1 #include <u.h>
2 #include <libc.h>
3 #include <draw.h>
4 
5 Image *
6 creadimage(Display *d, int fd, int dolock)
7 {
8 	char hdr[5*12+1];
9 	Rectangle r;
10 	int m, nb, miny, maxy, new, ldepth, ncblock;
11 	uchar *buf, *a;
12 	Image *i;
13 	u32int chan;
14 
15 	if(readn(fd, hdr, 5*12) != 5*12)
16 		return nil;
17 
18 	/*
19 	 * distinguish new channel descriptor from old ldepth.
20 	 * channel descriptors have letters as well as numbers,
21 	 * while ldepths are a single digit formatted as %-11d.
22 	 */
23 	new = 0;
24 	for(m=0; m<10; m++){
25 		if(hdr[m] != ' '){
26 			new = 1;
27 			break;
28 		}
29 	}
30 	if(hdr[11] != ' '){
31 		werrstr("creadimage: bad format");
32 		return nil;
33 	}
34 	if(new){
35 		hdr[11] = '\0';
36 		if((chan = strtochan(hdr)) == 0){
37 			werrstr("creadimage: bad channel string %s", hdr);
38 			return nil;
39 		}
40 	}else{
41 		ldepth = ((int)hdr[10])-'0';
42 		if(ldepth<0 || ldepth>3){
43 			werrstr("creadimage: bad ldepth %d", ldepth);
44 			return nil;
45 		}
46 		chan = drawld2chan[ldepth];
47 	}
48 	r.min.x=atoi(hdr+1*12);
49 	r.min.y=atoi(hdr+2*12);
50 	r.max.x=atoi(hdr+3*12);
51 	r.max.y=atoi(hdr+4*12);
52 	if(r.min.x>r.max.x || r.min.y>r.max.y){
53 		werrstr("creadimage: bad rectangle");
54 		return nil;
55 	}
56 
57 	if(d){
58 		if(dolock)
59 			lockdisplay(d);
60 		i = allocimage(d, r, chan, 0, 0);
61 		if(dolock)
62 			unlockdisplay(d);
63 		if(i == nil)
64 			return nil;
65 	}else{
66 		i = mallocz(sizeof(Image), 1);
67 		if(i == nil)
68 			return nil;
69 	}
70 	ncblock = _compblocksize(r, chantodepth(chan));
71 	buf = malloc(ncblock);
72 	if(buf == nil)
73 		goto Errout;
74 	miny = r.min.y;
75 	while(miny != r.max.y){
76 		if(readn(fd, hdr, 2*12) != 2*12){
77 		Errout:
78 			if(dolock)
79 				lockdisplay(d);
80 		Erroutlock:
81 			freeimage(i);
82 			if(dolock)
83 				unlockdisplay(d);
84 			free(buf);
85 			return nil;
86 		}
87 		maxy = atoi(hdr+0*12);
88 		nb = atoi(hdr+1*12);
89 		if(maxy<=miny || r.max.y<maxy){
90 			werrstr("creadimage: bad maxy %d", maxy);
91 			goto Errout;
92 		}
93 		if(nb<=0 || ncblock<nb){
94 			werrstr("creadimage: bad count %d", nb);
95 			goto Errout;
96 		}
97 		if(readn(fd, buf, nb)!=nb)
98 			goto Errout;
99 		if(d){
100 			if(dolock)
101 				lockdisplay(d);
102 			a = bufimage(i->display, 21+nb);
103 			if(a == nil)
104 				goto Erroutlock;
105 			a[0] = 'Y';
106 			BPLONG(a+1, i->id);
107 			BPLONG(a+5, r.min.x);
108 			BPLONG(a+9, miny);
109 			BPLONG(a+13, r.max.x);
110 			BPLONG(a+17, maxy);
111 			if(!new)	/* old image: flip the data bits */
112 				_twiddlecompressed(buf, nb);
113 			memmove(a+21, buf, nb);
114 			if(dolock)
115 				unlockdisplay(d);
116 		}
117 		miny = maxy;
118 	}
119 	free(buf);
120 	return i;
121 }