A lot to unwrap

- Make ShaderSources return a LoadResult
- Refactor SourceFile loading to do all parsing outside the ctor
- Don't immediately swallow import errors, instead forward them
- Change Span to reference SourceLines instead of SourceFile
- Still WIP, but functional at this stage

src/main/java/com/jozufozu/flywheel/backend/compile/CullingCompiler.java

@@ -1,5 +1,7 @@
 package com.jozufozu.flywheel.backend.compile;
 
+import java.util.List;
+
 import org.jetbrains.annotations.Nullable;
 
 import com.google.common.collect.ImmutableList;
@@ -24,7 +26,8 @@ public class CullingCompiler extends AbstractCompiler<InstanceType<?>> {
 		super(sources, keys);
 
 		this.uniformComponent = uniformComponent;
-		pipelineCompute = sources.find(Files.INDIRECT_CULL);
+		pipelineCompute = sources.find(Files.INDIRECT_CULL)
+				.unwrap();
 	}
 
 	@Nullable
@@ -40,9 +43,11 @@ public class CullingCompiler extends AbstractCompiler<InstanceType<?>> {
 		return programLinker.link(compute);
 	}
 
-	private ImmutableList<SourceComponent> getComputeComponents(InstanceType<?> instanceType) {
+	private List<SourceComponent> getComputeComponents(InstanceType<?> instanceType) {
 		var instanceAssembly = new IndirectComponent(sources, instanceType);
-		var instance = sources.find(instanceType.instanceShader());
+		ResourceLocation key = instanceType.instanceShader();
+		var instance = sources.find(key)
+				.unwrap();
 
 		return ImmutableList.of(uniformComponent, instanceAssembly, instance, pipelineCompute);
 	}

src/main/java/com/jozufozu/flywheel/backend/compile/FlwPrograms.java

@@ -5,9 +5,13 @@ import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.api.instance.InstanceType;
 import com.jozufozu.flywheel.api.uniform.ShaderUniforms;
 import com.jozufozu.flywheel.api.vertex.VertexType;
+import com.jozufozu.flywheel.backend.compile.component.MaterialAdapterComponent;
 import com.jozufozu.flywheel.backend.compile.component.UniformComponent;
 import com.jozufozu.flywheel.glsl.ShaderSources;
+import com.jozufozu.flywheel.glsl.generate.FnSignature;
+import com.jozufozu.flywheel.glsl.generate.GlslExpr;
 import com.jozufozu.flywheel.lib.context.Contexts;
+import com.jozufozu.flywheel.lib.material.MaterialIndices;
 
 import net.minecraft.server.packs.resources.ResourceManager;
 
@@ -25,8 +29,30 @@ public class FlwPrograms {
 						.toList())
 				.build(sources);
 
-		InstancingPrograms.reload(sources, pipelineKeys, uniformComponent);
+		var vertexMaterialComponent = MaterialAdapterComponent.builder(Flywheel.rl("vertex_material_adapter"))
-		IndirectPrograms.reload(sources, pipelineKeys, uniformComponent);
+				.materialSources(MaterialIndices.getAllVertexShaders())
+				.adapt(FnSignature.ofVoid("flw_materialVertex"))
+				.switchOn(GlslExpr.variable("_flw_materialVertexID"))
+				.build(sources);
+
+		var fragmentMaterialComponent = MaterialAdapterComponent.builder(Flywheel.rl("fragment_material_adapter"))
+				.materialSources(MaterialIndices.getAllFragmentShaders())
+				.adapt(FnSignature.ofVoid("flw_materialFragment"))
+				.adapt(FnSignature.create()
+						.returnType("bool")
+						.name("flw_discardPredicate")
+						.arg("vec4", "color")
+						.build(), GlslExpr.literal(false))
+				.adapt(FnSignature.create()
+						.returnType("vec4")
+						.name("flw_fogFilter")
+						.arg("vec4", "color")
+						.build(), GlslExpr.variable("color"))
+				.switchOn(GlslExpr.variable("_flw_materialFragmentID"))
+				.build(sources);
+
+		InstancingPrograms.reload(sources, pipelineKeys, uniformComponent, vertexMaterialComponent, fragmentMaterialComponent);
+		IndirectPrograms.reload(sources, pipelineKeys, uniformComponent, vertexMaterialComponent, fragmentMaterialComponent);
 	}
 
 	private static ImmutableList<PipelineProgramKey> createPipelineKeys() {

src/main/java/com/jozufozu/flywheel/backend/compile/IndirectPrograms.java

@@ -8,6 +8,7 @@ import com.google.common.collect.ImmutableList;
 import com.jozufozu.flywheel.api.context.Context;
 import com.jozufozu.flywheel.api.instance.InstanceType;
 import com.jozufozu.flywheel.api.vertex.VertexType;
+import com.jozufozu.flywheel.backend.compile.component.MaterialAdapterComponent;
 import com.jozufozu.flywheel.backend.compile.component.UniformComponent;
 import com.jozufozu.flywheel.gl.shader.GlProgram;
 import com.jozufozu.flywheel.glsl.ShaderSources;
@@ -22,12 +23,12 @@ public class IndirectPrograms {
 		this.culling = culling;
 	}
 
-	public static void reload(ShaderSources sources, ImmutableList<PipelineProgramKey> pipelineKeys, UniformComponent uniformComponent) {
+	public static void reload(ShaderSources sources, ImmutableList<PipelineProgramKey> pipelineKeys, UniformComponent uniformComponent, MaterialAdapterComponent vertexMaterialComponent, MaterialAdapterComponent fragmentMaterialComponent) {
 		if (instance != null) {
 			instance.delete();
 			instance = null;
 		}
-		var pipelineCompiler = new PipelineCompiler(sources, pipelineKeys, Pipelines.INDIRECT, uniformComponent);
+		var pipelineCompiler = new PipelineCompiler(sources, pipelineKeys, Pipelines.INDIRECT, vertexMaterialComponent, fragmentMaterialComponent, uniformComponent);
 		var cullingCompiler = new CullingCompiler(sources, createCullingKeys(), uniformComponent);
 
 		var pipelineResult = pipelineCompiler.compileAndReportErrors();

src/main/java/com/jozufozu/flywheel/backend/compile/InstancingPrograms.java

@@ -8,6 +8,7 @@ import com.google.common.collect.ImmutableList;
 import com.jozufozu.flywheel.api.context.Context;
 import com.jozufozu.flywheel.api.instance.InstanceType;
 import com.jozufozu.flywheel.api.vertex.VertexType;
+import com.jozufozu.flywheel.backend.compile.component.MaterialAdapterComponent;
 import com.jozufozu.flywheel.backend.compile.component.UniformComponent;
 import com.jozufozu.flywheel.gl.shader.GlProgram;
 import com.jozufozu.flywheel.glsl.ShaderSources;
@@ -20,12 +21,12 @@ public class InstancingPrograms {
 		this.pipeline = pipeline;
 	}
 
