
+        switch (kind) {
+            case BLEND -> ((BlendStateStack) s).restoreSlot(slot);
+            case BOOLEAN -> ((BooleanStateStack) s).restoreSlot(slot);
+            case CLIP_PLANE_BOOLEAN -> ((ClipPlaneBooleanState) s).restoreSlot(slot);
+            case TEXTURE_UNIT_BOOLEAN -> ((TextureUnitBooleanStateStack) s).restoreSlot(slot);
+            case COLOR_MASK -> ((ColorMaskStack) s).restoreSlot(slot);
+            case LIGHT_STATE -> ((LightStateStack) s).restoreSlot(slot);
+            case MATERIAL -> ((MaterialStateStack) s).restoreSlot(slot);
+            case STENCIL -> ((StencilStateStack) s).restoreSlot(slot);
+            case MATRIX_MODE -> ((MatrixModeStack) s).restoreSlot(slot);
+            case LIGHT_MODEL -> ((LightModelStateStack) s).restoreSlot(slot);
+            case ALPHA -> ((AlphaStateStack) s).restoreSlot(slot);
+            case POINT -> ((PointStateStack) s).restoreSlot(slot);
+            case FOG -> ((FogStateStack) s).restoreSlot(slot);
+            case VEC4F -> ((Vec4fStack) s).restoreSlot(slot);
+            case VEC3F -> ((Vec3fStack) s).restoreSlot(slot);
+            case INTEGER -> ((IntegerStateStack) s).restoreSlot(slot);
+            case DEPTH -> ((DepthStateStack) s).restoreSlot(slot);
+            case VIEWPORT -> ((ViewPortStateStack) s).restoreSlot(slot);
+            case POLYGON -> ((PolygonStateStack) s).restoreSlot(slot);
+            case COLOR4 -> ((Color4Stack) s).restoreSlot(slot);
+            case LINE -> ((LineStateStack) s).restoreSlot(slot);
+            case TEXTURE_BINDING -> ((TextureBindingStack) s).restoreSlot(slot);
+            case TEX_ENV -> ((TexEnvState) s).restoreSlot(slot);
+            case SCISSOR -> ((ScissorStateStack) s).restoreSlot(slot);
+            default -> throw new IllegalStateException("Unknown kind: " + kind);
+        }
+    }
+}

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

@@ -0,0 +1,88 @@
+package com.gtnewhorizons.angelica.glsm.stacks;
+
+import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
+import com.gtnewhorizons.angelica.glsm.GLContextState;
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+
+/**
+ *            __n__n__
+ *     .------`-\00/-'
+ *    /  ##  ## (oo)
+ *   / \## __   ./
+ *      |//YY \|/
+ *      |||   |||
+ *    Copy On Write State Stack
+ */
+public interface CowStateStack<T> extends IStateStack<T> {
+    CowDepths cowDepths();
+
+    void captureSlot(int slot);
+
+    void restoreSlot(int slot);
+
+    default int stackId() {
+        return cowDepths().id;
+    }
+
+    default void setStackId(int id) {
+        cowDepths().id = id;
+    }
+
+    default int restoreBit() {
+        return cowDepths().restoreBit;
+    }
+
+    default int restoreUnit() {
+        return cowDepths().restoreUnit;
+    }
+
+    default boolean topSlotChanged() {
+        return false;
+    }
+
+    @Override
+    default int pushDepth() {
+        final GLContextState o = cowDepths().owner;
+        return o == null ? 0 : o.attribDepth;
+    }
+
+    @Override
+    default void beforeModify() {
+        final CowDepths d = cowDepths();
+        final GLContextState o = d.owner;
+        if (o == null) return;
+        final int s = d.claim(o.attribDepth);
+        if (s >= 0) {
+            captureSlot(s);
+            GLStateManager.registerModifiedState(o, d.id);
+        }
+    }
+
+    @Override
+    default boolean isEmpty() {
+        return cowDepths().isEmpty();
+    }
+
+    default void drain() {
+        int s;
+        while ((s = cowDepths().pop()) >= 0) restoreSlot(s);
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    default T push() {
+        captureSlot(cowDepths().claimUnconditional());
+        return (T) this;
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    default T pop() {
+        final int s = cowDepths().pop();
+        if (s < 0) {
+            throw new IllegalStateException("Stack underflow");
+        }
+        restoreSlot(s);
+        return (T) this;
+    }
+}

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

@@ -1,49 +1,51 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.StateSet;
 import com.gtnewhorizons.angelica.glsm.hooks.VanillaStateLayer;
 import com.gtnewhorizons.angelica.glsm.states.DepthState;
 import lombok.Setter;
 
-public class DepthStateStack extends DepthState implements IStateStack<DepthStateStack> {
+public final class DepthStateStack extends DepthState implements CowStateStack<DepthStateStack> {
 
     protected final DepthState[] stack;
-
-    protected int pointer;
+    private final CowDepths cow = new CowDepths(StateSet.R_DEPTH);
 
