e2pdf / vendors / svggraph / ColourFilter.php

ColourFilter.php in E2Pdf – Export Pdf Tool for WordPress 1.32.32, at vendors/svggraph/ColourFilter.php

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1	<?php
2	/**
3	* Copyright (C) 2020 Graham Breach
4	*
5	* This program is free software: you can redistribute it and/or modify
6	* it under the terms of the GNU Lesser General Public License as published by
7	* the Free Software Foundation, either version 3 of the License, or
8	* (at your option) any later version.
9	*
10	* This program is distributed in the hope that it will be useful,
11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13	* GNU Lesser General Public License for more details.
14	*
15	* You should have received a copy of the GNU Lesser General Public License
16	* along with this program. If not, see <http://www.gnu.org/licenses/>.
17	*/
18	/**
19	* For more information, please contact <graham@goat1000.com>
20	*/
21
22	namespace Goat1000\SVGGraph;
23
24	/**
25	* Class for modifying a colour
26	*/
27	class ColourFilter {
28	private $colour;
29	private $filters;
30
31	public function __construct($colour, $filters)
32	{
33	// these are special cases, can't be processed
34	if($colour === 'transparent' \|\| $colour === 'none')
35	throw new \InvalidArgumentException('Unable to filter colour [' . $colour . ']');
36	$this->colour = new RGBColour($colour);
37
38	$filters = explode('/', $filters);
39	foreach($filters as $f) {
40	$filter = $f;
41	$args = [];
42	$fpos = strpos($f, '(');
43	$epos = strpos($f, ')');
44	if($fpos > 0) {
45	$filter = substr($f, 0, $fpos);
46	$a = '';
47	if($epos > $fpos)
48	$a = substr($f, $fpos + 1, $epos - $fpos - 1);
49	if($a !== '')
50	$args = preg_split('/[\s,]+/', $a);
51	}
52
53	if(method_exists($this, $filter))
54	call_user_func_array([$this, $filter], $args);
55	}
56	}
57
58	/**
59	* Increase or decrease brightness
60	*/
61	public function brightness($amount = '1.2')
62	{
63	list ($operator, $value) = $this->expression($amount);
64	if($value === null)
65	throw new \InvalidArgumentException('Invalid brightness [' . $amount . ']');
66	list($h, $s, $l) = $this->colour->getHSL();
67
68	$l = min(1.0, max(0.0, $operator === '+' ? $l + $value : $l * $value));
69	$this->colour->setHSL($h, $s, $l);
70	}
71
72	/**
73	* Increase or decrease saturation
74	*/
75	public function saturation($amount = '0.0')
76	{
77	list ($operator, $value) = $this->expression($amount);
78	if($value === null)
79	throw new \InvalidArgumentException('Invalid saturation [' . $amount . ']');
80	list($h, $s, $l) = $this->colour->getHSL();
81
82	$s = min(1.0, max(0.0, $operator === '+' ? $s + $value : $s * $value));
83	$this->colour->setHSL($h, $s, $l);
84	}
85
86	/**
87	* Modify the hue
88	*/
89	public function hue($amount = '60')
90	{
91	if(!is_numeric($amount))
92	throw new \InvalidArgumentException('Invalid hue [' . $amount . ']');
93	list($h, $s, $l) = $this->colour->getHSL();
94	$h += $amount;
95	$this->colour->setHSL($h, $s, $l);
96	}
97
98	/**
99	* Returns the expression to be applied
100	*/
101	public static function expression($a)
102	{
103	$operator = '*';
104	$value = null;
105	if($a[0] === '+' \|\| $a[0] === '-')
106	$operator = '+';
107
108	$p = strpos($a, '%');
109	if($p > 0)
110	$a = substr($a, 0, $p);
111
112	if(is_numeric($a))
113	$value = $p > 0 ? $a / 100 : $a;
114	return [$operator, $value];
115	}
116
117	public function __toString()
118	{
119	return $this->colour->getHex();
120	}
121	}
122
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