Reject eagerness return to lazy

- Eagerly load ALL shaders in ShaderSources, resolving imports there
- Compile and cache programs on-demand
- Move gl state try blocks to EngineImpl
- EngineImpl catches shader exceptions and triggers a fallback

common/src/backend/java/dev/engine_room/flywheel/backend/compile/FlwPrograms.java

@@ -6,11 +6,7 @@ import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.google.common.collect.ImmutableList;
-
 import dev.engine_room.flywheel.api.Flywheel;
-import dev.engine_room.flywheel.api.instance.InstanceType;
-import dev.engine_room.flywheel.api.material.LightShader;
 import dev.engine_room.flywheel.backend.MaterialShaderIndices;
 import dev.engine_room.flywheel.backend.compile.component.UberShaderComponent;
 import dev.engine_room.flywheel.backend.compile.core.CompilerStats;
@@ -43,9 +39,11 @@ public final class FlwPrograms {
 		var vertexComponentsHeader = loader.find(COMPONENTS_HEADER_VERT);
 		var fragmentComponentsHeader = loader.find(COMPONENTS_HEADER_FRAG);
 
+		// TODO: de-uber material shaders
 		var vertexMaterialComponent = createVertexMaterialComponent(loader);
 		var fragmentMaterialComponent = createFragmentMaterialComponent(loader);
 		var fogComponent = createFogComponent(loader);
+		// TODO: separate compilation for cutout OFF, but keep the rest uber'd
 		var cutoutComponent = createCutoutComponent(loader);
 
 		if (stats.errored() || vertexComponentsHeader == null || fragmentComponentsHeader == null || vertexMaterialComponent == null || fragmentMaterialComponent == null || fogComponent == null || cutoutComponent == null) {
@@ -57,21 +55,8 @@ public final class FlwPrograms {
 		List<SourceComponent> vertexComponents = List.of(vertexComponentsHeader, vertexMaterialComponent);
 		List<SourceComponent> fragmentComponents = List.of(fragmentComponentsHeader, fragmentMaterialComponent, fogComponent, cutoutComponent);
 
-		var pipelineKeys = createPipelineKeys();
-		InstancingPrograms.reload(sources, pipelineKeys, vertexComponents, fragmentComponents);
-		IndirectPrograms.reload(sources, pipelineKeys, vertexComponents, fragmentComponents);
-	}
-
-	private static ImmutableList<PipelineProgramKey> createPipelineKeys() {
-		ImmutableList.Builder<PipelineProgramKey> builder = ImmutableList.builder();
-		for (ContextShader contextShader : ContextShader.values()) {
-			for (InstanceType<?> instanceType : InstanceType.REGISTRY) {
-				for (LightShader light : LightShader.REGISTRY.getAll()) {
-					builder.add(new PipelineProgramKey(instanceType, contextShader, light));
-				}
-			}
-		}
-		return builder.build();
+		InstancingPrograms.reload(sources, vertexComponents, fragmentComponents);
+		IndirectPrograms.reload(sources, vertexComponents, fragmentComponents);
 	}
 
 	@Nullable

common/src/backend/java/dev/engine_room/flywheel/backend/compile/IndirectPrograms.java

@@ -1,7 +1,6 @@
 package dev.engine_room.flywheel.backend.compile;
 
 import java.util.List;
-import java.util.Map;
 
 import org.jetbrains.annotations.Nullable;
 
@@ -43,11 +42,11 @@ public class IndirectPrograms extends AtomicReferenceCounted {
 	@Nullable
 	private static IndirectPrograms instance;
 
-	private final Map<PipelineProgramKey, GlProgram> pipeline;
-	private final Map<InstanceType<?>, GlProgram> culling;
-	private final Map<ResourceLocation, GlProgram> utils;
+	private final CompilationHarness<PipelineProgramKey> pipeline;
+	private final CompilationHarness<InstanceType<?>> culling;
+	private final CompilationHarness<ResourceLocation> utils;
 
-	private IndirectPrograms(Map<PipelineProgramKey, GlProgram> pipeline, Map<InstanceType<?>, GlProgram> culling, Map<ResourceLocation, GlProgram> utils) {
+	private IndirectPrograms(CompilationHarness<PipelineProgramKey> pipeline, CompilationHarness<InstanceType<?>> culling, CompilationHarness<ResourceLocation> utils) {
 		this.pipeline = pipeline;
 		this.culling = culling;
 		this.utils = utils;
@@ -81,32 +80,16 @@ public class IndirectPrograms extends AtomicReferenceCounted {
 		return extensions.build();
 	}
 
-	static void reload(ShaderSources sources, ImmutableList<PipelineProgramKey> pipelineKeys, List<SourceComponent> vertexComponents, List<SourceComponent> fragmentComponents) {
+	static void reload(ShaderSources sources, List<SourceComponent> vertexComponents, List<SourceComponent> fragmentComponents) {
 		if (!GlCompat.SUPPORTS_INDIRECT) {
 			return;
 		}
 
-		IndirectPrograms newInstance = null;
-
 		var pipelineCompiler = PipelineCompiler.create(sources, Pipelines.INDIRECT, vertexComponents, fragmentComponents, EXTENSIONS);
 		var cullingCompiler = createCullingCompiler(sources);
 		var utilCompiler = createUtilCompiler(sources);
 
