Post-post-pre-refactor-refactor actual refactor

- Mark backends as unavailable if their shader compilation failed
- Update command output to notify when a fallback occurs

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

@@ -2,6 +2,8 @@ package com.jozufozu.flywheel.backend;
 
 import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.api.backend.Backend;
+import com.jozufozu.flywheel.backend.compile.IndirectPrograms;
+import com.jozufozu.flywheel.backend.compile.InstancingPrograms;
 import com.jozufozu.flywheel.backend.engine.batching.BatchingEngine;
 import com.jozufozu.flywheel.backend.engine.indirect.IndirectEngine;
 import com.jozufozu.flywheel.backend.engine.instancing.InstancingEngine;
@@ -31,7 +33,7 @@ public class Backends {
 			.engineFactory(level -> new InstancingEngine(256, Contexts.WORLD))
 			.fallback(() -> Backends.BATCHING)
 			.supported(() -> !ShadersModHandler.isShaderPackInUse() && GlCompat.getInstance()
-					.instancedArraysSupported())
+					.instancedArraysSupported() && InstancingPrograms.allLoaded())
 			.register(Flywheel.rl("instancing"));
 
 	/**
@@ -42,7 +44,7 @@ public class Backends {
 			.engineFactory(level -> new IndirectEngine(256))
 			.fallback(() -> Backends.INSTANCING)
 			.supported(() -> !ShadersModHandler.isShaderPackInUse() && GlCompat.getInstance()
-					.supportsIndirect())
+					.supportsIndirect() && IndirectPrograms.allLoaded())
 			.register(Flywheel.rl("indirect"));
 
 	public static void init() {

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

@@ -6,6 +6,7 @@ import java.util.Map;
 import org.jetbrains.annotations.Nullable;
 
 import com.google.common.collect.ImmutableList;
+import com.jozufozu.flywheel.Flywheel;
 import com.jozufozu.flywheel.gl.shader.GlProgram;
 import com.jozufozu.flywheel.glsl.ShaderSources;
 
@@ -28,7 +29,8 @@ public abstract class AbstractCompiler<K> {
 	@Nullable
 	protected abstract GlProgram compile(K key);
 
-	public Map<K, GlProgram> compile() {
+	@Nullable
+	public Map<K, GlProgram> compileAndReportErrors() {
 		stats.start();
 		Map<K, GlProgram> out = new HashMap<>();
 		for (var key : keys) {
@@ -38,6 +40,12 @@ public abstract class AbstractCompiler<K> {
 			}
 		}
 		stats.finish();
+
+		if (stats.errored()) {
+			Flywheel.LOGGER.error(stats.generateErrorLog());
+			return null;
+		}
+
 		return out;
 	}
 

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

@@ -25,15 +25,13 @@ public class CompilerStats {
 		var elapsed = StringUtil.formatTime(compileEnd - compileStart);
 
 		Flywheel.LOGGER.info("Compiled " + shaderCount + " shaders (with " + shaderErrors.size() + " compile errors) " + "and " + programCount + " programs (with " + programErrors.size() + " link errors) in " + elapsed);
-
 	}
 
-	// TODO: use this to turn off backends
 	public boolean errored() {
 		return errored;
 	}
 
-	private String generateLog() {
+	public String generateErrorLog() {
 		return String.join("\n", programErrors) + '\n' + shaderErrors.stream()
 				.map(FailedCompilation::getMessage)
 				.collect(Collectors.joining("\n"));

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

@@ -25,11 +25,18 @@ public class IndirectPrograms {
 	public static void reload(ShaderSources sources, ImmutableList<PipelineProgramKey> pipelineKeys, UniformComponent uniformComponent) {
 		if (instance != null) {
 			instance.delete();
+			instance = null;
 		}
-		var indirectCompiler = new PipelineCompiler(sources, pipelineKeys, Pipelines.INDIRECT, uniformComponent);
+		var pipelineCompiler = new PipelineCompiler(sources, pipelineKeys, Pipelines.INDIRECT, uniformComponent);
 		var cullingCompiler = new CullingCompiler(sources, createCullingKeys(), uniformComponent);
-		instance = new IndirectPrograms(indirectCompiler.compile(), cullingCompiler.compile());
-		indirectCompiler.delete();
+
+		var pipelineResult = pipelineCompiler.compileAndReportErrors();
+		var cullingResult = cullingCompiler.compileAndReportErrors();
+
+		if (pipelineResult != null && cullingResult != null) {
+			instance = new IndirectPrograms(pipelineResult, cullingResult);
+		}
+		pipelineCompiler.delete();
 		cullingCompiler.delete();
 	}
 
