A heck of a lot

- Reorganize everything
 - Isolate SourceFile related things
 - Should consider decoupling ShaderLoader from resource loading
 - Document a lot of newer things
 - Index functions
 - Awkward WorldContext builder
 - Template responsible for providing shader inputs
 - Template is now an abstract class
 - Template provides GLSL version
 - ProgramSpecs now only accept one file

src/main/java/com/jozufozu/flywheel/backend/Backend.java

@@ -16,6 +16,7 @@ import org.lwjgl.opengl.GLCapabilities;
 import com.jozufozu.flywheel.backend.gl.versioned.GlCompat;
 import com.jozufozu.flywheel.backend.instancing.InstanceData;
 import com.jozufozu.flywheel.backend.material.MaterialSpec;
+import com.jozufozu.flywheel.backend.source.ShaderSources;
 import com.jozufozu.flywheel.config.FlwConfig;
 import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
 
@@ -59,14 +60,6 @@ public class Backend {
 		OptifineHandler.init();
 	}
 
-	void clearContexts() {
-		SpecMetaRegistry.clear();
-		programSpecRegistry.clear();
-		contexts.forEach(IShaderContext::delete);
-		contexts.clear();
-		materialRegistry.clear();
-	}
-
 	/**
 	 * Get a string describing the Flywheel backend. When there are eventually multiple backends
 	 * (Meshlet, MDI, GL31 Draw Instanced are planned), this will name which one is in use.
@@ -98,7 +91,7 @@ public class Backend {
 	/**
 	 * Register a shader context.
 	 */
-	public <C extends ShaderContext<?>> C register(C spec) {
+	public <C extends IShaderContext<?>> C register(C spec) {
 		contexts.add(spec);
 		return spec;
 	}
@@ -201,6 +194,17 @@ public class Backend {
 		RenderWork.enqueue(Minecraft.getInstance().levelRenderer::allChanged);
 	}
 
+	/**
+	 * INTERNAL USE ONLY
+	 */
+	public void _clearContexts() {
+		SpecMetaRegistry.clear();
+		programSpecRegistry.clear();
+		contexts.forEach(IShaderContext::delete);
+		contexts.clear();
+		materialRegistry.clear();
+	}
+
 	public static void init() {
 	}
 }

src/main/java/com/jozufozu/flywheel/backend/FileResolution.java

@@ -1,56 +0,0 @@
-package com.jozufozu.flywheel.backend;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import javax.annotation.Nullable;
-
-import com.jozufozu.flywheel.backend.pipeline.SourceFile;
-import com.jozufozu.flywheel.backend.pipeline.error.ErrorBuilder;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
-
-import net.minecraft.util.ResourceLocation;
-
-public class FileResolution {
-
-	private final List<Span> foundSpans = new ArrayList<>();
-	private final ResourceLocation fileLoc;
-	private SourceFile file;
-
-
-	public FileResolution(ResourceLocation fileLoc) {
-		this.fileLoc = fileLoc;
-	}
-
-	public ResourceLocation getFileLoc() {
-		return fileLoc;
-	}
-
-	@Nullable
-	public SourceFile getFile() {
-		return file;
-	}
-
-	public void addSpan(Span span) {
-		foundSpans.add(span);
-	}
-
-	public void resolve(ShaderSources sources) {
-
-		try {
-			file = sources.source(fileLoc);
-		} catch (RuntimeException error) {
-			ErrorBuilder builder = new ErrorBuilder();
-			builder.error(String.format("could not find source for file %s", fileLoc));
-			for (Span span : foundSpans) {
-				builder.in(span.getSourceFile())
-						.pointAt(span, 2);
-			}
-			Backend.log.error(builder.build());
-		}
-	}
-
-	void invalidate() {
-
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/Index.java

@@ -1,34 +0,0 @@
-package com.jozufozu.flywheel.backend;
-
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-import com.google.common.collect.Multimap;
-import com.google.common.collect.MultimapBuilder;
-import com.jozufozu.flywheel.backend.pipeline.SourceFile;
-import com.jozufozu.flywheel.backend.pipeline.parse.ShaderStruct;
-
-import net.minecraft.util.ResourceLocation;
-
-/**
- * Indexes many shader source definitions to allow for error fix suggestions.
- */
-public class Index {
-
-	private final Multimap<String, ShaderStruct> knownNames = MultimapBuilder.hashKeys().hashSetValues().build();
-
-	public Index(Map<ResourceLocation, SourceFile> sources) {
-		Collection<SourceFile> files = sources.values();
-
-		for (SourceFile file : files) {
-			file.getStructs().forEach(knownNames::put);
-
-		}
-	}
-
-	public Collection<ShaderStruct> getStructDefinitionsMatching(CharSequence name) {
-		return knownNames.get(name.toString());
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/ShaderContext.java

@@ -1,33 +0,0 @@
-package com.jozufozu.flywheel.backend;
-
-import java.util.HashMap;
-import java.util.Map;
-import java.util.function.Supplier;
-
-import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
-import com.jozufozu.flywheel.core.shader.IMultiProgram;
-
-import net.minecraft.util.ResourceLocation;
-
-public abstract class ShaderContext<P extends GlProgram> implements IShaderContext<P> {
-
-	protected final Map<ResourceLocation, IMultiProgram<P>> programs = new HashMap<>();
-
-	public final Backend backend;
-
-	public ShaderContext(Backend backend) {
-		this.backend = backend;
-	}
-
-	@Override
-	public Supplier<P> getProgramSupplier(ResourceLocation spec) {
-		return programs.get(spec);
-	}
-
-	@Override
-	public void delete() {
-		programs.values()
-				.forEach(IMultiProgram::delete);
-		programs.clear();
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/gl/GLSLVersion.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.pipeline;
+package com.jozufozu.flywheel.backend.gl;
 
 public enum GLSLVersion {
 	V110(110),

src/main/java/com/jozufozu/flywheel/backend/instancing/InstanceManager.java

@@ -152,6 +152,14 @@ public abstract class InstanceManager<T> implements MaterialManager.OriginShiftL
 		}
 	}
 
+	public void queueUpdate(T obj) {
+		if (!Backend.getInstance()
+				.canUseInstancing()) return;
+		synchronized (queuedUpdates) {
+			queuedUpdates.add(obj);
+		}
+	}
+
 	/**
 	 * Update the instance associated with an object.
 	 *
@@ -185,14 +193,6 @@ public abstract class InstanceManager<T> implements MaterialManager.OriginShiftL
 		}
 	}
 
-	public void queueUpdate(T obj) {
-		if (!Backend.getInstance()
-				.canUseInstancing()) return;
-		synchronized (queuedUpdates) {
-			queuedUpdates.add(obj);
-		}
-	}
-
 	public void onLightUpdate(T obj) {
 		if (!Backend.getInstance()
 				.canUseInstancing()) return;

src/main/java/com/jozufozu/flywheel/backend/instancing/InstancedRenderDispatcher.java

@@ -27,6 +27,18 @@ public class InstancedRenderDispatcher {
 
 	private static final WorldAttached<InstanceWorld> instanceWorlds = new WorldAttached<>($ -> new InstanceWorld());
 
+	/**
+	 * Call this when you want to invoke
+	 * @param te
+	 */
+	public static void enqueueUpdate(TileEntity te) {
+		getTiles(te.getLevel()).queueUpdate(te);
+	}
+
+	public static void enqueueUpdate(Entity entity) {
+		getEntities(entity.level).queueUpdate(entity);
+	}
+
 	@Nonnull
 	public static InstanceManager<TileEntity> getTiles(IWorld world) {
 		return instanceWorlds.get(world)
@@ -52,14 +64,6 @@ public class InstancedRenderDispatcher {
 		instanceWorlds.get(world).tick();
 	}
 
-	public static void enqueueUpdate(TileEntity te) {
-		getTiles(te.getLevel()).queueUpdate(te);
-	}
-
-	public static void enqueueUpdate(Entity entity) {
-		getEntities(entity.level).queueUpdate(entity);
-	}
-
 	@SubscribeEvent
 	public static void onBeginFrame(BeginFrameEvent event) {
 		instanceWorlds.get(event.getWorld()).beginFrame(event);

src/main/java/com/jozufozu/flywheel/backend/pipeline/IShaderPipeline.java

@@ -4,6 +4,10 @@ import com.jozufozu.flywheel.core.shader.IMultiProgram;
 import com.jozufozu.flywheel.core.shader.WorldProgram;
 import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
 
+/**
+ * The main interface for compiling usable shaders from program specs.
+ * @param <P> the type of the program that this pipeline compiles.
+ */
 public interface IShaderPipeline<P extends WorldProgram> {
 
