<?php
/**
*
* This file is part of the phpBB Forum Software package.
*
* @copyright (c) phpBB Limited <https://www.phpbb.com>
* @license GNU General Public License, version 2 (GPL-2.0)
*
* For full copyright and license information, please see
* the docs/CREDITS.txt file.
*
*/
namespace phpbb\captcha;
class colour_manager
{
var $img;
var $mode;
var $colours;
var $named_colours;
/**
* Create the colour manager, link it to the image resource
*/
function __construct($img, $background = false, $mode = 'ahsv')
{
$this->img = $img;
$this->mode = $mode;
$this->colours = array();
$this->named_colours = array();
if ($background !== false)
{
$bg = $this->allocate_named('background', $background);
imagefill($this->img, 0, 0, $bg);
}
}
/**
* Lookup a named colour resource
*/
function get_resource($named_colour)
{
if (isset($this->named_colours[$named_colour]))
{
return $this->named_colours[$named_colour];
}
if (isset($this->named_rgb[$named_colour]))
{
return $this->allocate_named($named_colour, $this->named_rgb[$named_colour], 'rgb');
}
return false;
}
/**
* Assign a name to a colour resource
*/
function name_colour($name, $resource)
{
$this->named_colours[$name] = $resource;
}
/**
* names and allocates a colour resource
*/
function allocate_named($name, $colour, $mode = false)
{
$resource = $this->allocate($colour, $mode);
if ($resource !== false)
{
$this->name_colour($name, $resource);
}
return $resource;
}
/**
* allocates a specified colour into the image
*/
function allocate($colour, $mode = false)
{
if ($mode === false)
{
$mode = $this->mode;
}
if (!is_array($colour))
{
if (isset($this->named_rgb[$colour]))
{
return $this->allocate_named($colour, $this->named_rgb[$colour], 'rgb');
}
if (!is_int($colour))
{
return false;
}
$mode = 'rgb';
$colour = array(255 & ($colour >> 16), 255 & ($colour >> 8), 255 & $colour);
}
if (isset($colour['mode']))
{
$mode = $colour['mode'];
unset($colour['mode']);
}
if (isset($colour['random']))
{
unset($colour['random']);
// everything else is params
return $this->random_colour($colour, $mode);
}
$rgb = $this->model_convert($colour, $mode, 'rgb');
$store = ($this->mode == 'rgb') ? $rgb : $this->model_convert($colour, $mode, $this->mode);
$resource = imagecolorallocate($this->img, $rgb[0], $rgb[1], $rgb[2]);
$this->colours[$resource] = $store;
return $resource;
}
/**
* randomly generates a colour, with optional params
*/
function random_colour($params = array(), $mode = false)
{
if ($mode === false)
{
$mode = $this->mode;
}
switch ($mode)
{
case 'rgb':
// @TODO random rgb generation. do we intend to do this, or is it just too tedious?
break;
case 'ahsv':
case 'hsv':
default:
$default_params = array(
'hue_bias' => false, // degree / 'r'/'g'/'b'/'c'/'m'/'y' /'o'
'hue_range' => false, // if hue bias, then difference range +/- from bias
'min_saturation' => 30, // 0 - 100
'max_saturation' => 80, // 0 - 100
'min_value' => 30, // 0 - 100
'max_value' => 80, // 0 - 100
);
$alt = ($mode == 'ahsv') ? true : false;
$params = array_merge($default_params, $params);
$min_hue = 0;
$max_hue = 359;
$min_saturation = max(0, $params['min_saturation']);
$max_saturation = min(100, $params['max_saturation']);
$min_value = max(0, $params['min_value']);
$max_value = min(100, $params['max_value']);
if ($params['hue_bias'] !== false)
{
if (is_numeric($params['hue_bias']))
{
$h = intval($params['hue_bias']) % 360;
}
else
{
switch ($params['hue_bias'])
{
case 'o':
$h = $alt ? 60 : 30;
break;
case 'y':
$h = $alt ? 120 : 60;
break;
case 'g':
$h = $alt ? 180 : 120;
break;
case 'c':
$h = $alt ? 210 : 180;
break;
case 'b':
$h = 240;
break;
case 'm':
$h = 300;
break;
case 'r':
default:
$h = 0;
break;
}
}
$min_hue = $h + 360;
$max_hue = $h + 360;
if ($params['hue_range'])
{
$min_hue -= min(180, $params['hue_range']);
$max_hue += min(180, $params['hue_range']);
}
}
$h = mt_rand($min_hue, $max_hue);
$s = mt_rand($min_saturation, $max_saturation);
$v = mt_rand($min_value, $max_value);
return $this->allocate(array($h, $s, $v), $mode);
break;
}
}
/**
*/
function colour_scheme($resource, $include_original = true)
{
$mode = 'hsv';
if (($pre = $this->get_resource($resource)) !== false)
{
$resource = $pre;
}
$colour = $this->model_convert($this->colours[$resource], $this->mode, $mode);
$results = ($include_original) ? array($resource) : array();
$colour2 = $colour3 = $colour4 = $colour;
$colour2[0] += 150;
$colour3[0] += 180;
$colour4[0] += 210;
$results[] = $this->allocate($colour2, $mode);
$results[] = $this->allocate($colour3, $mode);
$results[] = $this->allocate($colour4, $mode);
return $results;
}
/**
*/
function mono_range($resource, $count = 5, $include_original = true)
{
if (is_array($resource))
{
$results = array();
for ($i = 0, $size = count($resource); $i < $size; ++$i)
{
$results = array_merge($results, $this->mono_range($resource[$i], $count, $include_original));
}
return $results;
}
$mode = (in_array($this->mode, array('hsv', 'ahsv'), true) ? $this->mode : 'ahsv');
if (($pre = $this->get_resource($resource)) !== false)
{
$resource = $pre;
}
$colour = $this->model_convert($this->colours[$resource], $this->mode, $mode);
$results = array();
if ($include_original)
{
$results[] = $resource;
$count--;
}
// This is a hard problem. I chicken out and try to maintain readability at the cost of less randomness.
