/palette.php

<?php
/**
 * This file is part of the PHP_Word_Cloud project.
 * http://github.com/sixty-nine/PHP_Word_Cloud
 *
 * @author Daniel Barsotti / dan [at] dreamcraft [dot] ch
 * @license http://creativecommons.org/licenses/by-nc-sa/3.0/
 *          Creative Commons Attribution-NonCommercial-ShareAlike 3.0
 */

/**
 * Generate color palettes (arrays of allocated colors)
 */
class Palette {

  private static $palettes = array(
    'aqua' => array('BED661', '89E894', '78D5E3', '7AF5F5', '34DDDD', '93E2D5'),
    'yellow/blue' => array('FFCC00', 'CCCCCC', '666699'),
    'grey' => array('87907D', 'AAB6A2', '555555', '666666'), 
    'brown' => array('CC6600', 'FFFBD0', 'FF9900', 'C13100'), 
    'army' => array('595F23', '829F53', 'A2B964', '5F1E02', 'E15417', 'FCF141'),
    'pastel' => array('EF597B', 'FF6D31', '73B66B', 'FFCB18', '29A2C6'),
    'red' => array('FFFF66', 'FFCC00', 'FF9900', 'FF0000'), 
  );

  /**
   * Construct a random color palette
   * @param object $im The GD image
   * @param integer $count The number of colors in the palette
   */
  public static function get_random_palette($im, $count = 5) {
    $palette = array();
    for ($i = 0; $i < $count; $i++) {
      $palette[] = imagecolorallocate($im, rand(0, 255), rand(0, 255), rand(0, 255));
    }
    return $palette;
  }

  /**
   * Construct a color palette from a list of hexadecimal colors (RRGGBB)
   * @param object $im The GD image
   * @param array $hex_array An array of hexadecimal color strings
   */
  public static function get_palette_from_hex($im, $hex_array) {
    $palette = array();
    foreach($hex_array as $hex) {
    if (strlen($hex) != 6) throw new Exception("Invalid palette color '$hex'");
      $palette[] = imagecolorallocate($im,
        hexdec(substr($hex, 0, 2)),
        hexdec(substr($hex, 2, 2)),
        hexdec(substr($hex, 4, 2)));
    }
    return $palette;
  }
  
  public static function get_named_palette($im, $name) {
    if (array_key_exists($name, self::$palettes)) {
      return self::get_palette_from_hex($im, self::$palettes[$name]);
    }
    return self::get_named_palette($im, 'grey');
  }
  
  public static function list_named_palettes() {
    return array_keys(self::$palettes);
  }
}