 	IMultiProgram<P> compile(ProgramSpec spec);

src/main/java/com/jozufozu/flywheel/backend/pipeline/ITemplate.java

@@ -1,41 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
-import com.jozufozu.flywheel.backend.loading.ProtoProgram;
-import com.jozufozu.flywheel.backend.pipeline.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.pipeline.parse.StructField;
-
-public interface ITemplate {
-	void generateTemplateSource(StringBuilder builder, ShaderType type, SourceFile file);
-
-	void attachAttributes(ProtoProgram program, SourceFile file);
-
-
-	static void prefixFields(StringBuilder builder, ShaderStruct struct, String qualifier, String prefix) {
-		ImmutableList<StructField> fields = struct.getFields();
-
-		for (StructField field : fields) {
-			builder.append(qualifier)
-					.append(' ')
-					.append(field.type)
-					.append(' ')
-					.append(prefix)
-					.append(field.name)
-					.append(";\n");
-		}
-	}
-
-	static void assignFields(StringBuilder builder, ShaderStruct struct, String prefix1, String prefix2) {
-		ImmutableList<StructField> fields = struct.getFields();
-
-		for (StructField field : fields) {
-			builder.append(prefix1)
-					.append(field.name)
-					.append(" = ")
-					.append(prefix2)
-					.append(field.name)
-					.append(";\n");
-		}
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/Includer.java

@@ -1,40 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline;
-
-import java.util.ArrayList;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-
-import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.pipeline.parse.Import;
-
-import net.minecraft.util.ResourceLocation;
-
-public class Includer {
-
-	public static List<SourceFile> recurseIncludes(SourceFile from) {
-		Set<ResourceLocation> seen = new HashSet<>();
-
-		seen.add(from.name);
-
-		List<SourceFile> out = new ArrayList<>();
-
-		process(seen, out, from);
-
-		return out;
-	}
-
-	private static void process(Set<ResourceLocation> seen, List<SourceFile> out, SourceFile source) {
-		ImmutableList<Import> imports = source.getIncludes();
-
-		for (Import use : imports) {
-
-			SourceFile file = use.getFile();
-			if (file != null && seen.add(file.name)) {
-				process(seen, out, file);
-
-				out.add(file);
-			}
-		}
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/pipeline/InstancingProgramMetaData.java

@@ -3,13 +3,14 @@ package com.jozufozu.flywheel.backend.pipeline;
 import java.util.Optional;
 
 import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.pipeline.error.ErrorReporter;
+import com.jozufozu.flywheel.backend.source.SourceFile;
-import com.jozufozu.flywheel.backend.pipeline.parse.ShaderFunction;
+import com.jozufozu.flywheel.backend.source.error.ErrorReporter;
-import com.jozufozu.flywheel.backend.pipeline.parse.ShaderStruct;
+import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
-import com.jozufozu.flywheel.backend.pipeline.parse.Variable;
+import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
+import com.jozufozu.flywheel.backend.source.parse.Variable;
+import com.jozufozu.flywheel.backend.source.span.Span;
 
-public class InstanceTemplateData {
+public class InstancingProgramMetaData {
 
 	public final SourceFile file;
 	public final ShaderFunction vertexMain;
@@ -21,15 +22,14 @@ public class InstanceTemplateData {
 	public final ShaderStruct vertex;
 	public final ShaderStruct instance;
 
-	public InstanceTemplateData(SourceFile file) {
+	public InstancingProgramMetaData(SourceFile file) {
 		this.file = file;
 
 		Optional<ShaderFunction> vertexFunc = file.findFunction("vertex");
 		Optional<ShaderFunction> fragmentFunc = file.findFunction("fragment");
 
-
 		if (!fragmentFunc.isPresent()) {
-			ErrorReporter.generateFileError(file, "could not find \"fragment\" function");
+			ErrorReporter.generateMissingFunction(file, "fragment", "\"fragment\" function not defined");
 		}
 		if (!vertexFunc.isPresent()) {
 			ErrorReporter.generateFileError(file, "could not find \"vertex\" function");
@@ -64,15 +64,15 @@ public class InstanceTemplateData {
 		Optional<ShaderStruct> maybeInstance = file.findStruct(instanceName);
 
 		if (!maybeVertex.isPresent()) {
-			ErrorReporter.generateMissingStruct(file, vertexName);
+			ErrorReporter.generateMissingStruct(file, vertexName, "struct not defined");
 		}
 
 		if (!maybeInterpolant.isPresent()) {
-			ErrorReporter.generateMissingStruct(file, interpolantName);
+			ErrorReporter.generateMissingStruct(file, interpolantName, "struct not defined");
 		}
 
 		if (!maybeInstance.isPresent()) {
-			ErrorReporter.generateMissingStruct(file, instanceName);
+			ErrorReporter.generateMissingStruct(file, instanceName, "struct not defined");
 		}
 
 		if (!maybeVertex.isPresent() || !maybeInterpolant.isPresent() || !maybeInstance.isPresent()) {

src/main/java/com/jozufozu/flywheel/backend/pipeline/InstancingTemplate.java

@@ -1,16 +1,19 @@
 package com.jozufozu.flywheel.backend.pipeline;
 
-import java.util.HashMap;
+import java.util.ArrayList;
-import java.util.Map;
+import java.util.Collection;
+import java.util.List;
 
 import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
-import com.jozufozu.flywheel.backend.loading.ProtoProgram;
+import com.jozufozu.flywheel.backend.source.SourceFile;
 
-public class InstancingTemplate implements ITemplate {
+public class InstancingTemplate extends Template<InstancingProgramMetaData> {
 
 	public static final InstancingTemplate INSTANCE = new InstancingTemplate();
 
-	private final Map<SourceFile, InstanceTemplateData> datas = new HashMap<>();
+	public InstancingTemplate() {
+		super(InstancingProgramMetaData::new);
+	}
 
 	@Override
 	public void generateTemplateSource(StringBuilder builder, ShaderType type, SourceFile file) {
@@ -22,51 +25,50 @@ public class InstancingTemplate implements ITemplate {
 	}
 
 	@Override
-	public void attachAttributes(ProtoProgram program, SourceFile file) {
+	public Collection<ShaderInput> getShaderInputs(SourceFile file) {
-		InstanceTemplateData data = getData(file);
+		InstancingProgramMetaData data = getMetadata(file);
-		data.vertex.addPrefixedAttributes(program, "a_v_");
-		data.instance.addPrefixedAttributes(program, "a_i_");
-	}
 
-	public InstanceTemplateData getData(SourceFile file) {
+		List<ShaderInput> inputs = new ArrayList<>(ShaderInput.fromStruct(data.vertex, "a_v_"));
-		return datas.computeIfAbsent(file, InstanceTemplateData::new);
+		inputs.addAll(ShaderInput.fromStruct(data.instance, "a_i_"));
+
+		return inputs;
 	}
 
 	public void vertexFooter(StringBuilder template, SourceFile file) {
-		InstanceTemplateData data = getData(file);
+		InstancingProgramMetaData data = getMetadata(file);
 
-		ITemplate.prefixFields(template, data.vertex, "attribute", "a_v_");
+		Template.prefixFields(template, data.vertex, "attribute", "a_v_");
-		ITemplate.prefixFields(template, data.instance, "attribute", "a_i_");
+		Template.prefixFields(template, data.instance, "attribute", "a_i_");
-		ITemplate.prefixFields(template, data.interpolant, "varying", "v2f_");
+		Template.prefixFields(template, data.interpolant, "varying", "v2f_");
 
 		template.append("void main() {\n");
 		template.append(data.vertexName)
 				.append(" v;\n");
-		ITemplate.assignFields(template, data.vertex, "v.", "a_v_");
+		Template.assignFields(template, data.vertex, "v.", "a_v_");
 
 		template.append(data.instanceName)
 				.append(" i;\n");
-		ITemplate.assignFields(template, data.instance, "i.", "a_i_");
+		Template.assignFields(template, data.instance, "i.", "a_i_");
 
 		template.append(data.interpolantName)
 				.append(" o = ")
 				.append(data.vertexMain.call("v", "i"))
 				.append(";\n");
 
-		ITemplate.assignFields(template, data.interpolant, "v2f_", "o.");
+		Template.assignFields(template, data.interpolant, "v2f_", "o.");
 
 		template.append('}');
 	}
 
 	public void fragmentFooter(StringBuilder template, SourceFile file) {
-		InstanceTemplateData data = getData(file);
+		InstancingProgramMetaData data = getMetadata(file);
 
