#include "lib9.h"#include "kernel.h"#include "draw.h" Image*readimage(Display *d, int fd, int dolock){	char hdr[5*12+1];	int dy;	int new;	uint l, n;	int m, j, chunk;	int miny, maxy;	Rectangle r;	int ldepth;	ulong chan;	uchar *tmp;	Image *i; 	if(libreadn(fd, hdr, 11) != 11) {		kwerrstr("readimage: short header");		return nil;	}	if(memcmp(hdr, "compressed\n", 11) == 0)		return creadimage(d, fd, dolock);	dolock &= 1;	if(libreadn(fd, hdr+11, 5*12-11) != 5*12-11) {		kwerrstr("readimage: short header");		return nil;	}	chunk = d->bufsize - 32;	/* a little room for header */ 	/*	 * distinguish new channel descriptor from old ldepth.	 * channel descriptors have letters as well as numbers,	 * while ldepths are a single digit formatted as %-11d.	 */	new = 0;	for(m=0; m<10; m++){		if(hdr[m] != ' '){			new = 1;			break;		}	}	if(hdr[11] != ' '){		kwerrstr("readimage: bad format");		return nil;	}	if(new){		hdr[11] = '\0';		if((chan = strtochan(hdr)) == 0){			kwerrstr("readimage: bad channel string %s", hdr);			return nil;		}	}else{		ldepth = ((int)hdr[10])-'0';		if(ldepth<0 || ldepth>3){			kwerrstr("readimage: bad ldepth %d", ldepth);			return nil;		}		chan = drawld2chan[ldepth];	} 	r.min.x = atoi(hdr+1*12);	r.min.y = atoi(hdr+2*12);	r.max.x = atoi(hdr+3*12);	r.max.y = atoi(hdr+4*12);	if(r.min.x>r.max.x || r.min.y>r.max.y){		kwerrstr("readimage: bad rectangle");		return nil;	} 	miny = r.min.y;	maxy = r.max.y; 	l = bytesperline(r, chantodepth(chan));	if(dolock)		dolock = lockdisplay(d);	i = allocimage(d, r, chan, 0, -1);	if(dolock)		unlockdisplay(d);	if(i == nil)		return nil;	tmp = malloc(chunk);	if(tmp == nil)		goto Err;	while(maxy > miny){		dy = maxy - miny;		if(dy*l > chunk)			dy = chunk/l;		if(dy <= 0){			kwerrstr("readimage: image too wide for buffer");			goto Err;		}		n = dy*l;		m = libreadn(fd, tmp, n);		if(m != n){			kwerrstr("readimage: read count %d not %d: %r", m, n);   Err:			if(dolock)				lockdisplay(d);   Err1: 			freeimage(i);			if(dolock)				unlockdisplay(d);			free(tmp);			return nil;		}		if(!new)	/* an old image: must flip all the bits */			for(j=0; j<chunk; j++)				tmp[j] ^= 0xFF; 		if(dolock)			lockdisplay(d);		if(loadimage(i, Rect(r.min.x, miny, r.max.x, miny+dy), tmp, chunk) <= 0)			goto Err1;		if(dolock)			unlockdisplay(d);		miny += dy;	}	free(tmp);	return i;}