Last updated: 18. 1.1998, 12:48
<* +M2EXTENSIONS *> MODULE Bounce; (*--------------------------------------- BOUNCE.C --- Bouncing Ball Program (c) Charles Petzold, 1996 Bounce.mod --- Translation to XDS Modula-2 (c) Peter Stadler, 1997 ---------------------------------------*) IMPORT Windows; IMPORT SYSTEM; CONST szAppName = "Bounce"; VAR hwnd : Windows.HWND; msg : Windows.MSG; wc : Windows.WNDCLASSEX; hBitmap : Windows.HBITMAP; cxClient, cyClient, xCenter, yCenter, cxTotal, cyTotal, cxRadius, cyRadius, cxMove, cyMove, xPixel, yPixel : INTEGER; hBrush : Windows.HBRUSH; hdc : Windows.HDC; hdcMem : Windows.HDC; iScale : INTEGER; (*++++*****************************************************************) PROCEDURE MaxInt (a,b : INTEGER) : INTEGER; (**********************************************************************) BEGIN IF(a>b) THEN RETURN a; ELSE RETURN b; END; END MaxInt; (*++++*****************************************************************) PROCEDURE MinInt (a,b : INTEGER) : INTEGER; (**********************************************************************) BEGIN IF(a>b) THEN RETURN b; ELSE RETURN a; END; END MinInt; (*++++*****************************************************************) PROCEDURE [Windows.CALLBACK] WndProc (hwnd : Windows.HWND; (**********************************************************************) iMsg : Windows.UINT; wParam : Windows.WPARAM; lParam : Windows.LPARAM) : Windows.LRESULT; BEGIN CASE (iMsg) OF | Windows.WM_CREATE : hdc := Windows.GetDC (hwnd); xPixel := Windows.GetDeviceCaps (hdc, Windows.ASPECTX); yPixel := Windows.GetDeviceCaps (hdc, Windows.ASPECTY); Windows.ReleaseDC (hwnd, hdc); RETURN 0; | Windows.WM_SIZE : cxClient := Windows.LOWORD (lParam); xCenter := cxClient / 2; cyClient := Windows.HIWORD (lParam); yCenter := cyClient / 2; iScale := MinInt (cxClient * xPixel, cyClient * yPixel) / 16; cxRadius := iScale / xPixel; cyRadius := iScale / yPixel; cxMove := MaxInt (1, cxRadius / 2); cyMove := MaxInt (1, cyRadius / 2); cxTotal := 2 * (cxRadius + cxMove); cyTotal := 2 * (cyRadius + cyMove); IF (hBitmap#NIL) THEN Windows.DeleteObject (SYSTEM.CAST(Windows.HGDIOBJ,hBitmap)); END; hdc := Windows.GetDC (hwnd); hdcMem := Windows.CreateCompatibleDC (hdc); hBitmap := Windows.CreateCompatibleBitmap (hdc, cxTotal, cyTotal); Windows.ReleaseDC (hwnd, hdc); Windows.SelectObject (hdcMem, SYSTEM.CAST(Windows.HGDIOBJ,hBitmap)); Windows.Rectangle (hdcMem, -1, -1, cxTotal + 1, cyTotal + 1); hBrush := Windows.CreateHatchBrush (Windows.HS_DIAGCROSS, 0000h); Windows.SelectObject (hdcMem, SYSTEM.CAST(Windows.HGDIOBJ,hBrush)); Windows.SetBkColor (hdcMem, Windows.RGB (255, 0, 255)); Windows.Ellipse (hdcMem, cxMove, cyMove, cxTotal - cxMove, cyTotal - cyMove); Windows.DeleteDC (hdcMem); Windows.DeleteObject (SYSTEM.CAST(Windows.HGDIOBJ,hBrush)); RETURN 0; | Windows.WM_TIMER : IF (hBitmap#NIL) THEN hdc := Windows.GetDC (hwnd); hdcMem := Windows.CreateCompatibleDC (hdc); Windows.SelectObject (hdcMem, SYSTEM.CAST(Windows.HGDIOBJ,hBitmap)); Windows.BitBlt (hdc, xCenter - cxTotal / 2, yCenter - cyTotal / 2, cxTotal, cyTotal, hdcMem, 0, 0, Windows.SRCCOPY); Windows.ReleaseDC (hwnd, hdc); Windows.DeleteDC (hdcMem); xCenter := xCenter+cxMove; yCenter := yCenter+cyMove; IF ((xCenter + cxRadius >= cxClient) OR (xCenter - cxRadius <= 0)) THEN cxMove := -cxMove; END; IF ((yCenter + cyRadius >= cyClient) OR (yCenter - cyRadius <= 0)) THEN cyMove := -cyMove; END; RETURN 0; ELSE RETURN Windows.DefWindowProc (hwnd, iMsg, wParam, lParam); END; | Windows.WM_DESTROY : IF (hBitmap#NIL) THEN Windows.DeleteObject (SYSTEM.CAST(Windows.HGDIOBJ,hBitmap)); END; Windows.KillTimer (hwnd, 1); Windows.PostQuitMessage (0); RETURN 0; ELSE RETURN Windows.DefWindowProc (hwnd, iMsg, wParam, lParam); END; END WndProc; (*++++*****************************************************************) PROCEDURE InitApplication () : BOOLEAN; (**********************************************************************) BEGIN wc.cbSize := SIZE(wc); wc.style := Windows.CS_HREDRAW + Windows.CS_VREDRAW; wc.lpfnWndProc := WndProc; wc.cbClsExtra := 0; wc.cbWndExtra := 0; wc.hInstance := Windows.MyInstance(); wc.hIcon := Windows.LoadIcon (NIL, Windows.IDI_APPLICATION); wc.hCursor := Windows.LoadCursor (NIL, Windows.IDC_ARROW); wc.hbrBackground := SYSTEM.CAST(Windows.HBRUSH, Windows.GetStockObject (Windows.WHITE_BRUSH)); wc.lpszMenuName := NIL; wc.lpszClassName := SYSTEM.ADR(szAppName); wc.hIconSm := Windows.LoadIcon (NIL,Windows.IDI_APPLICATION); RETURN Windows.RegisterClassEx(wc)#0; END InitApplication; (*++++*****************************************************************) PROCEDURE InitMainWindow () : BOOLEAN; (**********************************************************************) BEGIN hwnd := Windows.CreateWindow (szAppName, "Bouncing Ball: Translation to XDS Modula-2", Windows.WS_OVERLAPPEDWINDOW, Windows.CW_USEDEFAULT, Windows.CW_USEDEFAULT, Windows.CW_USEDEFAULT, Windows.CW_USEDEFAULT, NIL, NIL, Windows.MyInstance(), NIL); IF(Windows.SetTimer (hwnd, 1, 50, NIL)=0) THEN Windows.MessageBox (hwnd, "Too many clocks or timers!", szAppName, Windows.MB_ICONEXCLAMATION + Windows.MB_OK); RETURN FALSE; END; Windows.ShowWindow (hwnd, Windows.SW_SHOWDEFAULT); Windows.UpdateWindow (hwnd); RETURN TRUE; END InitMainWindow; BEGIN IF InitApplication() AND InitMainWindow() THEN WHILE (Windows.GetMessage(msg,NIL,0,0)) DO Windows.TranslateMessage(msg); Windows.DispatchMessage(msg); END; END; END Bounce.