-		ITemplate.prefixFields(template, data.interpolant, "varying", "v2f_");
+		Template.prefixFields(template, data.interpolant, "varying", "v2f_");
 
 		template.append("void main() {\n");
 		template.append(data.interpolantName)
 				.append(" o;\n");
-		ITemplate.assignFields(template, data.interpolant, "o.", "v2f_");
+		Template.assignFields(template, data.interpolant, "o.", "v2f_");
 
 		template.append(data.fragmentMain.call("o"))
 				.append(";\n");

src/main/java/com/jozufozu/flywheel/backend/pipeline/OneShotProgramMetaData.java

@@ -3,13 +3,14 @@ package com.jozufozu.flywheel.backend.pipeline;
 import java.util.Optional;
 
 import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.pipeline.error.ErrorReporter;
+import com.jozufozu.flywheel.backend.source.SourceFile;
-import com.jozufozu.flywheel.backend.pipeline.parse.ShaderFunction;
+import com.jozufozu.flywheel.backend.source.error.ErrorReporter;
-import com.jozufozu.flywheel.backend.pipeline.parse.ShaderStruct;
+import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
-import com.jozufozu.flywheel.backend.pipeline.parse.Variable;
+import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
+import com.jozufozu.flywheel.backend.source.parse.Variable;
+import com.jozufozu.flywheel.backend.source.span.Span;
 
-public class OneShotData {
+public class OneShotProgramMetaData {
 
 	public final SourceFile file;
 	public final ShaderFunction vertexMain;
@@ -19,7 +20,7 @@ public class OneShotData {
 	public final ShaderStruct vertex;
 	public final ShaderFunction fragmentMain;
 
-	public OneShotData(SourceFile file) {
+	public OneShotProgramMetaData(SourceFile file) {
 		this.file = file;
 
 		Optional<ShaderFunction> maybeVertexMain = file.findFunction("vertex");
@@ -27,29 +28,32 @@ public class OneShotData {
 
 		if (!maybeVertexMain.isPresent()) {
 			ErrorReporter.generateFileError(file, "could not find \"vertex\" function");
-			throw new RuntimeException();
 		}
 
 		if (!maybeFragmentMain.isPresent()) {
-			ErrorReporter.generateFileError(file, "could not find \"fragment\" function");
+			ErrorReporter.generateMissingFunction(file, "fragment", "\"fragment\" function not defined");
+		}
+
+		if (!maybeVertexMain.isPresent() || !maybeFragmentMain.isPresent()) {
 			throw new RuntimeException();
 		}
 
 		vertexMain = maybeVertexMain.get();
 		fragmentMain = maybeFragmentMain.get();
-		ImmutableList<Variable> parameters = fragmentMain.getParameters();
+		ImmutableList<Variable> fragmentParameters = fragmentMain.getParameters();
 		ImmutableList<Variable> vertexParameters = vertexMain.getParameters();
 
 		if (vertexParameters.size() != 1) {
 			ErrorReporter.generateSpanError(vertexMain.getArgs(), "a basic model requires vertex function to have one argument");
-			throw new RuntimeException();
 		}
 
-		if (parameters.size() != 1) {
+		if (fragmentParameters.size() != 1) {
-			ErrorReporter.generateSpanError(fragmentMain.getArgs(), "instancing requires fragment function to have 1 argument");
+			ErrorReporter.generateSpanError(fragmentMain.getArgs(), "fragment function must have exactly one argument");
-			throw new RuntimeException();
 		}
 
+		if (vertexParameters.size() != 1 || fragmentParameters.size() != 1) {
+			throw new RuntimeException();
+		}
 
 		interpolantName = vertexMain.getType();
 		vertexName = vertexParameters.get(0)
@@ -59,10 +63,10 @@ public class OneShotData {
 		Optional<ShaderStruct> maybeVertex = file.findStruct(vertexName);
 
 		if (!maybeVertex.isPresent())
-			ErrorReporter.generateMissingStruct(file, vertexName);
+			ErrorReporter.generateMissingStruct(file, vertexName, "struct not defined");
 
 		if (!maybeInterpolant.isPresent())
-			ErrorReporter.generateMissingStruct(file, interpolantName);
+			ErrorReporter.generateMissingStruct(file, interpolantName, "struct not defined");
 
 		if (!maybeVertex.isPresent() || !maybeInterpolant.isPresent()) {
 			throw new RuntimeException();

src/main/java/com/jozufozu/flywheel/backend/pipeline/OneShotTemplate.java

@@ -1,18 +1,17 @@
 package com.jozufozu.flywheel.backend.pipeline;
 
-import java.util.HashMap;
+import java.util.Collection;
-import java.util.Map;
-import java.util.Optional;
 
 import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
-import com.jozufozu.flywheel.backend.loading.ProtoProgram;
+import com.jozufozu.flywheel.backend.source.SourceFile;
 
-public class OneShotTemplate implements ITemplate {
+public class OneShotTemplate extends Template<OneShotProgramMetaData> {
 
 	public static final OneShotTemplate INSTANCE = new OneShotTemplate();
 
-
+	public OneShotTemplate() {
-	private final Map<SourceFile, OneShotData> datas = new HashMap<>();
+		super(OneShotProgramMetaData::new);
+	}
 
 	@Override
 	public void generateTemplateSource(StringBuilder builder, ShaderType type, SourceFile file) {
@@ -24,45 +23,42 @@ public class OneShotTemplate implements ITemplate {
 	}
 
 	@Override
-	public void attachAttributes(ProtoProgram program, SourceFile file) {
+	public Collection<ShaderInput> getShaderInputs(SourceFile file) {
-		OneShotData data = getData(file);
+		OneShotProgramMetaData data = getMetadata(file);
-		data.vertex.addPrefixedAttributes(program, "a_v_");
-	}
 
-	public OneShotData getData(SourceFile file) {
+		return ShaderInput.fromStruct(data.vertex, "a_v_");
-		return datas.computeIfAbsent(file, OneShotData::new);
 	}
 
 	public void vertexFooter(StringBuilder template, SourceFile file) {
-		OneShotData data = getData(file);
+		OneShotProgramMetaData data = getMetadata(file);
 
-		ITemplate.prefixFields(template, data.vertex, "attribute", "a_v_");
+		Template.prefixFields(template, data.vertex, "attribute", "a_v_");
-		ITemplate.prefixFields(template, data.interpolant, "varying", "v2f_");
+		Template.prefixFields(template, data.interpolant, "varying", "v2f_");
 
 		template.append("void main() {\n");
 		template.append(data.vertexName)
 				.append(" v;\n");
-		ITemplate.assignFields(template, data.vertex, "v.", "a_v_");
+		Template.assignFields(template, data.vertex, "v.", "a_v_");
 
 		template.append(data.interpolantName)
 				.append(" o = ")
 				.append(data.vertexMain.call("v"))
 				.append(";\n");
 
-		ITemplate.assignFields(template, data.interpolant, "v2f_", "o.");
+		Template.assignFields(template, data.interpolant, "v2f_", "o.");
 
 		template.append('}');
 	}
 
 	public void fragmentFooter(StringBuilder template, SourceFile file) {
-		OneShotData data = getData(file);
+		OneShotProgramMetaData data = getMetadata(file);
 
-		ITemplate.prefixFields(template, data.interpolant, "varying", "v2f_");
+		Template.prefixFields(template, data.interpolant, "varying", "v2f_");
 
 		template.append("void main() {\n");
 		template.append(data.interpolant.name)
 				.append(" o;\n");
-		ITemplate.assignFields(template, data.interpolant, "o.", "v2f_");
+		Template.assignFields(template, data.interpolant, "o.", "v2f_");
 
 		template.append(data.fragmentMain.call("o"))
 				.append(";\n");

src/main/java/com/jozufozu/flywheel/backend/pipeline/ProtoProgram.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.loading;
+package com.jozufozu.flywheel.backend.pipeline;
 
 import static org.lwjgl.opengl.GL20.GL_LINK_STATUS;
 import static org.lwjgl.opengl.GL20.GL_TRUE;
@@ -9,53 +9,48 @@ import static org.lwjgl.opengl.GL20.glGetProgramInfoLog;
 import static org.lwjgl.opengl.GL20.glGetProgrami;
 import static org.lwjgl.opengl.GL20.glLinkProgram;
 
-import java.util.EnumMap;
+import java.util.List;
-import java.util.Map;
-import java.util.function.IntConsumer;
-
-import org.lwjgl.opengl.GL20;
 
 import com.jozufozu.flywheel.backend.Backend;
 import com.jozufozu.flywheel.backend.gl.shader.GlShader;
 import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
 
-import it.unimi.dsi.fastutil.ints.IntArrayList;
+import it.unimi.dsi.fastutil.objects.ObjectArrayList;
-import it.unimi.dsi.fastutil.ints.IntList;
-import net.minecraft.util.ResourceLocation;
 
 public class ProtoProgram {
 	public final int program;
+	public final WorldShader parent;
 
-	public ResourceLocation name;
 	private int attributeIndex;
 
-	private final IntList shaders;
+	private final List<GlShader> shaders;
 
-	public ProtoProgram() {
+	public ProtoProgram(WorldShader parent) {
+		this.parent = parent;
 		this.program = glCreateProgram();
-		shaders = new IntArrayList(2);
+		shaders = new ObjectArrayList<>();
 	}
 