-		try {
-			var pipelineResult = pipelineCompiler.compileAndReportErrors(pipelineKeys);
-			var cullingResult = cullingCompiler.compileAndReportErrors(createCullingKeys());
-			var utils = utilCompiler.compileAndReportErrors(UTIL_SHADERS);
-
-			if (pipelineResult != null && cullingResult != null && utils != null) {
-				newInstance = new IndirectPrograms(pipelineResult, cullingResult, utils);
-			}
-		} catch (Throwable t) {
-			FlwPrograms.LOGGER.error("Failed to compile indirect programs", t);
-		}
-
-		pipelineCompiler.delete();
-		cullingCompiler.delete();
-		utilCompiler.delete();
+		IndirectPrograms newInstance = new IndirectPrograms(pipelineCompiler, cullingCompiler, utilCompiler);
 
 		setInstance(newInstance);
 	}
@@ -142,14 +125,6 @@ public class IndirectPrograms extends AtomicReferenceCounted {
 				.harness("utilities", sources);
 	}
 
-	private static ImmutableList<InstanceType<?>> createCullingKeys() {
-		ImmutableList.Builder<InstanceType<?>> builder = ImmutableList.builder();
-		for (InstanceType<?> instanceType : InstanceType.REGISTRY) {
-			builder.add(instanceType);
-		}
-		return builder.build();
-	}
-
 	static void setInstance(@Nullable IndirectPrograms newInstance) {
 		if (instance != null) {
 			instance.release();
@@ -169,6 +144,10 @@ public class IndirectPrograms extends AtomicReferenceCounted {
 		return instance != null;
 	}
 
+	public static void kill() {
+		setInstance(null);
+	}
+
 	public GlProgram getIndirectProgram(InstanceType<?> instanceType, ContextShader contextShader, LightShader light) {
 		return pipeline.get(new PipelineProgramKey(instanceType, contextShader, light));
 	}
@@ -195,11 +174,8 @@ public class IndirectPrograms extends AtomicReferenceCounted {
 
 	@Override
 	protected void _delete() {
-		pipeline.values()
-				.forEach(GlProgram::delete);
-		culling.values()
-				.forEach(GlProgram::delete);
-		utils.values()
-				.forEach(GlProgram::delete);
+		pipeline.delete();
+		culling.delete();
+		utils.delete();
 	}
 }

common/src/backend/java/dev/engine_room/flywheel/backend/compile/InstancingPrograms.java

@@ -1,7 +1,6 @@
 package dev.engine_room.flywheel.backend.compile;
 
 import java.util.List;
-import java.util.Map;
 
 import org.jetbrains.annotations.Nullable;
 
@@ -9,6 +8,7 @@ import com.google.common.collect.ImmutableList;
 
 import dev.engine_room.flywheel.api.instance.InstanceType;
 import dev.engine_room.flywheel.api.material.LightShader;
+import dev.engine_room.flywheel.backend.compile.core.CompilationHarness;
 import dev.engine_room.flywheel.backend.gl.GlCompat;
 import dev.engine_room.flywheel.backend.gl.shader.GlProgram;
 import dev.engine_room.flywheel.backend.glsl.GlslVersion;
@@ -22,9 +22,9 @@ public class InstancingPrograms extends AtomicReferenceCounted {
 	@Nullable
 	private static InstancingPrograms instance;
 
-	private final Map<PipelineProgramKey, GlProgram> pipeline;
+	private final CompilationHarness<PipelineProgramKey> pipeline;
 
-	private InstancingPrograms(Map<PipelineProgramKey, GlProgram> pipeline) {
+	private InstancingPrograms(CompilationHarness<PipelineProgramKey> pipeline) {
 		this.pipeline = pipeline;
 	}
 
@@ -36,26 +36,14 @@ public class InstancingPrograms extends AtomicReferenceCounted {
 		return extensions.build();
 	}
 
-	static void reload(ShaderSources sources, ImmutableList<PipelineProgramKey> pipelineKeys, List<SourceComponent> vertexComponents, List<SourceComponent> fragmentComponents) {
+	static void reload(ShaderSources sources, List<SourceComponent> vertexComponents, List<SourceComponent> fragmentComponents) {
 		if (!GlCompat.SUPPORTS_INSTANCING) {
 			return;
 		}
 
-		InstancingPrograms newInstance = null;
 
 		var pipelineCompiler = PipelineCompiler.create(sources, Pipelines.INSTANCING, vertexComponents, fragmentComponents, EXTENSIONS);
-
-		try {
-			var pipelineResult = pipelineCompiler.compileAndReportErrors(pipelineKeys);
-
-			if (pipelineResult != null) {
-				newInstance = new InstancingPrograms(pipelineResult);
-			}
-		} catch (Throwable t) {
-			FlwPrograms.LOGGER.error("Failed to compile instancing programs", t);
-		}
-
-		pipelineCompiler.delete();
+		InstancingPrograms newInstance = new InstancingPrograms(pipelineCompiler);
 
 		setInstance(newInstance);
 	}
@@ -79,13 +67,16 @@ public class InstancingPrograms extends AtomicReferenceCounted {
 		return instance != null;
 	}
 
