Support compute-only shader authoring variants

engine/src/Resources/Shader/Internal/ShaderAuthoringParserCore.cpp

@@ -298,6 +298,10 @@ bool ParseShaderAuthoring(
                 currentPass->fragmentEntryPoint = pragmaTokens[2].c_str();
                 continue;
             }
+            if (pragmaTokens.size() >= 3u && pragmaTokens[1] == "compute") {
+                currentPass->computeEntryPoint = pragmaTokens[2].c_str();
+                continue;
+            }
             if (pragmaTokens.size() >= 3u && pragmaTokens[1] == "target") {
                 currentPass->targetProfile = pragmaTokens[2].c_str();
                 continue;
@@ -591,10 +595,19 @@ bool ParseShaderAuthoring(
             if (pass.programSource.Empty()) {
                 return fail("a Pass is missing an HLSLPROGRAM block", 0);
             }
-            if (pass.vertexEntryPoint.Empty()) {
+            const bool hasCompute = !pass.computeEntryPoint.Empty();
+            const bool hasVertex = !pass.vertexEntryPoint.Empty();
+            const bool hasFragment = !pass.fragmentEntryPoint.Empty();
+            if (hasCompute && (hasVertex || hasFragment)) {
+                return fail("a Pass must not mix #pragma compute with graphics stage pragmas", 0);
+            }
+            if (hasCompute) {
+                continue;
+            }
+            if (!hasVertex) {
                 return fail("a Pass is missing a #pragma vertex directive", 0);
             }
-            if (pass.fragmentEntryPoint.Empty()) {
+            if (!hasFragment) {
                 return fail("a Pass is missing a #pragma fragment directive", 0);
             }
         }

engine/src/Resources/Shader/Internal/ShaderAuthoringShared.cpp

@@ -87,6 +87,7 @@ bool IsShaderAuthoringPragmaDirective(const std::string& line) {
 
     return pragmaTokens[1] == "vertex" ||
            pragmaTokens[1] == "fragment" ||
+           pragmaTokens[1] == "compute" ||
            pragmaTokens[1] == "target" ||
            pragmaTokens[1] == "multi_compile" ||
            pragmaTokens[1] == "multi_compile_local" ||

engine/src/Resources/Shader/Internal/ShaderRuntimeBuildUtils.cpp

@@ -362,6 +362,25 @@ ShaderPass BuildConcretePass(
         const Containers::String variantSource =
             BuildKeywordVariantSource(strippedCombinedSource, keywordSet);
 
+        if (!pass.computeEntryPoint.Empty()) {
+            ShaderStageVariant computeVariant = {};
+            computeVariant.stage = ShaderType::Compute;
+            computeVariant.backend = ShaderBackend::Generic;
+            computeVariant.language = ShaderLanguage::HLSL;
+            computeVariant.requiredKeywords = keywordSet;
+            computeVariant.entryPoint =
+                !pass.computeEntryPoint.Empty()
+                    ? pass.computeEntryPoint
+                    : GetDefaultEntryPoint(ShaderLanguage::HLSL, ShaderType::Compute);
+            computeVariant.profile = GetDefaultProfile(
+                ShaderLanguage::HLSL,
+                ShaderBackend::Generic,
+                ShaderType::Compute);
+            computeVariant.sourceCode = variantSource;
+            shaderPass.variants.PushBack(computeVariant);
+            continue;
+        }
+
         ShaderStageVariant vertexVariant = {};
         vertexVariant.stage = ShaderType::Vertex;
         vertexVariant.backend = ShaderBackend::Generic;
@@ -535,12 +554,12 @@ Containers::String GetDefaultProfile(
     ShaderType stage) {
     if (language == ShaderLanguage::HLSL) {
         switch (stage) {
-        case ShaderType::Vertex: return "vs_5_0";
-        case ShaderType::Fragment: return "ps_5_0";
-        case ShaderType::Geometry: return "gs_5_0";
-        case ShaderType::Compute: return "cs_5_0";
-        case ShaderType::Hull: return "hs_5_0";
-        case ShaderType::Domain: return "ds_5_0";
+        case ShaderType::Vertex: return "vs_5_1";
+        case ShaderType::Fragment: return "ps_5_1";
+        case ShaderType::Geometry: return "gs_5_1";
+        case ShaderType::Compute: return "cs_5_1";
+        case ShaderType::Hull: return "hs_5_1";
+        case ShaderType::Domain: return "ds_5_1";
         default: return Containers::String();
         }
     }

engine/src/Resources/Shader/ShaderIR.h

@@ -26,6 +26,7 @@ struct ShaderPassIR {
     Containers::Array<ShaderKeywordDeclaration> keywordDeclarations;
     Containers::String vertexEntryPoint;
     Containers::String fragmentEntryPoint;
+    Containers::String computeEntryPoint;
     Containers::String sharedProgramSource;
     Containers::String programSource;
     Containers::String targetProfile;