Looks good to me

- Make SimpleMaterial.Builder implement Material itself.
- Add way to copy a material.
- Move fog/cutout shaders to their own utility classes.
- Fix crumbling on cutout materials by overriding properties.
- Add helper in glsl for unpacking 2 shorts from one uint.
- Remove Fog enum.

src/main/java/com/jozufozu/flywheel/Flywheel.java

@@ -22,6 +22,8 @@ import com.jozufozu.flywheel.impl.visualization.VisualizationEventHandler;
 import com.jozufozu.flywheel.lib.context.Contexts;
 import com.jozufozu.flywheel.lib.instance.InstanceTypes;
 import com.jozufozu.flywheel.lib.light.LightUpdater;
+import com.jozufozu.flywheel.lib.material.CutoutShaders;
+import com.jozufozu.flywheel.lib.material.FogShaders;
 import com.jozufozu.flywheel.lib.material.StandardMaterialShaders;
 import com.jozufozu.flywheel.lib.memory.FlwMemoryTracker;
 import com.jozufozu.flywheel.lib.model.ModelCache;
@@ -129,6 +131,8 @@ public class Flywheel {
 	private static void onClientSetup(FMLClientSetupEvent event) {
 		VertexTypes.init();
 		InstanceTypes.init();
+		CutoutShaders.init();
+		FogShaders.init();
 		StandardMaterialShaders.init();
 		Contexts.init();
 

src/main/java/com/jozufozu/flywheel/api/material/Fog.java

@@ -1,16 +0,0 @@
-package com.jozufozu.flywheel.api.material;
-
-public enum Fog {
-	/**
-	 * Fade out to the fog color based on distance.
-	 */
-	LINEAR,
-	/**
-	 * Fade out to black based on distance.
-	 */
-	LINEAR_FADE,
-	/**
-	 * No fog.
-	 */
-	NONE,
-}

src/main/java/com/jozufozu/flywheel/backend/engine/indirect/IndirectBuffers.java

@@ -29,7 +29,7 @@ public class IndirectBuffers {
 	public static final long PTR_SIZE = Pointer.POINTER_SIZE;
 
 	// DRAW COMMAND
-	public static final long DRAW_COMMAND_STRIDE = 48;
+	public static final long DRAW_COMMAND_STRIDE = 52;
 	public static final long DRAW_COMMAND_OFFSET = 0;
 
 	// BITS
@@ -109,7 +109,7 @@ public class IndirectBuffers {
 	}
 
 	void createObjectStorage(int objectCount) {
-		freeObjectStogare();
+		freeObjectStorage();
 		var objectSize = objectStride * objectCount;
 		var targetSize = INT_SIZE * objectCount;
 
@@ -165,7 +165,7 @@ public class IndirectBuffers {
 		FlwMemoryTracker._allocGPUMemory(maxDrawCount * DRAW_COMMAND_STRIDE);
 	}
 
-	private void freeObjectStogare() {
+	private void freeObjectStorage() {
 		FlwMemoryTracker._freeGPUMemory(maxObjectCount * objectStride);
 	}
 
@@ -199,7 +199,7 @@ public class IndirectBuffers {
 	public void delete() {
 		nglDeleteBuffers(BUFFER_COUNT, buffers.ptr());
 		buffers.free();
-		freeObjectStogare();
+		freeObjectStorage();
 		freeDrawStorage();
 	}
 }

src/main/java/com/jozufozu/flywheel/backend/engine/instancing/InstancedCrumbling.java

@@ -10,12 +10,17 @@ import org.jetbrains.annotations.NotNull;
 import com.jozufozu.flywheel.api.backend.Engine;
 import com.jozufozu.flywheel.api.instance.Instance;
 import com.jozufozu.flywheel.api.material.Material;
+import com.jozufozu.flywheel.api.material.Transparency;
+import com.jozufozu.flywheel.api.material.WriteMask;
+import com.jozufozu.flywheel.backend.MaterialUtil;
 import com.jozufozu.flywheel.backend.compile.InstancingPrograms;
 import com.jozufozu.flywheel.backend.engine.InstanceHandleImpl;
 import com.jozufozu.flywheel.backend.engine.UniformBuffer;
 import com.jozufozu.flywheel.gl.GlStateTracker;
 import com.jozufozu.flywheel.gl.GlTextureUnit;
 import com.jozufozu.flywheel.lib.context.Contexts;
+import com.jozufozu.flywheel.lib.material.CutoutShaders;
+import com.jozufozu.flywheel.lib.material.SimpleMaterial;
 import com.mojang.blaze3d.systems.RenderSystem;
 
 import it.unimi.dsi.fastutil.ints.Int2ObjectArrayMap;
@@ -42,15 +47,20 @@ public class InstancedCrumbling {
 
