More loading tweaks

- Immutable function map
 - Parse #use directives on load
 - Recursive include gathering
 - More sane spec loading in WorldContext
 - StateSensitiveMultiProgram builder
 - Rename confusing game state things

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

@@ -133,10 +133,12 @@ public class ShaderSources implements ISelectiveResourceReloadListener {
 		}
 	}
 
+	@Deprecated
 	public void notifyError() {
 		shouldCrash = true;
 	}
 
+	@Deprecated
 	@Nonnull
 	public String getShaderSource(ResourceLocation loc) {
 		String source = shaderSource.get(loc);
@@ -172,12 +174,19 @@ public class ShaderSources implements ISelectiveResourceReloadListener {
 		}
 	}
 
+	@Deprecated
 	public Shader source(ResourceLocation name, ShaderType type) {
 		return new Shader(this, type, name, getShaderSource(name));
 	}
 
-	public static Stream<String> lines(String s) {
-		return new BufferedReader(new StringReader(s)).lines();
+	public SourceFile source(ResourceLocation name) {
+		SourceFile source = shaderSources.get(name);
+
+		if (source == null) {
+			throw new ShaderLoadingException(String.format("shader '%s' does not exist", name));
+		}
+
+		return source;
 	}
 
 	public String readToString(InputStream is) {

src/main/java/com/jozufozu/flywheel/backend/gl/buffer/GlBufferUsage.java

@@ -2,6 +2,10 @@ package com.jozufozu.flywheel.backend.gl.buffer;
 
 import org.lwjgl.opengl.GL15;
 
+/**
+ * Gives a hint to the driver about how you intend to use a buffer. For a detailed explanation, see
+ * <a href="https://www.khronos.org/opengl/wiki/Buffer_Object#Buffer_Object_Usage">this article</a>.
+ */
 public enum GlBufferUsage {
 	STREAM_DRAW(GL15.GL_STREAM_DRAW),
 	STREAM_READ(GL15.GL_STREAM_READ),

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

@@ -0,0 +1,44 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.Stack;
+
+import com.google.common.collect.ImmutableList;
+import com.jozufozu.flywheel.backend.ShaderSources;
+
+import net.minecraft.util.ResourceLocation;
+
+public class Includer {
+
+	public static List<SourceFile> recurseIncludes(SourceFile from) {
+		ShaderSources sources = from.getParent();
+
+		Set<ResourceLocation> seen = new HashSet<>();
+
+		seen.add(from.name);
+
+		List<SourceFile> out = new ArrayList<>();
+
+		process(sources, seen, out, from);
+
+		return out;
+	}
+
+	private static void process(ShaderSources sources, Set<ResourceLocation> seen, List<SourceFile> out, SourceFile source) {
+		ImmutableList<ResourceLocation> includes = source.getIncludes();
+
+		for (ResourceLocation include : includes) {
+
+			if (seen.add(include)) {
+				SourceFile file = sources.source(include);
+
+				process(sources, seen, out, file);
+
+				out.add(file);
+			}
+		}
+	}
+}

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

@@ -0,0 +1,24 @@
+package com.jozufozu.flywheel.backend.pipeline;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+public class PipelineProgramBuilder {
+
+	private final List<SourceFile> sources = new ArrayList<>();
+
+	public PipelineProgramBuilder() {
+
+	}
+
+	public PipelineProgramBuilder include(SourceFile file) {
+		sources.add(file);
+		return this;
+	}
+
+	public PipelineProgramBuilder includeAll(Collection<? extends SourceFile> files) {
+		sources.addAll(files);
+		return this;
+	}
+}

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

@@ -2,12 +2,17 @@ package com.jozufozu.flywheel.backend.pipeline;
 
 import java.io.BufferedReader;
 import java.io.StringReader;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import java.util.stream.Stream;
 
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.jozufozu.flywheel.backend.ShaderSources;
 import com.jozufozu.flywheel.backend.pipeline.parse.ShaderFunction;
 import com.jozufozu.flywheel.backend.pipeline.span.ErrorSpan;
@@ -27,25 +32,63 @@ public class SourceFile {
 
 	public final ResourceLocation name;
 	private final String source;
-	private final ShaderSources loader;
+	private final ShaderSources parent;
 
-	private final Map<String, ShaderFunction> functions = new HashMap<>();
+	// function name -> function object
+	private final ImmutableMap<String, ShaderFunction> functions;
+	private final ImmutableList<ResourceLocation> includes;
 
