学习顶点缓存与索引缓存(一)

Posted on 2008-08-04 15:35 orlando 阅读(1659) 评论(0)  编辑 收藏 引用

在学习了顶点缓存和索引缓存后运行了一个例子：

//=============================================================================
// Desc: 索引缓冲区
//=============================================================================

#include <d3d9.h>
#include <math.h>


//-----------------------------------------------------------------------------
// Desc: 全局变量
//-----------------------------------------------------------------------------
LPDIRECT3D9             g_pD3D       = NULL; // Direct3D对象
LPDIRECT3DDEVICE9       g_pd3dDevice = NULL; // Direct3D设备对象
LPDIRECT3DVERTEXBUFFER9 g_pVB        = NULL; // 顶点缓冲区对象
LPDIRECT3DINDEXBUFFER9  g_pIB   = NULL; // 索引缓冲区对象


//-----------------------------------------------------------------------------
// Desc: 顶点结构和灵活顶点格式
//-----------------------------------------------------------------------------
struct CUSTOMVERTEX
{   FLOAT x, y, z, rhw;   // 经过坐标转换的顶点位置
    DWORD color;          // 顶点漫反射颜色值
};
#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZRHW|D3DFVF_DIFFUSE)


//-----------------------------------------------------------------------------
// Desc: 初始化Direct3D
//-----------------------------------------------------------------------------
HRESULT InitD3D( HWND hWnd )
{
 //创建Direct3D对象, 该对象用于创建Direct3D设备对象
    if( NULL == ( g_pD3D = Direct3DCreate9( D3D_SDK_VERSION ) ) )
        return E_FAIL;

    //设置D3DPRESENT_PARAMETERS结构, 准备创建Direct3D设备对象
    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory( &d3dpp, sizeof(d3dpp) );
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;

 //创建Direct3D设备对象
    if( FAILED( g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
                                      D3DCREATE_SOFTWARE_VERTEXPROCESSING,
                                      &d3dpp, &g_pd3dDevice ) ) )
    {
        return E_FAIL;
    }

    return S_OK;
}


//-----------------------------------------------------------------------------
// Desc: 创建并填充顶点缓冲区和索引缓冲区
//-----------------------------------------------------------------------------
HRESULT InitVBAndIB()
{
 //顶点数据
 CUSTOMVERTEX g_Vertices[9];
 g_Vertices[0].x = 300;
 g_Vertices[0].y = 250;
 g_Vertices[0].z = 0.5f;
 g_Vertices[0].rhw = 1.0f;
 g_Vertices[0].color = 0xffff0000;
 for(int i=0; i<8; i++)
 {
  g_Vertices[i+1].x =  (float)(200*sin(i*3.14159/4.0)) + 300;
  g_Vertices[i+1].y = -(float)(200*cos(i*3.14159/4.0)) + 250;
  g_Vertices[i+1].z = 0.5f;
  g_Vertices[i+1].rhw = 1.0f;
  g_Vertices[i+1].color = 0xff00ff00;
 }

 //顶点索引数组
 WORD g_Indices[] ={ 0,1,2, 0,2,3, 0,3,4, 0,4,5, 0,5,6, 0,6,7, 0,7,8, 0,8,1 };

 //创建顶点缓冲区
    if( FAILED( g_pd3dDevice->CreateVertexBuffer( 9*sizeof(CUSTOMVERTEX),
                                                  0, D3DFVF_CUSTOMVERTEX,
                                                  D3DPOOL_DEFAULT, &g_pVB,NULL ) ) )
    {
        return E_FAIL;
    }

 //填充顶点缓冲区
    VOID* pVertices;
    if( FAILED( g_pVB->Lock( 0, sizeof(g_Vertices), (void**)&pVertices, 0 ) ) )
        return E_FAIL;
    memcpy( pVertices, g_Vertices, sizeof(g_Vertices) );
    g_pVB->Unlock();

 //创建索引缓冲区
 if( FAILED( g_pd3dDevice->CreateIndexBuffer( 24*sizeof(WORD),
                                                  0, D3DFMT_INDEX16,  //索引类型
                                                  D3DPOOL_DEFAULT, &g_pIB,NULL ) ) )
    {
        return E_FAIL;
    }

 //填充顶点缓冲区
    VOID* pIndices;
    if( FAILED( g_pIB->Lock( 0, sizeof(g_Indices), (void**)&pIndices, 0 ) ) )
        return E_FAIL;
    memcpy( pIndices, g_Indices, sizeof(g_Indices) );
    g_pIB->Unlock();

    return S_OK;
}


//-----------------------------------------------------------------------------
// Desc: 释放创建的对象
//-----------------------------------------------------------------------------
VOID Cleanup()
{
 //释放顶点缓冲区对象
    if( g_pVB != NULL )       
        g_pVB->Release();

 //释放索引缓冲区对象
 if(g_pIB != NULL)
  g_pIB->Release();

 //释放Direct3D设备对象
    if( g_pd3dDevice != NULL )
        g_pd3dDevice->Release();

 //释放Direct3D对象
    if( g_pD3D != NULL )
        g_pD3D->Release();
}


//-----------------------------------------------------------------------------
// Desc: 渲染图形
//-----------------------------------------------------------------------------
VOID Render()
{
 //清空后台缓冲区
    g_pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,255), 1.0f, 0 );

 //开始在后台缓冲区绘制图形
  if( SUCCEEDED( g_pd3dDevice->BeginScene()))
    {
  //在后台缓冲区绘制图形
        g_pd3dDevice->SetStreamSource( 0, g_pVB, 0, sizeof(CUSTOMVERTEX) );
        g_pd3dDevice->SetFVF( D3DFVF_CUSTOMVERTEX );
     g_pd3dDevice->SetIndices( g_pIB );  //设置索引缓冲区
     g_pd3dDevice->DrawIndexedPrimitive ( D3DPT_TRIANGLELIST, 0,0,9,0,8 );
    
