Willing and able

- Refine capabilities checks
- To compile with glsl 150:
  - Instancing needs ARB_shader_bit_encoding
  - Indirect needs gpu_shader5 and shading_language_420pack
- Require extensions instead of just enable, probably doesn't make a
  difference since we check for their presence first but require aligns
  with our intent better

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

@@ -54,6 +54,12 @@ public class IndirectPrograms extends AtomicReferenceCounted {
 
 	private static List<String> getExtensions(GlslVersion glslVersion) {
 		List<String> extensions = new ArrayList<>();
+		if (glslVersion.compareTo(GlslVersion.V400) < 0) {
+			extensions.add("GL_ARB_gpu_shader5");
+		}
+		if (glslVersion.compareTo(GlslVersion.V420) < 0) {
+			extensions.add("GL_ARB_shading_language_420pack");
+		}
 		if (glslVersion.compareTo(GlslVersion.V430) < 0) {
 			extensions.add("GL_ARB_shader_storage_buffer_object");
 		}
@@ -105,8 +111,8 @@ public class IndirectPrograms extends AtomicReferenceCounted {
 		return CULL.program()
 				.link(CULL.shader(GlCompat.MAX_GLSL_VERSION, ShaderType.COMPUTE)
 						.nameMapper(instanceType -> "culling/" + ResourceUtil.toDebugFileNameNoExtension(instanceType.cullShader()))
-						.enableExtensions(EXTENSIONS)
+						.requireExtensions(EXTENSIONS)
-						.enableExtensions(COMPUTE_EXTENSIONS)
+						.requireExtensions(COMPUTE_EXTENSIONS)
 						.define("_FLW_SUBGROUP_SIZE", GlCompat.SUBGROUP_SIZE)
 						.withResource(CULL_SHADER_API_IMPL)
 						.withComponent(InstanceStructComponent::new)
@@ -127,8 +133,8 @@ public class IndirectPrograms extends AtomicReferenceCounted {
 		return UTIL.program()
 				.link(UTIL.shader(GlCompat.MAX_GLSL_VERSION, ShaderType.COMPUTE)
 						.nameMapper(resourceLocation -> "utilities/" + ResourceUtil.toDebugFileNameNoExtension(resourceLocation))
-						.enableExtensions(EXTENSIONS)
+						.requireExtensions(EXTENSIONS)
-						.enableExtensions(COMPUTE_EXTENSIONS)
+						.requireExtensions(COMPUTE_EXTENSIONS)
 						.define("_FLW_SUBGROUP_SIZE", GlCompat.SUBGROUP_SIZE)
 						.withResource(s -> s))
 				.harness("utilities", sources);

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

@@ -1,5 +1,6 @@
 package com.jozufozu.flywheel.backend.compile;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 
@@ -9,11 +10,14 @@ import com.google.common.collect.ImmutableList;
 import com.jozufozu.flywheel.api.instance.InstanceType;
 import com.jozufozu.flywheel.backend.gl.GlCompat;
 import com.jozufozu.flywheel.backend.gl.shader.GlProgram;
+import com.jozufozu.flywheel.backend.glsl.GlslVersion;
 import com.jozufozu.flywheel.backend.glsl.ShaderSources;
 import com.jozufozu.flywheel.backend.glsl.SourceComponent;
 import com.jozufozu.flywheel.backend.util.AtomicReferenceCounted;
 
 public class InstancingPrograms extends AtomicReferenceCounted {
+	private static final List<String> EXTENSIONS = getExtensions(GlCompat.MAX_GLSL_VERSION);
+
 	@Nullable
 	private static InstancingPrograms instance;
 
@@ -23,6 +27,14 @@ public class InstancingPrograms extends AtomicReferenceCounted {
 		this.pipeline = pipeline;
 	}
 
+	private static List<String> getExtensions(GlslVersion glslVersion) {
+		List<String> extensions = new ArrayList<>();
+		if (glslVersion.compareTo(GlslVersion.V330) < 0) {
+			extensions.add("GL_ARB_shader_bit_encoding");
+		}
+		return extensions;
+	}
+
 	static void reload(ShaderSources sources, ImmutableList<PipelineProgramKey> pipelineKeys, List<SourceComponent> vertexComponents, List<SourceComponent> fragmentComponents) {
 		if (!GlCompat.SUPPORTS_INSTANCING) {
 			return;
@@ -30,7 +42,7 @@ public class InstancingPrograms extends AtomicReferenceCounted {
 