+	public static void kill() {
+		setInstance(null);
+	}
+
 	public GlProgram get(InstanceType<?> instanceType, ContextShader contextShader, LightShader light) {
 		return pipeline.get(new PipelineProgramKey(instanceType, contextShader, light));
 	}
 
 	@Override
 	protected void _delete() {
-		pipeline.values()
-				.forEach(GlProgram::delete);
+		pipeline.delete();
 	}
 }

common/src/backend/java/dev/engine_room/flywheel/backend/compile/core/CompilationHarness.java

@@ -1,6 +1,5 @@
 package dev.engine_room.flywheel.backend.compile.core;
 
-import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -16,6 +15,8 @@ public class CompilationHarness<K> {
 	private final ProgramLinker programLinker;
 	private final CompilerStats stats;
 
+	private final Map<K, GlProgram> programs = new HashMap<>();
+
 	public CompilationHarness(String marker, ShaderSources sources, KeyCompiler<K> compiler) {
 		this.compiler = compiler;
 		stats = new CompilerStats(marker);
@@ -24,23 +25,16 @@ public class CompilationHarness<K> {
 		programLinker = new ProgramLinker(stats);
 	}
 
-	@Nullable
-	public Map<K, GlProgram> compileAndReportErrors(Collection<K> keys) {
-		stats.start();
-		Map<K, GlProgram> out = new HashMap<>();
-		for (var key : keys) {
-			GlProgram glProgram = compiler.compile(key, sourceLoader, shaderCache, programLinker);
-			if (out != null && glProgram != null) {
-				out.put(key, glProgram);
-			} else {
-				out = null; // Return null when a preloading error occurs.
-			}
-		}
-		stats.finish();
+	public GlProgram get(K key) {
+		return programs.computeIfAbsent(key, this::compile);
+	}
 
-		if (stats.errored()) {
-			stats.emitErrorLog();
-			return null;
+	private GlProgram compile(K key) {
+		var out = compiler.compile(key, sourceLoader, shaderCache, programLinker);
+
+		if (out == null) {
+			// TODO: populate exception with error details
+			throw new ShaderException();
 		}
 
 		return out;
@@ -48,6 +42,10 @@ public class CompilationHarness<K> {
 
 	public void delete() {
 		shaderCache.delete();
+
+		for (var program : programs.values()) {
+			program.delete();
+		}
 	}
 
 	public interface KeyCompiler<K> {

common/src/backend/java/dev/engine_room/flywheel/backend/compile/core/ShaderException.java

@@ -0,0 +1,4 @@
+package dev.engine_room.flywheel.backend.compile.core;
+
+public class ShaderException extends RuntimeException {
+}

common/src/backend/java/dev/engine_room/flywheel/backend/engine/DrawManager.java

@@ -135,6 +135,8 @@ public abstract class DrawManager<N extends AbstractInstancer<?>> {
 		initializationQueue.clear();
 	}
 
+	public abstract void triggerFallback();
+
 	protected record UninitializedInstancer<N, I extends Instance>(InstancerKey<I> key, N instancer) {
 	}
 }

common/src/backend/java/dev/engine_room/flywheel/backend/engine/EngineImpl.java

@@ -13,6 +13,7 @@ import dev.engine_room.flywheel.api.task.Plan;
 import dev.engine_room.flywheel.api.visualization.VisualEmbedding;
 import dev.engine_room.flywheel.api.visualization.VisualType;
 import dev.engine_room.flywheel.api.visualization.VisualizationContext;
+import dev.engine_room.flywheel.backend.compile.core.ShaderException;
 import dev.engine_room.flywheel.backend.engine.embed.EmbeddedEnvironment;
 import dev.engine_room.flywheel.backend.engine.embed.Environment;
 import dev.engine_room.flywheel.backend.engine.embed.EnvironmentStorage;
@@ -90,17 +91,27 @@ public class EngineImpl implements Engine {
 			Uniforms.update(context);
 			environmentStorage.flush();
 			drawManager.flush(lightStorage, environmentStorage);
+		} catch (ShaderException e) {
+			triggerFallback();
 		}
 	}
 
 	@Override
 	public void render(RenderContext context, VisualType visualType) {
-		drawManager.render(visualType);
+		try (var state = GlStateTracker.getRestoreState()) {
+			drawManager.render(visualType);
+		} catch (ShaderException e) {
+			triggerFallback();
+		}
 	}
 
 	@Override
 	public void renderCrumbling(RenderContext context, List<CrumblingBlock> crumblingBlocks) {
-		drawManager.renderCrumbling(crumblingBlocks);
+		try (var state = GlStateTracker.getRestoreState()) {
+			drawManager.renderCrumbling(crumblingBlocks);
+		} catch (ShaderException e) {
+			triggerFallback();
+		}
 	}
 
 	@Override
@@ -110,6 +121,10 @@ public class EngineImpl implements Engine {
 		environmentStorage.delete();
 	}
 