-	public static void reload(ShaderSources sources, ImmutableList<PipelineProgramKey> pipelineKeys, UniformComponent uniformComponent) {
+	public static void reload(ShaderSources sources, ImmutableList<PipelineProgramKey> pipelineKeys, UniformComponent uniformComponent, MaterialAdapterComponent vertexMaterialComponent, MaterialAdapterComponent fragmentMaterialComponent) {
 		if (instance != null) {
 			instance.delete();
 			instance = null;
 		}
-		var instancingCompiler = new PipelineCompiler(sources, pipelineKeys, Pipelines.INSTANCED_ARRAYS, uniformComponent);
+		var instancingCompiler = new PipelineCompiler(sources, pipelineKeys, Pipelines.INSTANCED_ARRAYS, vertexMaterialComponent, fragmentMaterialComponent, uniformComponent);
 		var result = instancingCompiler.compileAndReportErrors();
 
 		if (result != null) {

src/main/java/com/jozufozu/flywheel/backend/compile/PipelineCompiler.java

@@ -1,9 +1,10 @@
 package com.jozufozu.flywheel.backend.compile;
 
+import java.util.List;
+
 import org.jetbrains.annotations.Nullable;
 
 import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.backend.compile.component.MaterialAdapterComponent;
 import com.jozufozu.flywheel.backend.compile.component.UniformComponent;
 import com.jozufozu.flywheel.gl.shader.GlProgram;
@@ -11,9 +12,6 @@ import com.jozufozu.flywheel.gl.shader.ShaderType;
 import com.jozufozu.flywheel.glsl.ShaderSources;
 import com.jozufozu.flywheel.glsl.SourceComponent;
 import com.jozufozu.flywheel.glsl.SourceFile;
-import com.jozufozu.flywheel.glsl.generate.FnSignature;
-import com.jozufozu.flywheel.glsl.generate.GlslExpr;
-import com.jozufozu.flywheel.lib.material.MaterialIndices;
 
 public class PipelineCompiler extends AbstractCompiler<PipelineProgramKey> {
 	private final Pipeline pipeline;
@@ -23,34 +21,17 @@ public class PipelineCompiler extends AbstractCompiler<PipelineProgramKey> {
 	private final SourceFile pipelineFragment;
 	private final SourceFile pipelineVertex;
 
-	public PipelineCompiler(ShaderSources sources, ImmutableList<PipelineProgramKey> keys, Pipeline pipeline, UniformComponent uniformComponent) {
+	public PipelineCompiler(ShaderSources sources, ImmutableList<PipelineProgramKey> keys, Pipeline pipeline, MaterialAdapterComponent vertexMaterialComponent, MaterialAdapterComponent fragmentMaterialComponent, UniformComponent uniformComponent) {
 		super(sources, keys);
 		this.pipeline = pipeline;
+		this.vertexMaterialComponent = vertexMaterialComponent;
+		this.fragmentMaterialComponent = fragmentMaterialComponent;
 		this.uniformComponent = uniformComponent;
 
-		vertexMaterialComponent = MaterialAdapterComponent.builder(Flywheel.rl("vertex_material_adapter"))
+		pipelineFragment = this.sources.find(pipeline.fragmentShader())
-				.materialSources(MaterialIndices.getAllVertexShaders())
+				.unwrap();
-				.adapt(FnSignature.ofVoid("flw_materialVertex"))
+		pipelineVertex = this.sources.find(pipeline.vertexShader())
-				.switchOn(GlslExpr.variable("_flw_materialVertexID"))
+				.unwrap();
-				.build(sources);
-		fragmentMaterialComponent = MaterialAdapterComponent.builder(Flywheel.rl("fragment_material_adapter"))
-				.materialSources(MaterialIndices.getAllFragmentShaders())
-				.adapt(FnSignature.ofVoid("flw_materialFragment"))
-				.adapt(FnSignature.create()
-						.returnType("bool")
-						.name("flw_discardPredicate")
-						.arg("vec4", "color")
-						.build(), GlslExpr.literal(false))
-				.adapt(FnSignature.create()
-						.returnType("vec4")
-						.name("flw_fogFilter")
-						.arg("vec4", "color")
-						.build(), GlslExpr.variable("color"))
-				.switchOn(GlslExpr.variable("_flw_materialFragmentID"))
-				.build(sources);
-
-		pipelineFragment = sources.find(pipeline.fragmentShader());
-		pipelineVertex = sources.find(pipeline.vertexShader());
 	}
 
 	@Nullable
@@ -71,23 +52,27 @@ public class PipelineCompiler extends AbstractCompiler<PipelineProgramKey> {
 		return glProgram;
 	}
 
-	private ImmutableList<SourceComponent> getVertexComponents(PipelineProgramKey key) {
+	private List<SourceComponent> getVertexComponents(PipelineProgramKey key) {
 		var instanceAssembly = pipeline.assembler()
 				.assemble(new Pipeline.InstanceAssemblerContext(sources, key.vertexType(), key.instanceType()));
 
 		var layout = sources.find(key.vertexType()
-				.layoutShader());
+						.layoutShader())
+				.unwrap();
 		var instance = sources.find(key.instanceType()
-				.instanceShader());
+						.instanceShader())
+				.unwrap();
 		var context = sources.find(key.contextShader()
-				.vertexShader());
+						.vertexShader())
+				.unwrap();
 
 		return ImmutableList.of(uniformComponent, vertexMaterialComponent, instanceAssembly, layout, instance, context, pipelineVertex);
 	}
 
