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#include <u.h>
#include <libc.h>
#include <draw.h>
static char channames[] = "rgbkamx";
char*
chantostr(char *buf, u32int cc)
{
u32int 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;
}
u32int
strtochan(char *s)
{
char *p, *q;
u32int c;
int t, n;
c = 0;
p=s;
while(*p && isspace((uchar)*p))
p++;
while(*p && !isspace((uchar)*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(u32int 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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