PHP implementation of Don Park Identicon algorithm with additional shapes and variations

IdenticonPlus.php

<?php
/**
 * Identicon++
 *
 * @description: PHP implementation of Don Park Identicon algorithm with additional shapes and variations.
 *
 * @author: Damien "Mistic" Sorel - http://strangeplanet.fr
 * @license: MIT
 * @version: 2.0.0
 * @date: 21/05/2015
 *
 * @usage: Init Identicon\IdenticonPlus with an hash and an optional array of options
 *    - size : image size (between 8 and 512, default 128)
 *    - colors : number of colors (1 or 2, default 2)
 *    - background : 6 hex background color used for antialiasing (default FFFFFF)
 *
 * @example: direct render
 *    > (new IdenticonPlus($_GET['hash'], $_GET))->display();
 *
 * @example: get image ressource
 *    > $img = (new IdenticonPlus($hash))->render();
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013-2015 Damien "Mistic" Sorel
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * 'Software'), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

namespace Identicon;

class IdenticonPlus
{
  /**
   * Shapes for corners and sides
   */
  static $SHAPES1;

  /**
   * Shapes for center
   */
  static $SHAPES2;


  /**
   * User hash
   * @var string
   */
  public $hash = null;

  /**
   * Image size (between 8 and 512)
   * @var int
   */
  public $size = 128;

  /**
   * Number of colors (1 or 2)
   * @var int
   */
  public $colors = 2;

  /**
   * Background color (6-hex without #)
   * @var string
   */
  public $background = 'FFFFFF';

  /**
   * Storage of the image
   * @var resource
   */
  private $_img = null;


  /**
   * class constructor
   * @param string $hash
   * @param array $options
   */
  public function __construct($hash=null, $options=array())
  {
    $this->hash = $hash;
    if (!$this->hash)
    {
      $this->hash = md5(uniqid(time(), true));
    }
    // we need 21 chars (84 bits)
    $this->hash = str_pad($this->hash, 21, $this->hash);

    // size is between 8 and 512
    if (array_key_exists('size', $options))
    {
      $this->size = max(8, min(intval($options['size']), 512));
    }

    // colors is 1 or 2
    if (array_key_exists('colors', $options))
    {
      $this->colors = max(1, min(intval($options['colors']), 2));
    }

    // background
    if (array_key_exists('background', $options))
    {
      $this->background = $options['background'];
    }
  }

  /**
   * Render the squareicon and returns the image resource
   * @return resource
   */
  public function render()
  {
    if ($this->_img != null)
    {
      return $this->_img;
    }

    if (!is_array($this->background))
    {
      $this->background = sscanf($this->background, '%2x%2x%2x');
    }

    ## PARSE HASH
    // sprite shapes (2 chars for each, 256 possibilities, modulated to X possibilities)
    $shapes = array(
      'corner' => hexdec(substr($this->hash, 0, 2)) % count(self::$SHAPES1),
      'side' =>   hexdec(substr($this->hash, 2, 2)) % count(self::$SHAPES1),
      'center' => hexdec(substr($this->hash, 4, 2)) % count(self::$SHAPES2),
    );

    // sprites rotations (1 char for each, 16 possibilities, truncated to 4 possibilities)
    $rots = array(
      'corner' => hexdec(substr($this->hash, 6, 1)) & 3,
      'side' =>   hexdec(substr($this->hash, 7, 1)) & 3,
    );

    // pattern variation (one bit for each sprite) + center sprite background (one bit)
    $vars = array();
    $tmp = decbin(hexdec(substr($this->hash, 8, 1)));
    $tmp = str_pad($tmp, 4, '0', STR_PAD_LEFT);
    list($vars['corner'], $vars['side'], $vars['center'], $center_bg) = str_split($tmp);

    $colors = array();

    // corner sprite color (2 chars for each, 24 bits)
    $colors['corner'] = array(
      hexdec(substr($this->hash, 9, 2)),
      hexdec(substr($this->hash, 11, 2)),
      hexdec(substr($this->hash, 13, 2)),
    );

    // shift color if same has background
    if ($colors['corner'][0]==$this->background[0] && $colors['corner'][1]==$this->background[1] && $colors['corner'][2]==$this->background[2])
    {
      $colors['corner'][0]+= $colors['corner'][0]==255 ? -1 : +1;
      $colors['corner'][1]+= $colors['corner'][1]==255 ? -1 : +1;
      $colors['corner'][2]+= $colors['corner'][2]==255 ? -1 : +1;
    }