     @Setter private VanillaStateLayer<DepthState> vanillaLayer;
 
     private final DepthState effective = new DepthState();
 
-    public DepthStateStack() {
+    public DepthStateStack(int id) {
+        cow.id = id;
         stack = new DepthState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new DepthState();
         }
     }
 
-    public DepthStateStack push() {
-        if(pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        VanillaStateLayer.capture(vanillaLayer, stack[pointer++].set(this));
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public DepthStateStack pop() {
-        if(pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
+    @Override
+    public void captureSlot(int s) {
+        VanillaStateLayer.capture(vanillaLayer, stack[s].set(this));
+    }
 
-        final DepthState saved = stack[--pointer];
+    @Override
+    public void restoreSlot(int s) {
+        final DepthState saved = stack[s];
         if (VanillaStateLayer.restore(vanillaLayer, saved)) {
             setExceptMask(saved);
         } else {
             set(saved);
         }
-        return this;
+    }
+
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
     }
 
     public boolean isEffectiveMaskEnabled() {
@@ -52,11 +54,8 @@ public class DepthStateStack extends DepthState implements IStateStack<DepthStat
         return effective.isEnabled();
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
-    }
-
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,41 +1,38 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.FogState;
 
-public class FogStateStack extends FogState implements IStateStack<FogStateStack> {
+public final class FogStateStack extends FogState implements CowStateStack<FogStateStack> {
 
     protected final FogState[] stack;
+    private final CowDepths cow = new CowDepths();
 
-    protected int pointer;
-
-    public FogStateStack() {
+    public FogStateStack(int id) {
+        cow.id = id;
         stack = new FogState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new FogState();
         }
     }
 
-    public FogStateStack push() {
-        if(pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public FogStateStack pop() {
-        if(pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,16 +1,15 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.IntegerState;
 
-public class IntegerStateStack extends IntegerState implements IStateStack<IntegerStateStack> {
+public final class IntegerStateStack extends IntegerState implements CowStateStack<IntegerStateStack> {
 
     protected final IntegerState[] stack;
+    private CowDepths cow = new CowDepths();
 
-    protected int pointer;
-
-    public IntegerStateStack(int val) {
+    public IntegerStateStack(int val, int id) {
+        cow.id = id;
         setValue(val);
         stack = new IntegerState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
@@ -19,34 +18,40 @@ public class IntegerStateStack extends IntegerState implements IStateStack<Integ
         }
     }
 
-    public IntegerStateStack push() {
-        if(pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        stack[pointer++].set(this);
+    public IntegerStateStack restoreBit(int bit) {
+        final int id = cow.id;
+        cow = new CowDepths(bit);
+        cow.id = id;
         return this;
     }
 
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
+    }
+
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
+    }
+
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
+    }
+
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
+    }
+
     public IntegerStateStack push(int value) {
         push().setValue(value);
         return this;
     }
 
-    public IntegerStateStack pop() {
-        if(pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-
-        set(stack[--pointer]);
-        return this;
-    }
-
-    public boolean isEmpty() {
-        return pointer == 0;
-    }
-
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,40 +1,39 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.LightModelState;
 
-public class LightModelStateStack extends LightModelState implements IStateStack<LightModelStateStack> {
+public final class LightModelStateStack extends LightModelState implements CowStateStack<LightModelStateStack> {
 
     protected final LightModelState[] stack;
+    private final CowDepths cow = new CowDepths();
 
-    protected int pointer;
-
-    public LightModelStateStack() {
+    public LightModelStateStack(int id) {
         super();
+        cow.id = id;
         stack = new LightModelState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new LightModelState();
         }
     }
 
-    public LightModelStateStack push() {
-        if (pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public LightModelStateStack pop() {
-        if (pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean isEmpty() { return pointer == 0; }
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
+    }
 }

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

@@ -1,40 +1,39 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.LightState;
 
-public class LightStateStack extends LightState implements IStateStack<LightStateStack> {
+public final class LightStateStack extends LightState implements CowStateStack<LightStateStack> {
 
     protected final LightState[] stack;
+    private final CowDepths cow = new CowDepths();
 
-    protected int pointer;
-
-    public LightStateStack(int light) {
+    public LightStateStack(int light, int id) {
         super(light);
+        cow.id = id;
         stack = new LightState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new LightState(light);
         }
     }
 
-    public LightStateStack push() {
-        if (pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public LightStateStack pop() {
-        if (pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean isEmpty() { return pointer == 0; }
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
+    }
 }

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

@@ -1,46 +1,44 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.StateSet;
 import com.gtnewhorizons.angelica.glsm.states.LineState;
 
-/**
- * Stack for GL line state (width, stipple factor, stipple pattern).
- * Used by GL_LINE_BIT push/pop attrib.
- */
-public class LineStateStack extends LineState implements IStateStack<LineStateStack> {
+public final class LineStateStack extends LineState implements CowStateStack<LineStateStack> {
 
     protected final LineState[] stack;
-    protected int pointer;
+    private final CowDepths cow = new CowDepths(StateSet.R_LINE);
 
