Update: Added in the abs function which cuts down code size a bit. I had been using my own abs function of sorts which was very ugly.

Thanks for the comments. It's great to get helpful commentary like this. While we're on the subject of efficiency I noticed this code:

    if ( $fromR > $toR) {
        $rstep = ($fromR - $toR) / length($string);
    } elsif ( $fromR < $toR) {
        $rstep = ($toR - $fromR) / length($string);
    }
[download]

is really just the same as abs($fromR - $toR). I'd edit this in but chipmunk currently has me locked out because he's editing it.

-Ben Jacobs
one thing i can tell you is you got to be free