refactor: formalize builtin pass matching

engine/include/XCEngine/Rendering/RenderMaterialUtility.h

@@ -11,11 +11,20 @@ namespace XCEngine {
 namespace Rendering {
 
 enum class BuiltinMaterialPass : Core::uint32 {
-    Forward = 0
+    ForwardLit = 0,
+    Unlit,
+    DepthOnly,
+    ShadowCaster,
+    ObjectId,
+    Forward = ForwardLit
 };
 
+inline Containers::String NormalizeBuiltinPassMetadataValue(const Containers::String& value) {
+    return value.Trim().ToLower();
+}
+
 inline bool IsForwardPassName(const Containers::String& value) {
-    const Containers::String normalized = value.Trim().ToLower();
+    const Containers::String normalized = NormalizeBuiltinPassMetadataValue(value);
     return normalized.Empty() ||
            normalized == Containers::String("forward") ||
            normalized == Containers::String("forwardbase") ||
@@ -23,6 +32,92 @@ inline bool IsForwardPassName(const Containers::String& value) {
            normalized == Containers::String("forwardonly");
 }
 
+inline bool IsUnlitPassName(const Containers::String& value) {
+    const Containers::String normalized = NormalizeBuiltinPassMetadataValue(value);
+    return normalized == Containers::String("unlit") ||
+           normalized == Containers::String("forwardunlit") ||
+           normalized == Containers::String("srpdefaultunlit");
+}
+
+inline bool IsDepthOnlyPassName(const Containers::String& value) {
+    const Containers::String normalized = NormalizeBuiltinPassMetadataValue(value);
+    return normalized == Containers::String("depthonly") ||
+           normalized == Containers::String("depth");
+}
+
+inline bool IsShadowCasterPassName(const Containers::String& value) {
+    const Containers::String normalized = NormalizeBuiltinPassMetadataValue(value);
+    return normalized == Containers::String("shadowcaster") ||
+           normalized == Containers::String("shadow");
+}
+
+inline bool IsObjectIdPassName(const Containers::String& value) {
+    const Containers::String normalized = value.Trim().ToLower();
+    return normalized == Containers::String("objectid") ||
+           normalized == Containers::String("editorobjectid");
+}
+
+inline bool MatchesBuiltinPassName(
+    const Containers::String& value,
+    BuiltinMaterialPass pass) {
+    switch (pass) {
+    case BuiltinMaterialPass::ForwardLit:
+        return IsForwardPassName(value);
+    case BuiltinMaterialPass::Unlit:
+        return IsUnlitPassName(value);
+    case BuiltinMaterialPass::DepthOnly:
+        return IsDepthOnlyPassName(value);
+    case BuiltinMaterialPass::ShadowCaster:
+        return IsShadowCasterPassName(value);
+    case BuiltinMaterialPass::ObjectId:
+        return IsObjectIdPassName(value);
+    default:
+        return false;
+    }
+}
+
+inline bool ShaderPassHasExplicitBuiltinMetadata(const Resources::ShaderPass& shaderPass) {
+    if (!shaderPass.name.Empty() &&
+        shaderPass.name != Containers::String("Default")) {
+        return true;
+    }
+
+    for (const Resources::ShaderPassTagEntry& tag : shaderPass.tags) {
+        if (NormalizeBuiltinPassMetadataValue(tag.name) == Containers::String("lightmode")) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+inline bool ShaderPassMatchesBuiltinPass(
+    const Resources::ShaderPass& shaderPass,
+    BuiltinMaterialPass pass) {
+    bool hasMetadata = false;
+
+    if (!shaderPass.name.Empty() &&
+        shaderPass.name != Containers::String("Default")) {
+        hasMetadata = true;
+        if (!MatchesBuiltinPassName(shaderPass.name, pass)) {
+            return false;
+        }
+    }
+
+    for (const Resources::ShaderPassTagEntry& tag : shaderPass.tags) {
+        if (NormalizeBuiltinPassMetadataValue(tag.name) != Containers::String("lightmode")) {
+            continue;
+        }
+
+        hasMetadata = true;
+        if (!MatchesBuiltinPassName(tag.value, pass)) {
+            return false;
+        }
+    }
+
+    return hasMetadata;
+}
+
 inline const Resources::Material* ResolveMaterial(
     const Components::MeshRendererComponent* meshRenderer,
     const Resources::Mesh* mesh,
@@ -72,28 +167,46 @@ inline bool IsTransparentRenderQueue(Core::int32 renderQueue) {
 
 inline bool MatchesBuiltinPass(const Resources::Material* material, BuiltinMaterialPass pass) {
     if (material == nullptr) {
-        return true;
+        return pass == BuiltinMaterialPass::ForwardLit;
     }
 