-	public void attachShader(GlShader glShader) {
+	public ProtoProgram compilePart(ShaderType type) {
-		glAttachShader(this.program, glShader.handle());
+		GlShader shader = parent.compile(type);
-	}
+		attachShader(shader);
-
+		return this;
-	public void addAttribute(String name, int attributeCount) {
-		glBindAttribLocation(this.program, attributeIndex, name);
-		attributeIndex += attributeCount;
 	}
 
 	/**
 	 * Links the attached shaders to this program.
 	 */
-	public ProtoProgram link(ResourceLocation name) {
+	public ProtoProgram link() {
-		this.name = name;
+
+		parent.template.getShaderInputs(parent.mainFile)
+				.forEach(this::addAttribute);
+
 		glLinkProgram(this.program);
 
 		String log = glGetProgramInfoLog(this.program);
 
 		if (!log.isEmpty()) {
-			Backend.log.debug("Program link log for " + name + ": " + log);
+			Backend.log.debug("Program link log for " + parent.name + ": " + log);
 		}
 
 		int result = glGetProgrami(this.program, GL_LINK_STATUS);
@@ -68,7 +63,18 @@ public class ProtoProgram {
 	}
 
 	public ProtoProgram deleteLinkedShaders() {
-		shaders.forEach((IntConsumer) GL20::glDeleteShader);
+		shaders.forEach(GlShader::delete);
 		return this;
 	}
+
+	private void attachShader(GlShader glShader) {
+		shaders.add(glShader);
+		glAttachShader(this.program, glShader.handle());
+	}
+
+	private void addAttribute(ShaderInput shaderInput) {
+		glBindAttribLocation(this.program, attributeIndex, shaderInput.name);
+		attributeIndex += shaderInput.attribCount;
+	}
+
 }

src/main/java/com/jozufozu/flywheel/backend/pipeline/ShaderInput.java

@@ -0,0 +1,38 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import java.util.Collection;
+import java.util.stream.Collectors;
+
+import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
+import com.jozufozu.flywheel.backend.source.parse.StructField;
+
+/**
+ * A single input to a shader.
+ */
+public class ShaderInput {
+	public final CharSequence name;
+	public final int attribCount;
+
+	public ShaderInput(CharSequence name, int attribCount) {
+		this.name = name;
+		this.attribCount = attribCount;
+	}
+
+	public ShaderInput withPrefix(CharSequence prefix) {
+		return new ShaderInput(prefix.toString() + name, attribCount);
+	}
+
+	public static Collection<ShaderInput> fromStruct(ShaderStruct struct, String prefix) {
+		return struct.getFields()
+				.stream()
+				.map(ShaderInput::from)
+				.map(a -> a.withPrefix(prefix))
+				.collect(Collectors.toList());
+	}
+
+	public static ShaderInput from(StructField field) {
+		int attributeCount = TypeHelper.getAttributeCount(field.type);
+
+		return new ShaderInput(field.name, attributeCount);
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/pipeline/Template.java

@@ -0,0 +1,82 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Function;
+
+import com.google.common.collect.ImmutableList;
+import com.jozufozu.flywheel.backend.gl.GLSLVersion;
+import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
+import com.jozufozu.flywheel.backend.source.SourceFile;
+import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
+import com.jozufozu.flywheel.backend.source.parse.StructField;
+
+/**
+ * A class that generates glsl glue code given a SourceFile.
+ *
+ * <p>
+ *     Shader files are written somewhat abstractly. Subclasses of Template handle those abstractions, using SourceFile
+ *     metadata to generate shader code that OpenGL can use to call into our shader programs.
+ * </p>
+ * @param <D> Holds metadata, generates errors.
+ */
+public abstract class Template<D> {
+
+	private final Map<SourceFile, D> metadata = new HashMap<>();
+
+	private final Function<SourceFile, D> parser;
+
+	protected Template(Function<SourceFile, D> parser) {
+		this.parser = parser;
+	}
+
+	/**
+	 * Generate the necessary glue code here.
+	 *
+	 * <p>
+	 *     See {@link InstancingTemplate} and {@link OneShotTemplate} for examples.
+	 * </p>
+	 * @param builder The builder to generate the source into.
+	 * @param type The shader stage glue code is needed for.
+	 * @param file The SourceFile with user written code.
+	 */
+	public abstract void generateTemplateSource(StringBuilder builder, ShaderType type, SourceFile file);
+
+	public abstract Collection<ShaderInput> getShaderInputs(SourceFile file);
+
+	public D getMetadata(SourceFile file) {
+		return metadata.computeIfAbsent(file, parser);
+	}
+
+	public GLSLVersion getVersion() {
+		return GLSLVersion.V120;
+	}
+
+	public static void prefixFields(StringBuilder builder, ShaderStruct struct, String qualifier, String prefix) {
+		ImmutableList<StructField> fields = struct.getFields();
+
+		for (StructField field : fields) {
+			builder.append(qualifier)
+					.append(' ')
+					.append(field.type)
+					.append(' ')
+					.append(prefix)
+					.append(field.name)
+					.append(";\n");
+		}
+	}
+
+	public static void assignFields(StringBuilder builder, ShaderStruct struct, String prefix1, String prefix2) {
+		ImmutableList<StructField> fields = struct.getFields();
+
+		for (StructField field : fields) {
+			builder.append(prefix1)
+					.append(field.name)
+					.append(" = ")
+					.append(prefix2)
+					.append(field.name)
+					.append(";\n");
+		}
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/pipeline/TypeHelper.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.loading;
+package com.jozufozu.flywheel.backend.pipeline;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

src/main/java/com/jozufozu/flywheel/backend/pipeline/WorldShader.java

@@ -1,37 +1,35 @@
 package com.jozufozu.flywheel.backend.pipeline;
 
 import java.util.List;
+import java.util.Optional;
 
-import com.jozufozu.flywheel.backend.FileResolution;
+import com.jozufozu.flywheel.backend.source.FileResolution;
 import com.jozufozu.flywheel.backend.gl.shader.GlShader;
 import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
+import com.jozufozu.flywheel.backend.source.SourceFile;
 
 import net.minecraft.util.ResourceLocation;
 
-public class ShaderBuilder {
+public class WorldShader {
 
 	public final ResourceLocation name;
-	public final ITemplate template;
+	public final Template<?> template;
-	public final FileResolution header;
+	public final CharSequence header;
 
 	public SourceFile mainFile;
-	private GLSLVersion version;
 
-	private StringBuilder source;
+	private CharSequence source;
 	private StringBuilder defines;
 
-	public ShaderBuilder(ResourceLocation name, ITemplate template, FileResolution header) {
+	public WorldShader(ResourceLocation name, Template<?> template, FileResolution header) {
 		this.name = name;
 		this.template = template;
-		this.header = header;
+		this.header = Optional.ofNullable(header.getFile())
+				.map(SourceFile::generateFinalSource)
+				.orElse("");
 	}
 
-	public ShaderBuilder setVersion(GLSLVersion version) {
+	public WorldShader setDefines(List<String> defs) {
-		this.version = version;
-		return this;
-	}
-
-	public ShaderBuilder setDefines(List<String> defs) {
 		defines = new StringBuilder();
 
 		for (String def : defs) {
@@ -42,35 +40,37 @@ public class ShaderBuilder {
 		return this;
 	}
 
-	public ShaderBuilder setMainSource(SourceFile file) {
+	public WorldShader setMainSource(SourceFile file) {
 		if (mainFile == file) return this;
 
 		mainFile = file;
-		source = new StringBuilder();
+		source = file.generateFinalSource();
-
-		file.generateFinalSource(source);
 
 		return this;
 	}
 
-	public GlShader compile(ResourceLocation name, ShaderType type) {
+	public GlShader compile(ShaderType type) {
 
 		StringBuilder finalSource = new StringBuilder();
 
 		finalSource.append("#version ")
-				.append(version)
+				.append(template.getVersion())
 				.append('\n')
 				.append("#define ")
 				.append(type.define)
 				.append('\n')
-				.append(defines != null ? defines : "");
+				.append(defines != null ? defines : "")
-		SourceFile file = header.getFile();
+				.append(header)
-		if (file != null) {
+				.append('\n')
-			file.generateFinalSource(finalSource);
+				.append(source)
-		}
+				.append('\n');
-		mainFile.generateFinalSource(finalSource);
+
 		template.generateTemplateSource(finalSource, type, mainFile);
 
 		return new GlShader(name, type, finalSource);
 	}
+
+	public ProtoProgram createProgram() {
+		return new ProtoProgram(this);
+	}
 }

src/main/java/com/jozufozu/flywheel/backend/pipeline/WorldShaderPipeline.java

@@ -1,22 +1,15 @@
 package com.jozufozu.flywheel.backend.pipeline;
 
