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用DX9画三角形,三个顶点要求

 
用DX9画三角形,三个顶点的顺序有要求吗
下面是全部代码,在 InitVB 函数中被注释掉的数组是我写的,没注释掉的是书上的代码,经过试验我的坐标不能显示出图形,而书上的坐标可以,这是为什么?
#include<Windows.h>
#include<tchar.h>
#include<d3d9.h>
#define null NULL
#define RETURN return

LPDIRECT3D9 g_pD3D = NULL;
LPDIRECT3DDEVICE9 g_pd3dDevice = NULL;
LPDIRECT3DVERTEXBUFFER9 g_pVB = NULL;

struct CUSTOMVERTEX
{
float x,y,z,rhw;
DWORD color;
};
#define FVF ( D3DFVF_XYZRHW | D3DFVF_DIFFUSE )

HRESULT InitD3D(HWND hWnd)
{
g_pD3D = Direct3DCreate9(D3D_SDK_VERSION);
D3DPRESENT_PARAMETERS d3dpp;
ZeroMemory(&d3dpp, sizeof(d3dpp));
d3dpp.Windowed = TRUE;
d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
g_pD3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd, D3DCREATE_HARDWARE_VERTEXPROCESSING,
&d3dpp,&g_pd3dDevice);
return S_OK;
}

HRESULT InitVB()
{
/* CUSTOMVERTEX v[]=
{
100, 0, 0.5, 1,100,
0, 100,0.5, 1,150,
200, 100,0.5, 1,200
};
*/
CUSTOMVERTEX v[]=
{
100, 000, 0,1,0xffff0000,
300, 50, 0,1,0xff00ff00,
500, 400, 0,1,0xff0000ff
};

g_pd3dDevice->CreateVertexBuffer(3*sizeof(v),0,FVF,D3DPOOL_DEFAULT,&g_pVB,0);

void* vb;
g_pVB->Lock(0,0,(void**)&vb,0);
memcpy(vb,v,sizeof(v));
g_pVB->Unlock();
return S_OK;
}
void Render()
{
g_pd3dDevice->Clear(0,0,D3DCLEAR_TARGET,D3DCOLOR_XRGB(255,255,0),1,0);

g_pd3dDevice->BeginScene();
g_pd3dDevice->SetStreamSource(0, g_pVB, 0, sizeof(CUSTOMVERTEX));
g_pd3dDevice->SetFVF(FVF);
g_pd3dDevice->DrawPrimitive(D3DPT_TRIANGLELIST,0,10);
g_pd3dDevice->EndScene();

g_pd3dDevice->Present(0,0,0,0);
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
message==WM_CLOSE ? PostQuitMessage(0) : 0;
return DefWindowProc(hWnd, message, wParam, lParam);
}
int WINAPI _tWinMain(HINSTANCE hInstance,HINSTANCE,PTSTR,int)
{
wchar_t cn[] = L"ClassName";
WNDCLASS wc;
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
wc.lpszMenuName = NULL;
wc.lpszClassName = cn;
RegisterClass(&wc);

HWND hWnd = CreateWindow(cn,0,WS_OVERLAPPEDWINDOW,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,CW_USEDEFAULT,
NULL,NULL,hInstance,NULL);
ShowWindow(hWnd, SW_SHOW);

InitD3D(hWnd);
InitVB();
MSG msg;
ZeroMemory(&msg, sizeof(msg));
while(msg.message!=WM_QUIT)
{
if( PeekMessage(&msg, NULL, 0, 0, PM_REMOVE) )
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
else
{
Render();
}
}
return 0;
}

------解决方案--------------------
有要求的,要么顺时针要么逆时针,要看你的背面消隐模式了
参考:http://blog.csdn.net/yaoxinchao/article/details/7982099
------解决方案--------------------
是逆序的问题,绕序不能从窗口看,窗口以向右向下为正方向,绕序要从观察坐标系中看,坐标系以向右向上位正方向
 
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用DX9画三角形,三个顶点要求