Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <draw.h>

static
int
unitsperline(Rectangle r, int d, int bitsperunit)
{
        ulong l, t;

        if(d <= 0 || d > 32)    /* being called wrong.  d is image depth. */
                abort();

        if(r.min.x >= 0){
                l = (r.max.x*d+bitsperunit-1)/bitsperunit;
                l -= (r.min.x*d)/bitsperunit;
        }else{                  /* make positive before divide */
                t = (-r.min.x*d+bitsperunit-1)/bitsperunit;
                l = t+(r.max.x*d+bitsperunit-1)/bitsperunit;
        }
        return l;
}

int
wordsperline(Rectangle r, int d)
{
        return unitsperline(r, d, 8*sizeof(ulong));
}

int
bytesperline(Rectangle r, int d)
{
        return unitsperline(r, d, 8);
}