-    public LineStateStack() {
+    public LineStateStack(int id) {
+        cow.id = id;
         stack = new LineState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new LineState();
         }
     }
 
-    public LineStateStack push() {
-        if (pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public LineStateStack pop() {
-        if (pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
     }
 
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,42 +1,39 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.MaterialState;
 
-public class MaterialStateStack extends MaterialState implements IStateStack<MaterialStateStack> {
+public final class MaterialStateStack extends MaterialState implements CowStateStack<MaterialStateStack> {
 
     protected final MaterialState[] stack;
+    private final CowDepths cow = new CowDepths();
 
-    protected int pointer;
-
-    public MaterialStateStack(int face) {
+    public MaterialStateStack(int face, int id) {
         super(face);
+        cow.id = id;
         stack = new MaterialState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new MaterialState(face);
         }
     }
 
-    public MaterialStateStack push() {
-        if (pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public MaterialStateStack pop() {
-        if (pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean isEmpty() { return pointer == 0; }
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
+    }
 
+    @Override
+    public int stackId() {
+        return cow.id;
+    }
 }
-

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

@@ -1,41 +1,38 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.states.MatrixMode;
 
-public class MatrixModeStack extends MatrixMode implements IStateStack<MatrixModeStack> {
+public final class MatrixModeStack extends MatrixMode implements CowStateStack<MatrixModeStack> {
 
     protected final MatrixMode[] stack;
+    private final CowDepths cow = new CowDepths();
 
-    protected int pointer;
-
-    public MatrixModeStack() {
+    public MatrixModeStack(int id) {
+        cow.id = id;
         stack = new MatrixMode[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new MatrixMode();
         }
     }
 
-    public MatrixModeStack push() {
-        if(pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public MatrixModeStack pop() {
-        if(pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,46 +1,44 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.StateSet;
 import com.gtnewhorizons.angelica.glsm.states.PointState;
 
-/**
- * Stack for GL point state (size).
- * Used by GL_POINT_BIT push/pop attrib.
- */
-public class PointStateStack extends PointState implements IStateStack<PointStateStack> {
+public final class PointStateStack extends PointState implements CowStateStack<PointStateStack> {
 
     protected final PointState[] stack;
-    protected int pointer;
+    private final CowDepths cow = new CowDepths(StateSet.R_POINT);
 
-    public PointStateStack() {
+    public PointStateStack(int id) {
+        cow.id = id;
         stack = new PointState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new PointState();
         }
     }
 
-    public PointStateStack push() {
-        if (pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public PointStateStack pop() {
-        if (pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
     }
 
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,46 +1,44 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.StateSet;
 import com.gtnewhorizons.angelica.glsm.states.PolygonState;
 
-/**
- * Stack for GL polygon state (mode, offset, cull face mode, front face).
- * Used by GL_POLYGON_BIT push/pop attrib.
- */
-public class PolygonStateStack extends PolygonState implements IStateStack<PolygonStateStack> {
+public final class PolygonStateStack extends PolygonState implements CowStateStack<PolygonStateStack> {
 
     protected final PolygonState[] stack;
-    protected int pointer;
+    private final CowDepths cow = new CowDepths(StateSet.R_POLYGON);
 
-    public PolygonStateStack() {
+    public PolygonStateStack(int id) {
+        cow.id = id;
         stack = new PolygonState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new PolygonState();
         }
     }
 
-    public PolygonStateStack push() {
-        if (pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public PolygonStateStack pop() {
-        if (pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
     }
 
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -0,0 +1,44 @@
+package com.gtnewhorizons.angelica.glsm.stacks;
+
+import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.StateSet;
+import com.gtnewhorizons.angelica.glsm.states.ScissorState;
+
+public final class ScissorStateStack extends ScissorState implements CowStateStack<ScissorStateStack> {
+
+    protected final ScissorState[] stack;
+    private final CowDepths cow = new CowDepths(StateSet.R_SCISSOR);
+
+    public ScissorStateStack(int id) {
+        cow.id = id;
+        stack = new ScissorState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
+        for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
+            stack[i] = new ScissorState();
+        }
+    }
+
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
+    }
+
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
+    }
+
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
+    }
+
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
+    }
+}

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

@@ -0,0 +1,30 @@
+package com.gtnewhorizons.angelica.glsm.stacks;
+
+public final class StackIdAllocator {
+
+    private StackIdAllocator() {}
+
+    private static int next = -1;
+    private static int perContext = -1;
+
+    public static void beginContext() {
+        next = 0;
+    }
+
+    public static void endContext() {
+        if (perContext == -1) {
+            perContext = next;
+        } else if (next != perContext) {
+            throw new IllegalStateException("stack id count changed across contexts: " + perContext + " -> " + next);
+        }
+        next = -1;
+    }
+
+    public static int nextId() {
+        return next >= 0 ? next++ : -1;
+    }
+
+    public static int allocated() {
+        return next;
+    }
+}

