📄 function.imagecolorallocatealpha.html

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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> <head>  <title>Allocate a color for an image</title>  <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.imagecolorallocate.html">imagecolorallocate</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.imagecolorat.html">imagecolorat</a></div> <div class="up"><a href="ref.image.html">GD Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.imagecolorallocatealpha" class="refentry"> <div class="refnamediv">  <h1 class="refname">imagecolorallocatealpha</h1>  <p class="verinfo">(PHP 4 &gt;= 4.3.2, PHP 5)</p><p class="refpurpose"><span class="refname">imagecolorallocatealpha</span> &mdash; <span class="dc-title">Allocate a color for an image</span></p> </div> <div class="refsect1 description">  <h3 class="title">Description</h3>  <div class="methodsynopsis dc-description">   <span class="type">int</span> <span class="methodname"><b><b>imagecolorallocatealpha</b></b></span>    ( <span class="methodparam"><span class="type">resource</span> <tt class="parameter">$image</tt></span>   , <span class="methodparam"><span class="type">int</span> <tt class="parameter">$red</tt></span>   , <span class="methodparam"><span class="type">int</span> <tt class="parameter">$green</tt></span>   , <span class="methodparam"><span class="type">int</span> <tt class="parameter">$blue</tt></span>   , <span class="methodparam"><span class="type">int</span> <tt class="parameter">$alpha</tt></span>   )</div>  <p class="para rdfs-comment">   <b>imagecolorallocatealpha()</b> behaves identically to   <a href="function.imagecolorallocate.html" class="function">imagecolorallocate()</a> with the addition of the transparency   parameter <i><tt class="parameter">alpha</tt></i>.  </p> </div> <div class="refsect1 parameters">  <h3 class="title">Parameters</h3>  <p class="para">   <dl>    <dt><span class="term"><i><tt class="parameter">image</tt></i></span><dd><p class="para">An image resource, returned by one of the image creation functions, such as <a href="function.imagecreatetruecolor.html" class="function">imagecreatetruecolor()</a>.</p></dd></dt>    <dt>     <span class="term"><i><tt class="parameter">red</tt></i></span>     <dd>      <p class="para">       Value of red component.      </p>     </dd>    </dt>    <dt>     <span class="term"><i><tt class="parameter">green</tt></i></span>     <dd>      <p class="para">       Value of green component.      </p>     </dd>    </dt>    <dt>     <span class="term"><i><tt class="parameter">blue</tt></i></span>     <dd>      <p class="para">       Value of blue component.      </p>     </dd>    </dt>    <dt>     <span class="term"><i><tt class="parameter">alpha</tt></i></span>     <dd>      <p class="para">       A value between <i>0</i> and <i>127</i>.       <i>0</i> indicates completely opaque while        <i>127</i> indicates completely transparent.      </p>     </dd>    </dt>   </dl>   The colors parameters are integers between 0 and 255 or hexadecimals   between 0x00 and 0xFF.  </p> </div> <div class="refsect1 returnvalues">  <h3 class="title">Return Values</h3>  <p class="para">   A color identifier or <b><tt>FALSE</tt></b> if the allocation failed.  </p> </div> <div class="refsect1 changelog">  <h3 class="title">ChangeLog</h3>  <p class="para">   <table class="informaltable">    <colgroup>     <thead valign="middle">      <tr valign="middle">       <th colspan="1">Version</th>       <th colspan="1">Description</th>      </tr>     </thead>     <tbody valign="middle" class="tbody">      <tr valign="middle">       <td colspan="1" rowspan="1" align="left">Prior to 5.1.3</td>       <td colspan="1" rowspan="1" align="left">        Returns -1 if the allocation failed.       </td>      </tr>     </tbody>    </colgroup>   </table>  </p> </div> <div class="refsect1 examples">  <h3 class="title">Examples</h3>  <p class="para">   <div class="example">    <p><b>Example #1 Example of using <b>imagecolorallocatealpha()</b></b></p>    <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB">&lt;?php<br />$size&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">300</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$image</span><span style="color: #007700">=</span><span style="color: #0000BB">imagecreatetruecolor</span><span style="color: #007700">(</span><span style="color: #0000BB">$size</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$size</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;something&nbsp;to&nbsp;get&nbsp;a&nbsp;white&nbsp;background&nbsp;with&nbsp;black&nbsp;border<br /></span><span style="color: #0000BB">$back&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">imagecolorallocate</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">255</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">255</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">255</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$border&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">imagecolorallocate</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">imagefilledrectangle</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$size&nbsp;</span><span style="color: #007700">-&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$size&nbsp;</span><span style="color: #007700">-&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$back</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">imagerectangle</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$size&nbsp;</span><span style="color: #007700">-&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$size&nbsp;</span><span style="color: #007700">-&nbsp;</span><span style="color: #0000BB">1</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$border</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$yellow_x&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">100</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$yellow_y&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">75</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$red_x&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">120</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$red_y&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">165</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$blue_x&nbsp;&nbsp;&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">187</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$blue_y&nbsp;&nbsp;&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">125</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$radius&nbsp;&nbsp;&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">150</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">//&nbsp;allocate&nbsp;colors&nbsp;with&nbsp;alpha&nbsp;values<br /></span><span style="color: #0000BB">$yellow&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">imagecolorallocatealpha</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">255</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">255</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">75</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$red&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">imagecolorallocatealpha</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">255</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">75</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$blue&nbsp;&nbsp;&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">imagecolorallocatealpha</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">0</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">255</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">75</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;drawing&nbsp;3&nbsp;overlapped&nbsp;circle<br /></span><span style="color: #0000BB">imagefilledellipse</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$yellow_x</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$yellow_y</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$radius</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$radius</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$yellow</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">imagefilledellipse</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$red_x</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$red_y</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$radius</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$radius</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$red</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">imagefilledellipse</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$blue_x</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$blue_y</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$radius</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$radius</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$blue</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;don't&nbsp;forget&nbsp;to&nbsp;output&nbsp;a&nbsp;correct&nbsp;header!<br /></span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Content-type:&nbsp;image/png'</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">//&nbsp;and&nbsp;finally,&nbsp;output&nbsp;the&nbsp;result<br /></span><span style="color: #0000BB">imagepng</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">imagedestroy</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span></span></code></div>    </div>    <div class="example-contents"><p>The above example will output something similar to:</p></div>    <div class="mediaobject">     <div class="imageobject">      <img src="figures/image.imagecolorallocatealpha.png" />     </div>    </div>   </div>  </p> </div> <div class="refsect1 notes">  <h3 class="title">Notes</h3>  <blockquote><p><b class="note">Note</b>: <span class="simpara">This function requires GD 2.0.1 or later (2.0.28 or later is recommended).</span></p></blockquote> </div> <div class="refsect1 seealso">  <h3 class="title">See Also</h3>  <p class="para">   <ul class="simplelist">    <li class="member"><a href="function.imagecolorallocate.html" class="function" rel="rdfs-seeAlso">imagecolorallocate()</a></li>    <li class="member"><a href="function.imagecolordeallocate.html" class="function" rel="rdfs-seeAlso">imagecolordeallocate()</a></li>   </ul>  </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.imagecolorallocate.html">imagecolorallocate</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.imagecolorat.html">imagecolorat</a></div> <div class="up"><a href="ref.image.html">GD Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div></body></html>
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