d3d_windowed

// Beginning Game Programming, Second Edition
// Chapter 5
// d3d_windowed program
//header files to include
#include <d3d9.h>
#include <time.h>
//application title
#define APPTITLE L"Direct3D_Windowed"
//forward declarations
LRESULT WINAPI WinProc(HWND,UINT,WPARAM,LPARAM);
ATOM MyRegisterClass(HINSTANCE);
int Game_Init(HWND);
void Game_Run(HWND);
void Game_End(HWND);
//Direct3D objects
LPDIRECT3D9 d3d = NULL;
LPDIRECT3DDEVICE9 d3ddev = NULL;
//window event callback function
LRESULT WINAPI WinProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam ) {
    switch( msg ) {
        case WM_DESTROY:
        Game_End(hWnd);
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc( hWnd, msg, wParam, lParam );
}
//helper function to set up the window properties
ATOM MyRegisterClass(HINSTANCE hInstance) {
    //create the window class structure
    WNDCLASSEX wc;
    wc.cbSize = sizeof(WNDCLASSEX);
    //fill the struct with info
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = (WNDPROC)WinProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = hInstance;
    wc.hIcon = NULL;
    wc.hCursor = LoadCursor(NULL, IDC_ARROW);
    wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    wc.lpszMenuName = NULL;
    wc.lpszClassName = APPTITLE;
    wc.hIconSm = NULL;
    //set up the window with the class info
    return RegisterClassEx(&wc);
}
//entry point for a Windows program
int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShow) {
    // declare variables
    MSG msg;
    // register the class
    MyRegisterClass(hInstance);
    // initialize application
    //note––got rid of initinstance
    HWND hWnd;
    //create a new window
    hWnd = CreateWindow(
    APPTITLE, //window class
    APPTITLE, //title bar
    WS_OVERLAPPEDWINDOW, //window style
    CW_USEDEFAULT, //x position of window
    CW_USEDEFAULT, //y position of window
    500, //width of the window
    400, //height of the window
    NULL, //parent window
    NULL, //menu
    hInstance, //application instance
    NULL); //window parameters
    //was there an error creating the window?
    if (!hWnd)
        return FALSE;
    //display the window
    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);
    //initialize the game
    if (!Game_Init(hWnd))
        return 0;
    // main message loop
    int done = 0;
    while (!done) {
        if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
            //look for quit message
            if (msg.message == WM_QUIT) {
                MessageBox(hWnd, L"Received WM_QUIT message", L"WinMain", MB_OK);
                done = 1;
            }
            //decode and pass messages on to WndProc
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
        else
            //process game loop (else prevents running after window is closed)
            Game_Run(hWnd);
        }
    return msg.wParam;
}
int Game_Init(HWND hwnd) {
    //display init message
    MessageBox(hwnd, L"Program is about to start", L"Game_Init", MB_OK);
    //initialize Direct3D
    d3d = Direct3DCreate9(D3D_SDK_VERSION);
    if (d3d == NULL) {
        MessageBox(hwnd, L"Error initializing Direct3D", L"Error", MB_OK);
        return 0;
    }
    //set Direct3D presentation parameters
    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory(&d3dpp, sizeof(d3dpp));
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
    //create Direct3D device
    d3d->CreateDevice(
    D3DADAPTER_DEFAULT,
    D3DDEVTYPE_HAL,
    hwnd,
    D3DCREATE_SOFTWARE_VERTEXPROCESSING,
    &d3dpp,
    &d3ddev);
    if (d3ddev == NULL) {
        MessageBox(hwnd, L"Error creating Direct3D device", L"Error", MB_OK);
        return 0;
    }
    //set random number seed
    srand(time(NULL));
    //return okay
    return 1;
}
void Game_Run(HWND hwnd) {
    //make sure the Direct3D device is valid
    if (d3ddev == NULL)
        return;
    //clear the screen with a green color
    d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,255,255), 1.0f, 0);
    //start rendering
    if (d3ddev->BeginScene()) {
        //do something here!
        //stop rendering
        d3ddev->EndScene();
    }
    //display the back buffer on the screen
    d3ddev->Present(NULL, NULL, NULL, NULL);
}
void Game_End(HWND hwnd) {
    //display close message
    MessageBox(hwnd, L"Program is about to end", L"Game_End", MB_OK);
    //release the Direct3D device
    if (d3ddev != NULL)
        d3ddev->Release();
    //release the Direct3D object
    if (d3d != NULL)
        d3d->Release();
}