 		InstancingPrograms newInstance = null;
 
-		var pipelineCompiler = PipelineCompiler.create(sources, Pipelines.INSTANCING, vertexComponents, fragmentComponents);
+		var pipelineCompiler = PipelineCompiler.create(sources, Pipelines.INSTANCING, vertexComponents, fragmentComponents, EXTENSIONS);
 
 		try {
 			var pipelineResult = pipelineCompiler.compileAndReportErrors(pipelineKeys);

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

@@ -37,7 +37,7 @@ public final class PipelineCompiler {
 									.nameLowerCase();
 							return "pipeline/" + pipeline.compilerMarker() + "/" + instance + "_" + context;
 						})
-						.enableExtensions(extensions)
+						.requireExtensions(extensions)
 						.onCompile((key, comp) -> key.contextShader()
 								.onCompile(comp))
 						.withResource(API_IMPL_VERT)
@@ -55,7 +55,7 @@ public final class PipelineCompiler {
 									.nameLowerCase();
 							return "pipeline/" + pipeline.compilerMarker() + "/" + context;
 						})
-						.enableExtensions(extensions)
+						.requireExtensions(extensions)
 						.enableExtension("GL_ARB_conservative_depth")
 						.onCompile((key, comp) -> key.contextShader()
 								.onCompile(comp))
@@ -91,8 +91,4 @@ public final class PipelineCompiler {
 				})
 				.harness(pipeline.compilerMarker(), sources);
 	}
-
-	static CompilationHarness<PipelineProgramKey> create(ShaderSources sources, Pipeline pipeline, List<SourceComponent> vertexComponents, List<SourceComponent> fragmentComponents) {
-		return create(sources, pipeline, vertexComponents, fragmentComponents, Collections.emptyList());
-	}
 }

common/src/backend/java/com/jozufozu/flywheel/backend/compile/core/Compilation.java

@@ -64,6 +64,12 @@ public class Compilation {
 				.append(" : enable\n");
 	}
 
+	public void requireExtension(String ext) {
+		fullSource.append("#extension ")
+				.append(ext)
+				.append(" : require\n");
+	}
+
 	public void define(String key, String value) {
 		fullSource.append("#define ")
 				.append(key)

common/src/backend/java/com/jozufozu/flywheel/backend/compile/core/Compile.java

@@ -113,6 +113,14 @@ public class Compile<K> {
 			});
 		}
 
+		public ShaderCompiler<K> requireExtensions(Collection<String> extensions) {
+			return onCompile(($, ctx) -> {
+				for (String extension : extensions) {
+					ctx.requireExtension(extension);
+				}
+			});
+		}
+
 		@Nullable
 		private GlShader compile(K key, ShaderCache compiler, SourceLoader loader) {
 			var components = new ArrayList<SourceComponent>();

common/src/backend/java/com/jozufozu/flywheel/backend/gl/GlCompat.java

@@ -111,25 +111,24 @@ public final class GlCompat {
 	}
 
 	private static boolean isInstancingSupported() {
-		if (!CAPABILITIES.OpenGL33) {
+		if (CAPABILITIES.OpenGL33) {
-			return false;
+			return true;
 		}
-		return true;
+		return CAPABILITIES.GL_ARB_shader_bit_encoding;
 	}
 
 	private static boolean isIndirectSupported() {
-		// The GL requirement cannot be lower because GL_ARB_compute_shader requires at least GL 4.2.
-		if (!CAPABILITIES.OpenGL42) {
-			return false;
-		}
 		if (CAPABILITIES.OpenGL46) {
 			return true;
 		}
 		return CAPABILITIES.GL_ARB_compute_shader
 				&& CAPABILITIES.GL_ARB_direct_state_access
+				&& CAPABILITIES.GL_ARB_gpu_shader5
 				&& CAPABILITIES.GL_ARB_multi_bind
 				&& CAPABILITIES.GL_ARB_multi_draw_indirect
 				&& CAPABILITIES.GL_ARB_shader_draw_parameters
-				&& CAPABILITIES.GL_ARB_shader_storage_buffer_object;
+				&& CAPABILITIES.GL_ARB_shader_storage_buffer_object
+				&& CAPABILITIES.GL_ARB_shading_language_420pack
+				&& CAPABILITIES.GL_ARB_vertex_attrib_binding;
 	}
 }