-	public SourceFile(ShaderSources loader, ResourceLocation name, String source) {
-		this.loader = loader;
+	// Sections of the source that must be trimmed for compilation.
+	private final List<Span> elisions = new ArrayList<>();
+
+	public SourceFile(ShaderSources parent, ResourceLocation name, String source) {
+		this.parent = parent;
 		this.name = name;
 		this.source = source;
 
-		parseFunctions();
+		functions = parseFunctions();
+		includes = parseIncludes();
 	}
 
 	public String getSource() {
 		return source;
 	}
 
-	protected void parseFunctions() {
+	public ShaderSources getParent() {
+		return parent;
+	}
+
+	public ImmutableMap<String, ShaderFunction> getFunctions() {
+		return functions;
+	}
+
+	public ImmutableList<ResourceLocation> getIncludes() {
+		return includes;
+	}
+
+	private ImmutableList<ResourceLocation> parseIncludes() {
+		Matcher uses = includePattern.matcher(source);
+
+		List<ResourceLocation> includes = new ArrayList<>();
+
+		while (uses.find()) {
+			Span use = Span.fromMatcher(this, uses);
+
+			elisions.add(use); // we have to trim that later
+
+			ResourceLocation loc = new ResourceLocation(uses.group(1)); // TODO: error gracefully
+
+			includes.add(loc);
+		}
+
+		return ImmutableList.copyOf(includes);
+	}
+
+	private ImmutableMap<String, ShaderFunction> parseFunctions() {
 		Matcher matcher = functionDeclaration.matcher(source);
 
+		Map<String, ShaderFunction> functions = new HashMap<>();
+
 		while (matcher.find()) {
 			Span type = Span.fromMatcher(this, matcher, 1);
 			Span name = Span.fromMatcher(this, matcher, 2);
@@ -68,6 +111,8 @@ public class SourceFile {
 
 			functions.put(name.get(), function);
 		}
+
+		return ImmutableMap.copyOf(functions);
 	}
 
 	private int findEndOfBlock(int end) {

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

@@ -1,5 +1,7 @@
 package com.jozufozu.flywheel.backend.pipeline;
 
+import java.util.List;
+
 import javax.annotation.Nullable;
 
 import com.jozufozu.flywheel.core.shader.IMultiProgram;
@@ -8,7 +10,14 @@ import com.jozufozu.flywheel.core.shader.WorldProgram;
 public class WorldShaderPipeline<P extends WorldProgram> {
 
 	@Nullable // TODO: temporary null return
-	public IMultiProgram<P> compile(SourceFile file) {
+	public P compile(SourceFile file) {
+
+		PipelineProgramBuilder builder = new PipelineProgramBuilder();
+
+		builder.includeAll(Includer.recurseIncludes(file));
+
+		builder.include(file);
+
 
 		return null;
 	}

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

@@ -23,6 +23,8 @@ import com.jozufozu.flywheel.backend.loading.ShaderTransformer;
 import com.jozufozu.flywheel.core.shader.ExtensibleGlProgram;
 import com.jozufozu.flywheel.core.shader.StateSensitiveMultiProgram;
 import com.jozufozu.flywheel.core.shader.WorldProgram;
+import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
+import com.jozufozu.flywheel.core.shader.spec.ProgramState;
 import com.jozufozu.flywheel.util.WorldAttached;
 
 import net.minecraft.util.ResourceLocation;
@@ -109,17 +111,7 @@ public class WorldContext<P extends WorldProgram> extends ShaderContext<P> {
 
 		specStream.get()
 				.map(backend::getSpec)
-				.forEach(spec -> {
-
-					try {
-						programs.put(spec.name, new StateSensitiveMultiProgram<>(factory, this, spec));
-
-						Backend.log.debug("Loaded program {}", spec.name);
-					} catch (Exception e) {
-						Backend.log.error("Program '{}': {}", spec.name, e);
-						backend.sources.notifyError();
-					}
-				});
+				.forEach(this::loadSpec);
 	}
 
 	@Override
@@ -154,6 +146,26 @@ public class WorldContext<P extends WorldProgram> extends ShaderContext<P> {
 			throw new ShaderLoadingException(String.format("%s is missing %s, cannot use in World Context", shader.type.name, declaration));
 	}
 