 				ShaderState shader = shaderStateEntry.getKey();
 
-				var material = shader.material();
+				var baseMaterial = shader.material();
+				int diffuseTexture = getDiffuseTexture(baseMaterial);
+
+				var crumblingMaterial = SimpleMaterial.from(baseMaterial)
+						.transparency(Transparency.CRUMBLING)
+						.writeMask(WriteMask.COLOR)
+						.polygonOffset(true)
+						.cutout(CutoutShaders.OFF);
 
 				var program = InstancingPrograms.get()
 						.get(shader.vertexType(), shader.instanceType(), Contexts.CRUMBLING);
 				UniformBuffer.syncAndBind(program);
 
-				InstancingEngine.uploadMaterialIDUniform(program, material);
+				InstancingEngine.uploadMaterialIDUniform(program, crumblingMaterial);
-
-				int renderTex = getDiffuseTexture(material);
 
 				for (Int2ObjectMap.Entry<List<Runnable>> progressEntry : byProgress.int2ObjectEntrySet()) {
 					var drawCalls = progressEntry.getValue();
@@ -59,17 +69,19 @@ public class InstancedCrumbling {
 						continue;
 					}
 
-					var crumblingType = ModelBakery.DESTROY_TYPES.get(progressEntry.getIntKey());
+					crumblingMaterial.baseTexture(ModelBakery.BREAKING_LOCATIONS.get(progressEntry.getIntKey()));
 
-					crumblingType.setupRenderState();
+					MaterialUtil.setup(crumblingMaterial);
 
-					RenderSystem.setShaderTexture(1, renderTex);
+					RenderSystem.setShaderTexture(1, diffuseTexture);
 					GlTextureUnit.T1.makeActive();
-					RenderSystem.bindTexture(renderTex);
+					RenderSystem.bindTexture(diffuseTexture);
 
 					drawCalls.forEach(Runnable::run);
 				}
 			}
+
+			MaterialUtil.reset();
 		}
 	}
 

src/main/java/com/jozufozu/flywheel/lib/material/CutoutShaders.java

@@ -0,0 +1,28 @@
+package com.jozufozu.flywheel.lib.material;
+
+import org.jetbrains.annotations.ApiStatus;
+
+import com.jozufozu.flywheel.Flywheel;
+import com.jozufozu.flywheel.api.material.CutoutShader;
+
+public class CutoutShaders {
+	/**
+	 * Do not discard any fragments based on alpha.
+	 */
+	public static final CutoutShader OFF = CutoutShader.REGISTRY.registerAndGet(new SimpleCutoutShader(Flywheel.rl("cutout/off.glsl")));
+	/**
+	 * Discard fragments with alpha close to or equal to zero.
+	 */
+	public static final CutoutShader EPSILON = CutoutShader.REGISTRY.registerAndGet(new SimpleCutoutShader(Flywheel.rl("cutout/epsilon.glsl")));
+	/**
+	 * Discard fragments with alpha less than to 0.5.
+	 */
+	public static final CutoutShader HALF = CutoutShader.REGISTRY.registerAndGet(new SimpleCutoutShader(Flywheel.rl("cutout/half.glsl")));
+
+	private CutoutShaders() {
+	}
+
+	@ApiStatus.Internal
+	public static void init() {
+	}
+}