-	private ImmutableList<SourceComponent> getFragmentComponents(PipelineProgramKey key) {
+	private List<SourceComponent> getFragmentComponents(PipelineProgramKey key) {
 		var context = sources.find(key.contextShader()
-				.fragmentShader());
+						.fragmentShader())
+				.unwrap();
 		return ImmutableList.of(uniformComponent, fragmentMaterialComponent, context, pipelineFragment);
 	}
 }

src/main/java/com/jozufozu/flywheel/backend/compile/SourceChecks.java

@@ -1,66 +1,55 @@
 package com.jozufozu.flywheel.backend.compile;
 
-import java.util.Optional;
-import java.util.function.BiConsumer;
-
-import org.jetbrains.annotations.Nullable;
-
-import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.glsl.SourceFile;
-import com.jozufozu.flywheel.glsl.error.ErrorReporter;
-import com.jozufozu.flywheel.glsl.parse.ShaderFunction;
-import com.jozufozu.flywheel.glsl.parse.ShaderVariable;
-
 // TODO: recycle to be invoked by the shader compiler
 public class SourceChecks {
-	public static final BiConsumer<ErrorReporter, SourceFile> LAYOUT_VERTEX = checkFunctionArity("flw_layoutVertex", 0);
+	//	public static final BiConsumer<ErrorReporter, SourceFile> LAYOUT_VERTEX = checkFunctionArity("flw_layoutVertex", 0);
-	public static final BiConsumer<ErrorReporter, SourceFile> INSTANCE_VERTEX = checkFunctionParameterTypeExists("flw_instanceVertex", 1, 0);
+	//	public static final BiConsumer<ErrorReporter, SourceFile> INSTANCE_VERTEX = checkFunctionParameterTypeExists("flw_instanceVertex", 1, 0);
-	public static final BiConsumer<ErrorReporter, SourceFile> MATERIAL_VERTEX = checkFunctionArity("flw_materialVertex", 0);
+	//	public static final BiConsumer<ErrorReporter, SourceFile> MATERIAL_VERTEX = checkFunctionArity("flw_materialVertex", 0);
-	public static final BiConsumer<ErrorReporter, SourceFile> MATERIAL_FRAGMENT = checkFunctionArity("flw_materialFragment", 0);
+	//	public static final BiConsumer<ErrorReporter, SourceFile> MATERIAL_FRAGMENT = checkFunctionArity("flw_materialFragment", 0);
-	public static final BiConsumer<ErrorReporter, SourceFile> CONTEXT_VERTEX = checkFunctionArity("flw_contextVertex", 0);
+	//	public static final BiConsumer<ErrorReporter, SourceFile> CONTEXT_VERTEX = checkFunctionArity("flw_contextVertex", 0);
-	public static final BiConsumer<ErrorReporter, SourceFile> CONTEXT_FRAGMENT = checkFunctionArity("flw_contextFragment", 0).andThen(checkFunctionArity("flw_initFragment", 0));
+	//	public static final BiConsumer<ErrorReporter, SourceFile> CONTEXT_FRAGMENT = checkFunctionArity("flw_contextFragment", 0).andThen(checkFunctionArity("flw_initFragment", 0));
-	public static final BiConsumer<ErrorReporter, SourceFile> PIPELINE = checkFunctionArity("main", 0);
+	//	public static final BiConsumer<ErrorReporter, SourceFile> PIPELINE = checkFunctionArity("main", 0);
-
+	//
-	public static BiConsumer<ErrorReporter, SourceFile> checkFunctionArity(String name, int arity) {
+	//	public static BiConsumer<ErrorReporter, SourceFile> checkFunctionArity(String name, int arity) {
-		return (errorReporter, file) -> checkFunctionArity(errorReporter, file, name, arity);
+	//		return (errorReporter, file) -> checkFunctionArity(errorReporter, file, name, arity);
-	}
+	//	}
-
+	//
-	public static BiConsumer<ErrorReporter, SourceFile> checkFunctionParameterTypeExists(String name, int arity, int param) {
+	//	public static BiConsumer<ErrorReporter, SourceFile> checkFunctionParameterTypeExists(String name, int arity, int param) {
-		return (errorReporter, file) -> {
+	//		return (errorReporter, file) -> {
-			var func = checkFunctionArity(errorReporter, file, name, arity);
+	//			var func = checkFunctionArity(errorReporter, file, name, arity);
-
+	//
-			if (func == null) {
+	//			if (func == null) {
-				return;
+	//				return;
-			}
+	//			}
-
+	//
-			var maybeStruct = func.getParameterType(param)
+	//			var maybeStruct = func.getParameterType(param)
-					.findStruct();
+	//					.findStruct();
-
+	//
-			if (maybeStruct.isEmpty()) {
+	//			if (maybeStruct.isEmpty()) {
-				errorReporter.generateMissingStruct(file, func.getParameterType(param), "struct not defined");
+	//				errorReporter.generateMissingStruct(file, func.getParameterType(param), "struct not defined");
-			}
+	//			}
-		};
+	//		};
-	}
+	//	}
-
+	//
-	/**
+	//	/**
-	 * @return {@code null} if the function doesn't exist, or if the function has the wrong arity.
+	//	 * @return {@code null} if the function doesn't exist, or if the function has the wrong arity.
-	 */
+	//	 */
-	@Nullable
+	//	@Nullable
-	private static ShaderFunction checkFunctionArity(ErrorReporter errorReporter, SourceFile file, String name, int arity) {
+	//	private static ShaderFunction checkFunctionArity(ErrorReporter errorReporter, SourceFile file, String name, int arity) {
-		Optional<ShaderFunction> maybeFunc = file.findFunction(name);
+	//		Optional<ShaderFunction> maybeFunc = file.findFunction(name);
-
+	//
-		if (maybeFunc.isEmpty()) {
+	//		if (maybeFunc.isEmpty()) {
-			errorReporter.generateMissingFunction(file, name, "\"" + name + "\" function not defined");
+	//			errorReporter.generateMissingFunction(file, name, "\"" + name + "\" function not defined");
-			return null;
+	//			return null;
-		}
+	//		}
-
+	//
-		ShaderFunction func = maybeFunc.get();
+	//		ShaderFunction func = maybeFunc.get();
-		ImmutableList<ShaderVariable> params = func.getParameters();
+	//		ImmutableList<ShaderVariable> params = func.getParameters();
-		if (params.size() != arity) {
+	//		if (params.size() != arity) {
-			errorReporter.generateFunctionArgumentCountError(name, arity, func.getArgs());
+	//			errorReporter.generateFunctionArgumentCountError(name, arity, func.getArgs());
-			return null;
+	//			return null;
-		}
+	//		}
-
+	//
-		return func;
+	//		return func;
-	}
+	//	}
 }

