feat: 实现 D3D12Shader 着色器类

- 添加 D3D12Shader.h/cpp
- 支持从文件编译着色器
- 支持从内存编译着色器
- 测试通过

engine/src/RHI/D3D12Shader.cpp

@@ -0,0 +1,70 @@
+#include "XCEngine/RHI/D3D12/D3D12Shader.h"
+#include <d3dcompiler.h>
+
+namespace XCEngine {
+namespace RHI {
+
+D3D12Shader::D3D12Shader()
+    : m_type(ShaderType::Vertex) {
+}
+
+D3D12Shader::~D3D12Shader() {
+    Shutdown();
+}
+
+bool D3D12Shader::CompileFromFile(const wchar_t* filePath, const char* entryPoint, const char* target) {
+    HRESULT hResult = D3DCompileFromFile(filePath, nullptr, nullptr, entryPoint, target,
+        D3DCOMPILE_DEBUG | D3DCOMPILE_SKIP_OPTIMIZATION, 0, &m_bytecode, &m_error);
+
+    if (FAILED(hResult)) {
+        if (m_error) {
+            const char* errorMsg = static_cast<const char*>(m_error->GetBufferPointer());
+            OutputDebugStringA(errorMsg);
+        }
+        return false;
+    }
+
+    if (strstr(target, "vs_")) {
+        m_type = ShaderType::Vertex;
+    } else if (strstr(target, "ps_")) {
+        m_type = ShaderType::Pixel;
+    } else if (strstr(target, "gs_")) {
+        m_type = ShaderType::Geometry;
+    } else if (strstr(target, "cs_")) {
+        m_type = ShaderType::Compute;
+    }
+
+    return true;
+}
+
+bool D3D12Shader::Compile(const void* sourceData, size_t sourceSize, const char* entryPoint, const char* target) {
+    HRESULT hResult = D3DCompile(sourceData, sourceSize, nullptr, nullptr, nullptr, entryPoint, target,
+        D3DCOMPILE_DEBUG | D3DCOMPILE_SKIP_OPTIMIZATION, 0, &m_bytecode, &m_error);
+
+    if (FAILED(hResult)) {
+        if (m_error) {
+            const char* errorMsg = static_cast<const char*>(m_error->GetBufferPointer());
+            OutputDebugStringA(errorMsg);
+        }
+        return false;
+    }
+
+    return true;
+}
+
+void D3D12Shader::Shutdown() {
+    m_bytecode.Reset();
+    m_error.Reset();
+}
+
+const D3D12_SHADER_BYTECODE D3D12Shader::GetBytecode() const {
+    D3D12_SHADER_BYTECODE bytecode = {};
+    if (m_bytecode) {
+        bytecode.pShaderBytecode = m_bytecode->GetBufferPointer();
+        bytecode.BytecodeLength = m_bytecode->GetBufferSize();
+    }
+    return bytecode;
+}
+
+} // namespace RHI
+} // namespace XCEngine