-    switch (pass) {
-    case BuiltinMaterialPass::Forward: {
     const Containers::String shaderPass = material->GetShaderPass();
-        if (!shaderPass.Empty() && !IsForwardPassName(shaderPass)) {
-            return false;
-        }
-
     const Containers::String lightMode = material->GetTag("LightMode");
-        if (!lightMode.Empty() && !IsForwardPassName(lightMode)) {
+    const bool hasMaterialShaderPass = !NormalizeBuiltinPassMetadataValue(shaderPass).Empty();
+    const bool hasMaterialLightMode = !NormalizeBuiltinPassMetadataValue(lightMode).Empty();
+    if (hasMaterialShaderPass || hasMaterialLightMode) {
+        if (hasMaterialShaderPass &&
+            !MatchesBuiltinPassName(shaderPass, pass)) {
             return false;
         }
+        if (hasMaterialLightMode &&
+            !MatchesBuiltinPassName(lightMode, pass)) {
+            return false;
+        }
+        return true;
+    }
 
+    const Resources::Shader* shader = material->GetShader();
+    if (shader != nullptr) {
+        bool shaderHasExplicitBuiltinMetadata = false;
+        for (const Resources::ShaderPass& shaderPassEntry : shader->GetPasses()) {
+            if (ShaderPassMatchesBuiltinPass(shaderPassEntry, pass)) {
                 return true;
             }
-    default:
-        return true;
+
+            if (ShaderPassHasExplicitBuiltinMetadata(shaderPassEntry)) {
+                shaderHasExplicitBuiltinMetadata = true;
             }
         }
 
+        if (shaderHasExplicitBuiltinMetadata) {
+            return false;
+        }
+    }
+
+    return pass == BuiltinMaterialPass::ForwardLit;
+}
+
 inline RHI::CullMode ToRHICullMode(Resources::MaterialCullMode mode) {
     switch (mode) {
     case Resources::MaterialCullMode::Front:

engine/src/Rendering/Pipelines/BuiltinForwardPipeline.cpp

@@ -439,7 +439,7 @@ bool BuiltinForwardPipeline::ExecuteForwardOpaquePass(const RenderPassContext& p
     RHI::RHIPipelineState* currentPipelineState = nullptr;
     for (const VisibleRenderItem& visibleItem : sceneData.visibleItems) {
         const Resources::Material* material = ResolveMaterial(visibleItem);
-        if (!MatchesBuiltinPass(material, BuiltinMaterialPass::Forward)) {
+        if (!MatchesBuiltinPass(material, BuiltinMaterialPass::ForwardLit)) {
             continue;
         }
 

tests/Rendering/unit/test_render_scene_extractor.cpp

@@ -13,6 +13,7 @@
 #include <XCEngine/Rendering/RenderSceneExtractor.h>
 #include <XCEngine/Resources/Material/Material.h>
 #include <XCEngine/Resources/Mesh/Mesh.h>
+#include <XCEngine/Resources/Shader/Shader.h>
 #include <XCEngine/Scene/Scene.h>
 
 using namespace XCEngine::Components;
@@ -359,22 +360,69 @@ TEST(RenderSceneExtractor_Test, FallsBackToEmbeddedMeshMaterialsWhenRendererHasN
     delete mesh;
 }
 
