Linguagem C - SetTimer(hwnd, ID_TIMER, 20, NULL);

#include <windows.h> #define ID_TIMER 1 LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow) { static TCHAR szAppName[] = TEXT("Bounce"); HWND hwnd; MSG msg; WNDCLASS wndclass; wndclass.style = CS_HREDRAW | CS_VREDRAW; wndclass.lpfnWndProc = WndProc; wndclass.cbClsExtra = 0; wndclass.cbWndExtra = 0; wndclass.hInstance = hInstance; wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION); wndclass.hCursor = LoadCursor(NULL, IDC_ARROW); wndclass.hbrBackground = (HBRUSH) WHITE_BRUSH; wndclass.lpszMenuName = NULL; wndclass.lpszClassName = szAppName; if(!RegisterClass(&wndclass)) { MessageBox(NULL, TEXT("This program requires Windows NT!"), szAppName, MB_ICONERROR); return 0; } hwnd = CreateWindow(szAppName, TEXT("Bouncing Ball"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL); ShowWindow(hwnd, iCmdShow); UpdateWindow(hwnd); while(GetMessage(&msg, NULL, 0, 0)) { TranslateMessage(&msg); DispatchMessage (&msg); } return msg.wParam; } LRESULT CALLBACK WndProc(HWND hwnd,UINT iMsg,WPARAM wParam,LPARAM lParam) { static HBITMAP hBitmap; static int cxClient, cyClient, xCenter, yCenter, cxTotal, cyTotal, cxRadius, cyRadius, cxMove, cyMove, xPixel, yPixel; HBRUSH hBrush; HDC hdc, hdcMem; int iScale; switch(iMsg) { case WM_CREATE: hdc = GetDC(hwnd); xPixel = GetDeviceCaps(hdc, ASPECTX); yPixel = GetDeviceCaps(hdc, ASPECTY); ReleaseDC(hwnd, hdc); SetTimer(hwnd, ID_TIMER, 20, NULL); return 0; case WM_SIZE: xCenter = (cxClient = LOWORD(lParam)) / 2; yCenter = (cyClient = HIWORD(lParam)) / 2; iScale = min(cxClient * xPixel, cyClient * yPixel) / 16; cxRadius = iScale / xPixel; cyRadius = iScale / yPixel; cxMove = max(1, cxRadius / 2); cyMove = max(1, cyRadius / 2); cxTotal = 2 * (cxRadius + cxMove); cyTotal = 2 * (cyRadius + cyMove); if(hBitmap) DeleteObject(hBitmap); hdc = GetDC(hwnd); hdcMem = CreateCompatibleDC(hdc); hBitmap=CreateCompatibleBitmap(hdc,cxTotal,cyTotal); ReleaseDC(hwnd, hdc); SelectObject(hdcMem, hBitmap); Rectangle(hdcMem, -1, -1, cxTotal + 1, cyTotal + 1); hBrush = CreateHatchBrush(HS_DIAGCROSS, 0L); SelectObject(hdcMem, hBrush); SetBkColor(hdcMem, RGB(0, 77, 0)); Ellipse(hdcMem,cxMove,cyMove,cxTotal-cxMove,cyTotal-cyMove); DeleteDC(hdcMem); DeleteObject(hBrush); return 0; case WM_TIMER: if(!hBitmap) break; hdc = GetDC(hwnd); hdcMem = CreateCompatibleDC(hdc); SelectObject(hdcMem, hBitmap); BitBlt(hdc,xCenter-cxTotal/2,yCenter-cyTotal/2,cxTotal,cyTotal, hdcMem, 0, 0, SRCCOPY); ReleaseDC(hwnd, hdc); DeleteDC(hdcMem); xCenter += cxMove; yCenter += cyMove; if((xCenter+cxRadius>=cxClient)||(xCenter-cxRadius<=0)) cxMove = -cxMove; if((yCenter+cyRadius>=cyClient)||(yCenter-cyRadius<=0)) cyMove =-cyMove; return 0; case WM_DESTROY: if(hBitmap) DeleteObject(hBitmap); KillTimer(hwnd, ID_TIMER); PostQuitMessage(0); return 0; } return DefWindowProc(hwnd, iMsg, wParam, lParam); }