Generator::image_gradientrect( GdImage $img, string $start, string $end )

	private function image_gradientrect( $img, $start, $end ) {
		$x  = 0;
		$y  = 0;
		$x1 = 90;
		$y1 = 90;

		if ( $x > $x1 || $y > $y1 ) {
			return false;
		}

		$start = str_replace( '#', '', $start );
		$end   = str_replace( '#', '', $end );

		$s = array(
			hexdec( substr( $start, 0, 2 ) ),
			hexdec( substr( $start, 2, 2 ) ),
			hexdec( substr( $start, 4, 2 ) ),
		);

		$e = array(
			hexdec( substr( $end, 0, 2 ) ),
			hexdec( substr( $end, 2, 2 ) ),
			hexdec( substr( $end, 4, 2 ) ),
		);

		$steps = $y1 - $y;
		for ( $i = 0; $i < $steps; $i++ ) {
			$r     = $s[0] - ( ( ( $s[0] - $e[0] ) / $steps ) * $i );
			$g     = $s[1] - ( ( ( $s[1] - $e[1] ) / $steps ) * $i );
			$b     = $s[2] - ( ( ( $s[2] - $e[2] ) / $steps ) * $i );
			$color = imagecolorallocate( $img, $r, $g, $b );
			imagefilledrectangle( $img, $x, $y + $i, $x1, $y + $i + 1, $color );
		}

		return true;
	}