src/main/java/com/jozufozu/flywheel/lib/material/FogShaders.java

@@ -0,0 +1,19 @@
+package com.jozufozu.flywheel.lib.material;
+
+import org.jetbrains.annotations.ApiStatus;
+
+import com.jozufozu.flywheel.Flywheel;
+import com.jozufozu.flywheel.api.material.FogShader;
+
+public class FogShaders {
+	public static final FogShader NONE = FogShader.REGISTRY.registerAndGet(new SimpleFogShader(Flywheel.rl("fog/none.glsl")));
+	public static final FogShader LINEAR = FogShader.REGISTRY.registerAndGet(new SimpleFogShader(Flywheel.rl("fog/linear.glsl")));
+	public static final FogShader LINEAR_FADE = FogShader.REGISTRY.registerAndGet(new SimpleFogShader(Flywheel.rl("fog/linear_fade.glsl")));
+
+	private FogShaders() {
+	}
+
+	@ApiStatus.Internal
+	public static void init() {
+	}
+}

src/main/java/com/jozufozu/flywheel/lib/material/Materials.java

@@ -37,26 +37,26 @@ public final class Materials {
 			.build();
 
 	public static final Material CHUNK_CUTOUT_MIPPED_SHADED = SimpleMaterial.builder()
-			.cutout(StandardMaterialShaders.EPSILON)
+			.cutout(CutoutShaders.EPSILON)
 			.fallbackRenderType(RenderType.cutoutMipped())
 			.vertexTransformer(SHADING_TRANSFORMER)
 			.build();
 	public static final Material CHUNK_CUTOUT_MIPPED_UNSHADED = SimpleMaterial.builder()
 			.diffuse(false)
-			.cutout(StandardMaterialShaders.EPSILON)
+			.cutout(CutoutShaders.EPSILON)
 			.fallbackRenderType(RenderType.cutoutMipped())
 			.build();
 
 	public static final Material CHUNK_CUTOUT_SHADED = SimpleMaterial.builder()
 			.mip(false)
-			.cutout(StandardMaterialShaders.EPSILON)
+			.cutout(CutoutShaders.EPSILON)
 			.fallbackRenderType(RenderType.cutout())
 			.vertexTransformer(SHADING_TRANSFORMER)
 			.build();
 	public static final Material CHUNK_CUTOUT_UNSHADED = SimpleMaterial.builder()
 			.diffuse(false)
 			.mip(false)
-			.cutout(StandardMaterialShaders.EPSILON)
+			.cutout(CutoutShaders.EPSILON)
 			.fallbackRenderType(RenderType.cutout())
 			.build();
 
@@ -73,14 +73,14 @@ public final class Materials {
 
 	public static final Material CHUNK_TRIPWIRE_SHADED = SimpleMaterial.builder()
 			.transparency(Transparency.TRANSLUCENT)
-			.cutout(StandardMaterialShaders.EPSILON)
+			.cutout(CutoutShaders.EPSILON)
 			.fallbackRenderType(RenderType.tripwire())
 			.vertexTransformer(SHADING_TRANSFORMER)
 			.build();
 	public static final Material CHUNK_TRIPWIRE_UNSHADED = SimpleMaterial.builder()
 			.diffuse(false)
 			.transparency(Transparency.TRANSLUCENT)
-			.cutout(StandardMaterialShaders.EPSILON)
+			.cutout(CutoutShaders.EPSILON)
 			.fallbackRenderType(RenderType.tripwire())
 			.build();
 
@@ -93,7 +93,7 @@ public final class Materials {
 			.baseTexture(Sheets.SHULKER_SHEET)
 			.mip(false)
 			.backfaceCull(false)
-			.cutout(StandardMaterialShaders.EPSILON)
+			.cutout(CutoutShaders.EPSILON)
 			.fallbackRenderType(Sheets.shulkerBoxSheet())
 			.build();
 	public static final Material BELL = SimpleMaterial.builder()

src/main/java/com/jozufozu/flywheel/lib/material/SimpleMaterial.java

@@ -50,6 +50,10 @@ public class SimpleMaterial implements Material {
 		return new Builder();
 	}
 
+	public static Builder from(Material material) {
+		return new Builder(material);
+	}
+
 	@Override
 	public MaterialShaders shaders() {
 		return shaders;
@@ -117,26 +121,58 @@ public class SimpleMaterial implements Material {
 
 	@Override
 	public WriteMask writeMask() {
-		return WriteMask.BOTH;
+		return writeMask;
 	}
 