@@ -46,6 +53,10 @@ public class IndirectPrograms {
 		return instance;
 	}
 
+	public static boolean allLoaded() {
+		return instance != null;
+	}
+
 	public GlProgram getIndirectProgram(VertexType vertexType, InstanceType<?> instanceType, Context contextShader) {
 		return pipeline.get(new PipelineProgramKey(vertexType, instanceType, contextShader));
 	}

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

@@ -23,9 +23,15 @@ public class InstancingPrograms {
 	public static void reload(ShaderSources sources, ImmutableList<PipelineProgramKey> pipelineKeys, UniformComponent uniformComponent) {
 		if (instance != null) {
 			instance.delete();
+			instance = null;
 		}
 		var instancingCompiler = new PipelineCompiler(sources, pipelineKeys, Pipelines.INSTANCED_ARRAYS, uniformComponent);
-		instance = new InstancingPrograms(instancingCompiler.compile());
+		var result = instancingCompiler.compileAndReportErrors();
+
+		if (result != null) {
+			instance = new InstancingPrograms(result);
+		}
+
 		instancingCompiler.delete();
 	}
 
@@ -34,6 +40,10 @@ public class InstancingPrograms {
 		return instance;
 	}
 
+	public static boolean allLoaded() {
+		return instance != null;
+	}
+
 	public GlProgram get(VertexType vertexType, InstanceType<?> instanceType, Context contextShader) {
 		return pipeline.get(new PipelineProgramKey(vertexType, instanceType, contextShader));
 	}

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

@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.backend.compile;
 
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import com.jozufozu.flywheel.gl.shader.GlProgram;
@@ -8,13 +9,15 @@ public sealed interface LinkResult {
 
 	@Nullable
 	default GlProgram unwrap() {
-		if (this instanceof Success s) {
-			return s.program();
-		}
 		return null;
 	}
 
 	record Success(GlProgram program, String log) implements LinkResult {
+		@Override
+		@NotNull
+		public GlProgram unwrap() {
+			return program;
+		}
 	}
 
 	record Failure(String failure) implements LinkResult {

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

@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.backend.compile;
 
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import com.jozufozu.flywheel.gl.shader.GlShader;
@@ -7,13 +8,15 @@ import com.jozufozu.flywheel.gl.shader.GlShader;
 public sealed interface ShaderResult {
 	@Nullable
 	default GlShader unwrap() {
-		if (this instanceof Success s) {
-			return s.shader();
-		}
 		return null;
 	}
 
 	record Success(GlShader shader, String infoLog) implements ShaderResult {
+		@Override
+		@NotNull
+		public GlShader unwrap() {
+			return shader;
+		}
 	}
 
 	record Failure(FailedCompilation failure) implements ShaderResult {

src/main/java/com/jozufozu/flywheel/config/FlwCommands.java

@@ -3,6 +3,7 @@ package com.jozufozu.flywheel.config;
 import java.util.function.BiConsumer;
 
 import com.jozufozu.flywheel.api.backend.Backend;
+import com.jozufozu.flywheel.api.backend.BackendManager;
 import com.jozufozu.flywheel.lib.uniform.FlwShaderUniforms;
 import com.mojang.brigadier.Command;
 import com.mojang.brigadier.arguments.IntegerArgumentType;
@@ -60,13 +61,25 @@ public class FlwCommands {
 					.executes(context -> {
 						LocalPlayer player = Minecraft.getInstance().player;
 						if (player != null) {
-							Backend backend = context.getArgument("id", Backend.class);
-							value.set(Backend.REGISTRY.getIdOrThrow(backend).toString());
-
-							Component message = backend.engineMessage();
-							player.displayClientMessage(message, false);
+							Backend requestedBackend = context.getArgument("id", Backend.class);
+							var requestedId = Backend.REGISTRY.getIdOrThrow(requestedBackend)
+									.toString();
+							value.set(requestedId);
 
+							// Reload renderers so we can report the backend that we fell back to.
 							Minecraft.getInstance().levelRenderer.allChanged();
+
+							var actualBackend = BackendManager.getBackend();
+							if (actualBackend == null) {
+								player.displayClientMessage(new TextComponent("Error switching backends, flywheel disabled"), false);
+							} else if (actualBackend != requestedBackend) {
+								player.displayClientMessage(new TextComponent("'" + requestedId + "' not available").withStyle(ChatFormatting.RED), false);
+								var component = actualBackend.engineMessage();
+								player.displayClientMessage(component, false);
+							} else {
+								Component message = requestedBackend.engineMessage();
+								player.displayClientMessage(message, false);
+							}
 						}
 						return Command.SINGLE_SUCCESS;
 					})));

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

@@ -80,10 +80,10 @@ public class ShaderSources {
 		if (findStack.contains(location)) {
 			generateRecursiveImportException(location);
 		}
-		findStack.add(location);
+		findStack.addLast(location);
 	}
 
 	private void popFindStack() {
-		findStack.pop();
+		findStack.removeLast();
 	}
 }