    // side sprite color (2 chars for each, 24 bits)
    if ($this->colors == 2)
    {
      $colors['side'] = array(
        hexdec(substr($this->hash, 15, 2)),
        hexdec(substr($this->hash, 17, 2)),
        hexdec(substr($this->hash, 19, 2)),
      );

      // shift color if same has background
    if ($colors['side'][0]==$this->background[0] && $colors['side'][1]==$this->background[1] && $colors['side'][2]==$this->background[2])
    {
      $colors['side'][0]+= $colors['side'][0]==255 ? -1 : +1;
      $colors['side'][1]+= $colors['side'][1]==255 ? -1 : +1;
      $colors['side'][2]+= $colors['side'][2]==255 ? -1 : +1;
    }
    }
    else
    {
      $colors['side'] = $colors['corner'];
    }


    ## RENDER IDENTICON
    // start with blank 3x3 image
    $this->_img = imagecreatetruecolor($this->size*3, $this->size*3);
    imageantialias($this->_img,  true);

    // assign white as background
    $bg = imagecolorallocate($this->_img, $this->background[0], $this->background[1], $this->background[2]);
    imagefilledrectangle($this->_img, 0, 0, $this->size, $this->size, $bg);

    // generate corner sprites
    $corner = $this->getsprite($shapes['corner'], $colors['corner'], $rots['corner'], $vars['corner']);
    imagecopy($this->_img, $corner, 0, 0, 0, 0, $this->size, $this->size);
    $corner = imagerotate($corner, 90, 0);
    imagecopy($this->_img, $corner, 0, $this->size*2, 0, 0, $this->size, $this->size);
    $corner = imagerotate($corner, 90, 0);
    imagecopy($this->_img, $corner, $this->size*2, $this->size*2, 0, 0, $this->size, $this->size);
    $corner = imagerotate($corner, 90, 0);
    imagecopy($this->_img, $corner, $this->size*2, 0, 0, 0, $this->size, $this->size);

    // generate side sprites
    $side = $this->getsprite($shapes['side'], $colors['side'], $rots['side'], $vars['side']);
    imagecopy($this->_img, $side, $this->size, 0, 0, 0, $this->size, $this->size);
    $side = imagerotate($side, 90, 0);
    imagecopy($this->_img, $side, 0, $this->size, 0, 0, $this->size, $this->size);
    $side = imagerotate($side, 90, 0);
    imagecopy($this->_img, $side, $this->size, $this->size*2, 0, 0, $this->size, $this->size);
    $side = imagerotate($side, 90, 0);
    imagecopy($this->_img, $side, $this->size*2, $this->size, 0, 0, $this->size, $this->size);

    // generate center sprite
    $center = $this->getcenter($shapes['center'], $colors['corner'], $colors['side'], $center_bg, $vars['center']);
    imagecopy($this->_img, $center, $this->size, $this->size, 0, 0, $this->size, $this->size);


    ## GENERATE FINAL IMAGE
    // create blank image according to specified dimensions
    $resized = imagecreatetruecolor($this->size, $this->size);
    imageantialias($resized, true);

    // assign white as background
    $bg = imagecolorallocate($resized, $this->background[0], $this->background[1], $this->background[2]);

    // resize identicon according to specification
    imagecopyresampled($resized, $this->_img, 0, 0, 0, 0, $this->size, $this->size, $this->size*3, $this->size*3);

    // make white transparent
    imagecolortransparent($resized, $bg);

    imagedestroy($this->_img);
    $this->_img = $resized;

    return $this->_img;
  }

  /**
   * Display all possible shapes
   */
  public static function reference()
  {
    // init
    $total1 = count(self::$SHAPES1);
    $total2 = count(self::$SHAPES2);

    $cols = 8;
    $lines = ceil($total1/$cols) + ceil($total2/$cols) + 2;

    $inst = new self(null, array(
      'size' => 32
    ));
    $inst->background = array(255,255,255);
    $inst->color = array(80,80,80);

    // create image
    $img = imagecreatetruecolor($inst->size*$cols, $inst->size*$lines);

    $bg = imagecolorallocate($img, $inst->background[0], $inst->background[1], $inst->background[2]);
    $fg = imagecolorallocate($img, 0, 0, 0);
    imagefilledrectangle($img, 0, 0, $inst->size*$cols, $inst->size*$lines, $bg);

