PrivateBin/lib/vizhash16x16.php
2016-07-11 14:15:20 +02:00

233 lines
6.3 KiB
PHP

<?php
/**
* VizHash_GD
*
* Visual Hash implementation in php4+GD,
* stripped down and modified version for PrivateBin
*
* @link http://sebsauvage.net/wiki/doku.php?id=php:vizhash_gd
* @copyright 2012 Sébastien SAUVAGE (sebsauvage.net)
* @license http://www.opensource.org/licenses/zlib-license.php The zlib/libpng License
* @version 0.0.4 beta PrivateBin 0.22
*/
/**
* vizhash16x16
*
* Example:
* $vz = new vizhash16x16();
* $data = $vz->generate('hello');
* header('Content-type: image/png');
* echo $data;
* exit;
*/
class vizhash16x16
{
/**
* hash values
*
* @access private
* @var array
*/
private $VALUES;
/**
* index of current value
*
* @access private
* @var int
*/
private $VALUES_INDEX;
/**
* image width
*
* @access private
* @var int
*/
private $width;
/**
* image height
*
* @access private
* @var int
*/
private $height;
/**
* salt used when generating the image
*
* @access private
* @var string
*/
private $salt;
/**
* constructor
*
* @access public
* @return void
*/
public function __construct()
{
$this->width = 16;
$this->height = 16;
$this->salt = serversalt::get();
}
/**
* Generate a 16x16 png corresponding to $text.
*
* @access public
* @param string $text
* @return string PNG data. Or empty string if GD is not available.
*/
public function generate($text)
{
if (!function_exists('gd_info')) return '';
// We hash the input string.
$hash=hash('sha1',$text.$this->salt).hash('md5',$text.$this->salt);
$hash=$hash.strrev($hash); # more data to make graphics
$hashlen=strlen($hash);
// We convert the hash into an array of integers.
$this->VALUES=array();
for($i=0; $i<$hashlen; $i=$i+2){ array_push($this->VALUES,hexdec(substr($hash,$i,2))); }
$this->VALUES_INDEX=0; // to walk the array.
// Then use these integers to drive the creation of an image.
$image = imagecreatetruecolor($this->width,$this->height);
$r0 = $this->getInt();$r=$r0;
$g0 = $this->getInt();$g=$g0;
$b0 = $this->getInt();$b=$b0;
// First, create an image with a specific gradient background.
$op='v'; if (($this->getInt()%2)==0) { $op='h'; };
$image = $this->degrade($image,$op,array($r0,$g0,$b0),array(0,0,0));
for($i=0; $i<7; $i=$i+1)
{
$action=$this->getInt();
$color = imagecolorallocate($image, $r,$g,$b);
$r = ($r0 + $this->getInt()/25)%256;
$g = ($g0 + $this->getInt()/25)%256;
$b = ($b0 + $this->getInt()/25)%256;
$r0=$r; $g0=$g; $b0=$b;
$this->drawshape($image,$action,$color);
}
$color = imagecolorallocate($image,$this->getInt(),$this->getInt(),$this->getInt());
$this->drawshape($image,$this->getInt(),$color);
ob_start();
imagepng($image);
$imagedata = ob_get_contents();
ob_end_clean();
imagedestroy($image);
return $imagedata;
}
/**
* Returns a single integer from the $VALUES array (0...255)
*
* @access private
* @return int
*/
private function getInt()
{
$v= $this->VALUES[$this->VALUES_INDEX];
$this->VALUES_INDEX++;
$this->VALUES_INDEX %= count($this->VALUES); // Warp around the array
return $v;
}
/**
* Returns a single integer from the array (roughly mapped to image width)
*
* @access private
* @return int
*/
private function getX()
{
return $this->width*$this->getInt()/256;
}
/**
* Returns a single integer from the array (roughly mapped to image height)
*
* @access private
* @return int
*/
private function getY()
{
return $this->height*$this->getInt()/256;
}
/**
* Gradient function
*
* taken from:
* http://www.supportduweb.com/scripts_tutoriaux-code-source-41-gd-faire-un-degrade-en-php-gd-fonction-degrade-imagerie.html
*
* @access private
* @param resource $img
* @param string $direction
* @param array $color1
* @param array $color2
* @return resource
*/
private function degrade($img,$direction,$color1,$color2)
{
if($direction=='h') { $size = imagesx($img); $sizeinv = imagesy($img); }
else { $size = imagesy($img); $sizeinv = imagesx($img);}
$diffs = array(
(($color2[0]-$color1[0])/$size),
(($color2[1]-$color1[1])/$size),
(($color2[2]-$color1[2])/$size)
);
for($i=0;$i<$size;$i++)
{
$r = $color1[0]+($diffs[0]*$i);
$g = $color1[1]+($diffs[1]*$i);
$b = $color1[2]+($diffs[2]*$i);
if($direction=='h') { imageline($img,$i,0,$i,$sizeinv,imagecolorallocate($img,$r,$g,$b)); }
else { imageline($img,0,$i,$sizeinv,$i,imagecolorallocate($img,$r,$g,$b)); }
}
return $img;
}
/**
* Draw a shape
*
* @access private
* @param resource $image
* @param int $action
* @param int $color
* @return void
*/
private function drawshape($image,$action,$color)
{
switch($action%7)
{
case 0:
ImageFilledRectangle ($image,$this->getX(),$this->getY(),$this->getX(),$this->getY(),$color);
break;
case 1:
case 2:
ImageFilledEllipse ($image, $this->getX(), $this->getY(), $this->getX(), $this->getY(), $color);
break;
case 3:
$points = array($this->getX(), $this->getY(), $this->getX(), $this->getY(), $this->getX(), $this->getY(),$this->getX(), $this->getY());
ImageFilledPolygon ($image, $points, 4, $color);
break;
default:
$start=$this->getInt()*360/256; $end=$start+$this->getInt()*180/256;
ImageFilledArc ($image, $this->getX(), $this->getY(), $this->getX(), $this->getY(),$start,$end,$color,IMG_ARC_PIE);
}
}
}