+	private void loadSpec(ProgramSpec spec) {
+
+		try {
+			StateSensitiveMultiProgram.Builder<P> builder = new StateSensitiveMultiProgram.Builder<>(factory.create(loadAndLink(spec, null)));
+
+			for (ProgramState state : spec.states) {
+				Program variant = loadAndLink(spec, state);
+
+				builder.withVariant(state.getContext(), factory.create(variant, state.getExtensions()));
+			}
+
+			programs.put(spec.name, builder.build());
+
+			Backend.log.debug("Loaded program {}", spec.name);
+		} catch (Exception e) {
+			Backend.log.error("Program '{}': {}", spec.name, e);
+			backend.sources.notifyError();
+		}
+	}
+
 	public interface TemplateFactory {
 		ProgramTemplate create(ShaderSources loader);
 	}

src/main/java/com/jozufozu/flywheel/core/shader/StateSensitiveMultiProgram.java

@@ -3,39 +3,26 @@ package com.jozufozu.flywheel.core.shader;
 import java.util.ArrayList;
 import java.util.List;
 
-import com.jozufozu.flywheel.backend.ShaderContext;
+import com.google.common.collect.ImmutableList;
 import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
-import com.jozufozu.flywheel.backend.loading.Program;
-import com.jozufozu.flywheel.core.shader.spec.IContextCondition;
-import com.jozufozu.flywheel.core.shader.spec.ProgramSpec;
-import com.jozufozu.flywheel.core.shader.spec.ProgramState;
+import com.jozufozu.flywheel.core.shader.spec.IGameStateCondition;
 import com.jozufozu.flywheel.util.Pair;
 
 public class StateSensitiveMultiProgram<P extends GlProgram> implements IMultiProgram<P> {
 
-	List<Pair<IContextCondition, P>> variants;
-	P fallback;
+	private final List<Pair<IGameStateCondition, P>> variants;
+	private final P fallback;
 
-	public StateSensitiveMultiProgram(ExtensibleGlProgram.Factory<P> factory, ShaderContext<P> context, ProgramSpec p) {
-		variants = new ArrayList<>(p.states.size());
-
-		for (ProgramState state : p.states) {
-
-			Program variant = context.loadAndLink(p, state);
-
-			Pair<IContextCondition, P> pair = Pair.of(state.getContext(), factory.create(variant, state.getExtensions()));
-
-			variants.add(pair);
-		}
-
-		fallback = factory.create(context.loadAndLink(p, null));
+	protected StateSensitiveMultiProgram(List<Pair<IGameStateCondition, P>> variants, P fallback) {
+		this.variants = variants;
+		this.fallback = fallback;
 	}
 
 	@Override
 	public P get() {
-		for (Pair<IContextCondition, P> variant : variants) {
+		for (Pair<IGameStateCondition, P> variant : variants) {
 			if (variant.getFirst()
-					.get()) return variant.getSecond();
+					.isMet()) return variant.getSecond();
 		}
 
 		return fallback;
@@ -43,11 +30,29 @@ public class StateSensitiveMultiProgram<P extends GlProgram> implements IMultiPr
 
 	@Override
 	public void delete() {
-		for (Pair<IContextCondition, P> variant : variants) {
+		for (Pair<IGameStateCondition, P> variant : variants) {
 			variant.getSecond()
 					.delete();
 		}
 
 		fallback.delete();
 	}
+
+	public static class Builder<P extends GlProgram> {
+		private final P fallback;
+		private final List<Pair<IGameStateCondition, P>> variants = new ArrayList<>();
+
+		public Builder(P fallback) {
+			this.fallback = fallback;
+		}
+
+		public Builder<P> withVariant(IGameStateCondition condition, P program) {
+			variants.add(Pair.of(condition, program));
+			return this;
+		}
+
+		public IMultiProgram<P> build() {
+			return new StateSensitiveMultiProgram<>(ImmutableList.copyOf(variants), fallback);
+		}
+	}
 }

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

@@ -5,18 +5,18 @@ import com.mojang.serialization.Codec;
 
 import net.minecraft.util.ResourceLocation;
 
-public class BooleanContextCondition implements IContextCondition {
+public class BooleanGameStateCondition implements IGameStateCondition {
 
-	public static final Codec<BooleanContextCondition> BOOLEAN_SUGAR = IGameStateProvider.CODEC.xmap(gameContext -> {
+	public static final Codec<BooleanGameStateCondition> BOOLEAN_SUGAR = IGameStateProvider.CODEC.xmap(gameContext -> {
 		if (gameContext instanceof IBooleanStateProvider) {
-			return new BooleanContextCondition(((IBooleanStateProvider) gameContext));
+			return new BooleanGameStateCondition(((IBooleanStateProvider) gameContext));
 		}
 
 		return null;
-	}, IContextCondition::contextProvider);
+	}, IGameStateCondition::getStateProvider);
 	protected final IBooleanStateProvider context;
 
-	public BooleanContextCondition(IBooleanStateProvider context) {
+	public BooleanGameStateCondition(IBooleanStateProvider context) {
 		this.context = context;
 	}
 
