Subversion Repositories planix.SVN

#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, d;

        c = 0;
        d = 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';
                d += n;
                c = (c<<8) | __DC(t, n);
                p += 2;
        }
        if(d==0 || (d>8 && d%8) || (d<8 && 8%d))
                return 0;
        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;
}