+	private void triggerFallback() {
+		drawManager.triggerFallback();
+	}
+
 	public <I extends Instance> Instancer<I> instancer(Environment environment, InstanceType<I> type, Model model, VisualType visualType, int bias) {
 		return drawManager.getInstancer(environment, type, model, visualType, bias);
 	}

common/src/backend/java/dev/engine_room/flywheel/backend/engine/indirect/IndirectDrawManager.java

@@ -29,12 +29,12 @@ import dev.engine_room.flywheel.backend.engine.MeshPool;
 import dev.engine_room.flywheel.backend.engine.TextureBinder;
 import dev.engine_room.flywheel.backend.engine.embed.EnvironmentStorage;
 import dev.engine_room.flywheel.backend.engine.uniform.Uniforms;
-import dev.engine_room.flywheel.backend.gl.GlStateTracker;
 import dev.engine_room.flywheel.backend.gl.array.GlVertexArray;
 import dev.engine_room.flywheel.backend.gl.buffer.GlBuffer;
 import dev.engine_room.flywheel.backend.gl.buffer.GlBufferType;
 import dev.engine_room.flywheel.lib.material.SimpleMaterial;
 import dev.engine_room.flywheel.lib.memory.MemoryBlock;
+import net.minecraft.client.Minecraft;
 import net.minecraft.client.resources.model.ModelBakery;
 
 public class IndirectDrawManager extends DrawManager<IndirectInstancer<?>> {
@@ -91,26 +91,24 @@ public class IndirectDrawManager extends DrawManager<IndirectInstancer<?>> {
 			return;
 		}
 
-		try (var state = GlStateTracker.getRestoreState()) {
-			TextureBinder.bindLightAndOverlay();
+		TextureBinder.bindLightAndOverlay();
 
-			vertexArray.bindForDraw();
-			lightBuffers.bind();
-			matrixBuffer.bind();
-			Uniforms.bindAll();
+		vertexArray.bindForDraw();
+		lightBuffers.bind();
+		matrixBuffer.bind();
+		Uniforms.bindAll();
 
-			if (needsBarrier) {
-				glMemoryBarrier(GL_SHADER_STORAGE_BARRIER_BIT);
-				needsBarrier = false;
-			}
-
-			for (var group : cullingGroups.values()) {
-				group.submit(visualType);
-			}
-
-			MaterialRenderState.reset();
-			TextureBinder.resetLightAndOverlay();
+		if (needsBarrier) {
+			glMemoryBarrier(GL_SHADER_STORAGE_BARRIER_BIT);
+			needsBarrier = false;
 		}
+
+		for (var group : cullingGroups.values()) {
+			group.submit(visualType);
+		}
+
+		MaterialRenderState.reset();
+		TextureBinder.resetLightAndOverlay();
 	}
 
 	@Override
@@ -194,63 +192,67 @@ public class IndirectDrawManager extends DrawManager<IndirectInstancer<?>> {
 			return;
 		}
 
-		try (var state = GlStateTracker.getRestoreState()) {
-			TextureBinder.bindLightAndOverlay();
+		TextureBinder.bindLightAndOverlay();
 
-			vertexArray.bindForDraw();
-			Uniforms.bindAll();
+		vertexArray.bindForDraw();
+		Uniforms.bindAll();
 
-			var crumblingMaterial = SimpleMaterial.builder();
+		var crumblingMaterial = SimpleMaterial.builder();
 
-			// Scratch memory for writing draw commands.
-			var block = MemoryBlock.malloc(IndirectBuffers.DRAW_COMMAND_STRIDE);
+		// Scratch memory for writing draw commands.
+		var block = MemoryBlock.malloc(IndirectBuffers.DRAW_COMMAND_STRIDE);
 
-			// Set up the crumbling program buffers. Nothing changes here between draws.
-			GlBufferType.DRAW_INDIRECT_BUFFER.bind(crumblingDrawBuffer.handle());
-			glBindBufferRange(GL_SHADER_STORAGE_BUFFER, BufferBindings.DRAW, crumblingDrawBuffer.handle(), 0, IndirectBuffers.DRAW_COMMAND_STRIDE);
+		// Set up the crumbling program buffers. Nothing changes here between draws.
+		GlBufferType.DRAW_INDIRECT_BUFFER.bind(crumblingDrawBuffer.handle());
+		glBindBufferRange(GL_SHADER_STORAGE_BUFFER, BufferBindings.DRAW, crumblingDrawBuffer.handle(), 0, IndirectBuffers.DRAW_COMMAND_STRIDE);
 
-			for (var groupEntry : byType.entrySet()) {
-				var byProgress = groupEntry.getValue();
+		for (var groupEntry : byType.entrySet()) {
+			var byProgress = groupEntry.getValue();
 
-				GroupKey<?> groupKey = groupEntry.getKey();
-				IndirectCullingGroup<?> cullingGroup = cullingGroups.get(groupKey.instanceType());
+			GroupKey<?> groupKey = groupEntry.getKey();
+			IndirectCullingGroup<?> cullingGroup = cullingGroups.get(groupKey.instanceType());
 
