Color class

Color.class.php

<?php namespace lang\functions\unittest;

/**
 * Represents an RGB color
 *
 * @see  http://docs.oracle.com/javase/8/docs/api/java/awt/Color.html
 */
class Color implements \lang\Value {
  const FACTOR= 0.7;
  private $r, $g, $b;

  public function __construct($r, $g, $b) {
    $this->r= $r;
    $this->g= $g;
    $this->b= $b;
  }

  public function brighter() {
    $i= (int)(1.0 / (1.0 - self::FACTOR));
    if (0 === $this->r && 0 === $this->g && 0 === $this->b) {
      return new self($i, $i, $i);
    } else {
      $r= ($this->r > 0 && $this->r < $i) ? $i : $this->r;
      $g= ($this->g > 0 && $this->g < $i) ? $i : $this->g;
      $b= ($this->b > 0 && $this->b < $i) ? $i : $this->b;
      return new self(
        min((int)($r / self::FACTOR), 0xff),
        min((int)($g / self::FACTOR), 0xff),
        min((int)($b / self::FACTOR), 0xff)
      );
    }
  }

  public function darker() {
    return new self(
      max((int)($this->r * self::FACTOR), 0),
      max((int)($this->g * self::FACTOR), 0),
      max((int)($this->b * self::FACTOR), 0)
    );
  }

  public function hashCode() {
    return sprintf('#%02x%02x%02x', $this->r, $this->g, $this->b);
  }

  public function toString() {
    return sprintf('%s(r= %d, g= %d, b= %d)', nameof($this), $this->r, $this->g, $this->b);
  }

  public function compareTo($that) {
    if ($that instanceof self) {
      $a= $this->r << 16 | $this->g << 8 | $this->b;
      $b= $that->r << 16 | $that->g << 8 | $that->b;
      return $a === $b ? 0 : ($a < $b ? -1 : 1);
    } else {
      return 1;
    }
  }
}