src/main/java/com/jozufozu/flywheel/backend/compile/component/IndirectComponent.java

@@ -35,7 +35,8 @@ public class IndirectComponent implements SourceComponent {
 
 	public IndirectComponent(ShaderSources sources, InstanceType<?> instanceType) {
 		this.layoutItems = instanceType.getLayout().layoutItems;
-		included = ImmutableList.of(sources.find(Pipelines.Files.UTIL_TYPES));
+		included = ImmutableList.of(sources.find(Pipelines.Files.UTIL_TYPES)
+				.unwrap());
 	}
 
 	@Override

src/main/java/com/jozufozu/flywheel/backend/compile/component/MaterialAdapterComponent.java

@@ -13,6 +13,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.jozufozu.flywheel.glsl.ShaderSources;
 import com.jozufozu.flywheel.glsl.SourceComponent;
+import com.jozufozu.flywheel.glsl.SourceFile;
 import com.jozufozu.flywheel.glsl.generate.FnSignature;
 import com.jozufozu.flywheel.glsl.generate.GlslBlock;
 import com.jozufozu.flywheel.glsl.generate.GlslBuilder;
@@ -145,7 +146,8 @@ public class MaterialAdapterComponent implements SourceComponent {
 
 			int index = 0;
 			for (var rl : materialSources) {
-				var sourceFile = sources.find(rl);
+				SourceFile sourceFile = sources.find(rl)
+						.unwrap();
 				final int finalIndex = index;
 				var adapterMap = createAdapterMap(adaptedFunctions, fnName -> "_" + fnName + "_" + finalIndex);
 				transformed.add(new StringSubstitutionSourceComponent(sourceFile, adapterMap));

src/main/java/com/jozufozu/flywheel/backend/compile/component/UniformComponent.java

@@ -67,7 +67,8 @@ public class UniformComponent implements SourceComponent {
 			var out = ImmutableList.<SourceFile>builder();
 
 			for (var fileResolution : uniformShaders) {
-				out.add(sources.find(fileResolution));
+				out.add(sources.find(fileResolution)
+						.unwrap());
 			}
 
 			return new UniformComponent(name, out.build());

src/main/java/com/jozufozu/flywheel/backend/compile/core/FailedCompilation.java

@@ -8,6 +8,7 @@ import java.util.stream.Stream;
 
 import org.jetbrains.annotations.NotNull;
 
+import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.glsl.SourceFile;
 import com.jozufozu.flywheel.glsl.SourceLines;
 import com.jozufozu.flywheel.glsl.error.ErrorBuilder;
@@ -15,7 +16,10 @@ import com.jozufozu.flywheel.glsl.span.Span;
 import com.jozufozu.flywheel.util.ConsoleColors;
 import com.jozufozu.flywheel.util.StringUtil;
 
+import net.minecraft.resources.ResourceLocation;
+
 public class FailedCompilation {
+	public static final ResourceLocation GENERATED_SOURCE_NAME = Flywheel.rl("generated_source");
 	private static final Pattern ERROR_LINE = Pattern.compile("(\\d+)\\((\\d+)\\) : (.*)");
 	private final List<SourceFile> files;
 	private final SourceLines generatedSource;
@@ -25,7 +29,7 @@ public class FailedCompilation {
 	public FailedCompilation(String shaderName, List<SourceFile> files, String generatedSource, String errorLog) {
 		this.shaderName = shaderName;
 		this.files = files;
-		this.generatedSource = new SourceLines(generatedSource);
+		this.generatedSource = new SourceLines(GENERATED_SOURCE_NAME, generatedSource);
 		this.errorLog = errorLog;
 	}
 

src/main/java/com/jozufozu/flywheel/backend/compile/core/ShaderCompiler.java

@@ -2,6 +2,7 @@ package com.jozufozu.flywheel.backend.compile.core;
 
 import java.util.HashMap;
 import java.util.LinkedHashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
@@ -10,7 +11,6 @@ import java.util.function.Consumer;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import com.google.common.collect.ImmutableList;
 import com.jozufozu.flywheel.gl.shader.GlShader;
 import com.jozufozu.flywheel.gl.shader.ShaderType;
 import com.jozufozu.flywheel.glsl.GLSLVersion;
@@ -29,7 +29,7 @@ public class ShaderCompiler {
 	}
 
 	@Nullable
-	public GlShader compile(GLSLVersion glslVersion, ShaderType shaderType, ImmutableList<SourceComponent> sourceComponents) {
+	public GlShader compile(GLSLVersion glslVersion, ShaderType shaderType, List<SourceComponent> sourceComponents) {
 		var key = new ShaderKey(glslVersion, shaderType, sourceComponents);
 		var cached = shaderCache.get(key);
 		if (cached != null) {
@@ -51,7 +51,7 @@ public class ShaderCompiler {
 	}
 
 	@NotNull
-	private ShaderResult compileUncached(Compilation ctx, ImmutableList<SourceComponent> sourceComponents) {
+	private ShaderResult compileUncached(Compilation ctx, List<SourceComponent> sourceComponents) {
 		ctx.enableExtension("GL_ARB_explicit_attrib_location");
 		ctx.enableExtension("GL_ARB_conservative_depth");
 
