/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h>#include <draw.h>#include <memdraw.h>#include <memlayer.h> intmemunload(Memimage *src, Rectangle r, uchar *data, int n){	Memimage *tmp;	Memlayer *dl;	Rectangle lr;	int dx;     Top:	dl = src->layer;	if(dl == nil)		return unloadmemimage(src, r, data, n); 	/* 	 * Convert to screen coordinates.	 */	lr = r;	r.min.x += dl->delta.x;	r.min.y += dl->delta.y;	r.max.x += dl->delta.x;	r.max.y += dl->delta.y;	dx = dl->delta.x&(7/src->depth);	if(dl->clear && dx==0){		src = dl->screen->image;		goto Top;	} 	/*	 * src is an obscured layer or data is unaligned	 */	if(dl->save && dx==0){		if(dl->refreshfn != nil)			return -1;	/* can't unload window if it's not Refbackup */		if(n > 0)			memlhide(src, r);		n = unloadmemimage(dl->save, lr, data, n);		return n;	}	tmp = allocmemimage(lr, src->chan);	if(tmp == nil)		return -1;	memdraw(tmp, lr, src, lr.min, nil, lr.min, S);	n = unloadmemimage(tmp, lr, data, n);	freememimage(tmp);	return n;}