#include <u.h>#include <libc.h>#include <draw.h>#include <memdraw.h> #define poolalloc(a, b) malloc(b)#define poolfree(a, b) free(b) voidmemimagemove(void *from, void *to){	Memdata *md; 	md = *(Memdata**)to;	if(md->base != from){		print("compacted data not right: #%p\n", md->base);		abort();	}	md->base = to; 	/* if allocmemimage changes this must change too */	md->bdata = (uchar*)md->base+sizeof(Memdata*)+sizeof(u32int);} Memimage*allocmemimaged(Rectangle r, u32int chan, Memdata *md, void *X){	int d;	u32int l;	Memimage *i; 	if(Dx(r) <= 0 || Dy(r) <= 0){		werrstr("bad rectangle %R", r);		return nil;	}	if((d = chantodepth(chan)) == 0) {		werrstr("bad channel descriptor %.8lux", chan);		return nil;	} 	l = wordsperline(r, d); 	i = mallocz(sizeof(Memimage), 1);	if(i == nil)		return nil; 	i->X = X;	i->data = md;	i->zero = sizeof(u32int)*l*r.min.y;		if(r.min.x >= 0)		i->zero += (r.min.x*d)/8;	else		i->zero -= (-r.min.x*d+7)/8;	i->zero = -i->zero;	i->width = l;	i->r = r;	i->clipr = r;	i->flags = 0;	i->layer = nil;	i->cmap = memdefcmap;	if(memsetchan(i, chan) < 0){		free(i);		return nil;	}	return i;} Memimage*_allocmemimage(Rectangle r, u32int chan){	int d;	uchar *p;	u32int l, nw;	Memdata *md;	Memimage *i; 	if((d = chantodepth(chan)) == 0) {		werrstr("bad channel descriptor %.8lux", chan);		return nil;	} 	l = wordsperline(r, d);	nw = l*Dy(r);	md = malloc(sizeof(Memdata));	if(md == nil)		return nil; 	md->ref = 1;	md->base = poolalloc(imagmem, sizeof(Memdata*)+(1+nw)*sizeof(u32int));	if(md->base == nil){		free(md);		return nil;	} 	p = (uchar*)md->base;	*(Memdata**)p = md;	p += sizeof(Memdata*); 	*(u32int*)p = getcallerpc(&r);	p += sizeof(u32int); 	/* if this changes, memimagemove must change too */	md->bdata = p;	md->allocd = 1; 	i = allocmemimaged(r, chan, md, nil);	if(i == nil){		poolfree(imagmem, md->base);		free(md);		return nil;	}	md->imref = i;	return i;} void_freememimage(Memimage *i){	if(i == nil)		return;	if(i->data->ref-- == 1 && i->data->allocd){		if(i->data->base)			poolfree(imagmem, i->data->base);		free(i->data);	}	free(i);} intmemsetchan(Memimage *i, u32int chan){	int d;	int t, j, k;	u32int cc;	int bytes; 	if((d = chantodepth(chan)) == 0) {		werrstr("bad channel descriptor");		return -1;	} 	i->depth = d;	i->chan = chan;	i->flags &= ~(Fgrey|Falpha|Fcmap|Fbytes);	bytes = 1;	for(cc=chan, j=0, k=0; cc; j+=NBITS(cc), cc>>=8, k++){		t=TYPE(cc);		if(t < 0 || t >= NChan){			werrstr("bad channel string");			return -1;		}		if(t == CGrey)			i->flags |= Fgrey;		if(t == CAlpha)			i->flags |= Falpha;		if(t == CMap && i->cmap == nil){			i->cmap = memdefcmap;			i->flags |= Fcmap;		} 		i->shift[t] = j;		i->mask[t] = (1<<NBITS(cc))-1;		i->nbits[t] = NBITS(cc);		if(NBITS(cc) != 8)			bytes = 0;	}	i->nchan = k;	if(bytes)		i->flags |= Fbytes;	return 0;}