    // draw standard shapes
    imagestring($img, 3, 10, 10, 'Sides and corners shapes', $fg);

    $x = 0; $y = 1;

    for ($i=0; $i<$total1; $i++, $x++) {
      if ($x == 8)
      {
        $x = 0;
        $y++;
      }

      $sprite = $inst->getsprite($i, $inst->color, 0, 0);
      imagecopy($img, $sprite, $x*$inst->size, $y*$inst->size, 0, 0, $inst->size, $inst->size);
    }

    // draw center shapes
    imagestring($img, 3, 10, ($y+1)*$inst->size+10, 'Center shapes', $fg);

    $x = 0; $y+=2;

    for ($i=0; $i<$total2; $i++, $x++) {
      if ($x == 8)
      {
        $x = 0;
        $y++;
      }

      $sprite = $inst->getcenter($i, $inst->color, $inst->color, 0, 0);
      imagecopy($img, $sprite, $x*$inst->size, $y*$inst->size, 0, 0, $inst->size, $inst->size);
    }

    // draw grid
    for ($i=1; $i<$cols; $i++)
    {
      imageline($img, $i*$inst->size, $inst->size, $i*$inst->size, (ceil($total1/$cols)+1)*$inst->size, $fg);
      imageline($img, $i*$inst->size, (ceil($total1/$cols)+2)*$inst->size, $i*$inst->size, $lines*$inst->size, $fg);
    }
    for ($i=1; $i<$lines; $i++)
    {
      imageline($img, 0, $i*$inst->size, $cols*$inst->size, $i*$inst->size, $fg);
    }

    // render
    header('Content-Type: image/png');
    imagepng($img);
  }

  /**
   * Display the squareicon to the browser
   */
  public function display()
  {
    header('Content-Type: image/png');
    imagepng($this->render());
  }

  /**
   * Destroy the internal resource storage
   */
  public function destroy()
  {
    if ($this->_img != null)
    {
      imagedestroy($this->_img);
      $this->_img = null;
    }
  }

  /**
   * Callback for map resize
   */
  private function resize($s)
  {
    return $s*$this->size;
  }

  /**
   * Generate sprite for corners and sides
   * @param int $shape
   * @param int[] $color
   * @param int $rotation
   * @param int $var
   */
  private function getsprite($shape, $color, $rotation, $var)
  {
    // create sprite image
    $sprite = imagecreatetruecolor($this->size, $this->size);
    imageantialias($sprite, true);

    // assign colors
    $c[0] = imagecolorallocate($sprite, $this->background[0], $this->background[1], $this->background[2]);
    $c[1] = imagecolorallocate($sprite, $color[0], $color[1], $color[2]);

    // draw background
    imagefilledrectangle($sprite, 0, 0, $this->size, $this->size, $c[!!$var]);

    // draw shape
    $this->drawshape($sprite, self::$SHAPES1[$shape], $c[!$var]);

    // rotate sprite
    if ($rotation!=0)
    {
      $sprite = imagerotate($sprite, 90*$rotation, 0);
    }

    return $sprite;
  }

  /**
   * Generate sprite for center block
   * @param int $shape
   * @param int[] $color1
   * @param int[] $color2
   * @param int $usebg
   * @param int $var
   */
  private function getcenter($shape, $color1, $color2, $usebg, $var)
  {
    // create sprite image
    $sprite = imagecreatetruecolor($this->size, $this->size);
    imageantialias($sprite, true);

    // assign colors
    if ($usebg>0 && (abs($color1[0]-$color2[0])>127 || abs($color1[1]-$color2[1])>127 || abs($color1[2]-$color2[2])>127))
    { // make sure there's enough contrast before we use background color of side sprite
      $c[0] = imagecolorallocate($sprite, $color2[0], $color2[1], $color2[2]);
    }
    else
    {
      $c[0] = imagecolorallocate($sprite, $this->background[0], $this->background[1], $this->background[2]);
    }
    $c[1] = imagecolorallocate($sprite, $color1[0], $color1[1], $color1[2]);

    // draw background
    imagefilledrectangle($sprite, 0, 0, $this->size, $this->size, $c[!!$var]);