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

@@ -1,46 +1,44 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.StateSet;
 import com.gtnewhorizons.angelica.glsm.states.StencilState;
 
-/**
- * Stack for GL stencil buffer state.
- * Used by GL_STENCIL_BUFFER_BIT push/pop attrib.
- */
-public class StencilStateStack extends StencilState implements IStateStack<StencilStateStack> {
+public final class StencilStateStack extends StencilState implements CowStateStack<StencilStateStack> {
 
     protected final StencilState[] stack;
-    protected int pointer;
+    private final CowDepths cow = new CowDepths(StateSet.R_STENCIL);
 
-    public StencilStateStack() {
+    public StencilStateStack(int id) {
+        cow.id = id;
         stack = new StencilState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new StencilState();
         }
     }
 
-    public StencilStateStack push() {
-        if (pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public StencilStateStack pop() {
-        if (pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
     }
 
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,49 +1,45 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.StateSet;
 import com.gtnewhorizons.angelica.glsm.states.TextureBinding;
 
-public class TextureBindingStack extends TextureBinding implements IStateStack<TextureBindingStack> {
+public final class TextureBindingStack extends TextureBinding implements CowStateStack<TextureBindingStack> {
 
     protected final TextureBinding[] stack;
+    private final CowDepths cow;
 
-    protected int pointer;
-
-    public TextureBindingStack() {
+    public TextureBindingStack(int id, int unit) {
+        cow = new CowDepths(StateSet.R_TEXTURE, unit);
+        cow.id = id;
         stack = new TextureBinding[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new TextureBinding();
         }
     }
 
-    public TextureBindingStack push() {
-        if(pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public TextureBindingStack pop() {
-        if(pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public TextureBinding peek() {
-        return stack[pointer];
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
     }
 
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -9,7 +9,7 @@ import org.lwjgl.opengl.GL13;
  * BooleanStateStack for per-texture-unit state.
  * Switches to correct unit (raw GL) before enable/disable calls.
  */
-public class TextureUnitBooleanStateStack extends BooleanStateStack {
+public final class TextureUnitBooleanStateStack extends BooleanStateStack {
     private final int unitIndex;
 
     public TextureUnitBooleanStateStack(int glCap, int unitIndex) {
@@ -24,17 +24,16 @@ public class TextureUnitBooleanStateStack extends BooleanStateStack {
 
     @Override
     public void setEnabled(boolean enabled) {
+        if (!GLStateManager.isCachingEnabled() || enabled != this.enabled) {
+            GLStateManager.beforeUncapturedTextureUnitChange(glCap, unitIndex);
+        }
         beforeModify();
         setEnabledWithUnitSwitch(enabled);
     }
 
     @Override
-    public TextureUnitBooleanStateStack popDepth() {
-        if (savedDepth > 0) {
-            final boolean oldValue = stack[--savedDepth];
-            setEnabledWithUnitSwitch(oldValue);
-        }
-        return this;
+    public void restoreSlot(int slot) {
+        setEnabledWithUnitSwitch(stack[slot]);
     }
 
     private void setEnabledWithUnitSwitch(boolean enabled) {

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

@@ -1,47 +1,42 @@
 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> {
+public final class Vec3fStack implements CowStateStack<Vec3fStack> {
 
     private final Vector3f value;
     private final float[][] stack;
-    private int pointer;
+    private final CowDepths cow = new CowDepths();
 
-    public Vec3fStack(Vector3f value) {
+    public Vec3fStack(Vector3f value, int id) {
         this.value = value;
+        cow.id = id;
         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;
+    public CowDepths cowDepths() {
+        return cow;
     }
 
     @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;
+    public void captureSlot(int s) {
+        stack[s][0] = value.x;
+        stack[s][1] = value.y;
+        stack[s][2] = value.z;
     }
 
     @Override
-    public boolean isEmpty() {
-        return pointer == 0;
+    public void restoreSlot(int s) {
+        value.set(stack[s][0], stack[s][1], stack[s][2]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,48 +1,43 @@
 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> {
+public final class Vec4fStack implements CowStateStack<Vec4fStack> {
 
     private final Vector4f value;
     private final float[][] stack;
-    private int pointer;
+    private final CowDepths cow = new CowDepths();
 
-    public Vec4fStack(Vector4f value) {
+    public Vec4fStack(Vector4f value, int id) {
         this.value = value;
+        cow.id = id;
         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;
+    public CowDepths cowDepths() {
+        return cow;
     }
 
     @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;
+    public void captureSlot(int s) {
+        stack[s][0] = value.x;
+        stack[s][1] = value.y;
+        stack[s][2] = value.z;
+        stack[s][3] = value.w;
     }
 