-TEST(RenderMaterialUtility_Test, MatchesBuiltinForwardPassMetadata) {
+TEST(RenderMaterialUtility_Test, MatchesBuiltinForwardLitPassMetadata) {
     Material forwardMaterial;
     forwardMaterial.SetShaderPass("ForwardLit");
     forwardMaterial.SetTag("LightMode", "ForwardBase");
-    EXPECT_TRUE(MatchesBuiltinPass(&forwardMaterial, BuiltinMaterialPass::Forward));
+    EXPECT_TRUE(MatchesBuiltinPass(&forwardMaterial, BuiltinMaterialPass::ForwardLit));
 
     Material noMetadataMaterial;
-    EXPECT_TRUE(MatchesBuiltinPass(&noMetadataMaterial, BuiltinMaterialPass::Forward));
+    EXPECT_TRUE(MatchesBuiltinPass(&noMetadataMaterial, BuiltinMaterialPass::ForwardLit));
 
     Material shadowMaterial;
     shadowMaterial.SetShaderPass("ShadowCaster");
-    EXPECT_FALSE(MatchesBuiltinPass(&shadowMaterial, BuiltinMaterialPass::Forward));
+    EXPECT_FALSE(MatchesBuiltinPass(&shadowMaterial, BuiltinMaterialPass::ForwardLit));
 
     Material depthOnlyMaterial;
     depthOnlyMaterial.SetTag("LightMode", "DepthOnly");
-    EXPECT_FALSE(MatchesBuiltinPass(&depthOnlyMaterial, BuiltinMaterialPass::Forward));
+    EXPECT_FALSE(MatchesBuiltinPass(&depthOnlyMaterial, BuiltinMaterialPass::ForwardLit));
+}
+
+TEST(RenderMaterialUtility_Test, MatchesBuiltinUnlitDepthAndObjectIdPassMetadata) {
+    Material unlitMaterial;
+    unlitMaterial.SetShaderPass("Unlit");
+    EXPECT_TRUE(MatchesBuiltinPass(&unlitMaterial, BuiltinMaterialPass::Unlit));
+    EXPECT_FALSE(MatchesBuiltinPass(&unlitMaterial, BuiltinMaterialPass::ForwardLit));
+
+    Material depthMaterial;
+    depthMaterial.SetTag("LightMode", "DepthOnly");
+    EXPECT_TRUE(MatchesBuiltinPass(&depthMaterial, BuiltinMaterialPass::DepthOnly));
+    EXPECT_FALSE(MatchesBuiltinPass(&depthMaterial, BuiltinMaterialPass::Unlit));
+
+    Material objectIdMaterial;
+    objectIdMaterial.SetShaderPass("ObjectId");
+    EXPECT_TRUE(MatchesBuiltinPass(&objectIdMaterial, BuiltinMaterialPass::ObjectId));
+    EXPECT_FALSE(MatchesBuiltinPass(&objectIdMaterial, BuiltinMaterialPass::ForwardLit));
+}
+
+TEST(RenderMaterialUtility_Test, ShaderPassMetadataCanDriveBuiltinPassMatching) {
+    Material material;
+    auto* shader = new Shader();
+
+    ShaderPass forwardPass = {};
+    forwardPass.name = "ForwardLit";
+    shader->AddPass(forwardPass);
+
+    ResourceHandle<Shader> shaderHandle(shader);
+    material.SetShader(shaderHandle);
+
+    EXPECT_TRUE(MatchesBuiltinPass(&material, BuiltinMaterialPass::ForwardLit));
+    EXPECT_FALSE(MatchesBuiltinPass(&material, BuiltinMaterialPass::Unlit));
+}
+
+TEST(RenderMaterialUtility_Test, ExplicitShaderPassMetadataDisablesImplicitForwardFallback) {
+    Material material;
+    auto* shader = new Shader();
+
+    ShaderPass unlitPass = {};
+    unlitPass.name = "Unlit";
+    shader->AddPass(unlitPass);
+
+    ResourceHandle<Shader> shaderHandle(shader);
+    material.SetShader(shaderHandle);
+
+    EXPECT_FALSE(MatchesBuiltinPass(&material, BuiltinMaterialPass::ForwardLit));
+    EXPECT_TRUE(MatchesBuiltinPass(&material, BuiltinMaterialPass::Unlit));
 }
 
 TEST(RenderMaterialUtility_Test, MapsMaterialRenderStateToRhiDescriptors) {