@@ -60,7 +60,7 @@ public class ShaderCompiler {
 		return ctx.compile();
 	}
 
-	private static void expand(ImmutableList<SourceComponent> rootSources, Consumer<SourceComponent> out) {
+	private static void expand(List<SourceComponent> rootSources, Consumer<SourceComponent> out) {
 		var included = new LinkedHashSet<SourceComponent>(); // use hash set to deduplicate. linked to preserve order
 		for (var component : rootSources) {
 			recursiveDepthFirstInclude(included, component);
@@ -76,7 +76,6 @@ public class ShaderCompiler {
 		included.addAll(component.included());
 	}
 
-	private record ShaderKey(GLSLVersion glslVersion, ShaderType shaderType,
+	private record ShaderKey(GLSLVersion glslVersion, ShaderType shaderType, List<SourceComponent> sourceComponents) {
-							 ImmutableList<SourceComponent> sourceComponents) {
 	}
 }

src/main/java/com/jozufozu/flywheel/glsl/LoadResult.java

@@ -0,0 +1,39 @@
+package com.jozufozu.flywheel.glsl;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import net.minecraft.resources.ResourceLocation;
+
+public sealed interface LoadResult {
+	static LoadResult success(SourceFile sourceFile) {
+		return new Success(sourceFile);
+	}
+
+	@Nullable SourceFile unwrap();
+
+	record Success(SourceFile source) implements LoadResult {
+		@Override
+		@NotNull
+		public SourceFile unwrap() {
+			return source;
+		}
+	}
+
+	record IOError(ResourceLocation location, IOException exception) implements LoadResult {
+		@Override
+		public SourceFile unwrap() {
+			return null;
+		}
+	}
+
+	record IncludeError(ResourceLocation location, List<LoadResult> innerFailures) implements LoadResult {
+		@Override
+		public SourceFile unwrap() {
+			return null;
+		}
+	}
+}

src/main/java/com/jozufozu/flywheel/glsl/ShaderSources.java

@@ -23,7 +23,7 @@ public class ShaderSources {
 
 	private final ResourceManager manager;
 
-	private final Map<ResourceLocation, SourceFile> cache = new HashMap<>();
+	private final Map<ResourceLocation, LoadResult> cache = new HashMap<>();
 
 	/**
 	 * Tracks where we are in the mutual recursion to detect circular imports.
@@ -35,7 +35,7 @@ public class ShaderSources {
 	}
 
 	@Nonnull
-	public SourceFile find(ResourceLocation location) {
+	public LoadResult find(ResourceLocation location) {
 		pushFindStack(location);
 		// Can't use computeIfAbsent because mutual recursion causes ConcurrentModificationExceptions
 		var out = cache.get(location);
@@ -48,15 +48,15 @@ public class ShaderSources {
 	}
 
 	@Nonnull
-	private SourceFile load(ResourceLocation loc) {
+	private LoadResult load(ResourceLocation loc) {
 		try {
 			var resource = manager.getResource(ResourceUtil.prefixed(SHADER_DIR, loc));
 
 			var sourceString = StringUtil.readToString(resource.getInputStream());
 
-			return new SourceFile(this, loc, sourceString);
+			return SourceFile.parse(this, loc, sourceString);
-		} catch (IOException ioException) {
+		} catch (IOException e) {
-			throw new ShaderLoadingException("Could not load shader " + loc, ioException);
+			return new LoadResult.IOError(loc, e);
 		}
 	}
 

src/main/java/com/jozufozu/flywheel/glsl/SourceFile.java

@@ -1,12 +1,17 @@
 package com.jozufozu.flywheel.glsl;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.Set;
 import java.util.regex.Matcher;
 
+import org.jetbrains.annotations.NotNull;
+
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.jozufozu.flywheel.glsl.parse.Import;
@@ -29,8 +34,6 @@ import net.minecraft.resources.ResourceLocation;
 public class SourceFile implements SourceComponent {
 	public final ResourceLocation name;
 
-	public final ShaderSources parent;
-
 	public final SourceLines source;
 
 	/**
@@ -51,30 +54,51 @@ public class SourceFile implements SourceComponent {
 
 	public final List<SourceFile> included;
 
-	public SourceFile(ShaderSources sourceFinder, ResourceLocation name, String source) {
+	public final String finalSource;
-		this.parent = sourceFinder;
+
+	private SourceFile(ResourceLocation name, SourceLines source, ImmutableMap<String, ShaderFunction> functions, ImmutableMap<String, ShaderStruct> structs, ImmutableList<Import> imports, ImmutableMap<String, ShaderField> fields, List<SourceFile> included, String finalSource) {
 		this.name = name;
-
+		this.source = source;
-		this.source = new SourceLines(source);
+		this.functions = functions;
-
+		this.structs = structs;
-		this.imports = parseImports(source);
+		this.imports = imports;
-		this.functions = parseFunctions(source);
+		this.fields = fields;
-		this.structs = parseStructs(source);
+		this.included = included;
-		this.fields = parseFields(source);
+		this.finalSource = finalSource;
-
-		this.included = imports.stream()
-				.map(i -> i.file)
-				.map(Span::toString)
-				.distinct()
-				.<SourceFile>mapMulti((file, sink) -> {
-					try {
-						var loc = new ResourceLocation(file);
-						var sourceFile = sourceFinder.find(loc);
-						sink.accept(sourceFile);
-					} catch (Exception ignored) {
 	}
-				})
+
-				.toList();
+	public static LoadResult parse(ShaderSources sourceFinder, ResourceLocation name, String stringSource) {
+		var source = new SourceLines(name, stringSource);
+
+		var imports = parseImports(source);
+
+		List<SourceFile> included = new ArrayList<>();
+		List<LoadResult> failures = new ArrayList<>();
+
+		Set<String> seen = new HashSet<>();
+		for (Import i : imports) {
+			var fileSpan = i.file();
+			String string = fileSpan.toString();
+			if (!seen.add(string)) {
+				continue;
+			}
+			var result = sourceFinder.find(new ResourceLocation(string));
+			if (result instanceof LoadResult.Success s) {
+				included.add(s.unwrap());
+			} else {
+				failures.add(result);
+			}
+		}
+		if (!failures.isEmpty()) {
+			return new LoadResult.IncludeError(name, failures);
+		}
+
+		var functions = parseFunctions(source);
+		var structs = parseStructs(source);
+		var fields = parseFields(source);
+
+		var finalSource = generateFinalSource(imports, source);
+		return LoadResult.success(new SourceFile(name, source, functions, structs, imports, fields, included, finalSource));
 	}
 
