用DX9画三角形，三个顶点要求

Posted 2020-09-06

 

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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