/*  * 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> void_memltorear(Memimage *i, Memimage *rear){	Memlayer *l;	Memscreen *s;	Memimage *f, *r, *rr;	Rectangle x;	int overlap; 	l = i->layer;	s = l->screen;	while(l->rear != rear){		r = l->rear;		x = l->screenr;		overlap = rectclip(&x, r->layer->screenr);		if(overlap){			memlhide(i, x);			l->clear = 0;		}		/* swap l and r in screen's list */		rr = r->layer->rear;		f = l->front;		if(rr == nil)			s->rearmost = i;		else			rr->layer->front = i;		if(f == nil)			s->frontmost = r;		else			f->layer->rear = r;		l->rear = rr;		l->front = r;		r->layer->rear = i;		r->layer->front = f;		if(overlap)			memlexpose(r, x);	}} voidmemltorear(Memimage *i){	_memltorear(i, nil);	_memlsetclear(i->layer->screen);} voidmemltorearn(Memimage **ip, int n){	Memimage *i, *rear;	Memscreen *s; 	if(n == 0)		return;	rear = nil;	while(--n >= 0){		i = *ip++;		_memltorear(i, rear);		rear = i;	}	s = rear->layer->screen;	_memlsetclear(s);}