diff options
Diffstat (limited to 'src/libdraw/md-cread.c')
-rw-r--r-- | src/libdraw/md-cread.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/libdraw/md-cread.c b/src/libdraw/md-cread.c new file mode 100644 index 00000000..4fa5942a --- /dev/null +++ b/src/libdraw/md-cread.c @@ -0,0 +1,96 @@ +#include <u.h> +#include <libc.h> +#include <draw.h> +#include <memdraw.h> + +Memimage* +creadmemimage(int fd) +{ + char hdr[5*12+1]; + Rectangle r; + int m, nb, miny, maxy, new, ldepth, ncblock; + uchar *buf; + Memimage *i; + u32int chan; + + if(readn(fd, hdr, 5*12) != 5*12){ + werrstr("readmemimage: short header (2)"); + return nil; + } + + /* + * 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] != ' '){ + werrstr("creadimage: bad format"); + return nil; + } + if(new){ + hdr[11] = '\0'; + if((chan = strtochan(hdr)) == 0){ + werrstr("creadimage: bad channel string %s", hdr); + return nil; + } + }else{ + ldepth = ((int)hdr[10])-'0'; + if(ldepth<0 || ldepth>3){ + werrstr("creadimage: 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){ + werrstr("creadimage: bad rectangle"); + return nil; + } + + i = allocmemimage(r, chan); + if(i == nil) + return nil; + ncblock = _compblocksize(r, i->depth); + buf = malloc(ncblock); + if(buf == nil) + goto Errout; + miny = r.min.y; + while(miny != r.max.y){ + if(readn(fd, hdr, 2*12) != 2*12){ + Shortread: + werrstr("readmemimage: short read"); + Errout: + freememimage(i); + free(buf); + return nil; + } + maxy = atoi(hdr+0*12); + nb = atoi(hdr+1*12); + if(maxy<=miny || r.max.y<maxy){ + werrstr("readimage: bad maxy %d", maxy); + goto Errout; + } + if(nb<=0 || ncblock<nb){ + werrstr("readimage: bad count %d", nb); + goto Errout; + } + if(readn(fd, buf, nb)!=nb) + goto Shortread; + if(!new) /* old image: flip the data bits */ + _twiddlecompressed(buf, nb); + cloadmemimage(i, Rect(r.min.x, miny, r.max.x, maxy), buf, nb); + miny = maxy; + } + free(buf); + return i; +} |