-	public static class Builder {
+	public static class Builder implements Material {
-		protected RenderType fallbackRenderType = RenderType.solid();
+		protected RenderType fallbackRenderType;
-		protected MaterialVertexTransformer vertexTransformer = (vertexList, level) -> {};
+		protected MaterialVertexTransformer vertexTransformer;
-		protected MaterialShaders shaders = StandardMaterialShaders.DEFAULT;
+		protected MaterialShaders shaders;
-		protected ResourceLocation baseTexture = InventoryMenu.BLOCK_ATLAS;
+		protected ResourceLocation baseTexture;
-		protected boolean diffuse = true;
+		protected boolean diffuse;
-		protected boolean lighting = true;
+		protected boolean lighting;
-		protected boolean blur = false;
+		protected boolean blur;
-		protected boolean backfaceCull = true;
+		protected boolean backfaceCull;
-		protected boolean polygonOffset = false;
+		protected boolean polygonOffset;
-		protected boolean mip = true;
+		protected boolean mip;
-		protected FogShader fog = StandardMaterialShaders.LINEAR;
+		protected FogShader fog;
-		protected Transparency transparency = Transparency.OPAQUE;
+		protected Transparency transparency;
-		protected CutoutShader cutout = StandardMaterialShaders.OFF;
+		protected CutoutShader cutout;
-		protected WriteMask writeMask = WriteMask.BOTH;
+		protected WriteMask writeMask;
 
 		public Builder() {
+			fallbackRenderType = RenderType.solid();
+			vertexTransformer = (vertexList, level) -> {
+			};
+			shaders = StandardMaterialShaders.DEFAULT;
+			baseTexture = InventoryMenu.BLOCK_ATLAS;
+			diffuse = true;
+			lighting = true;
+			blur = false;
+			backfaceCull = true;
+			polygonOffset = false;
+			mip = true;
+			fog = FogShaders.LINEAR;
+			transparency = Transparency.OPAQUE;
+			cutout = CutoutShaders.OFF;
+			writeMask = WriteMask.BOTH;
+		}
+
+		public Builder(Material material) {
+			fallbackRenderType = material.getFallbackRenderType();
+			vertexTransformer = material.getVertexTransformer();
+			shaders = material.shaders();
+			baseTexture = material.baseTexture();
+			diffuse = material.diffuse();
+			lighting = material.lighting();
+			blur = material.blur();
+			backfaceCull = material.backfaceCull();
+			polygonOffset = material.polygonOffset();
+			mip = material.mip();
+			fog = material.fog();
+			transparency = material.transparency();
+			cutout = material.cutout();
+			writeMask = material.writeMask();
 		}
 
 		public Builder fallbackRenderType(RenderType type) {
@@ -209,6 +245,76 @@ public class SimpleMaterial implements Material {
 			return this;
 		}
 
+		@Override
+		public MaterialShaders shaders() {
+			return shaders;
+		}
+
+		@Override
+		public RenderType getFallbackRenderType() {
+			return fallbackRenderType;
+		}
+
+		@Override
+		public MaterialVertexTransformer getVertexTransformer() {
+			return vertexTransformer;
+		}
+
+		@Override
+		public ResourceLocation baseTexture() {
+			return baseTexture;
+		}
+
+		@Override
+		public boolean diffuse() {
+			return diffuse;
+		}
+
+		@Override
+		public boolean lighting() {
+			return lighting;
+		}
+
+		@Override
+		public boolean blur() {
+			return blur;
+		}
+
+		@Override
+		public boolean backfaceCull() {
+			return backfaceCull;
+		}
+
+		@Override
+		public boolean polygonOffset() {
+			return polygonOffset;
+		}
+
+		@Override
+		public boolean mip() {
+			return mip;
+		}
+
+		@Override
+		public FogShader fog() {
+			return fog;
+		}
+
+		@Override
+		public Transparency transparency() {
+			return transparency;
+		}
+
+		@Override
+		public CutoutShader cutout() {
+			return cutout;
+		}
+
+		@Override
+		public WriteMask writeMask() {
+			return writeMask;
+		}
+
 		public SimpleMaterial build() {
 			return new SimpleMaterial(this);
 		}

src/main/java/com/jozufozu/flywheel/lib/material/StandardMaterialShaders.java

@@ -3,29 +3,11 @@ package com.jozufozu.flywheel.lib.material;
 import org.jetbrains.annotations.ApiStatus;
 