-				if (cullingGroup == null) {
-					continue;
-				}
-
-				cullingGroup.bindWithContextShader(ContextShader.CRUMBLING);
-
-				for (var progressEntry : byProgress.int2ObjectEntrySet()) {
-					Samplers.CRUMBLING.makeActive();
-					TextureBinder.bind(ModelBakery.BREAKING_LOCATIONS.get(progressEntry.getIntKey()));
-
-					for (var instanceHandlePair : progressEntry.getValue()) {
-						IndirectInstancer<?> instancer = instanceHandlePair.getFirst();
-						int instanceIndex = instanceHandlePair.getSecond().index;
-
-						for (IndirectDraw draw : instancer.draws()) {
-							// Transform the material to be suited for crumbling.
-							CommonCrumbling.applyCrumblingProperties(crumblingMaterial, draw.material());
-
-							MaterialRenderState.setup(crumblingMaterial);
-
-							// Upload the draw command.
-							draw.writeWithOverrides(block.ptr(), instanceIndex, crumblingMaterial);
-							crumblingDrawBuffer.upload(block);
-
-							// Submit! Everything is already bound by here.
-							glDrawElementsIndirect(GL_TRIANGLES, GL_UNSIGNED_INT, 0);
-						}
-					}
-
-				}
+			if (cullingGroup == null) {
+				continue;
 			}
 
-			MaterialRenderState.reset();
-			TextureBinder.resetLightAndOverlay();
+			cullingGroup.bindWithContextShader(ContextShader.CRUMBLING);
 
-			block.free();
+			for (var progressEntry : byProgress.int2ObjectEntrySet()) {
+				Samplers.CRUMBLING.makeActive();
+				TextureBinder.bind(ModelBakery.BREAKING_LOCATIONS.get(progressEntry.getIntKey()));
+
+				for (var instanceHandlePair : progressEntry.getValue()) {
+					IndirectInstancer<?> instancer = instanceHandlePair.getFirst();
+					int instanceIndex = instanceHandlePair.getSecond().index;
+
+					for (IndirectDraw draw : instancer.draws()) {
+						// Transform the material to be suited for crumbling.
+						CommonCrumbling.applyCrumblingProperties(crumblingMaterial, draw.material());
+
+						MaterialRenderState.setup(crumblingMaterial);
+
+						// Upload the draw command.
+						draw.writeWithOverrides(block.ptr(), instanceIndex, crumblingMaterial);
+						crumblingDrawBuffer.upload(block);
+
+						// Submit! Everything is already bound by here.
+						glDrawElementsIndirect(GL_TRIANGLES, GL_UNSIGNED_INT, 0);
+					}
+				}
+
+			}
 		}
+
+		MaterialRenderState.reset();
+		TextureBinder.resetLightAndOverlay();
+
+		block.free();
+	}
+
+	@Override
+	public void triggerFallback() {
+		IndirectPrograms.kill();
+		Minecraft.getInstance().levelRenderer.allChanged();
 	}
 }

common/src/backend/java/dev/engine_room/flywheel/backend/engine/instancing/InstancedDrawManager.java

@@ -25,12 +25,12 @@ import dev.engine_room.flywheel.backend.engine.MeshPool;
 import dev.engine_room.flywheel.backend.engine.TextureBinder;
 import dev.engine_room.flywheel.backend.engine.embed.EnvironmentStorage;
 import dev.engine_room.flywheel.backend.engine.uniform.Uniforms;
-import dev.engine_room.flywheel.backend.gl.GlStateTracker;
 import dev.engine_room.flywheel.backend.gl.TextureBuffer;
 import dev.engine_room.flywheel.backend.gl.array.GlVertexArray;
 import dev.engine_room.flywheel.backend.gl.shader.GlProgram;
 import dev.engine_room.flywheel.lib.material.LightShaders;
 import dev.engine_room.flywheel.lib.material.SimpleMaterial;
+import net.minecraft.client.Minecraft;
 import net.minecraft.client.resources.model.ModelBakery;
 
 public class InstancedDrawManager extends DrawManager<InstancedInstancer<?>> {
@@ -94,17 +94,15 @@ public class InstancedDrawManager extends DrawManager<InstancedInstancer<?>> {
 			return;
 		}
 
-		try (var state = GlStateTracker.getRestoreState()) {
-			Uniforms.bindAll();
-			vao.bindForDraw();
-			TextureBinder.bindLightAndOverlay();
-			light.bind();
+		Uniforms.bindAll();
+		vao.bindForDraw();
+		TextureBinder.bindLightAndOverlay();
+		light.bind();
 
-			stage.draw(instanceTexture, programs);
+		stage.draw(instanceTexture, programs);
 
-			MaterialRenderState.reset();
-			TextureBinder.resetLightAndOverlay();
-		}
+		MaterialRenderState.reset();
+		TextureBinder.resetLightAndOverlay();
 	}
 
 	@Override
@@ -162,46 +160,50 @@ public class InstancedDrawManager extends DrawManager<InstancedInstancer<?>> {
 
 		var crumblingMaterial = SimpleMaterial.builder();
 
-		try (var state = GlStateTracker.getRestoreState()) {
-			Uniforms.bindAll();
-			vao.bindForDraw();
-			TextureBinder.bindLightAndOverlay();
+		Uniforms.bindAll();
+		vao.bindForDraw();
+		TextureBinder.bindLightAndOverlay();
 