  //结束在后台缓冲区渲染图形
        g_pd3dDevice->EndScene();
    }

 //将在后台缓冲区绘制的图形提交到前台缓冲区显示
    g_pd3dDevice->Present( NULL, NULL, NULL, NULL );
}


//-----------------------------------------------------------------------------
// Desc: 消息处理
//-----------------------------------------------------------------------------
LRESULT WINAPI MsgProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam )
{
    switch( msg )
    {
        case WM_DESTROY:
            PostQuitMessage( 0 );
            return 0;
    }
    return DefWindowProc( hWnd, msg, wParam, lParam );
}


//-----------------------------------------------------------------------------
// Desc: 入口函数
//-----------------------------------------------------------------------------
INT WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR, INT )
{
 //注册窗口类
    WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC | CS_HREDRAW | CS_VREDRAW, MsgProc, 0L, 0L,
                      GetModuleHandle(NULL), NULL, NULL, NULL, NULL,
                      L"ClassName", NULL };
    RegisterClassEx( &wc );

 //创建窗口
    HWND hWnd = CreateWindow( L"ClassName", L"索引缓冲区",
                              WS_OVERLAPPEDWINDOW, 200, 100, 600, 550,
                              GetDesktopWindow(), NULL, wc.hInstance, NULL );

 //初始化Direct3D
    if( SUCCEEDED( InitD3D( hWnd ) ) )
    {
  //创建并填充顶点缓冲区和索引缓冲区
        if( SUCCEEDED( InitVBAndIB() ) )
        {
   //显示窗口
            ShowWindow( hWnd, SW_SHOWDEFAULT );
            UpdateWindow( hWnd );

   //进入消息循环
            MSG msg;
            ZeroMemory( &msg, sizeof(msg) );
            while( msg.message!=WM_QUIT )
            {
                if( PeekMessage( &msg, NULL, 0U, 0U, PM_REMOVE ) )
                {
     TranslateMessage( &msg );
     DispatchMessage( &msg );
                }
    else
    {
     Render();  //渲染图形
    }
            }
        }
    }

    UnregisterClass( L"ClassName", wc.hInstance );
    return 0;
}

但当我想把例子改成下面那样使用顶点缓存时发现不能达到目的

HRESULT InitVBAndIB()
{
 //顶点数据
 CUSTOMVERTEX g_Vertices[9];
 g_Vertices[0].x = 300;
 g_Vertices[0].y = 250;
 g_Vertices[0].z = 0.5f;
 g_Vertices[0].rhw = 1.0f;
 g_Vertices[0].color = 0xffff0000;
 for(int i=0; i<8; i++)
 {
  g_Vertices[i+1].x =  (float)(200*sin(i*3.14159/4.0)) + 300;
  g_Vertices[i+1].y = -(float)(200*cos(i*3.14159/4.0)) + 250;
  g_Vertices[i+1].z = 0.5f;
  g_Vertices[i+1].rhw = 1.0f;
  g_Vertices[i+1].color = 0xff00ff00;
 }

 //顶点索引数组
 WORD g_Indices[] ={ 0,1,2, 0,2,3, 0,3,4, 0,4,5, 0,5,6, 0,6,7, 0,7,8, 0,8,1 };

 //创建顶点缓冲区
    if( FAILED( g_pd3dDevice->CreateVertexBuffer( 9*sizeof(CUSTOMVERTEX),
                                                  0, D3DFVF_CUSTOMVERTEX,
                                                  D3DPOOL_DEFAULT, &g_pVB,NULL ) ) )
    {
        return E_FAIL;
    }

 //填充顶点缓冲区
    VOID* pVertices;
    if( FAILED( g_pVB->Lock( 0, sizeof(g_Vertices), (void**)&pVertices, 0 ) ) )
        return E_FAIL;
    memcpy( pVertices, g_Vertices, sizeof(g_Vertices) );
    g_pVB->Unlock();

     return S_OK;
}


//-----------------------------------------------------------------------------
// Desc: 释放创建的对象
//-----------------------------------------------------------------------------
VOID Cleanup()
{
 //释放顶点缓冲区对象
    if( g_pVB != NULL )       
        g_pVB->Release();

 //释放Direct3D设备对象
    if( g_pd3dDevice != NULL )
        g_pd3dDevice->Release();

 //释放Direct3D对象
    if( g_pD3D != NULL )
        g_pD3D->Release();
}


//-----------------------------------------------------------------------------
// Desc: 渲染图形
//-----------------------------------------------------------------------------
VOID Render()
{
 //清空后台缓冲区
    g_pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,255), 1.0f, 0 );

 //开始在后台缓冲区绘制图形
  if( SUCCEEDED( g_pd3dDevice->BeginScene()))
    {
  //在后台缓冲区绘制图形
        g_pd3dDevice->SetStreamSource( 0, g_pVB, 0, sizeof(CUSTOMVERTEX) );
        g_pd3dDevice->SetFVF( D3DFVF_CUSTOMVERTEX );
      g_pd3dDevice->DrawPrimitive ( D3DPT_TRIANGLELIST, 0,8 );
    
  //结束在后台缓冲区渲染图形
        g_pd3dDevice->EndScene();
    }

 //将在后台缓冲区绘制的图形提交到前台缓冲区显示
    g_pd3dDevice->Present( NULL, NULL, NULL, NULL );
}


后来才发现使用顶点缓冲区绘制图形时不能共用顶点，除非使用索引缓存

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