 	@Override
@@ -84,7 +108,26 @@ public class SourceFile implements SourceComponent {
 
 	@Override
 	public String source() {
-		return this.genFinalSource();
+		return finalSource;
+	}
+
+	@NotNull
+	private static String generateFinalSource(ImmutableList<Import> imports, SourceLines source) {
+		var out = new StringBuilder();
+
+		int lastEnd = 0;
+
+		for (var include : imports) {
+			var loc = include.self();
+
+			out.append(source, lastEnd, loc.startIndex());
+
+			lastEnd = loc.endIndex();
+		}
+
+		out.append(source, lastEnd, source.length());
+
+		return out.toString();
 	}
 
 	@Override
@@ -96,7 +139,7 @@ public class SourceFile implements SourceComponent {
 		int begin = source.lineStartIndex(lineNo);
 		int end = begin + source.lineString(lineNo)
 				.length();
-		return new StringSpan(this, source.getCharPos(begin), source.getCharPos(end));
+		return new StringSpan(source, begin, end);
 	}
 
 	public Span getLineSpanNoWhitespace(int line) {
@@ -108,7 +151,7 @@ public class SourceFile implements SourceComponent {
 			begin++;
 		}
 
-		return new StringSpan(this, source.getCharPos(begin), source.getCharPos(end));
+		return new StringSpan(source, begin, end);
 	}
 
 	/**
@@ -157,32 +200,6 @@ public class SourceFile implements SourceComponent {
 		return Optional.empty();
 	}
 
-	public CharSequence importStatement() {
-		return "#use " + '"' + name + '"';
-	}
-
-	public String printSource() {
-		return "Source for shader '" + name + "':\n" + source.printLinesWithNumbers();
-	}
-
-	private String genFinalSource() {
-		StringBuilder out = new StringBuilder();
-
-		int lastEnd = 0;
-
-		for (var include : imports) {
-			var loc = include.self;
-
-			out.append(this.source, lastEnd, loc.getStartPos());
-
-			lastEnd = loc.getEndPos();
-		}
-
-		out.append(this.source, lastEnd, this.source.length());
-
-		return out.toString();
-	}
-
 	@Override
 	public String toString() {
 		return name.toString();
@@ -199,19 +216,18 @@ public class SourceFile implements SourceComponent {
 		return System.identityHashCode(this);
 	}
 
-
 	/**
 	 * Scan the source for {@code #use "..."} directives.
 	 * Records the contents of the directive into an {@link Import} object, and marks the directive for elision.
 	 */
-	private ImmutableList<Import> parseImports(String source) {
+	private static ImmutableList<Import> parseImports(SourceLines source) {
 		Matcher uses = Import.PATTERN.matcher(source);
 
 		var imports = ImmutableList.<Import>builder();
 
 		while (uses.find()) {
-			Span use = Span.fromMatcher(this, uses);
+			Span use = Span.fromMatcher(source, uses);
-			Span file = Span.fromMatcher(this, uses, 1);
+			Span file = Span.fromMatcher(source, uses, 1);
 
 			imports.add(new Import(use, file));
 		}
@@ -219,19 +235,18 @@ public class SourceFile implements SourceComponent {
 		return imports.build();
 	}
 
-
 	/**
 	 * Scan the source for function definitions and "parse" them into objects that contain properties of the function.
 	 */
-	private ImmutableMap<String, ShaderFunction> parseFunctions(String source) {
+	private static ImmutableMap<String, ShaderFunction> parseFunctions(SourceLines source) {
 		Matcher matcher = ShaderFunction.PATTERN.matcher(source);
 
 		Map<String, ShaderFunction> functions = new HashMap<>();
 
 		while (matcher.find()) {
-			Span type = Span.fromMatcher(this, matcher, 1);
+			Span type = Span.fromMatcher(source, matcher, 1);
-			Span name = Span.fromMatcher(this, matcher, 2);
+			Span name = Span.fromMatcher(source, matcher, 2);
-			Span args = Span.fromMatcher(this, matcher, 3);
+			Span args = Span.fromMatcher(source, matcher, 3);
 
 			int blockStart = matcher.end();
 			int blockEnd = findEndOfBlock(source, blockStart);
@@ -239,11 +254,11 @@ public class SourceFile implements SourceComponent {
 			Span self;
 			Span body;
 			if (blockEnd > blockStart) {
-				self = new StringSpan(this, matcher.start(), blockEnd + 1);
+				self = new StringSpan(source, matcher.start(), blockEnd + 1);
-				body = new StringSpan(this, blockStart, blockEnd);
+				body = new StringSpan(source, blockStart, blockEnd);
 			} else {
-				self = new ErrorSpan(this, matcher.start(), matcher.end());
+				self = new ErrorSpan(source, matcher.start(), matcher.end());
-				body = new ErrorSpan(this, blockStart);
+				body = new ErrorSpan(source, blockStart);
 			}
 
 			ShaderFunction function = new ShaderFunction(self, type, name, args, body);
@@ -257,15 +272,15 @@ public class SourceFile implements SourceComponent {
 	/**
 	 * Scan the source for function definitions and "parse" them into objects that contain properties of the function.
 	 */
-	private ImmutableMap<String, ShaderStruct> parseStructs(String source) {
+	private static ImmutableMap<String, ShaderStruct> parseStructs(SourceLines source) {
 		Matcher matcher = ShaderStruct.PATTERN.matcher(source);
 
