//=============================================================================
// Desc: 坐標變換
//=============================================================================

#include <d3dx9.h>  //D3DX實用庫函數, 該頭文件中又包含了d3d9.h頭文件

//-----------------------------------------------------------------------------
// Desc: 全局變量
//-----------------------------------------------------------------------------
LPDIRECT3D9                g_pD3D       = NULL;    //Direct3D對象
LPDIRECT3DDEVICE9          g_pd3dDevice = NULL;    //Direct3D設備對象
LPDIRECT3DVERTEXBUFFER9    g_pVB        = NULL;    //頂點緩沖區對象
HWND        g_Wnd     = NULL;    //窗口句柄
D3DRECT                    g_ClentRect;
LPDIRECT3DINDEXBUFFER9  g_pIB  = NULL;

//-----------------------------------------------------------------------------
// Desc: 頂點結構
//-----------------------------------------------------------------------------
struct CUSTOMVERTEX
{
    D3DXVECTOR3 position;
    DWORD color;
};
#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZ|D3DFVF_DIFFUSE)

//-----------------------------------------------------------------------------
// Desc: 設置世界矩陣
//-----------------------------------------------------------------------------
VOID SetupWorldMatrice()
{
 //建立一個繞X軸動態旋轉的世界矩陣
    D3DXMATRIX matWorld;
    UINT  iTime  = timeGetTime() % 1000;
    FLOAT fAngle = iTime * (2.0f * D3DX_PI) / 1000.0f;
 D3DXMatrixIdentity( &matWorld );
    D3DXMatrixRotationX( &matWorld, fAngle );

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

//-----------------------------------------------------------------------------
// Desc: 設置觀察矩陣和投影矩陣
//-----------------------------------------------------------------------------
VOID SetupViewandProjMatrices()
{
    //建立并設置觀察矩陣
    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 );

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

//-----------------------------------------------------------------------------
// Desc: 設置視區
//-----------------------------------------------------------------------------
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 )
{
 //創建Direct3D對象, 該對象用于創建Direct3D設備對象
    if( NULL == ( g_pD3D = Direct3DCreate9( D3D_SDK_VERSION ) ) )
        return E_FAIL;

 //設置D3DPRESENT_PARAMETERS結構, 準備創建Direct3D設備對象
    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory( &d3dpp, sizeof(d3dpp) );
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;

 //創建Direct3D設備對象
    if( FAILED( g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
                                      D3DCREATE_SOFTWARE_VERTEXPROCESSING,
                                      &d3dpp, &g_pd3dDevice ) ) )
    {
        return E_FAIL;
    }

    //設置剔出模式為不剔出任何面(正面和反面)
    g_pd3dDevice->SetRenderState( D3DRS_CULLMODE, D3DCULL_NONE );

 //關閉光照處理, 默認情況下啟用光照處理
    g_pd3dDevice->SetRenderState( D3DRS_LIGHTING, FALSE );

 //設置觀察和投影矩陣
 SetupViewandProjMatrices();

 //設置視區
 SetupViewPort();

 return S_OK;
}

//-----------------------------------------------------------------------------
// Desc: 創建場景圖形
//-----------------------------------------------------------------------------
HRESULT InitGeometry()
{
 //創頂點緩沖區
    if( FAILED( g_pd3dDevice->CreateVertexBuffer( 50*2*sizeof(CUSTOMVERTEX),
                                                  0, D3DFVF_CUSTOMVERTEX,
                                                  D3DPOOL_DEFAULT, &g_pVB, NULL ) ) )
    {
        return E_FAIL;
    }

 //填充頂點緩沖區
    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();

 WORD g_Indices[100] ;
 int index;
 for (index=0;index<100;index++)
 {
  g_Indices[index]=index;
 }
  //創建索引緩沖區
 if( FAILED( g_pd3dDevice->CreateIndexBuffer( 100*sizeof(WORD),
                                                  0, D3DFMT_INDEX16,  //索引類型
                                                  D3DPOOL_DEFAULT, &g_pIB,NULL ) ) )
    {
        return E_FAIL;
    }

 //填充索引緩沖區
    VOID* pIndices;
    if( FAILED( g_pIB->Lock( 0, sizeof(g_Indices), (void**)&pIndices, 0 ) ) )
        return E_FAIL;
    memcpy( pIndices, g_Indices, sizeof(g_Indices) );
    g_pIB->Unlock();

    return S_OK;
}

//-----------------------------------------------------------------------------
// Desc: 釋放創建的對象
//-----------------------------------------------------------------------------
VOID Cleanup()
{
 //釋放頂點緩沖區對象
    if( g_pVB != NULL )
        g_pVB->Release();

 //釋放Direct3D設備對象
    if( g_pd3dDevice != NULL )
        g_pd3dDevice->Release();

 //釋放Direct3D對象
    if( g_pD3D != NULL )
        g_pD3D->Release();
}

//-----------------------------------------------------------------------------
// Desc: 渲染圖形
//-----------------------------------------------------------------------------
VOID Render()
{
 //清空后臺緩沖區
    g_pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(45, 50, 170), 1.0f, 0 );

 //開始在后臺緩沖區繪制圖形
    if( SUCCEEDED( g_pd3dDevice->BeginScene() ) )
    {
  //設置世界矩陣
        SetupWorldMatrice();

  //在后臺緩沖區繪制圖形

  g_pd3dDevice->SetStreamSource( 0, g_pVB, 0, sizeof(CUSTOMVERTEX) );
        g_pd3dDevice->SetFVF( D3DFVF_CUSTOMVERTEX );
     g_pd3dDevice->SetIndices( g_pIB );  //設置索引緩沖區
     g_pd3dDevice->DrawIndexedPrimitive ( D3DPT_LINELIST, 0,0,100,0,50 );

  //結束在后臺緩沖區渲染圖形
        g_pd3dDevice->EndScene();
    }

 //將在后臺緩沖區繪制的圖形提交到前臺緩沖區顯示
    g_pd3dDevice->Present( NULL, NULL, NULL, NULL );
}

//-----------------------------------------------------------------------------
// Desc: 消息處理
//-----------------------------------------------------------------------------
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: 入口函數
//-----------------------------------------------------------------------------
INT WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR, INT )
{
 //注冊窗口類
    WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC , MsgProc, 0L, 0L,
                      GetModuleHandle(NULL), NULL, NULL, NULL, NULL,
                      L"ClassName", NULL };
    RegisterClassEx( &wc );

 //創建窗口
    HWND hWnd = CreateWindow( L"ClassName", L"坐標變換",
                              WS_OVERLAPPEDWINDOW, 200, 100, 500,500,
                              GetDesktopWindow(), NULL, wc.hInstance, NULL );
 g_Wnd=hWnd;

 //初始化Direct3D
    if( SUCCEEDED( InitD3D( hWnd ) ) )
    {
  //創建場景圖形
        if( SUCCEEDED( InitGeometry() ) )
        {
   //顯示窗口
            ShowWindow( hWnd, SW_SHOWDEFAULT );
            UpdateWindow( hWnd );

   //進入消息循環
            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();  //渲染圖形
    }
            }
        }
    }

    UnregisterClass( L"ClassName", wc.hInstance );
    return 0;
}