tcreadimage.c - plan9port - [fork] Plan 9 from user space
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tcreadimage.c (2380B)
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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 }