C++小项目：directx11图形程序（五）：shadersclass

这个类是用来创建着色器并设置输入布局的。

这个类比较特殊，它创建的着色器与Effect文件有关，effect文件是用高级着色语言（hlsl）编写的。

shadersclass.h

 #pragma once
 #include <d3d11.h>
 #include <d3dcompiler.h>
 #include <D3DX11.h>
 #include <xnamath.h>

 #pragma comment(lib,"d3dx11.lib")
 #pragma comment(lib,"d3d11.lib")
 #pragma comment(lib,"d3dcompiler.lib")
 class shaderclass
 {
 public:
     shaderclass();
     ~shaderclass();
     bool Initialize(ID3D11Device *device, ID3D11DeviceContext* context);
     void Shutdown();
 private:
     bool CompileShaderFromFile(WCHAR* szFileName, LPCSTR szEntryPoint, LPCSTR szShaderModel, ID3DBlob** ppBlobOut);
 private:
     ID3DBlob* m_vsblob,*m_psblob;
     ID3D11PixelShader *m_pixelshader;
     ID3D11VertexShader *m_vertexshader;
     ID3D11InputLayout *m_layout;
 public:
     void GetShaders(ID3D11VertexShader*& vs, ID3D11PixelShader*& ps);
 };

这个着色器类比较简单，只创建了顶点着色器和像素着色器，还设置了一个简单的输入布局，这些工作都由Initialize()函数来做，私有函数CompileShaderFromFile()函数则是用来将effect文件编译成二进制文件的，GetShaders()则是用来获取创建好的着色器对象的。

shaderclass.cpp

 #include "shaderclass.h"

 shaderclass::shaderclass()
 {
 }

 shaderclass::~shaderclass()
 {
 }

 bool shaderclass::Initialize(ID3D11Device *device,ID3D11DeviceContext* context)
 {
     HRESULT hr = S_OK;
     bool result = CompileShaderFromFile(L"shader.fx", "VS", "vs_4_0", &m_vsblob);
     if (!result)
     {
         MessageBox(NULL,
             L"The FX file cannot be compiled.  Please run this executable from the directory that contains the FX file.", L"Error", MB_OK);
         return false;
     }

     hr = device->CreateVertexShader(m_vsblob->GetBufferPointer(), m_vsblob->GetBufferSize(), NULL, &m_vertexshader);
     if (FAILED(hr))
     {
         return false;
     }

     result = CompileShaderFromFile(L"shader.fx", "PS", "ps_4_0", &m_psblob);
     if (!result)
     {
         MessageBox(NULL,
             L"The FX file cannot be compiled.  Please run this executable from the directory that contains the FX file.", L"Error", MB_OK);
         return false;
     }

     hr = device->CreatePixelShader(m_psblob->GetBufferPointer(), m_psblob->GetBufferSize(), NULL, &m_pixelshader);
     if (FAILED(hr))
     {
         return false;
     }
     D3D11_INPUT_ELEMENT_DESC layout[] =
     {
         { "POSITION", , DXGI_FORMAT_R32G32B32_FLOAT, , , D3D11_INPUT_PER_VERTEX_DATA,  },
         { "TEXCOORD", , DXGI_FORMAT_R32G32_FLOAT, , , D3D11_INPUT_PER_VERTEX_DATA,  },
     };/////////////////
     UINT numElements = ARRAYSIZE(layout);    

     hr = device->CreateInputLayout(layout, numElements, m_vsblob->GetBufferPointer(),m_vsblob->GetBufferSize(), &m_layout);
     if (FAILED(hr))
     {
         return false;
     }
     context->IASetInputLayout(m_layout);

     return true;
 }
 void shaderclass::Shutdown()
 {
     if (m_layout)
     {
         m_layout->Release();
     }
     if (m_pixelshader)
     {
         m_pixelshader->Release();
     }
     if (m_psblob)
     {
         m_psblob->Release();
     }
     if (m_vertexshader)
     {
         m_vertexshader->Release();
     }
     if (m_vsblob)
     {
         m_vsblob->Release();
     }
 }

 bool shaderclass::CompileShaderFromFile(WCHAR* szFileName, LPCSTR szEntryPoint, LPCSTR szShaderModel, ID3DBlob** ppBlobOut)
 {
     HRESULT hr = S_OK;

     DWORD dwShaderFlags = D3DCOMPILE_ENABLE_STRICTNESS;
 #if defined( DEBUG ) || defined( _DEBUG )
     dwShaderFlags |= D3DCOMPILE_DEBUG;
 #endif

     ID3DBlob* pErrorBlob=;
     hr = D3DX11CompileFromFile(szFileName, NULL, NULL, szEntryPoint, szShaderModel,
         dwShaderFlags, , NULL, ppBlobOut, &pErrorBlob, NULL);

     if (FAILED(hr))
     {
         if (pErrorBlob != NULL)
             OutputDebugStringA((char*)pErrorBlob->GetBufferPointer());
         if (pErrorBlob) pErrorBlob->Release();
         return false;
     }
     if (pErrorBlob)
         pErrorBlob->Release();

     return true;
 }

 void shaderclass::GetShaders(ID3D11VertexShader*& vs,ID3D11PixelShader*& ps)
 {
     vs = m_vertexshader;
     ps = m_pixelshader;
 }

Initialize()：

• 调用CompileShaderFromFile()函数编译effect文件里的顶点处理函数，得到二进制文件，根据二进制文件创建顶点着色器，CompileShaderFromFile()函数的第一个参数“shader.fx”就是effect文件
• 编译effect文件里的像素处理函数，得到二进制文件并创建像素着色器
• 填充输入布局描述数据结构，并创建输入布局，成功后设置输入布局

CompileShaderFromFile()： 里面只是单纯的调用dx11API D3DX11CompileFromFile()函数

整个类的编写非常简单，这只是因为我很简单的创建了两个着色器。如果要创建更复杂的着色器，还要学习很多。

另附上effect文件

shader.fx

 Texture2D txDiffuse : register(t0);
 SamplerState samLinear : register(s0);

 cbuffer ConstantBuffer : register(b0)
 {
     matrix World;
     matrix View;
     matrix Projection;
 }

 struct VS_INPUT
 {
     float4 Pos : POSITION;
     float4 Tex : TEXCOORD0;
 };
 struct PS_INPUT
 {
     float4 Pos : SV_POSITION;
     float2 Tex : TEXCOORD0;
 };
 //--------------------------------------------------------------------------------------
 // Vertex Shader
 //--------------------------------------------------------------------------------------
 PS_INPUT VS(VS_INPUT input)
 {
     PS_INPUT output = (PS_INPUT);
     output.Pos = mul(input.Pos, World);
     output.Pos = mul(output.Pos, View);
     output.Pos = mul(output.Pos, Projection);
     output.Tex = input.Tex;

     return output;
 }
 //--------------------------------------------------------------------------------------
 // Pixel Shader
 //--------------------------------------------------------------------------------------
 float4 PS(PS_INPUT input) : SV_Target
 {
     return txDiffuse.Sample(samLinear, input.Tex);
 }