case GRAD_VER:
                $steps = ceil(abs($xr - $xl) + 1);
                $delta = $xr >= $xl ? 1 : -1;
                $this->GetColArray($from_color, $to_color, $steps, $colors, $this->numcolors);
                for ($i = 0, $x = $xl; $i < $steps; ++$i) {