refactor: add shader pass and backend variants

engine/include/XCEngine/Resources/Shader/Shader.h

@@ -22,6 +22,13 @@ enum class ShaderLanguage : Core::uint8 {
     SPIRV
 };
 
+enum class ShaderBackend : Core::uint8 {
+    Generic = 0,
+    D3D12,
+    OpenGL,
+    Vulkan
+};
+
 struct ShaderUniform {
     Containers::String name;
     Core::uint32 location;
@@ -36,6 +43,27 @@ struct ShaderAttribute {
     Core::uint32 type;
 };
 
+struct ShaderPassTagEntry {
+    Containers::String name;
+    Containers::String value;
+};
+
+struct ShaderStageVariant {
+    ShaderType stage = ShaderType::Fragment;
+    ShaderLanguage language = ShaderLanguage::GLSL;
+    ShaderBackend backend = ShaderBackend::Generic;
+    Containers::String entryPoint;
+    Containers::String profile;
+    Containers::String sourceCode;
+    Containers::Array<Core::uint8> compiledBinary;
+};
+
+struct ShaderPass {
+    Containers::String name;
+    Containers::Array<ShaderPassTagEntry> tags;
+    Containers::Array<ShaderStageVariant> variants;
+};
+
 class Shader : public IResource {
 public:
     Shader();
@@ -49,10 +77,10 @@ public:
     size_t GetMemorySize() const override { return m_memorySize; }
     void Release() override;
     
-    void SetShaderType(ShaderType type) { m_shaderType = type; }
+    void SetShaderType(ShaderType type);
     ShaderType GetShaderType() const { return m_shaderType; }
     
-    void SetShaderLanguage(ShaderLanguage lang) { m_language = lang; }
+    void SetShaderLanguage(ShaderLanguage lang);
     ShaderLanguage GetShaderLanguage() const { return m_language; }
     
     void SetSourceCode(const Containers::String& source);
@@ -66,11 +94,33 @@ public:
     
     void AddAttribute(const ShaderAttribute& attribute);
     const Containers::Array<ShaderAttribute>& GetAttributes() const { return m_attributes; }
+
+    void AddPass(const ShaderPass& pass);
+    void ClearPasses();
+    Core::uint32 GetPassCount() const { return static_cast<Core::uint32>(m_passes.Size()); }
+    const Containers::Array<ShaderPass>& GetPasses() const { return m_passes; }
+
+    void AddPassVariant(const Containers::String& passName, const ShaderStageVariant& variant);
+    void SetPassTag(
+        const Containers::String& passName,
+        const Containers::String& tagName,
+        const Containers::String& tagValue);
+    bool HasPass(const Containers::String& passName) const;
+    const ShaderPass* FindPass(const Containers::String& passName) const;
+    ShaderPass* FindPass(const Containers::String& passName);
+    const ShaderStageVariant* FindVariant(
+        const Containers::String& passName,
+        ShaderType stage,
+        ShaderBackend backend = ShaderBackend::Generic) const;
     
     class IRHIShader* GetRHIResource() const { return m_rhiResource; }
     void SetRHIResource(class IRHIShader* resource);
 
 private:
+    ShaderPass& GetOrCreatePass(const Containers::String& passName);
+    ShaderStageVariant& GetOrCreateLegacyVariant();
+    void SyncLegacyVariant();
+
     ShaderType m_shaderType = ShaderType::Fragment;
     ShaderLanguage m_language = ShaderLanguage::GLSL;
     
@@ -79,6 +129,7 @@ private:
     
     Containers::Array<ShaderUniform> m_uniforms;
     Containers::Array<ShaderAttribute> m_attributes;
+    Containers::Array<ShaderPass> m_passes;
     
     class IRHIShader* m_rhiResource = nullptr;
 };