 import com.jozufozu.flywheel.Flywheel;
-import com.jozufozu.flywheel.api.material.CutoutShader;
-import com.jozufozu.flywheel.api.material.FogShader;
 import com.jozufozu.flywheel.api.material.MaterialShaders;
 
 import net.minecraft.resources.ResourceLocation;
 
 public final class StandardMaterialShaders {
-	/**
-	 * Do not discard any fragments based on alpha.
-	 */
-	public static final CutoutShader OFF = CutoutShader.REGISTRY.registerAndGet(new SimpleCutoutShader(Flywheel.rl("cutout/off.glsl")));
-	/**
-	 * Discard fragments with alpha close to or equal to zero.
-	 */
-	public static final CutoutShader EPSILON = CutoutShader.REGISTRY.registerAndGet(new SimpleCutoutShader(Flywheel.rl("cutout/epsilon.glsl")));
-	/**
-	 * Discard fragments with alpha less than to 0.5.
-	 */
-	public static final CutoutShader HALF = CutoutShader.REGISTRY.registerAndGet(new SimpleCutoutShader(Flywheel.rl("cutout/half.glsl")));
-
-	public static final FogShader NONE = FogShader.REGISTRY.registerAndGet(new SimpleFogShader(Flywheel.rl("fog/none.glsl")));
-	public static final FogShader LINEAR = FogShader.REGISTRY.registerAndGet(new SimpleFogShader(Flywheel.rl("fog/linear.glsl")));
-	public static final FogShader LINEAR_FADE = FogShader.REGISTRY.registerAndGet(new SimpleFogShader(Flywheel.rl("fog/linear_fade.glsl")));
 
 	public static final MaterialShaders DEFAULT = MaterialShaders.REGISTRY.registerAndGet(new SimpleMaterialShaders(Files.DEFAULT_VERTEX, Files.DEFAULT_FRAGMENT));
 

src/main/resources/assets/flywheel/flywheel/context/crumbling.frag

@@ -9,6 +9,9 @@ vec4 flw_crumblingSampleColor;
 void flw_beginFragment() {
     flw_crumblingSampleColor = texture(flw_crumblingTex, _flw_crumblingTexCoord);
 
+    // Make the crumbling overlay transparent when the diffuse layer is transparent.
+    flw_crumblingSampleColor.a *= flw_fragColor.a;
+
     if (flw_crumblingSampleColor.a < 0.01) {
         discard;
     }

src/main/resources/assets/flywheel/flywheel/internal/indirect/draw.frag

@@ -18,9 +18,8 @@ out vec4 fragColor;
 
 void main() {
     _flw_materialFragmentID = _flw_material.x;
-    _flw_fogID = _flw_material.y & 0xFFFFu;
-    _flw_cutoutID = _flw_material.y >> 16u;
 
+    _flw_unpackUint2x16(_flw_material.y, _flw_cutoutID, _flw_fogID);
     _flw_unpackMaterial(_flw_material.z, flw_material);
 
     flw_sampleColor = texture(flw_diffuseTex, flw_vertexTexCoord);

src/main/resources/assets/flywheel/flywheel/internal/instancing/draw.frag

@@ -18,9 +18,8 @@ out vec4 fragColor;
 
 void main() {
     _flw_materialFragmentID = _flw_material_instancing.y;
-    _flw_fogID = _flw_material_instancing.z & 0xFFFFu;
-    _flw_cutoutID = _flw_material_instancing.z >> 16u;
 
+    _flw_unpackUint2x16(_flw_material_instancing.z, _flw_cutoutID, _flw_fogID);
     _flw_unpackMaterial(_flw_material_instancing.w, flw_material);
 
     flw_sampleColor = texture(flw_diffuseTex, flw_vertexTexCoord);

src/main/resources/assets/flywheel/flywheel/internal/material.glsl

@@ -23,3 +23,8 @@ void _flw_unpackMaterial(uint m, out FlwMaterial o) {
     o.writeMask = (m & WRITE_MASK_MASK) >> 6;
     o.transparency = (m & TRANSPARENCY_MASK) >> 8;
 }
+
+void _flw_unpackUint2x16(uint s, out uint hi, out uint lo) {
+    hi = (s >> 16) & 0xFFFFu;
+    lo = s & 0xFFFFu;
+}