C++ Exercises（十四）

//=============================================================================
// Desc: 坐标变换
//=============================================================================

#include <d3dx9.h>  //D3DX实用库函数, 该头文件中又包含了d3d9.h头文件


//-----------------------------------------------------------------------------
// 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
HWND                       g_Wnd        = NULL;    //窗口句柄
D3DRECT                    g_ClentRect;


//-----------------------------------------------------------------------------
// Desc: 顶点结构
//-----------------------------------------------------------------------------
struct CUSTOMVERTEX
{
    D3DXVECTOR3 position;
    DWORD color;
};
#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZ|D3DFVF_DIFFUSE)


//-----------------------------------------------------------------------------
// Desc: 设置世界矩阵
//-----------------------------------------------------------------------------
VOID SetupWorldMatrice()
{
    //建立一个绕X轴动态旋转的世界矩阵
    D3DXMATRIX matWorld;
    UINT  iTime  = timeGetTime() % 1000;
    FLOAT fAngle = iTime * (2.0f * D3DX_PI) / 1000.0f;//旋转角度
    D3DXMatrixIdentity( &matWorld );//单位矩阵
    D3DXMatrixRotationX( &matWorld, fAngle );//饶x轴选择

    //设置世界矩阵
    g_pd3dDevice->SetTransform( D3DTS_WORLD, &matWorld );
}


//-----------------------------------------------------------------------------
// Desc: 设置观察矩阵和投影矩阵
//-----------------------------------------------------------------------------
VOID SetupViewandProjMatrices()
{
    //建立并设置观察矩阵
    D3DXVECTOR3 vEyePt( 0.0f, 3.0f,-5.0f );
    D3DXVECTOR3 vLookatPt( 0.0f, 0.0f, 0.0f );
    D3DXVECTOR3 vUpVec( 0.0f, 1.0f, 0.0f );
    D3DXMATRIX matView;
    D3DXMatrixLookAtLH( &matView, &vEyePt, &vLookatPt, &vUpVec );
    g_pd3dDevice->SetTransform( D3DTS_VIEW, &matView );

    //建立并设置投影矩阵
    D3DXMATRIX matProj;
    D3DXMatrixPerspectiveFovLH( &matProj, D3DX_PI/4, 1.0f, 1.0f, 100.0f );
    g_pd3dDevice->SetTransform( D3DTS_PROJECTION, &matProj );
}


//-----------------------------------------------------------------------------
// Desc: 设置视区
//-----------------------------------------------------------------------------
VOID SetupViewPort()
{
    RECT rect;
    GetClientRect(g_Wnd,&rect);
    D3DVIEWPORT9 vp;
    vp.X      = 0;
    vp.Y      = 0;
    vp.Width  = rect.right;
    vp.Height = rect.bottom;
    vp.MinZ   = 0.0f;
    vp.MaxZ   = 1.0f;
    g_pd3dDevice->SetViewport(&vp);
}


//-----------------------------------------------------------------------------
// 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(正面和反面)
    g_pd3dDevice->SetRenderState( D3DRS_CULLMODE, D3DCULL_NONE );

    //关闭光照处理, 默认情况下启用光照处理
    g_pd3dDevice->SetRenderState( D3DRS_LIGHTING, FALSE );

    //设置观察和投影矩阵
    SetupViewandProjMatrices();

    //设置视区
    SetupViewPort();

    return S_OK;
}


//-----------------------------------------------------------------------------
// Desc: 创建场景图形
//-----------------------------------------------------------------------------
HRESULT InitGeometry()
{
    //创顶点缓冲区
    if( FAILED( g_pd3dDevice->CreateVertexBuffer( 50*2*sizeof(CUSTOMVERTEX),
                                                  0, D3DFVF_CUSTOMVERTEX,
                                                  D3DPOOL_DEFAULT, &g_pVB, NULL ) ) )
    {
        return E_FAIL;
    }

    //填充顶点缓冲区
    CUSTOMVERTEX* pVertices;
    if( FAILED( g_pVB->Lock( 0, 0, (void**)&pVertices, 0 ) ) )
        return E_FAIL;
    for( DWORD i=0; i<50; i++ )
    {
        FLOAT theta = (2*D3DX_PI*i)/(50-1);
        pVertices[2*i+0].position = D3DXVECTOR3( sinf(theta),-1.0f, cosf(theta) );
        pVertices[2*i+0].color   =0xffffff00;
        pVertices[2*i+1].position = D3DXVECTOR3( sinf(theta), 1.0f, cosf(theta) );
        pVertices[2*i+1].color   =0xffffff00;
    }
    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() ) )
    {
        //设置世界矩阵
        SetupWorldMatrice();

        //在后台缓冲区绘制图形
        g_pd3dDevice->SetStreamSource( 0, g_pVB, 0, sizeof(CUSTOMVERTEX) );
        g_pd3dDevice->SetFVF( D3DFVF_CUSTOMVERTEX );
        g_pd3dDevice->DrawPrimitive( D3DPT_TRIANGLESTRIP, 0, 2*50-2 );

        //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;
    }

    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"坐标变换",
                              WS_OVERLAPPEDWINDOW, 200, 100, 500,500,
                              GetDesktopWindow(), NULL, wc.hInstance, NULL );
    g_Wnd=hWnd;

    //初始化Direct3D
    if( SUCCEEDED( InitD3D( hWnd ) ) )
    {
        //创建场景图形
        if( SUCCEEDED( InitGeometry() ) )
        {
            //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;
}