-import static org.lwjgl.opengl.GL11.GL_TRUE;
-import static org.lwjgl.opengl.GL20.GL_LINK_STATUS;
 import static org.lwjgl.opengl.GL20.glGetProgramInfoLog;
-import static org.lwjgl.opengl.GL20.glGetProgrami;
 
 import java.util.List;
 
 import javax.annotation.Nullable;
 
-import org.lwjgl.opengl.GL20;
+import com.jozufozu.flywheel.backend.source.FileResolution;
-
+import com.jozufozu.flywheel.backend.source.ShaderSources;
-import com.jozufozu.flywheel.backend.Backend;
-import com.jozufozu.flywheel.backend.FileResolution;
-import com.jozufozu.flywheel.backend.ShaderSources;
-import com.jozufozu.flywheel.backend.gl.shader.GlShader;
 import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
-import com.jozufozu.flywheel.backend.loading.ProtoProgram;
+import com.jozufozu.flywheel.backend.source.SourceFile;
 import com.jozufozu.flywheel.core.shader.ExtensibleGlProgram;
 import com.jozufozu.flywheel.core.shader.GameStateProgram;
 import com.jozufozu.flywheel.core.shader.IMultiProgram;
@@ -32,10 +25,10 @@ public class WorldShaderPipeline<P extends WorldProgram> implements IShaderPipel
 
 	private final ExtensibleGlProgram.Factory<P> factory;
 
-	private final ITemplate template;
+	private final Template<?> template;
 	private final FileResolution header;
 
-	public WorldShaderPipeline(ShaderSources sources, ExtensibleGlProgram.Factory<P> factory, ITemplate template, FileResolution header) {
+	public WorldShaderPipeline(ShaderSources sources, ExtensibleGlProgram.Factory<P> factory, Template<?> template, FileResolution header) {
 		this.sources = sources;
 		this.factory = factory;
 		this.template = template;
@@ -44,48 +37,40 @@ public class WorldShaderPipeline<P extends WorldProgram> implements IShaderPipel
 
 	public IMultiProgram<P> compile(ProgramSpec spec) {
 
-		SourceFile file = sources.source(spec.vert);
+		SourceFile file = sources.source(spec.source);
 
 		return compile(spec.name, file, spec.getStates());
 	}
 
 	public IMultiProgram<P> compile(ResourceLocation name, SourceFile file, List<ProgramState> variants) {
-		ShaderBuilder shader = new ShaderBuilder(name, template, header)
+		WorldShader shader = new WorldShader(name, template, header)
-				.setMainSource(file)
+				.setMainSource(file);
-				.setVersion(GLSLVersion.V110);
 
-		GameStateProgram.Builder<P> builder = GameStateProgram.builder(compile(shader, name, null));
+		GameStateProgram.Builder<P> builder = GameStateProgram.builder(compile(shader, null));
 
 		for (ProgramState variant : variants) {
-			builder.withVariant(variant.getContext(), compile(shader, name, variant));
+			builder.withVariant(variant.getContext(), compile(shader, variant));
 		}
 
 		return builder.build();
 	}
 
-	private P compile(ShaderBuilder shader, ResourceLocation name, @Nullable ProgramState variant) {
+	private P compile(WorldShader shader, @Nullable ProgramState variant) {
 
 		if (variant != null) {
 			shader.setDefines(variant.getDefines());
 		}
 
-		GlShader vertex = shader.compile(name, ShaderType.VERTEX);
+		ProtoProgram program = shader.createProgram()
-		GlShader fragment = shader.compile(name, ShaderType.FRAGMENT);
+				.compilePart(ShaderType.VERTEX)
-
+				.compilePart(ShaderType.FRAGMENT)
-		ProtoProgram program = new ProtoProgram();
+				.link()
-
+				.deleteLinkedShaders();
-		program.attachShader(vertex);
-		program.attachShader(fragment);
-
-		template.attachAttributes(program, shader.mainFile);
-
-		program.link(name);
-		program.deleteLinkedShaders();
 
 		if (variant != null) {
-			return factory.create(name, program.program, variant.getExtensions());
+			return factory.create(shader.name, program.program, variant.getExtensions());
 		} else {
-			return factory.create(name, program.program, null);
+			return factory.create(shader.name, program.program, null);
 		}
 	}
 }

src/main/java/com/jozufozu/flywheel/backend/pipeline/error/ErrorReporter.java

@@ -1,50 +0,0 @@
-package com.jozufozu.flywheel.backend.pipeline.error;
-
-import java.util.Optional;
-
-import com.jozufozu.flywheel.backend.Backend;
-import com.jozufozu.flywheel.backend.pipeline.SourceFile;
-import com.jozufozu.flywheel.backend.pipeline.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
-
-public class ErrorReporter {
-
-	public static void generateSpanError(Span span, String message) {
-		SourceFile file = span.getSourceFile();
-
-		ErrorBuilder builder = new ErrorBuilder();
-
-		CharSequence error = builder.error(message)
-				.in(file)
-				.pointAt(span, 2)
-				.build();
-
-		Backend.log.error(error);
-	}
-
-	public static void generateFileError(SourceFile file, String message) {
-
-		ErrorBuilder builder = new ErrorBuilder();
-
-		CharSequence error = builder.error(message)
-				.in(file)
-				.build();
-
-		Backend.log.error(error);
-	}
-
-	public static void generateMissingStruct(SourceFile file, Span vertexName) {
-		Optional<Span> span = file.parent.index.getStructDefinitionsMatching(vertexName)
-				.stream()
-				.findFirst()
-				.map(ShaderStruct::getName);
-		ErrorBuilder builder = new ErrorBuilder();
-
-		ErrorBuilder error = builder.error("struct not defined")
-				.in(file)
-				.pointAt(vertexName, 2)
-				.hintIncludeFor(span.orElse(null));
-
-		Backend.log.error(error.build());
-	}
-}

src/main/java/com/jozufozu/flywheel/backend/source/FileResolution.java

@@ -0,0 +1,86 @@
+package com.jozufozu.flywheel.backend.source;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.annotation.Nullable;
+
+import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.backend.source.error.ErrorBuilder;
+import com.jozufozu.flywheel.backend.source.span.Span;
+
+import net.minecraft.util.ResourceLocation;
+
+/**
+ * A reference to a source file that might not be loaded when the owning object is created.
+ *
+ * <p>
+ *     FileResolutions are used primarily while parsing import statements. {@link FileResolution#file} is initially
+ *     null, but will be populated later on, after <em>all</em> SourceFiles are loaded (assuming
+ *     {@link FileResolution#fileLoc} references an actual file).
+ * </p>
+ */
+public class FileResolution {
+
+	/**
+	 * Spans that have references that resolved to this.
+	 */
+	private final List<Span> foundSpans = new ArrayList<>();
+	private final ShaderSources parent;
+	private final ResourceLocation fileLoc;
+	private SourceFile file;
+
+	public FileResolution(ShaderSources parent, ResourceLocation fileLoc) {
+		this.parent = parent;
+		this.fileLoc = fileLoc;
+	}
+
+	public ResourceLocation getFileLoc() {
+		return fileLoc;
+	}
+
+	@Nullable
+	public SourceFile getFile() {
+		return file;
+	}
+
+	/**
+	 * Store the given span so this resolution can know all the places that reference the file.
+	 *
+	 * <p>
+	 *     Used for error reporting.
+	 * </p>
+	 * @param span A span where this file is referenced.
+	 */
+	public void addSpan(Span span) {
+		foundSpans.add(span);
+	}
+
+	/**
+	 * Check to see if this file actually resolves to something.
+	 *
+	 * <p>
+	 *     Called after all files are loaded. If we can't find the file here, it doesn't exist.
+	 * </p>
+	 */
+	void resolve() {
+
+		try {
+			file = this.parent.source(fileLoc);
+		} catch (RuntimeException error) {
+			ErrorBuilder builder = new ErrorBuilder();
+			builder.error(String.format("could not find source for file %s", fileLoc));
+			// print the location of all places where this file was referenced
+			for (Span span : foundSpans) {
+				builder.in(span.getSourceFile())
+						.pointAt(span, 2);
+			}
+			Backend.log.error(builder.build());
+		}
+	}
+
+	void invalidate() {
+		foundSpans.clear();
+		file = null;
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/source/Index.java