-			for (var groupEntry : byType.entrySet()) {
-				var byProgress = groupEntry.getValue();
+		for (var groupEntry : byType.entrySet()) {
+			var byProgress = groupEntry.getValue();
 
-				GroupKey<?> shader = groupEntry.getKey();
+			GroupKey<?> shader = groupEntry.getKey();
 
-				var program = programs.get(shader.instanceType(), ContextShader.CRUMBLING, LightShaders.SMOOTH_WHEN_EMBEDDED);
-				program.bind();
+			var program = programs.get(shader.instanceType(), ContextShader.CRUMBLING, LightShaders.SMOOTH_WHEN_EMBEDDED);
+			program.bind();
 
-				for (var progressEntry : byProgress.int2ObjectEntrySet()) {
-					Samplers.CRUMBLING.makeActive();
-					TextureBinder.bind(ModelBakery.BREAKING_LOCATIONS.get(progressEntry.getIntKey()));
+			for (var progressEntry : byProgress.int2ObjectEntrySet()) {
+				Samplers.CRUMBLING.makeActive();
+				TextureBinder.bind(ModelBakery.BREAKING_LOCATIONS.get(progressEntry.getIntKey()));
 
-					for (var instanceHandlePair : progressEntry.getValue()) {
-						InstancedInstancer<?> instancer = instanceHandlePair.getFirst();
-						var index = instanceHandlePair.getSecond().index;
+				for (var instanceHandlePair : progressEntry.getValue()) {
+					InstancedInstancer<?> instancer = instanceHandlePair.getFirst();
+					var index = instanceHandlePair.getSecond().index;
 
-						program.setInt("_flw_baseInstance", index);
+					program.setInt("_flw_baseInstance", index);
 
-						for (InstancedDraw draw : instancer.draws()) {
-							CommonCrumbling.applyCrumblingProperties(crumblingMaterial, draw.material());
-							uploadMaterialUniform(program, crumblingMaterial);
+					for (InstancedDraw draw : instancer.draws()) {
+						CommonCrumbling.applyCrumblingProperties(crumblingMaterial, draw.material());
+						uploadMaterialUniform(program, crumblingMaterial);
 
-							MaterialRenderState.setup(crumblingMaterial);
+						MaterialRenderState.setup(crumblingMaterial);
 
-							Samplers.INSTANCE_BUFFER.makeActive();
+						Samplers.INSTANCE_BUFFER.makeActive();
 
-							draw.renderOne(instanceTexture);
-						}
+						draw.renderOne(instanceTexture);
 					}
 				}
 			}
-
-			MaterialRenderState.reset();
-			TextureBinder.resetLightAndOverlay();
 		}
+
+		MaterialRenderState.reset();
+		TextureBinder.resetLightAndOverlay();
+	}
+
+	@Override
+	public void triggerFallback() {
+		InstancingPrograms.kill();
+		Minecraft.getInstance().levelRenderer.allChanged();
 	}
 
 	public static void uploadMaterialUniform(GlProgram program, Material material) {

common/src/backend/java/dev/engine_room/flywheel/backend/glsl/ShaderSources.java

@@ -11,7 +11,10 @@ import java.util.Map;
 
 import org.jetbrains.annotations.VisibleForTesting;
 
+import dev.engine_room.flywheel.backend.compile.FlwPrograms;
+import dev.engine_room.flywheel.lib.util.StringUtil;
 import net.minecraft.resources.ResourceLocation;
+import net.minecraft.server.packs.resources.Resource;
 import net.minecraft.server.packs.resources.ResourceManager;
 
 /**
@@ -20,62 +23,96 @@ import net.minecraft.server.packs.resources.ResourceManager;
 public class ShaderSources {
 	public static final String SHADER_DIR = "flywheel/";
 
-	private final ResourceManager manager;
-
 	@VisibleForTesting
-	protected final Map<ResourceLocation, LoadResult> cache = new HashMap<>();
-
-	/**
-	 * Tracks where we are in the mutual recursion to detect circular imports.
-	 */
-	private final Deque<ResourceLocation> findStack = new ArrayDeque<>();
+	protected final Map<ResourceLocation, LoadResult> cache;
 
 	public ShaderSources(ResourceManager manager) {
-		this.manager = manager;
+		var sourceFinder = new SourceFinder(manager);
+
+		long loadStart = System.nanoTime();
+		manager.listResources("flywheel", ShaderSources::isShader)
+				.forEach(sourceFinder::rootLoad);
+
+		long loadEnd = System.nanoTime();
+
+		FlwPrograms.LOGGER.info("Loaded {} shader sources in {}", sourceFinder.results.size(), StringUtil.formatTime(loadEnd - loadStart));
+
+		this.cache = sourceFinder.results;
 	}
 
