basicprimitive.cpp

一本书上的例子

//=============================================================================
// Desc: 基本图元绘制
//=============================================================================

#include <d3d9.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
int                     g_iType      = 1;      //图元类型


//-----------------------------------------------------------------------------
// Desc: 顶点结构
//-----------------------------------------------------------------------------
struct CUSTOMVERTEX
{
    FLOAT x, y, z, rhw;
    DWORD color;
};
#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;

	//设置剔出模式为不剔出任何面
	g_pd3dDevice->SetRenderState(D3DRS_CULLMODE,  D3DCULL_NONE);

	//设置图元填充模式为线框模式
	g_pd3dDevice->SetRenderState(D3DRS_FILLMODE, D3DFILL_WIREFRAME);

    return S_OK;
}


//-----------------------------------------------------------------------------
// Desc: 创建并填充顶点缓冲区
//-----------------------------------------------------------------------------
HRESULT InitVB()
{
	//顶点数据
    CUSTOMVERTEX vertices[] =
    {
		{  50.0f, 250.0f, 0.5f, 1.0f, 0xffff0000, },
        { 150.0f,  50.0f, 0.5f, 1.0f, 0xffff0000, }, 
        { 250.0f, 250.0f, 0.5f, 1.0f, 0xffff0000, },
        

		{ 350.0f,  50.0f, 0.5f, 1.0f, 0xffff0000, }, 
		{ 450.0f, 250.0f, 0.5f, 1.0f, 0xffff0000, },
		{ 550.0f, 50.0f,  0.5f, 1.0f, 0xffff0000, }
    };

	//创建顶点缓冲区
    if( FAILED( g_pd3dDevice->CreateVertexBuffer( 6*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(vertices), (void**)&pVertices, 0 ) ) )
        return E_FAIL;
    memcpy( pVertices, vertices, sizeof(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(45, 50, 170), 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 );
		switch(g_iType)  //选择绘制图元的类型
		{
		case 1:   //三角形条带
			g_pd3dDevice->DrawPrimitive( D3DPT_TRIANGLESTRIP, 0, 4 );
			break;

		case 2:   //三角形列表
			g_pd3dDevice->DrawPrimitive( D3DPT_TRIANGLELIST, 0, 2 );
			break;

		case 3:   //线段条带
			g_pd3dDevice->DrawPrimitive( D3DPT_LINESTRIP, 0, 5 );
			break;

		case 4:  //线段列表
			g_pd3dDevice->DrawPrimitive( D3DPT_LINELIST, 0, 3 );
			break;

		case 5:  //点列表
			g_pd3dDevice->DrawPrimitive( D3DPT_POINTLIST, 0, 6 );
			break;

		case 6:
			g_pd3dDevice->DrawPrimitive(  D3DPT_TRIANGLEFAN, 0, 4);
			break;
		}

		//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:
		Cleanup();
		PostQuitMessage( 0 );
		return 0;

	case WM_KEYDOWN:
		switch(wParam)  //设置渲染图元类型
		{
		case 49:  //"1"键
		case 50:  //"2"键
		case 51:  //"3"键
		case 52:  //"4"键
		case 53:  //"5"键		
		case 54:  //"6"键
			g_iType = (int)wParam-48;
			break;
		}

	}

	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, MsgProc, 0L, 0L,
                      GetModuleHandle(NULL), NULL, NULL, NULL, NULL,
                      L"ClassName", NULL };
    RegisterClassEx( &wc );

	//创建窗口
    HWND hWnd = CreateWindow(  L"ClassName", L"基本图元",
                              WS_OVERLAPPEDWINDOW, 100, 100, 600, 300,
                              GetDesktopWindow(), NULL, wc.hInstance, NULL );

	//初始化Direct3D
    if( SUCCEEDED( InitD3D( hWnd ) ) )
    {
		//创建并填充顶点缓冲区
        if( SUCCEEDED( InitVB() ) )
        {
			//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;
}