e2pdf / vendors / svggraph / GradientList.php

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

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1	<?php
2	/**
3	* Copyright (C) 2019-2022 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	* Creates and stores gradients
26	*/
27	class GradientList {
28
29	private $graph;
30	private $gradients = [];
31	private $gradient_map = [];
32
33	public function __construct(&$graph)
34	{
35	$this->graph =& $graph;
36	}
37
38	/**
39	* Adds a gradient to the list, returning the element ID for use in url
40	*/
41	public function addGradient($colours, $key = null, $radial = false)
42	{
43	if($key === null \|\| !isset($this->gradients[$key])) {
44
45	if($radial) {
46	// if this is a radial gradient, it must end with 'r'
47	$last = count($colours) - 1;
48	if(strlen($colours[$last]) == 1)
49	$colours[$last] = 'r';
50	else
51	$colours[] = 'r';
52	}
53
54	// find out if this gradient already stored
55	$hash = md5(serialize($colours));
56	if(isset($this->gradient_map[$hash]))
57	return $this->gradient_map[$hash];
58
59	$id = $this->graph->newID();
60	if($key === null)
61	$key = $id;
62	$this->gradients[$key] = ['id' => $id, 'colours' => $colours];
63	$this->gradient_map[$hash] = $id;
64	return $id;
65	}
66	return $this->gradients[$key]['id'];
67	}
68
69	/**
70	* Creates a gradient element
71	*/
72	private function makeGradient($key)
73	{
74	$stops = '';
75	$direction = 'v';
76	$type = 'linearGradient';
77	$colours = $this->gradients[$key]['colours'];
78	$id = $this->gradients[$key]['id'];
79
80	if(in_array($colours[count($colours)-1], ['h', 'v', 'r']))
81	$direction = array_pop($colours);
82	if($direction == 'r') {
83	$type = 'radialGradient';
84	$gradient = ['id' => $id];
85	} else {
86	$x2 = $direction == 'v' ? 0 : '100%';
87	$y2 = $direction == 'h' ? 0 : '100%';
88	$gradient = ['id' => $id, 'x1' => 0, 'x2' => $x2, 'y1' => 0, 'y2' => $y2];
89	}
90
91	$segments = $this->decompose($colours);
92	foreach($segments as $segment) {
93	list($offset, $colour, $opacity) = $segment;
94	$stop = ['offset' => $offset . '%', 'stop-color' => $colour];
95	if(is_numeric($opacity))
96	$stop['stop-opacity'] = $opacity;
97	$stops .= $this->graph->element('stop', $stop);
98	}
99
100	return $this->graph->element($type, $gradient, null, $stops);
101	}
102
103	/**
104	* Calculates a colour component from a gradient step
105	*/
106	private function calcComponent($c0, $c1, $o0, $o1, $d)
107	{
108	return $c0 + ($c1 - $c0) * ($d - $o0) / ($o1 - $o0);
109	}
110
111	/**
112	* Returns the colour at a position in the gradient
113	*/
114	public function getColour($key, $position)
115	{
116	if(!isset($this->gradients[$key]))
117	return '';
118	$colours = $this->gradients[$key]['colours'];
119	if(in_array($colours[count($colours)-1], ['h', 'v', 'r']))
120	$direction = array_pop($colours);
121	$segments = $this->decompose($colours);
122
123	// function to produce colour string
124	$make_colour = function($r, $g, $b, $o) {
125	$str = "rgb({$r},{$g},{$b})";
126	if(!is_numeric($o) \|\| $o >= 1)
127	return $str;
128	if($o <= 0)
129	return 'none';
130	$str .= ':' . $o;
131	return $str;
132	};
133
134	$position = min(100, max(0, $position));
135	$seg0 = $segments[0];
136	$seg1 = null;
137	foreach($segments as $seg) {
138	if(abs($seg[0] - $position) < 0.1) {
139	// stop colour at or close to requested position
140	$c = $seg[1]->rgb();
141	$c_string = $make_colour($c[0], $c[1], $c[2], $seg[2]);
142	$colour = new Colour($this->graph, $c_string);
143	return $colour;
144	}
145
146	if($seg[0] > $position) {
147	$seg1 = $seg;
148	break;
149	}
150	$seg0 = $seg;
151	}
152	if($seg1 === null) {
153	$seg1 = array_pop($segments);
154	$seg1[0] = 100;
155	}
156
157	$c0 = $seg0[1]->rgb();
158	$c1 = $seg1[1]->rgb();
159	$vr = $this->calcComponent($c0[0], $c1[0], $seg0[0], $seg1[0], $position);
160	$vg = $this->calcComponent($c0[1], $c1[1], $seg0[0], $seg1[0], $position);
161	$vb = $this->calcComponent($c0[2], $c1[2], $seg0[0], $seg1[0], $position);
162
163	$o0 = $seg0[2] === null ? 1 : $seg0[2];
164	$o1 = $seg1[2] === null ? 1 : $seg1[2];
165	$vo = $this->calcComponent($o0, $o1, $seg0[0], $seg1[0], $position);
166	$c_string = $make_colour($vr, $vg, $vb, $vo);
167	$colour = new Colour($this->graph, $c_string);
168	return $colour;
169	}
170
171	/**
172	* Breaks gradient array down into components
173	*/
174	public function decompose($colours)
175	{
176	$col_mul = 100 / (count($colours) - 1);
177	$offset = 0;
178	$decomposed = [];
179	foreach($colours as $pos => $colour) {
180	$opacity = null;
181	$poffset = $pos * $col_mul;
182	if(strpos($colour, ':') !== false) {
183	// opacity, stop offset or both
184	$parts = explode(':', $colour);
185	if(is_numeric($parts[0]) \|\| count($parts) == 3) {
186	$poffset = array_shift($parts);
187	}
188	// stick the other parts back together and let the Colour class
189	// figure it out
190	$colour = new Colour($this->graph, implode(':', $parts));
191	$opacity = $colour->opacity();
192	if($opacity == 1)
193	$opacity = null;
194	} else {
195	$colour = new Colour($this->graph, $colour);
196	}
197	// set the offset to the most meaningful number
198	$offset = min(100, max(0, $offset, $poffset));
199	$decomposed[] = [$offset, $colour, $opacity];
200	}
201	return $decomposed;
202	}
203
204	/**
205	* Defines the list of gradients
206	*/
207	public function makeGradients(&$defs)
208	{
209	foreach($this->gradients as $key => $gradient)
210	$defs->add($this->makeGradient($key));
211	}
212	}
213
214