顶点着色器例子——Diffuse Lighting(《龙书》)
#include "d3dUtility.h" // // Globals // IDirect3DDevice9* Device = 0; const int Width = 640; const int Height = 480; IDirect3DVertexShader9* DiffuseShader = 0; //顶点着色器 ID3DXConstantTable* DiffuseConstTable = 0; //shader的常量表 ID3DXMesh* Teapot = 0; //常量表中shader变量句柄,用于设置shader中对应变量的值 D3DXHANDLE ViewMatrixHandle = 0; D3DXHANDLE ViewProjMatrixHandle = 0; D3DXHANDLE AmbientMtrlHandle = 0; D3DXHANDLE DiffuseMtrlHandle = 0; D3DXHANDLE LightDirHandle = 0; D3DXMATRIX Proj; // // Framework functions // bool Setup() { HRESULT hr = 0; // // Create geometry: // D3DXCreateTeapot(Device, &Teapot, 0); // // 编译着色器 // ID3DXBuffer* shader = 0; ID3DXBuffer* errorBuffer = 0; hr = D3DXCompileShaderFromFile( "diffuse.txt",//shader文件名 0, 0, "Main", // entry point function name "vs_1_1", D3DXSHADER_DEBUG | D3DXSHADER_ENABLE_BACKWARDS_COMPATIBILITY, &shader,//编译后的着色器代码 &errorBuffer,//存储错误代码 &DiffuseConstTable);//获取常量表 // output any error messages if( errorBuffer ) { ::MessageBox(0, (char*)errorBuffer->GetBufferPointer(), 0, 0); d3d::Release<ID3DXBuffer*>(errorBuffer); } if(FAILED(hr)) { ::MessageBox(0, "D3DXCompileShaderFromFile() - FAILED", 0, 0); return false; } // // 创建着色器 // hr = Device->CreateVertexShader( (DWORD*)shader->GetBufferPointer(),//前面得到的编译后的着色器代码 &DiffuseShader);//创建的着色器 if(FAILED(hr)) { ::MessageBox(0, "CreateVertexShader - FAILED", 0, 0); return false; } d3d::Release<ID3DXBuffer*>(shader); // // Get Handles,根据shader变量名获取句柄(关联变量,以便于外部设置shader变量的值) // ViewMatrixHandle = DiffuseConstTable->GetConstantByName(0, "ViewMatrix"); ViewProjMatrixHandle= DiffuseConstTable->GetConstantByName(0, "ViewProjMatrix"); AmbientMtrlHandle = DiffuseConstTable->GetConstantByName(0, "AmbientMtrl"); DiffuseMtrlHandle = DiffuseConstTable->GetConstantByName(0, "DiffuseMtrl"); LightDirHandle = DiffuseConstTable->GetConstantByName(0, "LightDirection"); // // Set shader constants:(设置shader变量的值,有些shader变量需要在C++代码中初始化,即外部初始化) // // Light direction: D3DXVECTOR4 directionToLight(-0.57f, 0.57f, -0.57f, 0.0f); DiffuseConstTable->SetVector(Device, LightDirHandle, &directionToLight); // Materials: D3DXVECTOR4 ambientMtrl(0.0f, 0.0f, 1.0f, 1.0f); D3DXVECTOR4 diffuseMtrl(0.0f, 0.0f, 1.0f, 1.0f); DiffuseConstTable->SetVector(Device,AmbientMtrlHandle,&ambientMtrl); DiffuseConstTable->SetVector(Device,DiffuseMtrlHandle,&diffuseMtrl); DiffuseConstTable->SetDefaults(Device); //此方法在应用程序的设置用应调用一次,设置常量的默认值 // Compute projection matrix.