Create_Surface

// Beginning Game Programming, Second Edition
// Chapter 6
// Create_Surface program
//header files to include
#include <d3d9.h>
#include <time.h>
//application title
#define APPTITLE L"Create_Surface"
//macros to read the keyboard asynchronously
#define KEY_DOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
#define KEY_UP(vk_code)((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0)
//screen resolution
#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480
//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;
LPDIRECT3DSURFACE9 backbuffer = NULL;
LPDIRECT3DSURFACE9 surface = 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
    HWND hWnd;
    //create a new window
    hWnd = CreateWindow(
    APPTITLE, //window class
    APPTITLE, //title bar
    WS_EX_TOPMOST | WS_VISIBLE | WS_POPUP, //window style
    CW_USEDEFAULT, //x position of window
    CW_USEDEFAULT, //y position of window
    SCREEN_WIDTH, //width of the window
    SCREEN_HEIGHT, //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)
                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) {
    HRESULT result;
    //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 = FALSE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = D3DFMT_X8R8G8B8;
    d3dpp.BackBufferCount = 1;
    d3dpp.BackBufferWidth = SCREEN_WIDTH;
    d3dpp.BackBufferHeight = SCREEN_HEIGHT;
    d3dpp.hDeviceWindow = hwnd;
    //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));
    //clear the backbuffer to black
    d3ddev->Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,0), 1.0f, 0);
    //create pointer to the back buffer
    d3ddev->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &backbuffer);
    //create surface
    result = d3ddev->CreateOffscreenPlainSurface(
    100, //width of the surface
    100, //height of the surface
    D3DFMT_X8R8G8B8, //surface format
    D3DPOOL_DEFAULT, //memory pool to use
    &surface, //pointer to the surface
    NULL); //reserved (always NULL)
    if (!result)
        return 1;
    //return okay
    return 1;
}
void Game_Run(HWND hwnd) {
    RECT rect;
    int r,g,b;
    //make sure the Direct3D device is valid
    if (d3ddev == NULL)
        return;
    //start rendering
    if (d3ddev->BeginScene()) {
        //fill the surface with random color
        r = rand() % 255;
        g = rand() % 255;
        b = rand() % 255;
        d3ddev->ColorFill(surface, NULL, D3DCOLOR_XRGB(r,g,b));
        //copy the surface to the backbuffer
        rect.left = rand() % SCREEN_WIDTH/2;
        rect.right = rect.left + rand() % SCREEN_WIDTH/2;
        rect.top = rand() % SCREEN_HEIGHT;
        rect.bottom = rect.top + rand() % SCREEN_HEIGHT/2;
        d3ddev->StretchRect(surface, NULL, backbuffer, &rect, D3DTEXF_NONE);
        //stop rendering
        d3ddev->EndScene();
    }
    //display the back buffer on the screen
    d3ddev->Present(NULL, NULL, NULL, NULL);
    //check for escape key (to exit program)
    if (KEY_DOWN(VK_ESCAPE))
        PostMessage(hwnd, WM_DESTROY, 0, 0);
}
void Game_End(HWND hwnd) {
    //free the surface
    surface->Release();
    //release the Direct3D device
    if (d3ddev != NULL)
    d3ddev->Release();
    //release the Direct3D object
    if (d3d != NULL)
    d3d->Release();
}