-	public ShaderSources(ResourceManager manager, Map<ResourceLocation, LoadResult> preloadCache) {
-		this.manager = manager;
-		cache.putAll(preloadCache);
+	private static ResourceLocation locationWithoutFlywheelPrefix(ResourceLocation loc) {
+		return new ResourceLocation(loc.getNamespace(), loc.getPath()
+				.substring(SHADER_DIR.length()));
 	}
 
 	public LoadResult find(ResourceLocation location) {
-		if (findStack.contains(location)) {
-			// Make a copy of the find stack with the offending location added on top to show the full path.
+		return cache.computeIfAbsent(location, loc -> new LoadResult.Failure(new LoadError.ResourceError(loc)));
+	}
+
+	private static boolean isShader(ResourceLocation loc) {
+		var path = loc.getPath();
+		return path.endsWith(".glsl") || path.endsWith(".vert") || path.endsWith(".frag") || path.endsWith(".comp");
+	}
+
+	private static class SourceFinder {
+		private final Deque<ResourceLocation> findStack = new ArrayDeque<>();
+		private final Map<ResourceLocation, LoadResult> results = new HashMap<>();
+		private final ResourceManager manager;
+
+		public SourceFinder(ResourceManager manager) {
+			this.manager = manager;
+		}
+
+		public void rootLoad(ResourceLocation loc, Resource resource) {
+			var strippedLoc = locationWithoutFlywheelPrefix(loc);
+
+			if (results.containsKey(strippedLoc)) {
+				// Some other source already #included this one.
+				return;
+			}
+
+			this.results.put(strippedLoc, readResource(strippedLoc, resource));
+		}
+
+		public LoadResult recursiveLoad(ResourceLocation location) {
+			if (findStack.contains(location)) {
+				// Make a copy of the find stack with the offending location added on top to show the full path.
+				findStack.addLast(location);
+				var copy = List.copyOf(findStack);
+				findStack.removeLast();
+				return new LoadResult.Failure(new LoadError.CircularDependency(location, copy));
+			}
 			findStack.addLast(location);
-			var copy = List.copyOf(findStack);
+
+			LoadResult out = _find(location);
+
 			findStack.removeLast();
-			return new LoadResult.Failure(new LoadError.CircularDependency(location, copy));
+			return out;
 		}
-		findStack.addLast(location);
 
-		LoadResult out = _find(location);
-
-		findStack.removeLast();
-		return out;
-	}
-
-	private LoadResult _find(ResourceLocation location) {
-		// Can't use computeIfAbsent because mutual recursion causes ConcurrentModificationExceptions
-		var out = cache.get(location);
-		if (out == null) {
-			out = load(location);
-			cache.put(location, out);
+		private LoadResult _find(ResourceLocation location) {
+			// Can't use computeIfAbsent because mutual recursion causes ConcurrentModificationExceptions
+			var out = results.get(location);
+			if (out == null) {
+				out = load(location);
+				results.put(location, out);
+			}
+			return out;
 		}
-		return out;
-	}
 
-	@VisibleForTesting
-	protected LoadResult load(ResourceLocation loc) {
-		return manager.getResource(loc.withPrefix(SHADER_DIR))
-				.map(resource -> {
-					try (InputStream stream = resource.open()) {
-						String sourceString = new String(stream.readAllBytes(), StandardCharsets.UTF_8);
-						return SourceFile.parse(this, loc, sourceString);
-					} catch (IOException e) {
-						return new LoadResult.Failure(new LoadError.IOError(loc, e));
-					}
-				})
-				.orElseGet(() -> new LoadResult.Failure(new LoadError.ResourceError(loc)));
+		private LoadResult load(ResourceLocation loc) {
+			return manager.getResource(loc.withPrefix(SHADER_DIR))
+					.map(resource -> readResource(loc, resource))
+					.orElseGet(() -> new LoadResult.Failure(new LoadError.ResourceError(loc)));
+		}
+
+		private LoadResult readResource(ResourceLocation loc, Resource resource) {
+			try (InputStream stream = resource.open()) {
+				String sourceString = new String(stream.readAllBytes(), StandardCharsets.UTF_8);
+				return SourceFile.parse(this::recursiveLoad, loc, sourceString);
+			} catch (IOException e) {
+				return new LoadResult.Failure(new LoadError.IOError(loc, e));
+			}
+		}
 	}
 }

common/src/backend/java/dev/engine_room/flywheel/backend/glsl/SourceFile.java

@@ -5,6 +5,7 @@ import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Function;
 
 import org.jetbrains.annotations.Nullable;
 
@@ -69,7 +70,7 @@ public class SourceFile implements SourceComponent {
 		return new LoadResult.Success(new SourceFile(name, new SourceLines(name, ""), ImmutableMap.of(), ImmutableMap.of(), ImmutableList.of(), ImmutableMap.of(), ImmutableList.of(), ""));
 	}
 
-	public static LoadResult parse(ShaderSources sourceFinder, ResourceLocation name, String stringSource) {
+	public static LoadResult parse(Function<ResourceLocation, LoadResult> sourceFinder, ResourceLocation name, String stringSource) {
 		var source = new SourceLines(name, stringSource);
 
 		var imports = Import.parseImports(source);
@@ -93,7 +94,7 @@ public class SourceFile implements SourceComponent {
 				continue;
 			}
 