    // draw shape
    $this->drawshape($sprite, self::$SHAPES2[$shape], $c[!$var]);

    return $sprite;
  }

  /**
   * Draw components of a shape into a sprite
   * @param resource $sprite
   * @param array $shape
   * @param int $color
   */
  private function drawshape($sprite, $shape, $color)
  {
    if (!is_array($shape[0]))
    {
      $shape = array($shape);
    }

    foreach ($shape as $subshape)
    {
      if ($subshape[0] === 'c')
      {
        imagefilledellipse($sprite, $this->size*$subshape[2], $this->size*$subshape[3], $this->size*$subshape[1], $this->size*$subshape[1], $color);
      }
      else
      {
        $subshape = array_map(array($this, 'resize'), $subshape);
        imagefilledpolygon($sprite, $subshape, count($subshape)/2, $color);
      }
    }
  }

}


IdenticonPlus::$SHAPES1 = array(
  // triangle
  array(0.5,1,1,0,1,1),
  // small triangle
  array(0,1,0.5,0.5,0.5,1),
  // parallelogram
  array(0.5,0,1,0,0.5,1,0,1),
  // chevron
  array(0,0,0.5,0,1,0.5,0.5,1,0,1,0.5,0.5),
  // ribbon
  array(0,0.5,0.5,0,1,0.5,0.5,1,0.5,0.5),
  // horseshoe
  array(0.5,0,1,0.5,0.5,1,0,0.5,0.3,0.5,0.5,0.71,0.71,0.5,0.5,0.3),
  // mouse ears
  array(0.5,0,1,0,1,1,0.5,1,1,0.5),
  // trough
  array(0,0.5,0.5,1,1,0.5,0.5,0,1,0,1,1,0,1),
  // sails
  array(0,0.5,1,0,1,1,0,1,1,0.5),
  // fins
  array(1,0,1,1,0.5,1,1,0.5,0.5,0.5),
  // sail & fin
  array(1,0,1,1,0,1,1,0.5,0.5,0.5),
  // fish
  array(0.5,0,0.5,1,1,1,1,0.5,0,0.5),
  // tiles couples
  array(0,0,0,0.5,0.5,0,0.5,0.5,0,0.5,0.5,1,0.5,0.5,1,0.5,0.5,1,1,1,1,0.5,0.5,0),
  // kite
  array(0,0,1,0,0.5,0.5,1,0.5,0.5,1,0.5,0.5,0,1),
  // rays
  array(0.5,0,1,0,1,1,0.5,1,1,0.75,0.5,0.5,1,0.25),
  // double rhombus
  array(0.5,0,0.5,1,1,0.5,1,0,0,1,0,0.5),
  // radioactive
  array(0.5,0,1,0,0,1,0,0.5,1,0.5,0.5,1),
  // tiles
  array(0,0,1,0,0,1,0,0.5,1,0.5,0.5,1,0.5,0,0,0.5),
  // hourglass
  array(0,0,1,1,0,1,1,0),
  // large corner
  array(0,0,1,0,0,1),
  // arrow
  array(0.5,0,1,0.5,0,1),
  // beak
  array(0,1,0.5,0,1,0,1,0.5),
  // diamond
  array(0.5,0,0.75,0.5,0.5,1,0.25,0.5),
  // pyramid
  array(0,0.5,1,0.5,0.5,1),
  // pyramid 2
  array(0,0,1,0,0.5,0.5),
  // double pyramid
  array(array(0,0.5,1,0.5,0.5,1),array(0,0,1,0,0.5,0.5)),
  // not a pyramid
  array(0.5,0,1,1,0,1),
  // not an empty pyramid
  array(0,0,1,0,0.5,1,0,0,0.30,0.20,0.5,0.6,0.7,0.20,0.30,0.20),
  // big arrow
  array(0,0,0.5,0.5,1,0,0.5,1),
  // triforce
  array(0,0,1,0,1,1,0,1,1,0.5,0.5,0.25,0.5,0.75,0,0.5,0.5,0.25),
  // spikes 1
  array(0,0,1,0,0.75,0.5,0.5,0,0.25,0.5),
  // spikes 2
  array(array(0,0,0.5,0,0.25,0.5),array(1,1,0.5,1,0.75,0.5)),
  // spikes 3
  array(array(0,0,0.5,0,0.25,0.5),array(1,0,1,0.5,0.5,0.25)),
  // spikes 4
  array(array(0,0,0.5,0,0.25,0.5),array(1,0,1,0.5,0.5,0.25),array(0,0.5,0.5,0.75,0,1)),
  // big spikes
  array(0,0,1,0,0.75,1,0.5,0,0.25,1),
  // big spikes 2
  array(array(0,0,0.5,0,0.25,1),array(0.5,1,0.75,0,1,1)),
  // two diamonds
  array(0.5,0,0.75,0.25,0.25,0.75,0.5,1,0.75,0.75,0.25,0.25),
  // tartan
  array(0,0,1,0,0,0.5,1,1,0,1,1,0.5),
  // ruby
  array(0.50,0,1,0,1,0.5,0.5,1,0,1,0,0.5),
  // geneva space monument
  array(1,0,0.5,1,0,1),
  // xbox
  array(array(0,0,1,0.5,1,1),array(1,0,0,1,0,0.5)),
  // doors
  array(array(0,0,1,0,0.5,0.25),array(0,1,0.5,0.75,1,1)),
  // big checker
  array(0,0,0.5,0,0.5,1,1,1,1,0.5,0,0.5),
  // one quarter
  array(0,0,0.5,0,0.5,0.5,0,0.5),
  // half fill
  array(0,0,1,0,1,0.5,0,0.5),
  // chicane
  array(0.5,0,1,0,1,0.5,0.5,0.75,0.5,1,0,1,0,0.5,0.5,0.25),
  // chicane 2
  array(0,0,1,1,1,0.5,0.75,0.25,0.25,0.75,0,0.5),
);

