InvertCorners_VintageMacintosh/invertcorners.c

#include <Quickdraw.h>

int main(void) 
{
																// Setup 
	Rect s;
	RgnHandle CornersRgn;
	RgnHandle WholeRgn;
	InitGraf(&qd.thePort);
	InitWindows();
	s = qd.screenBits.bounds;

																// Whole screen set
	RectRgn(qd.thePort->visRgn, &s);
																// Draw the rounded corners
	WholeRgn = NewRgn();
	OpenRgn();
	FrameRoundRect(&s, 16, 16);
	CloseRgn(WholeRgn);
																// Invert just the corners	
	CornersRgn = NewRgn();
	DiffRgn(qd.thePort->visRgn, WholeRgn, CornersRgn);
	InvertRgn(CornersRgn);
																// Set screen as rounded screen
	CopyRgn(WholeRgn, qd.thePort->visRgn);
	DisposeRgn(WholeRgn);
}