78 lines
1.1 KiB
C
78 lines
1.1 KiB
C
#include <u.h>
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#include <libc.h>
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#include <draw.h>
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static char channames[] = "rgbkamx";
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char*
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chantostr(char *buf, ulong cc)
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{
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ulong c, rc;
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char *p;
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if(chantodepth(cc) == 0)
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return nil;
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/* reverse the channel descriptor so we can easily generate the string in the right order */
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rc = 0;
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for(c=cc; c; c>>=8){
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rc <<= 8;
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rc |= c&0xFF;
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}
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p = buf;
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for(c=rc; c; c>>=8) {
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*p++ = channames[TYPE(c)];
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*p++ = '0'+NBITS(c);
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}
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*p = 0;
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return buf;
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}
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/* avoid pulling in ctype when using with drawterm etc. */
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static int
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xisspace(char c)
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{
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return c==' ' || c== '\t' || c=='\r' || c=='\n';
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}
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ulong
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strtochan(char *s)
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{
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char *p, *q;
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ulong c;
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int t, n;
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c = 0;
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p=s;
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while(*p && xisspace(*p))
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p++;
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while(*p && !xisspace(*p)){
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if((q = strchr(channames, p[0])) == nil)
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return 0;
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t = q-channames;
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if(p[1] < '0' || p[1] > '9')
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return 0;
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n = p[1]-'0';
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c = (c<<8) | __DC(t, n);
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p += 2;
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}
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return c;
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}
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int
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chantodepth(ulong c)
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{
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int n;
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for(n=0; c; c>>=8){
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if(TYPE(c) >= NChan || NBITS(c) > 8 || NBITS(c) <= 0)
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return 0;
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n += NBITS(c);
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}
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if(n==0 || (n>8 && n%8) || (n<8 && 8%n))
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return 0;
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return n;
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}
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