Color helper function

colorize.php

/**
 * Colorize helper.
 */
class Colorize
{

    /**
     * RGB array for a color.
     *
     * @var array
     */
    protected array $color = [0, 0, 0];


    /**
     * Constructor.
     *
     * @param null $color
     */
    public function __construct($color = null) {

        if ($color) {
            if (is_array($color))
                $this->color = $color;
            else
                $this->color = static::convertHexToRgb($color);
        }
        else
            $this->generateRandom();
    }


    /**
     * Calculate the contrast color.
     *
     * @return $this
     */
    public function calculateContrastColor()
    {
        $yiq = (($this->color[0] * 299) + ($this->color[1] * 587) + ($this->color[2] * 114)) / 1000;
        return new static($yiq >= 128 ? [0,0,0] : [255,255,255]);
    }


    /**
     * Generate a color from a string.
     *
     * @param string $text
     * @return $this
     */
    public function generateFromString(string $text) : static
    {
        $hex = dechex(crc32($text));
        $hex = substr($hex, 0, 6);

        $this->color = static::convertHexToRgb($hex);

        return $this;
    }


    /**
     * Generate a random color.
     *
     * @return $this
     */
    public function generateRandom() : static
    {
        $this->color = static::generateRandomRgb();

        return $this;
    }

    
    /**
     * Get color as RGB values.
     *
     * @param string|null $sep
     * @return array|string
     */
    public function asRgb(?string $sep = null) : array|string {
        return $sep ? implode($sep, $this->color) : $this->color;
    }


    /**
     * Get color as Hex value.
     *
     * @param string $prefix
     * @return string
     */
    public function asHex(string $prefix = '#') : string {
        return sprintf("%s%02x%02x%02x", $prefix, $this->color[0], $this->color[1], $this->color[2]);
    }


    /**
     * Generate a random color.
     *
     * @return array
     */
    protected static function generateRandomRgb() : array {
        $rgb = [0, 0, 0];

        foreach ($rgb as &$color)
            $color = mt_rand(0, 255);

        return $rgb;
    }


    /**
     * Helper that convert Hex string into RGB.
     *
     * @param string $hex
     * @return array
     */
    public static function convertHexToRgb(string $hex) : array {
        return array_map(
            function ($c) {
                return hexdec(str_pad($c, 2, $c));
            },
            str_split(ltrim($hex, '#'), strlen($hex) > 4 ? 2 : 1)
        );
    }
}