@@ -0,0 +1,42 @@
+package com.jozufozu.flywheel.backend.source;
+
+import java.util.Collection;
+import java.util.Map;
+
+import com.google.common.collect.Multimap;
+import com.google.common.collect.MultimapBuilder;
+import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
+import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
+
+import net.minecraft.util.ResourceLocation;
+
+/**
+ * Indexes many shader source definitions to allow for error fix suggestions.
+ */
+public class Index {
+
+	private final Multimap<String, ShaderStruct> knownStructs = MultimapBuilder.hashKeys()
+			.hashSetValues()
+			.build();
+
+	private final Multimap<String, ShaderFunction> knownFunctions = MultimapBuilder.hashKeys()
+			.hashSetValues()
+			.build();
+
+	public Index(Map<ResourceLocation, SourceFile> sources) {
+		Collection<SourceFile> files = sources.values();
+
+		for (SourceFile file : files) {
+			file.getStructs().forEach(knownStructs::put);
+			file.getFunctions().forEach(knownFunctions::put);
+		}
+	}
+
+	public Collection<ShaderStruct> getStructDefinitionsMatching(CharSequence name) {
+		return knownStructs.get(name.toString());
+	}
+
+	public Collection<ShaderFunction> getFunctionDefinitionsMatching(CharSequence name) {
+		return knownFunctions.get(name.toString());
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/source/ShaderLoadingException.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.loading;
+package com.jozufozu.flywheel.backend.source;
 
 public class ShaderLoadingException extends RuntimeException {
 	public ShaderLoadingException() {

src/main/java/com/jozufozu/flywheel/backend/source/ShaderSources.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend;
+package com.jozufozu.flywheel.backend.source;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -7,16 +7,14 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.function.Predicate;
 
-import javax.annotation.Nonnull;
-
 import com.google.common.collect.Lists;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonElement;
-import com.jozufozu.flywheel.backend.gl.shader.ShaderType;
+import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.backend.IShaderContext;
+import com.jozufozu.flywheel.backend.ResourceUtil;
 import com.jozufozu.flywheel.backend.instancing.InstancedRenderDispatcher;
-import com.jozufozu.flywheel.backend.loading.ShaderLoadingException;
-import com.jozufozu.flywheel.backend.pipeline.SourceFile;
 import com.jozufozu.flywheel.core.crumbling.CrumblingRenderer;
 import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
 import com.jozufozu.flywheel.event.GatherContextEvent;
@@ -36,6 +34,13 @@ import net.minecraftforge.resource.IResourceType;
 import net.minecraftforge.resource.ISelectiveResourceReloadListener;
 import net.minecraftforge.resource.VanillaResourceType;
 
+/**
+ * The main entity for loading shaders.
+ *
+ * <p>
+ *     This class is responsible for invoking the loading, parsing, and compilation stages.
+ * </p>
+ */
 public class ShaderSources implements ISelectiveResourceReloadListener {
 	public static final String SHADER_DIR = "flywheel/shaders/";
 	public static final String PROGRAM_DIR = "flywheel/programs/";
@@ -70,7 +75,7 @@ public class ShaderSources implements ISelectiveResourceReloadListener {
 	}
 
 	public FileResolution resolveFile(ResourceLocation fileLoc) {
-		return resolutions.computeIfAbsent(fileLoc, FileResolution::new);
+		return resolutions.computeIfAbsent(fileLoc, l -> new FileResolution(this, l));
 	}
 
 	@Deprecated
@@ -86,17 +91,17 @@ public class ShaderSources implements ISelectiveResourceReloadListener {
 			if (backend.gl20()) {
 				shouldCrash = false;
 
-				backend.clearContexts();
+				backend._clearContexts();
+				resolutions.values().forEach(FileResolution::invalidate);
+				shaderSources.clear();
 				ModLoader.get()
 						.postEvent(new GatherContextEvent(backend));
 
-				resolutions.values().forEach(FileResolution::invalidate);
-
 				loadProgramSpecs(manager);
 				loadShaderSources(manager);
 
 				for (FileResolution resolution : resolutions.values()) {
-					resolution.resolve(this);
+					resolution.resolve();
 				}
 
 				for (IShaderContext<?> context : backend.allContexts()) {

src/main/java/com/jozufozu/flywheel/backend/source/SourceFile.java

@@ -1,29 +1,22 @@
-package com.jozufozu.flywheel.backend.pipeline;
+package com.jozufozu.flywheel.backend.source;
 
-import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import java.util.Queue;
-import java.util.Set;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import javax.annotation.Nullable;
-
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
-import com.jozufozu.flywheel.backend.FileResolution;
+import com.jozufozu.flywheel.backend.source.parse.Import;
-import com.jozufozu.flywheel.backend.ShaderSources;
+import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
-import com.jozufozu.flywheel.backend.pipeline.parse.Import;
+import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
-import com.jozufozu.flywheel.backend.pipeline.parse.ShaderFunction;
+import com.jozufozu.flywheel.backend.source.span.CharPos;
-import com.jozufozu.flywheel.backend.pipeline.parse.ShaderStruct;
+import com.jozufozu.flywheel.backend.source.span.ErrorSpan;
-import com.jozufozu.flywheel.backend.pipeline.span.CharPos;
+import com.jozufozu.flywheel.backend.source.span.Span;
-import com.jozufozu.flywheel.backend.pipeline.span.ErrorSpan;
+import com.jozufozu.flywheel.backend.source.span.StringSpan;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
-import com.jozufozu.flywheel.backend.pipeline.span.StringSpan;
 import com.jozufozu.flywheel.util.StringUtil;
 
 import it.unimi.dsi.fastutil.ints.IntArrayList;
@@ -142,6 +135,12 @@ public class SourceFile {
 		return "#use " + '"' + name + '"';
 	}
 
+	public CharSequence generateFinalSource() {
+		StringBuilder builder = new StringBuilder();
+		generateFinalSource(builder);
+		return builder;
+	}
+
 	public void generateFinalSource(StringBuilder source) {
 		for (Import include : getIncludes()) {
 			SourceFile file = include.getFile();

src/main/java/com/jozufozu/flywheel/backend/source/error/ErrorBuilder.java

@@ -1,11 +1,7 @@
-package com.jozufozu.flywheel.backend.pipeline.error;
+package com.jozufozu.flywheel.backend.source.error;
 
-import java.util.Optional;
+import com.jozufozu.flywheel.backend.source.SourceFile;
-
+import com.jozufozu.flywheel.backend.source.span.Span;
-import javax.annotation.Nullable;
-
-import com.jozufozu.flywheel.backend.pipeline.SourceFile;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
 import com.jozufozu.flywheel.util.FlwUtil;
 
 public class ErrorBuilder {
@@ -40,6 +36,11 @@ public class ErrorBuilder {
 		return line(String.valueOf(no), content);
 	}
 
+	public ErrorBuilder numberedLine(int no, int width, CharSequence content) {
+		String fmt = "%1$" + width + 's';
+		return line(String.format(fmt, no), content);
+	}
+
 	public ErrorBuilder line(CharSequence leftColumn, CharSequence rightColumn) {
 
 		internal.append(leftColumn)
@@ -54,10 +55,10 @@ public class ErrorBuilder {
 		return this;
 	}
 
-	public ErrorBuilder hintIncludeFor(Span span) {
+	public ErrorBuilder hintIncludeFor(Span span, CharSequence msg) {
 		if (span == null) return this;
 
-		hint("add " + span.getSourceFile().importStatement())
+		hint("add " + span.getSourceFile().importStatement() + " " + msg)
 				.in(span.getSourceFile())
 				.pointAt(span, 1);
 
@@ -77,14 +78,13 @@ public class ErrorBuilder {
 
 			int digits = FlwUtil.numDigits(lastLine);
 
-
 			int firstCol = span.getStart().getCol();
 			int lastCol = span.getEnd().getCol();
 
 			for (int i = firstLine; i <= lastLine; i++) {
 				CharSequence line = file.getLine(i);
 
-				numberedLine(i + 1, line);
+				numberedLine(i + 1, digits, line);
 
 				if (i == spanLine) {
 					line(FlwUtil.repeatChar(' ', digits), generateUnderline(firstCol, lastCol));

