小菜鸟的C++游戏编程学习日记(二)

                                                      作者：杨帆
                     
                       参考书籍：Beginning Game ProGramming(中文版)
                       学习时间：2016.7.27   

#include <windows.h>#include <iostream>#include <time.h>      //include header sourceusing namespace std;const string APPTITLE = "Game Loop";HWND hWnd;HDC hDc;bool gameover = false;     //local and draws a bitmap from file and then free the memory//(not really suitable for a game loop but it's self contained)void DrawBitmap(char* filename,int x,int y){    //load the bitmap image    HBITMAP image = (HBITMAP)LoadImage(0, "000.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);    //read the bitmap's properties    BITMAP bmp;    GetObject(image, sizeof(BITMAP), &bmp);    //creat a device context for the bitmap    HDC hdcImage = CreateCompatibleDC(hDc);    SelectObject(hdcImage, image);    //draw the bitmap to the window (bit block transfer)    BitBlt(        hDc,                                //destination device context        x, y,                               //x,y location on destination        bmp.bmWidth, bmp.bmHeight,          //width,height of source bitmap        hdcImage,                           //source bitmap device context        0, 0,                               //start x,y on source bitmap        SRCCOPY                             //bit method    );    //delete the device context and bitmap    DeleteDC(hdcImage);    DeleteObject((HBITMAP)image);}//startup and loading code goes herebool GameInit(){    //start up the random number generator    srand((unsigned)time(NULL));    return true;}//update function called from inside game loopvoid GameRun(){    if (gameover == true)     {        return;    }    //get the drawing surface    RECT rect;    GetClientRect(hWnd, &rect);    //draw bitmap at random location     int x = rand() % (rect.right - rect.left);    int y = rand() % (rect.bottom - rect.top);    DrawBitmap("000.bmp", x, y);}//shut down code void GameEnd(){    //free the device     ReleaseDC(hWnd,hDc);}//window callback functionLRESULT CALLBACK WinProc(HWND hwnd,UINT message,WPARAM wparam,LPARAM lparam){    switch (message)    {    case WM_DESTROY:        gameover = true;        PostQuitMessage(0);        break;    default:        break;    }    return DefWindowProc(hwnd, message, wparam, lparam);}//register the windowATOM MyRegisterWindowClass(HINSTANCE hInstance){    // creat a window class struct    WNDCLASSEX wc;                wc.cbClsExtra = 0;    wc.cbSize = sizeof(WNDCLASSEX);    wc.cbWndExtra = 0;    wc.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);    wc.hCursor = LoadCursor(NULL, IDC_ARROW);    wc.hIcon = NULL;    wc.hIconSm = NULL;    wc.hInstance = hInstance;    wc.lpfnWndProc = (WNDPROC)WinProc;    wc.lpszClassName = APPTITLE.c_str();    wc.lpszMenuName = NULL;    wc.style = CS_HREDRAW | CS_VREDRAW;    return RegisterClassEx(&wc);}//helper function to create the window and refresh itBOOL InitInstance(HINSTANCE hInstance,int nCmdShow){    //creat new window    hWnd = CreateWindow(        APPTITLE.c_str(),                   //ClassName        APPTITLE.c_str(),                   //WindowName        WS_OVERLAPPEDWINDOW,                //style        CW_USEDEFAULT, CW_USEDEFAULT,       //x,y position in window (use default)        800, 500,                           //window size        NULL, NULL,                         //WndParent      hMenu        hInstance,                          //Window instance        NULL                                //lParam    );    //was here an error creating the window    if (!hWnd)    {        return 0;    }    //display the window    ShowWindow(hWnd, nCmdShow);    UpdateWindow(hWnd);    //get device context for drawing    hDc = GetDC(hWnd);    return 1;}//Entry point functionint WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nCmdShow){    MSG msg;    //creat window    MyRegisterWindowClass(hInstance);    if (!InitInstance(hInstance,nCmdShow))    {        return 0;    }    //initialize the game    if (!GameInit())    {        return 0;    }    //main message loop    while (!gameover)    {        //process windows events        if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))        {            TranslateMessage(&msg);            DispatchMessage(&msg);        }        //process  game loop        GameRun();    }    //free game resource    GameEnd();    return msg.wParam;}

          这里对比昨天主要是对消息循环进行了新的处理，使得游戏过程有了一个完整的循环过程。并且藉此和之前看过的一点视频学习了关于贴图的知识，利用之前有的资源写了另一份代码。效果如下(没错就是会动的):