#include <lib9.h>#include <image.h>#include <memimage.h>#include <memlayer.h> static ulong colorword; static Memdata colordata = {	nil,	&colorword}; static Memimage paint ={	{ 0, 0, 1, 1 },	{ -1000000, -1000000, 10000000, 1000000 },	0,	1,	&colordata,	0,	1,	0,}; static voidsetcolor(int val, int ldepth){	int bpp; 	paint.ldepth = ldepth;	bpp = 1<<ldepth;	val &= ~(0xFF>>bpp);	/* color is now in low part of word; replicate through pixel */	for(; bpp<32; bpp<<=1)		val |= val<<bpp;	colorword = val;} Memimage*memlalloc(Memscreen *s, Rectangle screenr, Refreshfn refreshfn, void *refreshptr, int val){	Memlayer *l;	Memimage *n; 	n = malloc(sizeof(Memimage));	if(n == nil)		return nil; 	l = malloc(sizeof(Memlayer));	if(l == nil){		free(n);		return nil;	} 	if(refreshfn) {		l->save = nil;	}	else{		l->save = allocmemimage(screenr, s->image->ldepth);		if(l->save == nil){			free(l);			free(n);			return nil;		}		/* allocmemimage doesn't initialize memory; this paints save area */		if(val >= 0)			memfillcolor(l->save, val);	} 	n->r = screenr;	n->clipr = screenr;	n->ldepth = s->image->ldepth;	n->repl = 0;	n->data = s->image->data;	n->zero = s->image->zero;	n->width = s->image->width;	n->layer = l; 	l->screen = s;	l->refreshfn = refreshfn;	l->screenr = screenr;	l->delta = Pt(0,0); 	/* start with new window behind all existing ones */	l->front = s->rearmost;	l->rear = nil;	if(s->rearmost)		s->rearmost->layer->rear = n;	s->rearmost = n;	if(s->frontmost == nil)		s->frontmost = n;	l->clear = 0; 	/* don't set it until we're done */	l->refreshptr = nil;	 	/* now pull new window to front */	memltofront(n); 	/* now set it */	l->refreshptr = refreshptr; 	/*	 * paint with requested color; 	 * previously exposed areas are already right	 * if this window has backing store, but just 	 * painting the whole thing is simplest.	 */ 	if(val >= 0){		setcolor(val, s->image->ldepth);		memdraw(n, n->r, &paint, n->r.min, memones, n->r.min);	}	return n;}