while ($count > 0)
{
$colour[1] = ($colour[1] + mt_rand(40,60)) % 99;
$colour[2] = ($colour[2] + mt_rand(40,60));
$results[] = $this->allocate($colour, $mode);
$count--;
}
return $results;
}
/**
* Convert from one colour model to another
*/
function model_convert($colour, $from_model, $to_model)
{
if ($from_model == $to_model)
{
return $colour;
}
switch ($to_model)
{
case 'hsv':
switch ($from_model)
{
case 'ahsv':
return $this->ah2h($colour);
break;
case 'rgb':
return $this->rgb2hsv($colour);
break;
}
break;
case 'ahsv':
switch ($from_model)
{
case 'hsv':
return $this->h2ah($colour);
break;
case 'rgb':
return $this->h2ah($this->rgb2hsv($colour));
break;
}
break;
case 'rgb':
switch ($from_model)
{
case 'hsv':
return $this->hsv2rgb($colour);
break;
case 'ahsv':
return $this->hsv2rgb($this->ah2h($colour));
break;
}
break;
}
return false;
}
/**
* Slightly altered from wikipedia's algorithm
*/
function hsv2rgb($hsv)
{
$this->normalize_hue($hsv[0]);
$h = $hsv[0];
$s = min(1, max(0, $hsv[1] / 100));
$v = min(1, max(0, $hsv[2] / 100));
// calculate hue sector
$hi = floor($hsv[0] / 60);
// calculate opposite colour
$p = $v * (1 - $s);
// calculate distance between hex vertices
$f = ($h / 60) - $hi;
// coming in or going out?
if (!($hi & 1))
{
$f = 1 - $f;
}
// calculate adjacent colour
$q = $v * (1 - ($f * $s));
switch ($hi)
{
case 0:
$rgb = array($v, $q, $p);
break;
case 1:
$rgb = array($q, $v, $p);
break;
case 2:
$rgb = array($p, $v, $q);
break;
case 3:
$rgb = array($p, $q, $v);
break;
case 4:
$rgb = array($q, $p, $v);
break;
case 5:
$rgb = array($v, $p, $q);
break;
default:
return array(0, 0, 0);
break;
}
return array(255 * $rgb[0], 255 * $rgb[1], 255 * $rgb[2]);
}
/**
* (more than) Slightly altered from wikipedia's algorithm
*/
function rgb2hsv($rgb)
{
$r = min(255, max(0, $rgb[0]));
$g = min(255, max(0, $rgb[1]));
$b = min(255, max(0, $rgb[2]));
$max = max($r, $g, $b);
$min = min($r, $g, $b);
$v = $max / 255;
$s = (!$max) ? 0 : 1 - ($min / $max);
// if max - min is 0, we want hue to be 0 anyway.
$h = $max - $min;
if ($h)
{
switch ($max)
{
case $g:
$h = 120 + (60 * ($b - $r) / $h);
break;
case $b:
$h = 240 + (60 * ($r - $g) / $h);
break;
case $r:
$h = 360 + (60 * ($g - $b) / $h);
break;
}
}
$this->normalize_hue($h);
return array($h, $s * 100, $v * 100);
}
/**
*/
function normalize_hue(&$hue)
{
$hue %= 360;
if ($hue < 0)
{
$hue += 360;
}
}
/**
* Alternate hue to hue
*/
function ah2h($ahue)
{
if (is_array($ahue))
{
$ahue[0] = $this->ah2h($ahue[0]);
return $ahue;
}
$this->normalize_hue($ahue);
// blue through red is already ok
if ($ahue >= 240)
{
return $ahue;
}
// ahue green is at 180
if ($ahue >= 180)
{
// return (240 - (2 * (240 - $ahue)));
return (2 * $ahue) - 240; // equivalent
}
// ahue yellow is at 120 (RYB rather than RGB)
if ($ahue >= 120)
{
return $ahue - 60;
}
return $ahue / 2;
}
/**
* hue to Alternate hue
*/
function h2ah($hue)
{
if (is_array($hue))
{
$hue[0] = $this->h2ah($hue[0]);
return $hue;
}
$this->normalize_hue($hue);
// blue through red is already ok
if ($hue >= 240)
{
return $hue;
}
else if ($hue <= 60)
{
return $hue * 2;
}
else if ($hue <= 120)
{
return $hue + 60;
}
else
{
return ($hue + 240) / 2;
}
}
}