 		ImmutableMap.Builder<String, ShaderStruct> structs = ImmutableMap.builder();
 		while (matcher.find()) {
-			Span self = Span.fromMatcher(this, matcher);
+			Span self = Span.fromMatcher(source, matcher);
-			Span name = Span.fromMatcher(this, matcher, 1);
+			Span name = Span.fromMatcher(source, matcher, 1);
-			Span body = Span.fromMatcher(this, matcher, 2);
+			Span body = Span.fromMatcher(source, matcher, 2);
-			Span variableName = Span.fromMatcher(this, matcher, 3);
+			Span variableName = Span.fromMatcher(source, matcher, 3);
 
 			ShaderStruct shaderStruct = new ShaderStruct(self, name, body, variableName);
 
@@ -278,16 +293,16 @@ public class SourceFile implements SourceComponent {
 	/**
 	 * Scan the source for function definitions and "parse" them into objects that contain properties of the function.
 	 */
-	private ImmutableMap<String, ShaderField> parseFields(String source) {
+	private static ImmutableMap<String, ShaderField> parseFields(SourceLines source) {
 		Matcher matcher = ShaderField.PATTERN.matcher(source);
 
 		ImmutableMap.Builder<String, ShaderField> fields = ImmutableMap.builder();
 		while (matcher.find()) {
-			Span self = Span.fromMatcher(this, matcher);
+			Span self = Span.fromMatcher(source, matcher);
-			Span location = Span.fromMatcher(this, matcher, 1);
+			Span location = Span.fromMatcher(source, matcher, 1);
-			Span decoration = Span.fromMatcher(this, matcher, 2);
+			Span decoration = Span.fromMatcher(source, matcher, 2);
-			Span type = Span.fromMatcher(this, matcher, 3);
+			Span type = Span.fromMatcher(source, matcher, 3);
-			Span name = Span.fromMatcher(this, matcher, 4);
+			Span name = Span.fromMatcher(source, matcher, 4);
 
 			fields.put(location.get(), new ShaderField(self, location, decoration, type, name));
 		}
@@ -298,13 +313,16 @@ public class SourceFile implements SourceComponent {
 	/**
 	 * Given the position of an opening brace, scans through the source for a paired closing brace.
 	 */
-	private static int findEndOfBlock(String source, int start) {
+	private static int findEndOfBlock(CharSequence source, int start) {
 		int blockDepth = 0;
 		for (int i = start + 1; i < source.length(); i++) {
 			char ch = source.charAt(i);
 
-			if (ch == '{') blockDepth++;
+			if (ch == '{') {
-			else if (ch == '}') blockDepth--;
+				blockDepth++;
+			} else if (ch == '}') {
+				blockDepth--;
+			}
 
 			if (blockDepth < 0) {
 				return i;

src/main/java/com/jozufozu/flywheel/glsl/SourceLines.java

@@ -11,11 +11,13 @@ import com.jozufozu.flywheel.glsl.span.CharPos;
 import it.unimi.dsi.fastutil.ints.IntArrayList;
 import it.unimi.dsi.fastutil.ints.IntList;
 import it.unimi.dsi.fastutil.ints.IntLists;
+import net.minecraft.resources.ResourceLocation;
 
 public class SourceLines implements CharSequence {
 
 	private static final Pattern newLine = Pattern.compile("(\\r\\n|\\r|\\n)");
 
+	public final ResourceLocation name;
 	/**
 	 * 0-indexed line to char pos mapping.
 	 */
@@ -27,7 +29,8 @@ public class SourceLines implements CharSequence {
 	private final ImmutableList<String> lines;
 	public final String raw;
 
-	public SourceLines(String raw) {
+	public SourceLines(ResourceLocation name, String raw) {
+		this.name = name;
 		this.raw = raw;
 		this.lineStarts = createLineLookup(raw);
 		this.lines = getLines(raw, lineStarts);

src/main/java/com/jozufozu/flywheel/glsl/error/ErrorBuilder.java

@@ -59,6 +59,10 @@ public class ErrorBuilder {
 		return pointAtFile(file.name.toString());
 	}
 
+	public ErrorBuilder pointAtFile(SourceLines source) {
+		return pointAtFile(source.name.toString());
+	}
+
 	public ErrorBuilder pointAtFile(String file) {
 		lines.add(new FileLine(file));
 		return this;
@@ -69,13 +73,13 @@ public class ErrorBuilder {
 			return this;
 		}
 
-		SourceFile sourceFile = span.getSourceFile();
+		var source = span.source();
 
-		String builder = "add " + sourceFile.importStatement() + ' ' + msg + "\n defined here:";
+		String builder = "add " + "#use " + '"' + source.name + '"' + ' ' + msg + "\n defined here:";
 
 		header(ErrorLevel.HINT, builder);
 
-		return this.pointAtFile(sourceFile)
+		return this.pointAtFile(source)
 				.pointAt(span, 0);
 	}
 
@@ -85,12 +89,12 @@ public class ErrorBuilder {
 
 	public ErrorBuilder pointAt(Span span, int ctxLines) {
 		if (span.lines() == 1) {
-			SourceLines lines = span.getSourceFile().source;
+			SourceLines lines = span.source();
 
 			int spanLine = span.firstLine();
-			int firstCol = span.getStart()
+			int firstCol = span.start()
 					.col();
-			int lastCol = span.getEnd()
+			int lastCol = span.end()
 					.col();
 
 			pointAtLine(lines, spanLine, ctxLines, firstCol, lastCol);

src/main/java/com/jozufozu/flywheel/glsl/error/ErrorReporter.java

@@ -62,7 +62,7 @@ public class ErrorReporter {
 	}
 
 	public ErrorBuilder generateSpanError(Span span, String message) {
-		SourceFile file = span.getSourceFile();
+		var file = span.source();
 
 		return error(message).pointAtFile(file)
 				.pointAt(span, 2);

src/main/java/com/jozufozu/flywheel/glsl/parse/Import.java

@@ -4,16 +4,6 @@ import java.util.regex.Pattern;
 
 import com.jozufozu.flywheel.glsl.span.Span;
 
-public class Import {
+public record Import(Span self, Span file) {
-
 	public static final Pattern PATTERN = Pattern.compile("^\\s*#\\s*use\\s+\"(.*)\"", Pattern.MULTILINE);
-
-	public final Span self;
-	public final Span file;
-
-	public Import(Span self, Span file) {
-		this.self = self;
-		this.file = file;
-	}
-
 }

src/main/java/com/jozufozu/flywheel/glsl/span/ErrorSpan.java

@@ -1,20 +1,20 @@
 package com.jozufozu.flywheel.glsl.span;
 