IdenticonPlus::$SHAPES2 = array(
  // circle
  array('c', 0.9, 0.5, 0.5),
  // small circle
  array('c', 0.5, 0.5, 0.5),
  // 4 circles
  array(array('c', 0.4, 0.25, 0.25), array('c', 0.4, 0.25, 0.75), array('c', 0.4, 0.75, 0.25), array('c', 0.4, 0.75, 0.75)),
  // square
  array(0,0,1,0,1,1,0,1),
  // medium square
  array(0.25,0.25,0.75,0.25,0.75,0.75,0.25,0.75),
  // small square
  array(0.33,0.33,0.67,0.33,0.67,0.67,0.33,0.67),
  // checkerboard
  array(0,0,0.33,0,0.33,1,0,1,0,0.67,1,0.67,1,1,0.67,1,0.67,0,1,0,1,0.33,0,0.33),
  // switzerland
  array(0.33,0,0.67,0,0.67,0.33,1,0.33,1,0.67,0.67,0.67,0.67,1,0.33,1,0.33,0.67,0,0.67,0,0.33,0.33,0.33),
  // diamond
  array(0.5,0,1,0.5,0.5,1,0,0.5),
  // medium diamond
  array(0.5,0.15,0.855,0.5,0.5,0.855,0.15,0.5),
  // small diamond
  array(0.5,0.25,0.75,0.5,0.5,0.75,0.25,0.5),
  // empty diamond
  array(0.5,0,1,0.5,0.5,1,0,0.5,0.5,0,0.5,0.25,0.25,0.5,0.5,0.75,0.75,0.5,0.5,0.25),
  // empty diamond 2
  array(0.5,0,1,0.5,0.5,1,0,0.5,0.5,0,0.5,0.33,0.33,0.33,0.33,0.67,0.67,0.67,0.67,0.33,0.5,0.33),
  // cross
  array(array(0,0.25,1,0.75,1,0.25,0,0.75),array(0.75,0,0.25,1,0.75,1,0.25,0)),
  // morning star
  array(0,0,0.5,0.25,1,0,0.75,0.5,1,1,0.5,0.75,0,1,0.25,0.5),
  // night star
  array(0.5,0,0.67,0.33,1,0.5,0.67,0.67,0.5,1,0.33,0.67,0,0.5,0.33,0.33),
  // empty star
  array(0,0,0.5,0.25,1,0,0.75,0.5,1,1,0.5,0.75,0,1,0.25,0.5,0.5,0.75,0.75,0.5,0.5,0.25,0.25,0.5),
  // spikes
  array(array(0,0,0.5,0,0.25,0.5),array(1,0,1,0.5,0.5,0.25),array(0,0.5,0.5,0.75,0,1),array(0.5,1,0.75,0.5,1,1)),
  // revert spikes
  array(array(0.5,0,1,0.25,0.5,0.5),array(1,0.5,0.75,1,0.5,0.5),array(0.5,1,0,0.75,0.5,0.5),array(0,0.5,0.25,0,0.5,0.5)),
  // cross 2
  array(0,0,0.21,0,0.5,0.3,0.8,0,1,0,1,0.2,0.7,0.5,1,0.81,1,1,0.81,1,0.5,0.7,0.2,1,0,1,0,0.8,0.3,0.5,0,0.21),
);