-			var result = sourceFinder.find(location);
+			var result = sourceFinder.apply(location);
 
 			if (result instanceof LoadResult.Success s) {
 				included.add(s.unwrap());

common/src/test/java/dev/engine_room/flywheel/backend/glsl/MockShaderSources.java

@@ -1,36 +1,62 @@
 package dev.engine_room.flywheel.backend.glsl;
 
 import java.io.FileNotFoundException;
+import java.util.ArrayDeque;
+import java.util.Deque;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
-import org.junit.jupiter.api.Assertions;
-
 import net.minecraft.resources.ResourceLocation;
-import net.minecraft.server.packs.resources.ResourceManager;
 
-public class MockShaderSources extends ShaderSources {
+public class MockShaderSources {
 	private final Map<ResourceLocation, String> sources = new HashMap<>();
+	private final Map<ResourceLocation, LoadResult> cache = new HashMap<>();
+	private final Deque<ResourceLocation> findStack = new ArrayDeque<>();
+
 
 	public MockShaderSources() {
-		super(ResourceManager.Empty.INSTANCE);
+
 	}
 
 	public void add(ResourceLocation loc, String source) {
 		sources.put(loc, source);
 	}
 
-	@Override
-	protected LoadResult load(ResourceLocation loc) {
+	public LoadResult find(ResourceLocation location) {
+		if (findStack.contains(location)) {
+			// Make a copy of the find stack with the offending location added on top to show the full path.
+			findStack.addLast(location);
+			var copy = List.copyOf(findStack);
+			findStack.removeLast();
+			return new LoadResult.Failure(new LoadError.CircularDependency(location, copy));
+		}
+		findStack.addLast(location);
+
+		LoadResult out = load(location);
+
+		findStack.removeLast();
+		return out;
+	}
+
+	private LoadResult load(ResourceLocation loc) {
+		var out = cache.get(loc);
+		if (out != null) {
+			return out;
+		}
+
+		var loadResult = _load(loc);
+
+		cache.put(loc, loadResult);
+
+		return loadResult;
+	}
+
+	private LoadResult _load(ResourceLocation loc) {
 		var maybeFound = sources.get(loc);
 		if (maybeFound == null) {
 			return new LoadResult.Failure(new LoadError.IOError(loc, new FileNotFoundException(loc.toString())));
 		}
-		return SourceFile.parse(this, loc, maybeFound);
-	}
-
-	public LoadResult assertLoaded(ResourceLocation loc) {
-		Assertions.assertTrue(cache.containsKey(loc), "Expected " + loc + " to be cached");
-		return cache.get(loc);
+		return SourceFile.parse(this::find, loc, maybeFound);
 	}
 }

common/src/test/java/dev/engine_room/flywheel/backend/glsl/TestShaderSourceLoading.java

@@ -38,7 +38,6 @@ public class TestShaderSourceLoading extends TestBase {
 		sources.add(FLW_B, "");
 
 		findAndAssertSuccess(sources, FLW_A);
-		sources.assertLoaded(FLW_B);
 	}
 
 	@Test
@@ -78,7 +77,6 @@ public class TestShaderSourceLoading extends TestBase {
 		sources.add(FLW_B, "");
 
 		SourceFile a = findAndAssertSuccess(sources, FLW_A);
-		sources.assertLoaded(FLW_B);
 
 		var includeB = assertSingletonList(a.imports);
 		assertEquals(FLW_B.toString(), includeB.file()
@@ -99,7 +97,6 @@ public class TestShaderSourceLoading extends TestBase {
 		sources.add(FLW_B, "");
 
 		SourceFile a = findAndAssertSuccess(sources, FLW_A);
-		sources.assertLoaded(FLW_B);
 
 		assertEquals(2, a.imports.size());
 		for (Import include : a.imports) {
@@ -112,7 +109,7 @@ public class TestShaderSourceLoading extends TestBase {
 
 				""", a.finalSource, "Both include statements should be elided.");
 
-		LoadResult bResult = sources.assertLoaded(FLW_B);
+		LoadResult bResult = sources.find(FLW_B);
 		SourceFile b = assertSuccessAndUnwrap(FLW_B, bResult);
 
 		assertEquals(ImmutableList.of(b), a.included);
@@ -148,7 +145,6 @@ public class TestShaderSourceLoading extends TestBase {
 				""");
 
 		var aErr = findAndAssertError(LoadError.IncludeError.class, sources, FLW_A);
-		sources.assertLoaded(FLW_B);
 
 		var recursiveInclude = assertSimpleNestedErrorsToDepth(LoadError.CircularDependency.class, aErr, 2);
 		assertEquals(ImmutableList.of(FLW_A, FLW_B, FLW_A), recursiveInclude.stack());
@@ -168,8 +164,6 @@ public class TestShaderSourceLoading extends TestBase {
 				""");
 
 		var aErr = findAndAssertError(LoadError.IncludeError.class, sources, FLW_A);
-		sources.assertLoaded(FLW_B);
-		sources.assertLoaded(FLW_C);
 
 		var recursiveInclude = assertSimpleNestedErrorsToDepth(LoadError.CircularDependency.class, aErr, 3);
 		assertEquals(ImmutableList.of(FLW_A, FLW_B, FLW_C, FLW_A), recursiveInclude.stack());