     @Override
-    public boolean isEmpty() {
-        return pointer == 0;
+    public void restoreSlot(int s) {
+        value.set(stack[s][0], stack[s][1], stack[s][2], stack[s][3]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -1,45 +1,44 @@
 package com.gtnewhorizons.angelica.glsm.stacks;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.StateSet;
 import com.gtnewhorizons.angelica.glsm.states.ViewportState;
 
-public class ViewPortStateStack extends ViewportState implements IStateStack<ViewPortStateStack> {
+public final class ViewPortStateStack extends ViewportState implements CowStateStack<ViewPortStateStack> {
 
     protected final ViewportState[] stack;
+    private final CowDepths cow = new CowDepths(StateSet.R_VIEWPORT);
 
-    protected int pointer;
-
-    public ViewPortStateStack() {
+    public ViewPortStateStack(int id) {
+        cow.id = id;
         stack = new ViewportState[GLStateManager.MAX_ATTRIB_STACK_DEPTH];
         for (int i = 0; i < GLStateManager.MAX_ATTRIB_STACK_DEPTH; i++) {
             stack[i] = new ViewportState();
         }
     }
 
-    public ViewPortStateStack push() {
-        if(pointer == stack.length) {
-            throw new IllegalStateException("Stack overflow size " + (pointer + 1) + " reached");
-        }
-
-        stack[pointer++].set(this);
-        return this;
+    @Override
+    public CowDepths cowDepths() {
+        return cow;
     }
 
-    public ViewPortStateStack pop() {
-        if(pointer == 0) {
-            throw new IllegalStateException("Stack underflow");
-        }
-
-        set(stack[--pointer]);
-        return this;
+    @Override
+    public void captureSlot(int s) {
+        stack[s].set(this);
     }
 
-    public boolean isEmpty() {
-        return pointer == 0;
+    @Override
+    public void restoreSlot(int s) {
+        set(stack[s]);
     }
 
-    public boolean topChanged() {
-        return pointer > 0 && !sameAs(stack[pointer - 1]);
+    @Override
+    public boolean topSlotChanged() {
+        return !cow.isEmpty() && !sameAs(stack[cow.top()]);
+    }
+
+    @Override
+    public int stackId() {
+        return cow.id;
     }
 }

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

@@ -46,8 +46,10 @@ public class BooleanState implements ISettableState<BooleanState> {
     public void setEnabled(boolean enabled) {
         final boolean bypass = !GLStateManager.isCachingEnabled();
         if (stateUnknown || bypass || enabled != this.enabled || (this.glCap == GL11.GL_BLEND && GLStateManager.vendorIsAMD() && GLStateManager.isPoppingAttributes())) {
+            GLStateManager.beforeUncapturedCapabilityChange(glCap);
             stateUnknown = false;
             this.enabled = enabled;
+            onEnabledChanged();
             if (!ffpStateOnly) {
                 if (enabled) {
                     RENDER_BACKEND.enable(this.glCap);
@@ -58,6 +60,8 @@ public class BooleanState implements ISettableState<BooleanState> {
         }
     }
 
+    protected void onEnabledChanged() {}
+
     @Override
     public BooleanState set(BooleanState state) {
         this.enabled = state.enabled;

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

@@ -0,0 +1,40 @@
+package com.gtnewhorizons.angelica.glsm.states;
+
+import com.gtnewhorizons.angelica.glsm.RenderSystem;
+
+public class SamplerUnitArray {
+
+    private static final int MIN_UNITS = 16;
+
+    private int[] samplers;
+
+    public int get(int unit) {
+        final int[] local = samplers;
+        return local != null && unit >= 0 && unit < local.length ? local[unit] : 0;
+    }
+
+    public boolean set(int unit, int sampler) {
+        if (unit < 0) return false;
+        int[] local = samplers;
+        if (local == null) {
+            local = new int[Math.max(MIN_UNITS, RenderSystem.getMaxCombinedTextureImageUnits())];
+            samplers = local;
+        }
+        if (unit >= local.length) return false;
+        local[unit] = sampler;
+        return true;
+    }
+
+    public void unbindEverywhere(int sampler) {
+        final int[] local = samplers;
+        if (local == null) return;
+        for (int i = 0; i < local.length; i++) {
+            if (local[i] == sampler) local[i] = 0;
+        }
+    }
+
+    public int size() {
+        final int[] local = samplers;
+        return local == null ? 0 : local.length;
+    }
+}

