#include<d3d9.h>
#include<d3dx9.h>#pragma comment(lib, "d3d9.lib")#pragma comment(lib, "d3dx9.lib")#define WINDOW_CLASS    "UGPDX"#define WINDOW_NAME     "Ortho Projection Matrix"#define WINDOW_WIDTH    640#define WINDOW_HEIGHT   480// Function Prototypes...bool InitializeD3D(HWND hWnd, bool
 
 fullscreen);
bool InitializeObjects();
void RenderScene();
void Shutdown();


// Direct3D object and device.LPDIRECT3D9 g_D3D = NULL;
LPDIRECT3DDEVICE9 g_D3DDevice = NULL;
D3DXMATRIX g_ortho;

// Vertex buffer to hold the geometry.LPDIRECT3DVERTEXBUFFER9 g_VertexBuffer = NULL;

// A structure for our custom vertex type
 
struct stD3DVertex
{
float x, y, z;
    unsigned long color;
};

// Our custom FVF, which describes our custom vertex structure#define D3DFVF_VERTEX (D3DFVF_XYZ | D3DFVF_DIFFUSE)


LRESULT WINAPI MsgProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch(msg)
    {
case WM_DESTROY:
        PostQuitMessage(
 
0);
return0;
break;

case WM_KEYUP:
if(wParam == VK_ESCAPE) PostQuitMessage(0);
break;
    }

return DefWindowProc(hWnd, msg, wParam, lParam);
}


int WINAPI WinMain(HINSTANCE hInst, HINSTANCE prevhInst, LPSTR cmdLine, int show)
{
// Register the window class    WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC, MsgProc, 0L, 0L,
        GetModuleHandle(NULL), NULL, NULL, NULL, NULL,
        WINDOW_CLASS, NULL };
    RegisterClassEx(&wc);

// Create the application's window    HWND hWnd = CreateWindow(WINDOW_CLASS, WINDOW_NAME, WS_OVERLAPPEDWINDOW,
100, 100, WINDOW_WIDTH, WINDOW_HEIGHT, GetDesktopWindow(),
        NULL, wc.hInstance, NULL);

// Initialize Direct3Dif(InitializeD3D(hWnd, false))
    {
// Show the window        ShowWindow(hWnd, SW_SHOWDEFAULT);
        UpdateWindow(hWnd);

// Enter the message loop        MSG msg;
        ZeroMemory(&msg, sizeof(msg));

while(msg.message != WM_QUIT)
        {
if(PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE))
            {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }
else
                RenderScene();
        }
    }

// Release any and all resources.    Shutdown();

// Unregister our window.    UnregisterClass(WINDOW_CLASS, wc.hInstance);
return0;
}


bool InitializeD3D(HWND hWnd, bool fullscreen)
{
    D3DDISPLAYMODE displayMode;

// Create the D3D object.    g_D3D = Direct3DCreate9(D3D_SDK_VERSION);
if(g_D3D == NULL) returnfalse;

// Get the desktop display mode.if(FAILED(g_D3D->GetAdapterDisplayMode(D3DADAPTER_DEFAULT, &displayMode)))
returnfalse;

// Set up the structure used to create the D3DDevice    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory(&d3dpp, sizeof(d3dpp));

if(fullscreen)
    {
        d3dpp.Windowed = FALSE;
        d3dpp.BackBufferWidth = WINDOW_WIDTH;
        d3dpp.BackBufferHeight = WINDOW_HEIGHT;
    }
else
        d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = displayMode.Format;

// Create the D3DDeviceif(FAILED(g_D3D->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
        D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &g_D3DDevice)))
    {
returnfalse;
    }

// Initialize any objects we will be displaying.if(!InitializeObjects()) returnfalse;

returntrue;
}


bool InitializeObjects()
{
// 生成正交投影矩陣
//正交投影中，投影向量和觀察平面垂直，物體座標沿觀察座標系的z軸平行投影到觀察平面上，
//觀察點和觀察平面間的距離不會影響物體的投影大小
//對於正交投影來說，它的取景範圍是一個長方體，只有在這個長方體中的景物才會被繪製出來。
// Set the projection matrix.    D3DXMatrixOrthoLH(&g_ortho, WINDOW_WIDTH, WINDOW_HEIGHT, 0.1f, 1000.0f);
    g_D3DDevice->SetTransform(D3DTS_PROJECTION, &g_ortho);

// Set default rendering states.    g_D3DDevice->SetRenderState(D3DRS_LIGHTING, FALSE);

//代表是否繪製三角形的反面。
// D3DCULL_MODE是背面隱藏消除的意思. 
//SetRenderState( D3DRS_CULLMODE, D3DCULL_NONE )則正反面都繪製。 
//SetRenderState( D3DRS_CULLMODE, D3DCULL_CW ); //繪製順時針三角形。 
//SetRenderState( D3DRS_CULLMODE, D3DCULL_CCW )繪製逆時針三角形。    g_D3DDevice->SetRenderState(D3DRS_CULLMODE, D3DCULL_NONE);

// Fill in our structure to draw an object.
// x, y, z, color.    stD3DVertex objData[] =
    {
        {-150.0f, -150.0f, 0.1f, D3DCOLOR_XRGB(255,0,0)},
        {150.0f, -150.0f, 0.1f, D3DCOLOR_XRGB(0,255,0)},
        {0.0f, 150.0f, 0.1f, D3DCOLOR_XRGB(0,0,255)}
    };

// Create the vertex buffer.if(FAILED(g_D3DDevice->CreateVertexBuffer(3*sizeof(stD3DVertex), 0,
        D3DFVF_VERTEX, D3DPOOL_DEFAULT, &g_VertexBuffer, NULL))) returnfalse;

// Fill the vertex buffer.void*ptr;
if(FAILED(g_VertexBuffer->Lock(0, sizeof(objData), (void**)&ptr, 0))) returnfalse;
    memcpy(ptr, objData, sizeof(objData));
    g_VertexBuffer->Unlock();

returntrue;
}


void RenderScene()
{
// Clear the backbuffer.    g_D3DDevice->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,0), 1.0f, 0);

// Begin the scene.  Start rendering.    g_D3DDevice->BeginScene();

// Bind data to the stream, set fvf so D3D knows how our data
// is made up, then render the object.    g_D3DDevice->SetStreamSource(0, g_VertexBuffer, 0, sizeof(stD3DVertex));
    g_D3DDevice->SetFVF(D3DFVF_VERTEX);
    g_D3DDevice->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 1);

// End the scene.  Stop rendering.    g_D3DDevice->EndScene();

// Display the scene.    g_D3DDevice->Present(NULL, NULL, NULL, NULL);
}


void Shutdown()
{
if(g_D3DDevice != NULL) g_D3DDevice->Release();
if(g_D3D != NULL) g_D3D->Release();
if(g_VertexBuffer != NULL) g_VertexBuffer->Release();
}