feat(RHI): 实现 RHISampler 抽象基类

- 新增 RHISampler 抽象基类
- D3D12Sampler 继承 RHISampler
- OpenGLSampler 继承 RHISampler，使用 OpenGLSamplerDesc
- 文档更新 RHISampler 差异处理策略

engine/include/XCEngine/RHI/D3D12/D3D12Sampler.h

@@ -3,6 +3,7 @@
 #include <d3d12.h>
 #include <wrl/client.h>
 
+#include "../RHISampler.h"
 #include "D3D12Enum.h"
 
 using Microsoft::WRL::ComPtr;
@@ -10,17 +11,21 @@ using Microsoft::WRL::ComPtr;
 namespace XCEngine {
 namespace RHI {
 
-class D3D12Sampler {
+class D3D12Sampler : public RHISampler {
 public:
     D3D12Sampler();
-    ~D3D12Sampler();
+    ~D3D12Sampler() override;
 
     bool Initialize(ID3D12Device* device, const D3D12_SAMPLER_DESC& desc);
-    void Shutdown();
+    void Shutdown() override;
 
     D3D12_SAMPLER_DESC GetDesc() const { return m_desc; }
 
-    void* GetNativeHandle() const { return nullptr; }
+    void* GetNativeHandle() override { return nullptr; }
+    unsigned int GetID() override { return 0; }
+
+    void Bind(unsigned int unit) override { }
+    void Unbind(unsigned int unit) override { }
 
 private:
     D3D12_SAMPLER_DESC m_desc;

engine/include/XCEngine/RHI/OpenGL/OpenGLSampler.h

@@ -2,6 +2,9 @@
 
 #include <GLFW/glfw3.h>
 
+#include "../RHISampler.h"
+#include "../RHITypes.h"
+
 namespace XCEngine {
 namespace RHI {
 
@@ -26,7 +29,7 @@ enum class SamplerCompareMode {
     CompareToRef
 };
 
-struct SamplerDesc {
+struct OpenGLSamplerDesc {
     SamplerFilter minFilter = SamplerFilter::LinearMipmapLinear;
     SamplerFilter magFilter = SamplerFilter::Linear;
     SamplerWrapMode wrapS = SamplerWrapMode::Repeat;
@@ -39,22 +42,24 @@ struct SamplerDesc {
     float maxLod = 1000.0f;
 };
 
-class OpenGLSampler {
+class OpenGLSampler : public RHISampler {
 public:
     OpenGLSampler();
-    ~OpenGLSampler();
+    ~OpenGLSampler() override;
 
-    bool Initialize(const SamplerDesc& desc);
-    void Shutdown();
+    bool Initialize(const OpenGLSamplerDesc& desc);
+    void Shutdown() override;
 
-    void Bind(unsigned int unit);
-    void Unbind(unsigned int unit);
+    void Bind(unsigned int unit) override;
+    void Unbind(unsigned int unit) override;
 
     unsigned int GetID() const { return m_sampler; }
+    unsigned int GetID() override { return m_sampler; }
+    void* GetNativeHandle() override { return reinterpret_cast<void*>(static_cast<uintptr_t>(m_sampler)); }
 
 private:
     unsigned int m_sampler;
-    SamplerDesc m_desc;
+    OpenGLSamplerDesc m_desc;
 };
 
 } // namespace RHI

engine/include/XCEngine/RHI/RHISampler.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include "RHITypes.h"
+#include "RHIEnums.h"
+
+namespace XCEngine {
+namespace RHI {
+
+class RHISampler {
+public:
+    virtual ~RHISampler() = default;
+
+    virtual void Shutdown() = 0;
+
+    virtual void Bind(unsigned int unit) = 0;
+    virtual void Unbind(unsigned int unit) = 0;
+
+    virtual void* GetNativeHandle() = 0;
+    virtual unsigned int GetID() = 0;
+};
+
+} // namespace RHI
+} // namespace XCEngine

engine/src/RHI/OpenGL/OpenGLSampler.cpp

@@ -34,7 +34,7 @@ OpenGLSampler::OpenGLSampler() : m_sampler(0) {
 OpenGLSampler::~OpenGLSampler() {
 }
 
-bool OpenGLSampler::Initialize(const SamplerDesc& desc) {
+bool OpenGLSampler::Initialize(const OpenGLSamplerDesc& desc) {
     m_desc = desc;
     glGenSamplers(1, &m_sampler);