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

@@ -0,0 +1,54 @@
+package com.gtnewhorizons.angelica.glsm.states;
+
+import java.nio.IntBuffer;
+
+public class ScissorState implements ISettableState<ScissorState> {
+    public int x;
+    public int y;
+    public int width;
+    public int height;
+
+    public void setScissor(int x, int y, int width, int height) {
+        this.x = x;
+        this.y = y;
+        this.width = width;
+        this.height = height;
+    }
+
+    public void get(IntBuffer params) {
+        params.put(0, x);
+        params.put(1, y);
+        params.put(2, width);
+        params.put(3, height);
+    }
+
+    public void get(int[] params) {
+        params[0] = x;
+        params[1] = y;
+        params[2] = width;
+        params[3] = height;
+    }
+
+    @Override
+    public ScissorState set(ScissorState state) {
+        this.x = state.x;
+        this.y = state.y;
+        this.width = state.width;
+        this.height = state.height;
+
+        return this;
+    }
+
+    @Override
+    public boolean sameAs(Object state) {
+        if (this == state) return true;
+        if (!(state instanceof ScissorState scissorState)) return false;
+        return x == scissorState.x && y == scissorState.y && width == scissorState.width && height == scissorState.height;
+    }
+
+    @Override
+    public ScissorState copy() {
+        return new ScissorState().set(this);
+    }
+
+}

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

@@ -1,14 +1,15 @@
 package com.gtnewhorizons.angelica.glsm.states;
 
-import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.stacks.CowDepths;
+import com.gtnewhorizons.angelica.glsm.stacks.CowStateStack;
 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 final class TexEnvState implements CowStateStack<TexEnvState> {
 
     public int mode;
 
@@ -30,22 +31,25 @@ public class TexEnvState implements IStateStack<TexEnvState> {
     public float envColorA;
 
     private final TexEnvState[] stack;
-    private int pointer;
+    private final CowDepths cow;
     private final boolean isStackEntry;
 
-    public TexEnvState() {
+    public TexEnvState(int id) {
         this(false);
+        cow.id = id;
     }
 
     private TexEnvState(boolean isStackEntry) {
         this.isStackEntry = isStackEntry;
         if (isStackEntry) {
             stack = null;
+            cow = 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);
             }
+            cow = new CowDepths();
         }
         reset();
     }
@@ -80,31 +84,27 @@ public class TexEnvState implements IStateStack<TexEnvState> {
     }
 
     @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;
+    public CowDepths cowDepths() {
+        if (cow == null) throw new IllegalStateException("Cannot push/pop a stack entry");
+        return cow;
     }
 
     @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;
+    public void captureSlot(int s) {
+        stack[s].copyFrom(this);
     }
 
     @Override
-    public boolean isEmpty() {
-        return pointer == 0;
+    public void restoreSlot(int s) {
+        copyFrom(stack[s]);
     }
 
     public boolean isCombineMode() {
         return mode == GL13.GL_COMBINE;
     }
+
+    @Override
+    public int stackId() {
+        return cow == null ? -1 : cow.id;
+    }
 }

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

@@ -1,6 +1,8 @@
 package com.gtnewhorizons.angelica.glsm.states;
 
+import com.gtnewhorizon.gtnhlib.client.renderer.stacks.IStateStack;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
+import com.gtnewhorizons.angelica.glsm.stacks.StackIdAllocator;
 import com.gtnewhorizons.angelica.glsm.stacks.TextureBindingStack;
 import com.gtnewhorizons.angelica.glsm.stacks.TextureUnitBooleanStateStack;
 import lombok.Getter;
@@ -8,7 +10,11 @@ import org.joml.Matrix4fStack;
 import org.lwjgl.opengl.GL11;
 import org.lwjgl.opengl.GL12;
 
+import java.util.ArrayList;
+import java.util.List;
+
 public class TextureUnitArray {
+    private final List<IStateStack<?>> idStacks = new ArrayList<>();
     private final TextureBindingStack[] bindings;
     private final TextureUnitBooleanStateStack[] states;
     private final TextureUnitBooleanStateStack[] texture1DStates;
@@ -22,6 +28,9 @@ public class TextureUnitArray {
     @Getter
     public final Matrix4fStack[] textureMatricies;
 
+    public int texMatIdentityMask;
+    public int texMatIdentityGen;
+
     public TextureUnitArray() {
         bindings = new TextureBindingStack[GLStateManager.MAX_TEXTURE_UNITS];
         states = new TextureUnitBooleanStateStack[GLStateManager.MAX_TEXTURE_UNITS];
@@ -36,20 +45,35 @@ public class TextureUnitArray {
         textureMatricies = new Matrix4fStack[GLStateManager.MAX_TEXTURE_UNITS];
 
         for (int i = 0; i < GLStateManager.MAX_TEXTURE_UNITS; i++) {
-            bindings[i] = new TextureBindingStack();
-            states[i] = new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_2D, i);
-            texture1DStates[i] = new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_1D, i);
-            texture3DStates[i] = new TextureUnitBooleanStateStack(GL12.GL_TEXTURE_3D, i);
-            texGenSStates[i] = new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_GEN_S, i);
-            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);
+            bindings[i] = member(new TextureBindingStack(StackIdAllocator.nextId(), i));
+            states[i] = track(new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_2D, i));
+            texture1DStates[i] = track(new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_1D, i));
+            texture3DStates[i] = track(new TextureUnitBooleanStateStack(GL12.GL_TEXTURE_3D, i));
+            texGenSStates[i] = track(new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_GEN_S, i));
+            texGenTStates[i] = track(new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_GEN_T, i));
+            texGenRStates[i] = track(new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_GEN_R, i));
+            texGenQStates[i] = track(new TextureUnitBooleanStateStack(GL11.GL_TEXTURE_GEN_Q, i));
             texGenStates[i] = new TexGenState();
-            texEnvStates[i] = new TexEnvState();
+            texEnvStates[i] = member(new TexEnvState(StackIdAllocator.nextId()));
             textureMatricies[i] = new Matrix4fStack(GLStateManager.MAX_TEXTURE_STACK_DEPTH);
         }
     }
 