src/main/java/com/jozufozu/flywheel/backend/source/error/ErrorReporter.java

@@ -0,0 +1,73 @@
+package com.jozufozu.flywheel.backend.source.error;
+
+import java.util.Optional;
+
+import com.jozufozu.flywheel.backend.Backend;
+import com.jozufozu.flywheel.backend.source.SourceFile;
+import com.jozufozu.flywheel.backend.source.parse.ShaderFunction;
+import com.jozufozu.flywheel.backend.source.parse.ShaderStruct;
+import com.jozufozu.flywheel.backend.source.span.Span;
+
+public class ErrorReporter {
+
+	public static void generateSpanError(Span span, String message) {
+		SourceFile file = span.getSourceFile();
+
+		ErrorBuilder builder = new ErrorBuilder();
+
+		CharSequence error = builder.error(message)
+				.in(file)
+				.pointAt(span, 2)
+				.build();
+
+		Backend.log.error(error);
+	}
+
+	public static void generateFileError(SourceFile file, String message) {
+
+		ErrorBuilder builder = new ErrorBuilder();
+
+		CharSequence error = builder.error(message)
+				.in(file)
+				.build();
+
+		Backend.log.error(error);
+	}
+
+	public static void generateMissingStruct(SourceFile file, Span vertexName, CharSequence msg) {
+		generateMissingStruct(file, vertexName, msg, "");
+	}
+
+	public static void generateMissingStruct(SourceFile file, Span vertexName, CharSequence msg, CharSequence hint) {
+		Optional<Span> span = file.parent.index.getStructDefinitionsMatching(vertexName)
+				.stream()
+				.findFirst()
+				.map(ShaderStruct::getName);
+		ErrorBuilder builder = new ErrorBuilder();
+
+		ErrorBuilder error = builder.error(msg)
+				.in(file)
+				.pointAt(vertexName, 2)
+				.hintIncludeFor(span.orElse(null), hint);
+
+		Backend.log.error(error.build());
+	}
+
+	public static void generateMissingFunction(SourceFile file, CharSequence functionName, CharSequence msg) {
+		generateMissingFunction(file, functionName, msg, "");
+	}
+
+	public static void generateMissingFunction(SourceFile file, CharSequence functionName, CharSequence msg, CharSequence hint) {
+		Optional<Span> span = file.parent.index.getFunctionDefinitionsMatching(functionName)
+				.stream()
+				.findFirst()
+				.map(ShaderFunction::getName);
+		ErrorBuilder builder = new ErrorBuilder();
+
+		ErrorBuilder error = builder.error(msg)
+				.in(file)
+				.hintIncludeFor(span.orElse(null), hint);
+
+		Backend.log.error(error.build());
+	}
+}

src/main/java/com/jozufozu/flywheel/backend/source/error/package-info.java

@@ -0,0 +1,6 @@
+@ParametersAreNonnullByDefault @MethodsReturnNonnullByDefault
+package com.jozufozu.flywheel.backend.source.error;
+
+import javax.annotation.ParametersAreNonnullByDefault;
+
+import mcp.MethodsReturnNonnullByDefault;

src/main/java/com/jozufozu/flywheel/backend/source/package-info.java

@@ -1,5 +1,5 @@
 @ParametersAreNonnullByDefault @MethodsReturnNonnullByDefault
-package com.jozufozu.flywheel.backend.loading;
+package com.jozufozu.flywheel.backend.source;
 
 import javax.annotation.ParametersAreNonnullByDefault;
 

src/main/java/com/jozufozu/flywheel/backend/source/parse/AbstractShaderElement.java

@@ -1,6 +1,6 @@
-package com.jozufozu.flywheel.backend.pipeline.parse;
+package com.jozufozu.flywheel.backend.source.parse;
 
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
+import com.jozufozu.flywheel.backend.source.span.Span;
 
 public abstract class AbstractShaderElement {
 

src/main/java/com/jozufozu/flywheel/backend/source/parse/Import.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.pipeline.parse;
+package com.jozufozu.flywheel.backend.source.parse;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -6,11 +6,11 @@ import java.util.Optional;
 
 import javax.annotation.Nullable;
 
-import com.jozufozu.flywheel.backend.FileResolution;
+import com.jozufozu.flywheel.backend.source.FileResolution;
-import com.jozufozu.flywheel.backend.ShaderSources;
+import com.jozufozu.flywheel.backend.source.ShaderSources;
-import com.jozufozu.flywheel.backend.pipeline.error.ErrorReporter;
+import com.jozufozu.flywheel.backend.source.error.ErrorReporter;
-import com.jozufozu.flywheel.backend.pipeline.SourceFile;
+import com.jozufozu.flywheel.backend.source.SourceFile;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
+import com.jozufozu.flywheel.backend.source.span.Span;
 
 import net.minecraft.util.ResourceLocation;
 

src/main/java/com/jozufozu/flywheel/backend/source/parse/ShaderFunction.java

@@ -1,11 +1,11 @@
-package com.jozufozu.flywheel.backend.pipeline.parse;
+package com.jozufozu.flywheel.backend.source.parse;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
 import com.google.common.collect.ImmutableList;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
+import com.jozufozu.flywheel.backend.source.span.Span;
 
 public class ShaderFunction extends AbstractShaderElement {
 

src/main/java/com/jozufozu/flywheel/backend/source/parse/ShaderStruct.java

@@ -1,13 +1,11 @@
-package com.jozufozu.flywheel.backend.pipeline.parse;
+package com.jozufozu.flywheel.backend.source.parse;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
-import com.jozufozu.flywheel.backend.loading.ProtoProgram;
+import com.jozufozu.flywheel.backend.source.span.Span;
-import com.jozufozu.flywheel.backend.loading.TypeHelper;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
 
 public class ShaderStruct extends AbstractShaderElement {
 
@@ -65,14 +63,6 @@ public class ShaderStruct extends AbstractShaderElement {
 		return fields.build();
 	}
 
-	public void addPrefixedAttributes(ProtoProgram builder, String prefix) {
-		for (StructField field : fields) {
-			int attributeCount = TypeHelper.getAttributeCount(field.type);
-
-			builder.addAttribute(prefix + field.name, attributeCount);
-		}
-	}
-
 	@Override
 	public String toString() {
 		return "struct " + name;

src/main/java/com/jozufozu/flywheel/backend/source/parse/StructField.java

@@ -1,9 +1,8 @@
-package com.jozufozu.flywheel.backend.pipeline.parse;
+package com.jozufozu.flywheel.backend.source.parse;
 
 import java.util.regex.Pattern;
 
-import com.jozufozu.flywheel.backend.pipeline.error.ErrorReporter;
+import com.jozufozu.flywheel.backend.source.span.Span;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
 
 public class StructField extends AbstractShaderElement {
 	public static final Pattern fieldPattern = Pattern.compile("(\\S+)\\s*(\\S+);");

src/main/java/com/jozufozu/flywheel/backend/source/parse/Variable.java

@@ -1,7 +1,6 @@
-package com.jozufozu.flywheel.backend.pipeline.parse;
+package com.jozufozu.flywheel.backend.source.parse;
 
-import com.jozufozu.flywheel.backend.pipeline.error.ErrorReporter;
+import com.jozufozu.flywheel.backend.source.span.Span;
-import com.jozufozu.flywheel.backend.pipeline.span.Span;
 
 public class Variable extends AbstractShaderElement {
 

src/main/java/com/jozufozu/flywheel/backend/source/parse/package-info.java

@@ -1,6 +1,6 @@
 @ParametersAreNonnullByDefault
 @MethodsReturnNonnullByDefault
-package com.jozufozu.flywheel.backend.pipeline.parse;
+package com.jozufozu.flywheel.backend.source.parse;
 
 import javax.annotation.ParametersAreNonnullByDefault;
 

src/main/java/com/jozufozu/flywheel/backend/source/span/CharPos.java

@@ -1,4 +1,4 @@
-package com.jozufozu.flywheel.backend.pipeline.span;
+package com.jozufozu.flywheel.backend.source.span;
 
 /**
  * A position in a file.

src/main/java/com/jozufozu/flywheel/backend/source/span/ErrorSpan.java

@@ -1,6 +1,6 @@
-package com.jozufozu.flywheel.backend.pipeline.span;
+package com.jozufozu.flywheel.backend.source.span;
 
-import com.jozufozu.flywheel.backend.pipeline.SourceFile;
+import com.jozufozu.flywheel.backend.source.SourceFile;
 
 /**
  * Represents a (syntactically) malformed segment of code.

src/main/java/com/jozufozu/flywheel/backend/source/span/Span.java

@@ -1,8 +1,8 @@
-package com.jozufozu.flywheel.backend.pipeline.span;
+package com.jozufozu.flywheel.backend.source.span;
 
 import java.util.regex.Matcher;
 
-import com.jozufozu.flywheel.backend.pipeline.SourceFile;
+import com.jozufozu.flywheel.backend.source.SourceFile;
 
 /**
  * A span of code in a {@link SourceFile}.

src/main/java/com/jozufozu/flywheel/backend/source/span/StringSpan.java

@@ -1,6 +1,6 @@
-package com.jozufozu.flywheel.backend.pipeline.span;
+package com.jozufozu.flywheel.backend.source.span;
 
-import com.jozufozu.flywheel.backend.pipeline.SourceFile;
+import com.jozufozu.flywheel.backend.source.SourceFile;
 
 public class StringSpan extends Span {
 

src/main/java/com/jozufozu/flywheel/backend/source/span/package-info.java

@@ -0,0 +1,6 @@
+@ParametersAreNonnullByDefault @MethodsReturnNonnullByDefault
+package com.jozufozu.flywheel.backend.source.span;
+
+import javax.annotation.ParametersAreNonnullByDefault;
+
+import mcp.MethodsReturnNonnullByDefault;

src/main/java/com/jozufozu/flywheel/core/Contexts.java

@@ -2,7 +2,7 @@ package com.jozufozu.flywheel.core;
 
 import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.backend.Backend;
-import com.jozufozu.flywheel.backend.FileResolution;
+import com.jozufozu.flywheel.backend.source.FileResolution;
 import com.jozufozu.flywheel.backend.ResourceUtil;
 import com.jozufozu.flywheel.backend.SpecMetaRegistry;
 import com.jozufozu.flywheel.backend.pipeline.IShaderPipeline;
@@ -40,8 +40,8 @@ public class Contexts {
 		IShaderPipeline<CrumblingProgram> crumblingPipeline = new WorldShaderPipeline<>(backend.sources, CrumblingProgram::new, InstancingTemplate.INSTANCE, crumblingBuiltins);
 		IShaderPipeline<WorldProgram> worldPipeline = new WorldShaderPipeline<>(backend.sources, WorldProgram::new, InstancingTemplate.INSTANCE, worldBuiltins);
 
