PHP function to convert hex color to RGB with alpha support

rgbtohex.php

/**
 * Convert the hex color to rgba.
 * @param $hex - #fa11cc
 * @param mixed $alpha - from 0.0 to 1.0
 * @return array rgba
 */
function hexToRgb($hex, $alpha = false)
{
    $hex = str_replace('#', '', $hex);
    $length = strlen($hex);
    $rgb['red'] = hexdec($length == 6 ? substr($hex, 0, 2) : ($length == 3 ? str_repeat(substr($hex, 0, 1), 2) : 0)) / 255;
    $rgb['green'] = hexdec($length == 6 ? substr($hex, 2, 2) : ($length == 3 ? str_repeat(substr($hex, 1, 1), 2) : 0)) / 255;
    $rgb['blue'] = hexdec($length == 6 ? substr($hex, 4, 2) : ($length == 3 ? str_repeat(substr($hex, 2, 1), 2) : 0)) / 255;
    if ($alpha) {
        $rgb['alpha'] = $alpha;
    }

    return $rgb;
}