Last updated: 17. 1.1998, 20:23
<* +M2EXTENSIONS *> MODULE Clover; (*-------------------------------------------------- CLOVER.C --- Clover Drawing Program using Regions (c) Charles Petzold, 1996 Clover.mod --- Translation to XDS Modula-2 (c) Peter Stadler, 1997 --------------------------------------------------*) IMPORT Windows; IMPORT SYSTEM; IMPORT RealMath; CONST TWO_PI = 2.0 * 3.14159; CONST szAppName = "Clover"; VAR hwnd : Windows.HWND; msg : Windows.MSG; wc : Windows.WNDCLASSEX; hRgnClip : Windows.HRGN; cxClient : INTEGER; cyClient : INTEGER; (*++++*****************************************************************) PROCEDURE [Windows.CALLBACK] WndProc(hwnd : Windows.HWND; (**********************************************************************) iMsg : Windows.UINT; wParam : Windows.WPARAM; lParam : Windows.LPARAM) : Windows.LRESULT; VAR fAngle : CARDINAL; fRadius : REAL; fx : REAL; fy : REAL; hCursor : Windows.HCURSOR; hdc : Windows.HDC; hRgnTemp : ARRAY[0..5] OF Windows.HRGN; i : INTEGER; ps : Windows.PAINTSTRUCT; BEGIN CASE (iMsg) OF | Windows.WM_SIZE: cxClient := Windows.LOWORD (lParam); cyClient := Windows.HIWORD (lParam); hCursor := Windows.SetCursor (Windows.LoadCursor (NIL, Windows.IDC_WAIT)); Windows.ShowCursor (TRUE); IF (hRgnClip#NIL) THEN Windows.DeleteObject (SYSTEM.CAST(Windows.HGDIOBJ,hRgnClip) ); END; hRgnTemp[0] := Windows.CreateEllipticRgn (0, cyClient / 3, cxClient / 2, 2 * cyClient / 3); hRgnTemp[1] := Windows.CreateEllipticRgn (cxClient / 2, cyClient / 3, cxClient, 2 * cyClient / 3); hRgnTemp[2] := Windows.CreateEllipticRgn (cxClient / 3, 0, 2 * cxClient / 3, cyClient / 2); hRgnTemp[3] := Windows.CreateEllipticRgn (cxClient / 3, cyClient / 2, 2 * cxClient / 3, cyClient); hRgnTemp[4] := Windows.CreateRectRgn (0, 0, 1, 1); hRgnTemp[5] := Windows.CreateRectRgn (0, 0, 1, 1); hRgnClip := Windows.CreateRectRgn (0, 0, 1, 1); Windows.CombineRgn (hRgnTemp[4], hRgnTemp[0], hRgnTemp[1], Windows.RGN_OR); Windows.CombineRgn (hRgnTemp[5], hRgnTemp[2], hRgnTemp[3], Windows.RGN_OR); Windows.CombineRgn (hRgnClip, hRgnTemp[4], hRgnTemp[5], Windows.RGN_XOR); FOR i := 0 TO 6-1 DO Windows.DeleteObject (SYSTEM.CAST(Windows.HGDIOBJ,hRgnTemp[i])); END; Windows.SetCursor (hCursor); Windows.ShowCursor (FALSE); RETURN 0; | Windows.WM_PAINT: hdc := Windows.BeginPaint (hwnd, ps); Windows.SetViewportOrgEx (hdc, cxClient / 2, cyClient / 2, NIL); Windows.SelectClipRgn (hdc, hRgnClip); fx := VAL(REAL,(cxClient*cxClient))/4.0; fy := VAL(REAL,(cyClient*cyClient))/4.0; fRadius := RealMath.sqrt(fx+fy); FOR fAngle := 0 TO 360-1 DO Windows.MoveToEx (hdc, 0, 0, NIL); Windows.LineTo (hdc, VAL(INTEGER,(fRadius * RealMath.cos (VAL(REAL,fAngle)*TWO_PI/360.) + 0.5)), VAL(INTEGER,(-fRadius * RealMath.sin (VAL(REAL,fAngle)*TWO_PI/360.) + 0.5))); END; Windows.EndPaint (hwnd, ps); RETURN 0; | Windows.WM_DESTROY: Windows.DeleteObject (SYSTEM.CAST(Windows.HGDIOBJ,hRgnClip)); Windows.PostQuitMessage (0); RETURN 0; ELSE RETURN Windows.DefWindowProc (hwnd, iMsg, wParam, lParam); END; END WndProc; (*++++*****************************************************************) PROCEDURE InitApplication () : BOOLEAN; (**********************************************************************) VAR rc : CARDINAL; 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); rc := Windows.RegisterClassEx(wc); RETURN rc #0; END InitApplication; (*++++*****************************************************************) PROCEDURE InitMainWindow () : BOOLEAN; (**********************************************************************) BEGIN hwnd := Windows.CreateWindow ( szAppName, (* window class name *) "Draw a Clover: Translation to XDS Modula-2", (* window caption *) Windows.WS_OVERLAPPEDWINDOW, (* window style *) Windows.CW_USEDEFAULT, (* initial x position *) Windows.CW_USEDEFAULT, (* initial y position *) Windows.CW_USEDEFAULT, (* initial x size *) Windows.CW_USEDEFAULT, (* initial y size *) NIL, (* parent window handle *) NIL, (* window menu handle *) wc.hInstance, (* program instance handle *) NIL); (* creation parameters *) IF hwnd = NIL THEN 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 Clover.