sys/src/libdraw/creadimage.c

   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         ulong 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         setmalloctag(i, getcallerpc(&d));
  71         ncblock = _compblocksize(r, chantodepth(chan));
  72         buf = malloc(ncblock);
  73         if(buf == nil)
  74                 goto Errout;
  75         miny = r.min.y;
  76         while(miny != r.max.y){
  77                 if(readn(fd, hdr, 2*12) != 2*12){
  78                 Errout:
  79                         if(dolock)
  80                                 lockdisplay(d);
  81                 Erroutlock:
  82                         freeimage(i);
  83                         if(dolock)
  84                                 unlockdisplay(d);
  85                         free(buf);
  86                         return nil;
  87                 }
  88                 maxy = atoi(hdr+0*12);
  89                 nb = atoi(hdr+1*12);
  90                 if(maxy<=miny || r.max.y<maxy){
  91                         werrstr("creadimage: bad maxy %d", maxy);
  92                         goto Errout;
  93                 }
  94                 if(nb<=0 || ncblock<nb){
  95                         werrstr("creadimage: bad count %d", nb);
  96                         goto Errout;
  97                 }
  98                 if(readn(fd, buf, nb)!=nb)
  99                         goto Errout;
 100                 if(d){
 101                         if(dolock)
 102                                 lockdisplay(d);
 103                         a = bufimage(i->display, 21+nb);
 104                         if(a == nil)
 105                                 goto Erroutlock;
 106                         a[0] = 'Y';
 107                         BPLONG(a+1, i->id);
 108                         BPLONG(a+5, r.min.x);
 109                         BPLONG(a+9, miny);
 110                         BPLONG(a+13, r.max.x);
 111                         BPLONG(a+17, maxy);
 112                         if(!new)        /* old image: flip the data bits */
 113                                 _twiddlecompressed(buf, nb);
 114                         memmove(a+21, buf, nb);
 115                         if(dolock)
 116                                 unlockdisplay(d);
 117                 }
 118                 miny = maxy;
 119         }
 120         free(buf);
 121         return i;
 122 }