在學習了頂點緩存和索引緩存后運行了一個例子：
//=============================================================================
// Desc: 索引緩沖區
//=============================================================================
#include <d3d9.h>
#include <math.h>
//-----------------------------------------------------------------------------
// Desc: 全局變量
//-----------------------------------------------------------------------------
LPDIRECT3D9 g_pD3D = NULL; // Direct3D對象
LPDIRECT3DDEVICE9 g_pd3dDevice = NULL; // Direct3D設備對象
LPDIRECT3DVERTEXBUFFER9 g_pVB = NULL; // 頂點緩沖區對象
LPDIRECT3DINDEXBUFFER9 g_pIB = NULL; // 索引緩沖區對象
//-----------------------------------------------------------------------------
// Desc: 頂點結構和靈活頂點格式
//-----------------------------------------------------------------------------
struct CUSTOMVERTEX
{ FLOAT x, y, z, rhw; // 經過坐標轉換的頂點位置
DWORD color; // 頂點漫反射顏色值
};
#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZRHW|D3DFVF_DIFFUSE)
//-----------------------------------------------------------------------------
// Desc: 初始化Direct3D
//-----------------------------------------------------------------------------
HRESULT InitD3D( HWND hWnd )
{
//創建Direct3D對象, 該對象用于創建Direct3D設備對象
if( NULL == ( g_pD3D = Direct3DCreate9( D3D_SDK_VERSION ) ) )
return E_FAIL;
//設置D3DPRESENT_PARAMETERS結構, 準備創建Direct3D設備對象
D3DPRESENT_PARAMETERS d3dpp;
ZeroMemory( &d3dpp, sizeof(d3dpp) );
d3dpp.Windowed = TRUE;
d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
//創建Direct3D設備對象
if( FAILED( g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
D3DCREATE_SOFTWARE_VERTEXPROCESSING,
&d3dpp, &g_pd3dDevice ) ) )
{
return E_FAIL;
}
return S_OK;
}
//-----------------------------------------------------------------------------
// Desc: 創建并填充頂點緩沖區和索引緩沖區
//-----------------------------------------------------------------------------
HRESULT InitVBAndIB()
{
//頂點數據
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;
}
//頂點索引數組
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 };
//創建頂點緩沖區
if( FAILED( g_pd3dDevice->CreateVertexBuffer( 9*sizeof(CUSTOMVERTEX),
0, D3DFVF_CUSTOMVERTEX,
D3DPOOL_DEFAULT, &g_pVB,NULL ) ) )
{
return E_FAIL;
}
//填充頂點緩沖區
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();
//創建索引緩沖區
if( FAILED( g_pd3dDevice->CreateIndexBuffer( 24*sizeof(WORD),
0, D3DFMT_INDEX16, //索引類型
D3DPOOL_DEFAULT, &g_pIB,NULL ) ) )
{
return E_FAIL;
}
//填充頂點緩沖區
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: 釋放創建的對象
//-----------------------------------------------------------------------------
VOID Cleanup()
{
//釋放頂點緩沖區對象
if( g_pVB != NULL )
g_pVB->Release();
//釋放索引緩沖區對象
if(g_pIB != NULL)
g_pIB->Release();
//釋放Direct3D設備對象
if( g_pd3dDevice != NULL )
g_pd3dDevice->Release();
//釋放Direct3D對象
if( g_pD3D != NULL )
g_pD3D->Release();
}
//-----------------------------------------------------------------------------
// Desc: 渲染圖形
//-----------------------------------------------------------------------------
VOID Render()
{
//清空后臺緩沖區
g_pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,255), 1.0f, 0 );
//開始在后臺緩沖區繪制圖形
if( SUCCEEDED( g_pd3dDevice->BeginScene()))
{
//在后臺緩沖區繪制圖形
g_pd3dDevice->SetStreamSource( 0, g_pVB, 0, sizeof(CUSTOMVERTEX) );
g_pd3dDevice->SetFVF( D3DFVF_CUSTOMVERTEX );
g_pd3dDevice->SetIndices( g_pIB ); //設置索引緩沖區
g_pd3dDevice->DrawIndexedPrimitive ( D3DPT_TRIANGLELIST, 0,0,9,0,8 );
//結束在后臺緩沖區渲染圖形
g_pd3dDevice->EndScene();
}
//將在后臺緩沖區繪制的圖形提交到前臺緩沖區顯示
g_pd3dDevice->Present( NULL, NULL, NULL, NULL );
}
//-----------------------------------------------------------------------------
// Desc: 消息處理
//-----------------------------------------------------------------------------
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: 入口函數
//-----------------------------------------------------------------------------
INT WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR, INT )
{
//注冊窗口類
WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC | CS_HREDRAW | CS_VREDRAW, MsgProc, 0L, 0L,
GetModuleHandle(NULL), NULL, NULL, NULL, NULL,
L"ClassName", NULL };
RegisterClassEx( &wc );
//創建窗口
HWND hWnd = CreateWindow( L"ClassName", L"索引緩沖區",
WS_OVERLAPPEDWINDOW, 200, 100, 600, 550,
GetDesktopWindow(), NULL, wc.hInstance, NULL );
//初始化Direct3D
if( SUCCEEDED( InitD3D( hWnd ) ) )
{
//創建并填充頂點緩沖區和索引緩沖區
if( SUCCEEDED( InitVBAndIB() ) )
{
//顯示窗口
ShowWindow( hWnd, SW_SHOWDEFAULT );
UpdateWindow( hWnd );
//進入消息循環
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(); //渲染圖形
}
}
}
}
UnregisterClass( L"ClassName", wc.hInstance );
return 0;
}
但當我想把例子改成下面那樣使用頂點緩存時發現不能達到目的
HRESULT InitVBAndIB()
{
//頂點數據
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;
}
//頂點索引數組
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 };
//創建頂點緩沖區
if( FAILED( g_pd3dDevice->CreateVertexBuffer( 9*sizeof(CUSTOMVERTEX),
0, D3DFVF_CUSTOMVERTEX,
D3DPOOL_DEFAULT, &g_pVB,NULL ) ) )
{
return E_FAIL;
}
//填充頂點緩沖區
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: 釋放創建的對象
//-----------------------------------------------------------------------------
VOID Cleanup()
{
//釋放頂點緩沖區對象
if( g_pVB != NULL )
g_pVB->Release();
//釋放Direct3D設備對象
if( g_pd3dDevice != NULL )
g_pd3dDevice->Release();
//釋放Direct3D對象
if( g_pD3D != NULL )
g_pD3D->Release();
}
//-----------------------------------------------------------------------------
// Desc: 渲染圖形
//-----------------------------------------------------------------------------
VOID Render()
{
//清空后臺緩沖區
g_pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,255), 1.0f, 0 );
//開始在后臺緩沖區繪制圖形
if( SUCCEEDED( g_pd3dDevice->BeginScene()))
{
//在后臺緩沖區繪制圖形
g_pd3dDevice->SetStreamSource( 0, g_pVB, 0, sizeof(CUSTOMVERTEX) );
g_pd3dDevice->SetFVF( D3DFVF_CUSTOMVERTEX );
g_pd3dDevice->DrawPrimitive ( D3DPT_TRIANGLELIST, 0,8 );
//結束在后臺緩沖區渲染圖形
g_pd3dDevice->EndScene();
}
//將在后臺緩沖區繪制的圖形提交到前臺緩沖區顯示
g_pd3dDevice->Present( NULL, NULL, NULL, NULL );
}
后來才發現使用頂點緩沖區繪制圖形時不能共用頂點，除非使用索引緩存