+    private <T extends TextureUnitBooleanStateStack> T track(T s) {
+        s.setStackId(StackIdAllocator.nextId());
+        idStacks.add(s);
+        return s;
+    }
+
+    private <T extends IStateStack<?>> T member(T s) {
+        idStacks.add(s);
+        return s;
+    }
+
+    public List<IStateStack<?>> idStacks() {
+        return idStacks;
+    }
+
     public TextureBindingStack getTextureUnitBindings(int index) {
         return bindings[index];
     }

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

@@ -3,7 +3,8 @@ package com.gtnewhorizons.angelica.glsm.streaming;
 import com.gtnewhorizons.angelica.config.SystemProperties;
 import com.gtnewhorizons.angelica.glsm.GLStateManager;
 import com.gtnewhorizons.angelica.glsm.RenderSystem;
-import it.unimi.dsi.fastutil.objects.ObjectArrayFIFOQueue;
+import it.unimi.dsi.fastutil.ints.IntArrayFIFOQueue;
+import it.unimi.dsi.fastutil.longs.LongArrayFIFOQueue;
 import org.lwjgl.opengl.GL30;
 import org.lwjgl.opengl.GL32;
 import org.lwjgl.opengl.GL44;
@@ -11,7 +12,6 @@ import org.lwjgl.opengl.GL44;
 import java.nio.ByteBuffer;
 
 import static com.gtnewhorizon.gtnhlib.bytebuf.MemoryUtilities.memAddress0;
-import static com.gtnewhorizons.angelica.glsm.backend.BackendManager.RENDER_BACKEND;
 
 /**
  * Persistent-mapped fence-reclaimed ring over any buffer target. Callers reserve a range and
@@ -28,7 +28,8 @@ final class GlStreamingRing {
     private static final long SYNC_WAIT_SLICE_NANOS = 10_000_000L;
     private static final long SYNC_WAIT_TOTAL_NANOS = 5_000_000_000L;
 
-    private final ObjectArrayFIFOQueue<FencedRegion> fenceQueue = new ObjectArrayFIFOQueue<>();
+    private final LongArrayFIFOQueue fenceIds = new LongArrayFIFOQueue();
+    private final IntArrayFIFOQueue fenceBytes = new IntArrayFIFOQueue();
     private int writePos;
     private int remaining;
     private int pendingBytes;
@@ -51,13 +52,13 @@ final class GlStreamingRing {
 
     static GlStreamingRing create(int target, int capacity, boolean forceOrphan) {
         if (forceOrphan || !RenderSystem.supportsBufferStorage()) return null;
-        final int id = RENDER_BACKEND.genBuffers();
-        RENDER_BACKEND.bindBuffer(target, id);
+        final int id = GLStateManager.glGenBuffers();
+        GLStateManager.glBindBuffer(target, id);
         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(target, capacity, storageFlags);
         final int mapFlags = GL44.GL_MAP_PERSISTENT_BIT | GL30.GL_MAP_WRITE_BIT | GL44.GL_MAP_COHERENT_BIT;
-        final ByteBuffer mapped = RENDER_BACKEND.mapBufferRange(target, 0, capacity, mapFlags);
-        RENDER_BACKEND.bindBuffer(target, 0);
+        final ByteBuffer mapped = GLStateManager.glMapBufferRange(target, 0, capacity, mapFlags);
+        GLStateManager.glBindBuffer(target, 0);
         if (mapped == null) {
             GLStateManager.glDeleteBuffers(id);
             GLStateManager.LOGGER.warn("Persistent map failed for streaming ring (target=0x{}, {} bytes)", Integer.toHexString(target), capacity);
@@ -92,7 +93,7 @@ final class GlStreamingRing {
 
     private boolean ensureRemaining(int needed) {
         while (remaining < needed) {
-            if (fenceQueue.isEmpty()) {
+            if (fenceIds.isEmpty()) {
                 if (pendingBytes == 0) return false;
                 fence();
             }
@@ -103,7 +104,8 @@ final class GlStreamingRing {
 
     private void fence() {
         if (pendingBytes > 0) {
-            fenceQueue.enqueue(new FencedRegion(RENDER_BACKEND.fenceSync(GL32.GL_SYNC_GPU_COMMANDS_COMPLETE, 0), pendingBytes));
+            fenceIds.enqueue(GLStateManager.glFenceSync(GL32.GL_SYNC_GPU_COMMANDS_COMPLETE, 0));
+            fenceBytes.enqueue(pendingBytes);
             pendingBytes = 0;
             fencesIssued++;
         }
@@ -114,30 +116,32 @@ final class GlStreamingRing {
     }
 
