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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