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