     private void reclaim() {
-        while (!fenceQueue.isEmpty()) {
-            final FencedRegion region = fenceQueue.first();
-            if (!signaled(RENDER_BACKEND.clientWaitSync(region.fenceId, 0, 0L))) break;
-            GLStateManager.glDeleteSync(region.fenceId);
-            fenceQueue.dequeue();
-            remaining += region.bytes;
+        while (!fenceIds.isEmpty()) {
+            final long fenceId = fenceIds.firstLong();
+            if (!signaled(GLStateManager.glClientWaitSync(fenceId, 0, 0L))) break;
+            GLStateManager.glDeleteSync(fenceId);
+            fenceIds.dequeueLong();
+            remaining += fenceBytes.dequeueInt();
         }
     }
 
     private void syncOldest() {
-        final FencedRegion region = fenceQueue.dequeue();
+        final long fenceId = fenceIds.dequeueLong();
+        final int bytes = fenceBytes.dequeueInt();
         forcedReclaims++;
         final long deadline = System.nanoTime() + SYNC_WAIT_TOTAL_NANOS;
         long remainingNanos = SYNC_WAIT_TOTAL_NANOS;
         int status;
         do {
-            status = RENDER_BACKEND.clientWaitSync(region.fenceId, GL32.GL_SYNC_FLUSH_COMMANDS_BIT, Math.min(SYNC_WAIT_SLICE_NANOS, remainingNanos));
+            status = GLStateManager.glClientWaitSync(fenceId, GL32.GL_SYNC_FLUSH_COMMANDS_BIT,
+                Math.min(SYNC_WAIT_SLICE_NANOS, remainingNanos));
             remainingNanos = deadline - System.nanoTime();
         } while (status == GL32.GL_TIMEOUT_EXPIRED && remainingNanos > 0);
         if (!signaled(status)) {
             GLStateManager.LOGGER.warn("Streaming ring fence wait did not signal (status=0x{}); reclaiming anyway", Integer.toHexString(status));
         }
-        GLStateManager.glDeleteSync(region.fenceId);
-        remaining += region.bytes;
+        GLStateManager.glDeleteSync(fenceId);
+        remaining += bytes;
         reclaim();
     }
 
@@ -156,17 +160,16 @@ final class GlStreamingRing {
     int forcedReclaims() { return forcedReclaims; }
 
     void destroy() {
-        while (!fenceQueue.isEmpty()) {
-            GLStateManager.glDeleteSync(fenceQueue.dequeue().fenceId);
+        while (!fenceIds.isEmpty()) {
+            GLStateManager.glDeleteSync(fenceIds.dequeueLong());
         }
+        fenceBytes.clear();
         if (bufferId != 0) {
-            RENDER_BACKEND.bindBuffer(target, bufferId);
-            RENDER_BACKEND.unmapBuffer(target);
-            RENDER_BACKEND.bindBuffer(target, 0);
+            GLStateManager.glBindBuffer(target, bufferId);
+            GLStateManager.glUnmapBuffer(target);
+            GLStateManager.glBindBuffer(target, 0);
             GLStateManager.glDeleteBuffers(bufferId);
             bufferId = 0;
         }
     }
-
-    private record FencedRegion(long fenceId, int bytes) {}
 }

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

@@ -5,8 +5,6 @@ import org.lwjgl.opengl.GL15;
 
 import java.nio.ByteBuffer;
 
-import static com.gtnewhorizons.angelica.glsm.backend.BackendManager.RENDER_BACKEND;
-
 /**
  * Streaming buffer using the classic orphan pattern.
  */
@@ -16,19 +14,19 @@ public final class OrphanStreamingBuffer {
     private int capacity;
 
     public OrphanStreamingBuffer() {
-        this.bufferId = RENDER_BACKEND.genBuffers();
+        this.bufferId = GLStateManager.glGenBuffers();
     }
 
     public void upload(ByteBuffer data) {
-        RENDER_BACKEND.bindBuffer(GL15.GL_ARRAY_BUFFER, bufferId);
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, bufferId);
         capacity = StreamingUploader.upload(data, capacity);
-        RENDER_BACKEND.bindBuffer(GL15.GL_ARRAY_BUFFER, 0);
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
     }
 
     void upload(StreamingUploader.UploadStrategy strategy, ByteBuffer data) {
-        RENDER_BACKEND.bindBuffer(GL15.GL_ARRAY_BUFFER, bufferId);
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, bufferId);
         capacity = StreamingUploader.upload(strategy, data, capacity);
-        RENDER_BACKEND.bindBuffer(GL15.GL_ARRAY_BUFFER, 0);
+        GLStateManager.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0);
     }
 
     public int getCapacity() {