@@ -26,12 +26,12 @@ public class BooleanContextCondition implements IContextCondition {
 	}
 
 	@Override
-	public IGameStateProvider contextProvider() {
+	public IGameStateProvider getStateProvider() {
 		return context;
 	}
 
 	@Override
-	public boolean get() {
+	public boolean isMet() {
 		return context.isTrue();
 	}
 }

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

@@ -4,11 +4,11 @@ import com.jozufozu.flywheel.core.shader.gamestate.IGameStateProvider;
 
 import net.minecraft.util.ResourceLocation;
 
-public interface IContextCondition {
+public interface IGameStateCondition {
 
 	ResourceLocation getID();
 
-	IGameStateProvider contextProvider();
+	IGameStateProvider getStateProvider();
 
-	boolean get();
+	boolean isMet();
 }

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

@@ -13,10 +13,10 @@ import com.mojang.serialization.codecs.RecordCodecBuilder;
 public class ProgramState {
 
 	// TODO: Use Codec.dispatch
-	private static final Codec<IContextCondition> WHEN = Codec.either(BooleanContextCondition.BOOLEAN_SUGAR, SpecificValueCondition.CODEC)
+	private static final Codec<IGameStateCondition> WHEN = Codec.either(BooleanGameStateCondition.BOOLEAN_SUGAR, SpecificValueCondition.CODEC)
 			.flatXmap(either -> either.map(DataResult::success, DataResult::success), any -> {
-				if (any instanceof BooleanContextCondition) {
-					return DataResult.success(Either.left((BooleanContextCondition) any));
+				if (any instanceof BooleanGameStateCondition) {
+					return DataResult.success(Either.left((BooleanGameStateCondition) any));
 				}
 
 				if (any instanceof SpecificValueCondition) {
@@ -27,24 +27,24 @@ public class ProgramState {
 			});
 
 	public static final Codec<ProgramState> CODEC = RecordCodecBuilder.create(state -> state.group(WHEN.fieldOf("when")
-																										   .forGetter(ProgramState::getContext), CodecUtil.oneOrMore(Codec.STRING)
-																										   .optionalFieldOf("define", Collections.emptyList())
-																										   .forGetter(ProgramState::getDefines), CodecUtil.oneOrMore(IProgramExtension.CODEC)
-																										   .optionalFieldOf("extend", Collections.emptyList())
-																										   .forGetter(ProgramState::getExtensions))
+			.forGetter(ProgramState::getContext), CodecUtil.oneOrMore(Codec.STRING)
+			.optionalFieldOf("define", Collections.emptyList())
+			.forGetter(ProgramState::getDefines), CodecUtil.oneOrMore(IProgramExtension.CODEC)
+			.optionalFieldOf("extend", Collections.emptyList())
+			.forGetter(ProgramState::getExtensions))
 			.apply(state, ProgramState::new));
 
-	private final IContextCondition context;
+	private final IGameStateCondition context;
 	private final List<String> defines;
 	private final List<IProgramExtension> extensions;
 
-	public ProgramState(IContextCondition context, List<String> defines, List<IProgramExtension> extensions) {
+	public ProgramState(IGameStateCondition context, List<String> defines, List<IProgramExtension> extensions) {
 		this.context = context;
 		this.defines = defines;
 		this.extensions = extensions;
 	}
 
-	public IContextCondition getContext() {
+	public IGameStateCondition getContext() {
 		return context;
 	}
 

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

@@ -6,10 +6,10 @@ import com.mojang.serialization.codecs.RecordCodecBuilder;
 
 import net.minecraft.util.ResourceLocation;
 
-public class SpecificValueCondition implements IContextCondition {
+public class SpecificValueCondition implements IGameStateCondition {
 
 	public static final Codec<SpecificValueCondition> CODEC = RecordCodecBuilder.create(condition -> condition.group(IGameStateProvider.CODEC.fieldOf("provider")
-																															 .forGetter(SpecificValueCondition::contextProvider), Codec.STRING.fieldOf("value")
+																															 .forGetter(SpecificValueCondition::getStateProvider), Codec.STRING.fieldOf("value")
 																															 .forGetter(SpecificValueCondition::getValue))
 			.apply(condition, SpecificValueCondition::new));
 
@@ -31,12 +31,12 @@ public class SpecificValueCondition implements IContextCondition {
 	}
 
 	@Override
-	public IGameStateProvider contextProvider() {
+	public IGameStateProvider getStateProvider() {
 		return context;
 	}
 
 	@Override
-	public boolean get() {
+	public boolean isMet() {
 		return required.equals(context.getValue()
 									   .toString());
 	}