1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.12 $ -->
<refentry xml:id="function.imagecolorallocatealpha" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>imagecolorallocatealpha</refname>
<refpurpose>Allocate a color for an image</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>int</type><methodname>imagecolorallocatealpha</methodname>
<methodparam><type>resource</type><parameter>image</parameter></methodparam>
<methodparam><type>int</type><parameter>red</parameter></methodparam>
<methodparam><type>int</type><parameter>green</parameter></methodparam>
<methodparam><type>int</type><parameter>blue</parameter></methodparam>
<methodparam><type>int</type><parameter>alpha</parameter></methodparam>
</methodsynopsis>
<para>
<function>imagecolorallocatealpha</function> behaves identically to
<function>imagecolorallocate</function> with the addition of the transparency
parameter <parameter>alpha</parameter>.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
&gd.image.description;
<varlistentry>
<term><parameter>red</parameter></term>
<listitem>
<para>
Value of red component.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>green</parameter></term>
<listitem>
<para>
Value of green component.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>blue</parameter></term>
<listitem>
<para>
Value of blue component.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>alpha</parameter></term>
<listitem>
<para>
A value between <literal>0</literal> and <literal>127</literal>.
<literal>0</literal> indicates completely opaque while
<literal>127</literal> indicates completely transparent.
</para>
</listitem>
</varlistentry>
</variablelist>
The colors parameters are integers between 0 and 255 or hexadecimals
between 0x00 and 0xFF.
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
A color identifier or &false; if the allocation failed.
</para>
</refsect1>
<refsect1 role="changelog">
&reftitle.changelog;
<para>
<informaltable>
<tgroup cols="2">
<thead>
<row>
<entry>&Version;</entry>
<entry>&Description;</entry>
</row>
</thead>
<tbody>
<row>
<entry>Prior to 5.1.3</entry>
<entry>
Returns -1 if the allocation failed.
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title>Example of using <function>imagecolorallocatealpha</function></title>
<programlisting role="php">
<![CDATA[
<?php
$size = 300;
$image=imagecreatetruecolor($size, $size);
// something to get a white background with black border
$back = imagecolorallocate($image, 255, 255, 255);
$border = imagecolorallocate($image, 0, 0, 0);
imagefilledrectangle($image, 0, 0, $size - 1, $size - 1, $back);
imagerectangle($image, 0, 0, $size - 1, $size - 1, $border);
$yellow_x = 100;
$yellow_y = 75;
$red_x = 120;
$red_y = 165;
$blue_x = 187;
$blue_y = 125;
$radius = 150;
// allocate colors with alpha values
$yellow = imagecolorallocatealpha($image, 255, 255, 0, 75);
$red = imagecolorallocatealpha($image, 255, 0, 0, 75);
$blue = imagecolorallocatealpha($image, 0, 0, 255, 75);
// drawing 3 overlapped circle
imagefilledellipse($image, $yellow_x, $yellow_y, $radius, $radius, $yellow);
imagefilledellipse($image, $red_x, $red_y, $radius, $radius, $red);
imagefilledellipse($image, $blue_x, $blue_y, $radius, $radius, $blue);
// don't forget to output a correct header!
header('Content-type: image/png');
// and finally, output the result
imagepng($image);
imagedestroy($image);
?>
]]>
</programlisting>
&example.outputs.similar;
<mediaobject>
<imageobject>
<imagedata fileref="figures/image.imagecolorallocatealpha.png"/>
</imageobject>
</mediaobject>
</example>
</para>
</refsect1>
<refsect1 role="notes">
&reftitle.notes;
¬e.gd.2;
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>imagecolorallocate</function></member>
<member><function>imagecolordeallocate</function></member>
</simplelist>
</para>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"../../../../manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->
|
