www.pudn.com > Windows Game Programming Gurus Examp > demo4_4.cpp
// DEMO4_4.CPP - Ellipse Animation Demo // INCLUDES /////////////////////////////////////////////// #define WIN32_LEAN_AND_MEAN // just say no to MFC #include// include all the windows headers #include // include useful macros #include // very important and include WINMM.LIB too! #include #include #include // DEFINES //////////////////////////////////////////////// // defines for windows #define WINDOW_CLASS_NAME "WINCLASS1" #define WINDOW_WIDTH 400 #define WINDOW_HEIGHT 300 // MACROS ///////////////////////////////////////////////// #define KEYDOWN(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 1 : 0) #define KEYUP(vk_code) ((GetAsyncKeyState(vk_code) & 0x8000) ? 0 : 1) // GLOBALS //////////////////////////////////////////////// HWND main_window_handle = NULL; // globally track main window HINSTANCE hinstance_app = NULL; // globally track hinstance char buffer[80]; // general printing buffer // FUNCTIONS ////////////////////////////////////////////// LRESULT CALLBACK WindowProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam) { // this is the main message handler of the system PAINTSTRUCT ps; // used in WM_PAINT HDC hdc; // handle to a device context //char buffer[80]; // used to print strings // what is the message switch(msg) { case WM_CREATE: { // do initialization stuff here // return success return(0); } break; case WM_PAINT: { // simply validate the window hdc = BeginPaint(hwnd,&ps); // end painting EndPaint(hwnd,&ps); // return success return(0); } break; case WM_DESTROY: { // kill the application, this sends a WM_QUIT message PostQuitMessage(0); // return success return(0); } break; default:break; } // end switch // process any messages that we didn't take care of return (DefWindowProc(hwnd, msg, wparam, lparam)); } // end WinProc // WINMAIN //////////////////////////////////////////////// int WINAPI WinMain( HINSTANCE hinstance, HINSTANCE hprevinstance, LPSTR lpcmdline, int ncmdshow) { WNDCLASSEX winclass; // this will hold the class we create HWND hwnd; // generic window handle MSG msg; // generic message HDC hdc; // graphics device context // first fill in the window class stucture winclass.cbSize = sizeof(WNDCLASSEX); winclass.style = CS_DBLCLKS | CS_OWNDC | CS_HREDRAW | CS_VREDRAW; winclass.lpfnWndProc = WindowProc; winclass.cbClsExtra = 0; winclass.cbWndExtra = 0; winclass.hInstance = hinstance; winclass.hIcon = LoadIcon(NULL, IDI_APPLICATION); winclass.hCursor = LoadCursor(NULL, IDC_ARROW); winclass.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH); winclass.lpszMenuName = NULL; winclass.lpszClassName = WINDOW_CLASS_NAME; winclass.hIconSm = LoadIcon(NULL, IDI_APPLICATION); // save hinstance in global hinstance_app = hinstance; // register the window class if (!RegisterClassEx(&winclass)) return(0); // create the window if (!(hwnd = CreateWindowEx(NULL, // extended style WINDOW_CLASS_NAME, // class "Ellipse Animation Demo", // title WS_OVERLAPPEDWINDOW | WS_VISIBLE, 0,0, // initial x,y WINDOW_WIDTH, // initial width WINDOW_HEIGHT,// initial height NULL, // handle to parent NULL, // handle to menu hinstance,// instance of this application NULL))) // extra creation parms return(0); // save main window handle main_window_handle = hwnd; // get the graphics device context once this time and keep it // this is possible due to the CS_OWNDC flag hdc = GetDC(hwnd); // seed random number generator srand(GetTickCount()); // create the pens and brushes HPEN white_pen = CreatePen(PS_SOLID, 1, RGB(255,255,255)); HPEN black_pen = CreatePen(PS_SOLID, 1, RGB(0,0,0)); HBRUSH green_brush = CreateSolidBrush(RGB(0,255,0)); HBRUSH black_brush = CreateSolidBrush(RGB(0,0,0)); // starting position of ball int ball_x = WINDOW_WIDTH/2; int ball_y = WINDOW_HEIGHT/2; // initial velocity of ball int xv = -4+rand()%8; int yv = -4+rand()%8; // enter main event loop, but this time we use PeekMessage() // instead of GetMessage() to retrieve messages while(TRUE) { // test if there is a message in queue, if so get it if (PeekMessage(&msg,NULL,0,0,PM_REMOVE)) { // test if this is a quit if (msg.message == WM_QUIT) break; // translate any accelerator keys TranslateMessage(&msg); // send the message to the window proc DispatchMessage(&msg); } // end if // ERASE the last position of the ball // first select the black pen and brush into context SelectObject(hdc, black_pen); SelectObject(hdc, black_brush); // draw the ball Ellipse(hdc, ball_x, ball_y, ball_x + 32, ball_y + 32); // MOVE the ball ball_x+=xv; ball_y+=yv; // test for collisions, first x-axis if (ball_x < 0 || ball_x > WINDOW_WIDTH - 32) { // invert x-velocity of ball xv=-xv; // push ball back ball_x+=xv; } // end if else // test for y-axis collisions if (ball_y < 0 || ball_y > WINDOW_HEIGHT - 32) { // invert y-velocity of ball yv=-yv; // push ball back ball_y+=yv; } // end if // now select the green and white colors for brush and pen SelectObject(hdc, white_pen); SelectObject(hdc, green_brush); // DRAW the ball Ellipse(hdc, ball_x, ball_y, ball_x + 32, ball_y + 32); // main game processing goes here if (KEYDOWN(VK_ESCAPE)) SendMessage(hwnd, WM_CLOSE, 0,0); // slow system down a little Sleep(10); } // end while // delete all the objects DeleteObject(white_pen); DeleteObject(black_pen); DeleteObject(green_brush); DeleteObject(black_brush); // release the device context ReleaseDC(hwnd,hdc); // return to Windows like this return(msg.wParam); } // end WinMain ///////////////////////////////////////////////////////////