计算投影矩阵 D3DXMatrixPerspectiveFovLH( &Proj, D3DX_PI * 0.25f, (float)Width / (float)Height, 1.0f, 1000.0f); //固定管线:Device->SetTransform(D3DTS_PROJECTION, &Proj); return true; } void Cleanup() { d3d::Release<ID3DXMesh*>(Teapot); d3d::Release<IDirect3DVertexShader9*>(DiffuseShader); d3d::Release<ID3DXConstantTable*>(DiffuseConstTable); } bool Display(float timeDelta) { if( Device ) { // // Update the scene: Allow user to rotate around scene. // static float angle = (3.0f * D3DX_PI) / 2.0f; static float height = 3.0f; if( ::GetAsyncKeyState(VK_LEFT) & 0x8000f ) angle -= 0.5f * timeDelta; if( ::GetAsyncKeyState(VK_RIGHT) & 0x8000f ) angle += 0.5f * timeDelta; if( ::GetAsyncKeyState(VK_UP) & 0x8000f ) height += 5.0f * timeDelta; if( ::GetAsyncKeyState(VK_DOWN) & 0x8000f ) height -= 5.0f * timeDelta; D3DXVECTOR3 position( cosf(angle) * 7.0f, height, sinf(angle) * 7.0f ); D3DXVECTOR3 target(0.0f, 0.0f, 0.0f); D3DXVECTOR3 up(0.0f, 1.0f, 0.0f); D3DXMATRIX V; D3DXMatrixLookAtLH(&V, &position, &target, &up); //固定管线:Device->SetTransform(D3DTS_VIEW, &V);//设置照相机的位置 DiffuseConstTable->SetMatrix(Device, ViewMatrixHandle, &V); D3DXMATRIX ViewProj = V * Proj; DiffuseConstTable->SetMatrix(Device, ViewProjMatrixHandle, &ViewProj); // // Render // Device->Clear(0, 0, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0xffffffff, 1.0f, 0); Device->BeginScene(); //启用定点着色器 //Device->SetVertexShader(DiffuseShader); Teapot->DrawSubset(0); Device->EndScene(); Device->Present(0, 0, 0, 0); } return true; } // // WndProc // LRESULT CALLBACK d3d::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) { switch( msg ) { case WM_DESTROY: ::PostQuitMessage(0); break; case WM_KEYDOWN: if( wParam == VK_ESCAPE ) ::DestroyWindow(hwnd); break; } return ::DefWindowProc(hwnd, msg, wParam, lParam); } // // WinMain // int WINAPI WinMain(HINSTANCE hinstance, HINSTANCE prevInstance, PSTR cmdLine, int showCmd) { if(!d3d::InitD3D(hinstance, Width, Height, true, D3DDEVTYPE_HAL, &Device)) { ::MessageBox(0, "InitD3D() - FAILED", 0, 0); return 0; } if(!Setup()) { ::MessageBox(0, "Setup() - FAILED", 0, 0); return 0; } d3d::EnterMsgLoop( Display ); Cleanup(); Device->Release(); return 0; }
// File: diffuse.txt
matrix ViewMatrix;
matrix ViewProjMatrix;
vector AmbientMtrl;
vector DiffuseMtrl
vector LightDirection;
vector DiffuseLightIntensity = {0.0f, 0.0f, 1.0f, 1.0f};
vector AmbientLightIntensity = {0.0f, 0.0f, 0.2f, 1.0f};
struct VS_INPUT
{
vector position : POSITION;
vector normal : NORMAL;
};
struct VS_OUTPUT
{
vector position : POSITION;
vector diffuse : COLOR;
};
VS_OUTPUT Main(VS_INPUT input)
{
VS_OUTPUT output = (VS_OUTPUT)0;
// Transform position to homogeneous clip space(齐次裁剪空间)
// and store in the output.position member.
output.position = mul(input.position, ViewProjMatrix);
// Transform lights and normals to view space(视口空间). Set w
// componentes to zero since we're transforming vectors
// here and not points.
LightDirection.w = 0.0f;
input.normal.w = 0.0f;
LightDirection = mul(LightDirection, ViewMatrix);
input.normal = mul(input.normal, ViewMatrix);
// Compute cosine of the angle between light and normal.
float s = dot(LightDirection, input.normal);
if( s < 0.0f )
s = 0.0f;
output.diffuse = (AmbientMtrl * AmbientLightIntensity) + (s * (DiffuseLightIntensity * DiffuseMtrl));
return output;
}