-import com.jozufozu.flywheel.glsl.SourceFile;
+import com.jozufozu.flywheel.glsl.SourceLines;
 
 /**
  * Represents a (syntactically) malformed segment of code.
  */
 public class ErrorSpan extends Span {
-	public ErrorSpan(SourceFile in, int loc) {
+	public ErrorSpan(SourceLines in, int loc) {
 		super(in, loc, loc);
 	}
 
-	public ErrorSpan(SourceFile in, int start, int end) {
+	public ErrorSpan(SourceLines in, int start, int end) {
 		super(in, start, end);
 	}
 
-	public ErrorSpan(SourceFile in, CharPos start, CharPos end) {
+	public ErrorSpan(SourceLines in, CharPos start, CharPos end) {
 		super(in, start, end);
 	}
 

src/main/java/com/jozufozu/flywheel/glsl/span/Span.java

@@ -1,13 +1,11 @@
 package com.jozufozu.flywheel.glsl.span;
 
-import java.util.Optional;
 import java.util.regex.Matcher;
 
 import org.jetbrains.annotations.NotNull;
 
 import com.jozufozu.flywheel.glsl.SourceFile;
-import com.jozufozu.flywheel.glsl.parse.ShaderFunction;
+import com.jozufozu.flywheel.glsl.SourceLines;
-import com.jozufozu.flywheel.glsl.parse.ShaderStruct;
 
 /**
  * A segment of code in a {@link SourceFile}.
@@ -17,16 +15,15 @@ import com.jozufozu.flywheel.glsl.parse.ShaderStruct;
  * </p>
  */
 public abstract class Span implements CharSequence, Comparable<Span> {
-
+	protected final SourceLines in;
-	protected final SourceFile in;
 	protected final CharPos start;
 	protected final CharPos end;
 
-	public Span(SourceFile in, int start, int end) {
+	public Span(SourceLines in, int start, int end) {
-		this(in, in.source.getCharPos(start), in.source.getCharPos(end));
+		this(in, in.getCharPos(start), in.getCharPos(end));
 	}
 
-	public Span(SourceFile in, CharPos start, CharPos end) {
+	public Span(SourceLines in, CharPos start, CharPos end) {
 		this.in = in;
 		this.start = start;
 		this.end = end;
@@ -35,29 +32,29 @@ public abstract class Span implements CharSequence, Comparable<Span> {
 	/**
 	 * @return The file that contains this code segment.
 	 */
-	public SourceFile getSourceFile() {
+	public SourceLines source() {
 		return in;
 	}
 
-	public CharPos getStart() {
+	public CharPos start() {
 		return start;
 	}
 
-	public CharPos getEnd() {
+	public CharPos end() {
 		return end;
 	}
 
 	/**
 	 * @return the string index at the (inclusive) beginning of this code segment.
 	 */
-	public int getStartPos() {
+	public int startIndex() {
 		return start.pos();
 	}
 
 	/**
 	 * @return the string index at the (exclusive) end of this code segment.
 	 */
-	public int getEndPos() {
+	public int endIndex() {
 		return end.pos();
 	}
 
@@ -93,12 +90,12 @@ public abstract class Span implements CharSequence, Comparable<Span> {
 
 	@Override
 	public int length() {
-		return getEndPos() - getStartPos();
+		return endIndex() - startIndex();
 	}
 
 	@Override
 	public char charAt(int index) {
-		return in.source.charAt(start.pos() + index);
+		return in.charAt(start.pos() + index);
 	}
 
 	@Override
@@ -111,7 +108,7 @@ public abstract class Span implements CharSequence, Comparable<Span> {
 		return get();
 	}
 
-	public static Span fromMatcher(SourceFile src, Matcher m, int group) {
+	public static Span fromMatcher(SourceLines src, Matcher m, int group) {
 		return new StringSpan(src, m.start(group), m.end(group));
 	}
 
@@ -119,7 +116,7 @@ public abstract class Span implements CharSequence, Comparable<Span> {
 		return superSpan.subSpan(m.start(group), m.end(group));
 	}
 
-	public static Span fromMatcher(SourceFile src, Matcher m) {
+	public static Span fromMatcher(SourceLines src, Matcher m) {
 		return new StringSpan(src, m.start(), m.end());
 	}
 
@@ -127,22 +124,8 @@ public abstract class Span implements CharSequence, Comparable<Span> {
 		return superSpan.subSpan(m.start(), m.end());
 	}
 
-	public Optional<ShaderStruct> findStruct() {
-		if (isErr()) {
-			return Optional.empty();
-		}
-		return in.findStructByName(this.toString());
-	}
-
-	public Optional<ShaderFunction> findFunction() {
-		if (isErr()) {
-			return Optional.empty();
-		}
-		return in.findFunction(this.toString());
-	}
-
 	@Override
 	public int compareTo(@NotNull Span o) {
-		return Integer.compareUnsigned(getStartPos(), o.getStartPos());
+		return Integer.compareUnsigned(startIndex(), o.startIndex());
 	}
 }

src/main/java/com/jozufozu/flywheel/glsl/span/StringSpan.java

@@ -1,14 +1,10 @@
 package com.jozufozu.flywheel.glsl.span;
 
-import com.jozufozu.flywheel.glsl.SourceFile;
+import com.jozufozu.flywheel.glsl.SourceLines;
 
 public class StringSpan extends Span {
 
-	public StringSpan(SourceFile in, int start, int end) {
+	public StringSpan(SourceLines in, int start, int end) {
-		super(in, start, end);
-	}
-
-	public StringSpan(SourceFile in, CharPos start, CharPos end) {
 		super(in, start, end);
 	}
 
@@ -19,7 +15,7 @@ public class StringSpan extends Span {
 
 	@Override
 	public String get() {
-		return in.source.raw.substring(start.pos(), end.pos());
+		return in.raw.substring(start.pos(), end.pos());
 	}
 
 	@Override