-		CRUMBLING = backend.register(new WorldContext<>(backend, crumblingPipeline).withName(Names.CRUMBLING));
+		CRUMBLING = backend.register(WorldContext.builder(backend, Names.CRUMBLING).build(crumblingPipeline));
-		WORLD = backend.register(new WorldContext<>(backend, worldPipeline).withName(Names.WORLD));
+		WORLD = backend.register(WorldContext.builder(backend, Names.WORLD).build(worldPipeline));
 	}
 
 	public static class Names {

src/main/java/com/jozufozu/flywheel/core/WorldContext.java

@@ -1,40 +1,33 @@
 package com.jozufozu.flywheel.core;
 
+import java.util.HashMap;
+import java.util.Map;
 import java.util.function.Supplier;
 import java.util.stream.Stream;
 
 import com.jozufozu.flywheel.backend.Backend;
-import com.jozufozu.flywheel.backend.ShaderContext;
+import com.jozufozu.flywheel.backend.IShaderContext;
 import com.jozufozu.flywheel.backend.material.MaterialSpec;
 import com.jozufozu.flywheel.backend.pipeline.IShaderPipeline;
+import com.jozufozu.flywheel.core.shader.IMultiProgram;
 import com.jozufozu.flywheel.core.shader.WorldProgram;
 import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
 
 import net.minecraft.util.ResourceLocation;
 
-public class WorldContext<P extends WorldProgram> extends ShaderContext<P> {
+public class WorldContext<P extends WorldProgram> implements IShaderContext<P> {
-	protected ResourceLocation name;
+	public final Backend backend;
-	protected Supplier<Stream<ResourceLocation>> specStream;
+	protected final Map<ResourceLocation, IMultiProgram<P>> programs = new HashMap<>();
+	protected final ResourceLocation name;
+	protected final Supplier<Stream<ResourceLocation>> specStream;
 
 	public final IShaderPipeline<P> pipeline;
 
-	public WorldContext(Backend backend, IShaderPipeline<P> factory) {
+	public WorldContext(Backend backend, ResourceLocation name, Supplier<Stream<ResourceLocation>> specStream, IShaderPipeline<P> pipeline) {
-		super(backend);
+		this.backend = backend;
-		this.pipeline = factory;
-
-		specStream = () -> backend.allMaterials()
-				.stream()
-				.map(MaterialSpec::getProgramName);
-	}
-
-	public WorldContext<P> withName(ResourceLocation name) {
 		this.name = name;
-		return this;
-	}
-
-	public WorldContext<P> withSpecStream(Supplier<Stream<ResourceLocation>> specStream) {
 		this.specStream = specStream;
-		return this;
+		this.pipeline = pipeline;
 	}
 
 	@Override
@@ -59,4 +52,45 @@ public class WorldContext<P extends WorldProgram> extends ShaderContext<P> {
 			backend.sources.notifyError();
 		}
 	}
+
+	@Override
+	public Supplier<P> getProgramSupplier(ResourceLocation spec) {
+		return programs.get(spec);
+	}
+
+	@Override
+	public void delete() {
+		programs.values()
+				.forEach(IMultiProgram::delete);
+		programs.clear();
+	}
+
+	public static Builder builder(Backend backend, ResourceLocation name) {
+		return new Builder(backend, name);
+	}
+
+	public static class Builder {
+		private final Backend backend;
+		private final ResourceLocation name;
+		private Supplier<Stream<ResourceLocation>> specStream;
+
+		public Builder(Backend backend, ResourceLocation name) {
+			this.backend = backend;
+			this.name = name;
+		}
+
+		public Builder setSpecStream(Supplier<Stream<ResourceLocation>> specStream) {
+			this.specStream = specStream;
+			return this;
+		}
+
+		public <P extends WorldProgram> WorldContext<P> build(IShaderPipeline<P> pipeline) {
+			if (specStream == null) {
+				specStream = () -> backend.allMaterials()
+						.stream()
+						.map(MaterialSpec::getProgramName);
+			}
+			return new WorldContext<>(backend, name, specStream, pipeline);
+		}
+	}
 }

src/main/java/com/jozufozu/flywheel/core/shader/spec/ProgramSpec.java

@@ -1,56 +1,54 @@
 package com.jozufozu.flywheel.core.shader.spec;
 
-import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 
+import com.jozufozu.flywheel.backend.source.SourceFile;
 import com.mojang.serialization.Codec;
 import com.mojang.serialization.codecs.RecordCodecBuilder;
 
 import net.minecraft.util.ResourceLocation;
 
+/**
+ * An object describing a shader program that can be loaded by flywheel.
+ *
+ * <p>
+ *     These are defined through json. All ProgramSpecs in <code>assets/modid/flywheel/programs</code> are parsed and
+ *     processed. One ProgramSpec typically specifies one "material" that can be used in game to render things.
+ * </p>
+ * <p>
+ *     All shader source files in <code>assets/modid/flywheel/shaders</code> are completely loaded and parsed into
+ *     {@link SourceFile SourceFiles}, but not compiled until one of them is
+ *     referenced by a ProgramSpec.
+ * </p>
+ */
 public class ProgramSpec {
 
 	// TODO: Block model style inheritance?
 	public static final Codec<ProgramSpec> CODEC = RecordCodecBuilder.create(instance -> instance.group(
-			ResourceLocation.CODEC.fieldOf("vert")
+			ResourceLocation.CODEC.fieldOf("source")
-					.forGetter(ProgramSpec::getVert),
+					.forGetter(ProgramSpec::getSource),
-			ResourceLocation.CODEC.fieldOf("frag")
-					.forGetter(ProgramSpec::getFrag),
 			ProgramState.CODEC.listOf()
 					.optionalFieldOf("states", Collections.emptyList())
 					.forGetter(ProgramSpec::getStates))
 			.apply(instance, ProgramSpec::new));
 
 	public ResourceLocation name;
-	public final ResourceLocation vert;
+	public final ResourceLocation source;
-	public final ResourceLocation frag;
 
 	public final List<ProgramState> states;
 
-	public ProgramSpec(ResourceLocation vert, ResourceLocation frag, List<ProgramState> states) {
+	public ProgramSpec(ResourceLocation source, List<ProgramState> states) {
-		this.vert = vert;
+		this.source = source;
-		this.frag = frag;
 		this.states = states;
 	}
 
-	public ProgramSpec(ResourceLocation name, ResourceLocation vert, ResourceLocation frag) {
-		this.name = name;
-		this.vert = vert;
-		this.frag = frag;
-		this.states = new ArrayList<>();
-	}
-
 	public void setName(ResourceLocation name) {
 		this.name = name;
 	}
 
-	public ResourceLocation getVert() {
+	public ResourceLocation getSource() {
-		return vert;
+		return source;
-	}
-
-	public ResourceLocation getFrag() {
-		return frag;
 	}
 
 	public List<ProgramState> getStates() {

src/main/java/com/jozufozu/flywheel/mixin/RenderHooksMixin.java

@@ -95,6 +95,9 @@ public class RenderHooksMixin {
 
 	// Instancing
 
+	/**
+	 * This gets called when a block is marked for rerender by vanilla.
+	 */
 	@Inject(at = @At("TAIL"), method = "setBlockDirty(Lnet/minecraft/util/math/BlockPos;Lnet/minecraft/block/BlockState;Lnet/minecraft/block/BlockState;)V")
 	private void checkUpdate(BlockPos pos, BlockState lastState, BlockState newState, CallbackInfo ci) {
 		InstancedRenderDispatcher.getTiles(level)

src/main/resources/assets/flywheel/flywheel/programs/model.json

@@ -1,6 +1,5 @@
 {
-  "vert": "flywheel:model.vert",
+  "source": "flywheel:model.vert",
-  "frag": "flywheel:block.frag",
   "states": [
     {
       "when": {

src/main/resources/assets/flywheel/flywheel/programs/oriented.json

@@ -1,6 +1,5 @@
 {
-  "vert": "flywheel:oriented.vert",
+  "source": "flywheel:oriented.vert",
-  "frag": "flywheel:block.frag",
   "states": [
     {
       "when": {