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<title>Set the alpha blending flag to use layering effects</title>
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<div class="refnamediv">
<h1 class="refname">imagelayereffect</h1>
<p class="verinfo">(PHP 4 >= 4.3.0, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">imagelayereffect</span> — <span class="dc-title">Set the alpha blending flag to use layering effects</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.imagelayereffect-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>imagelayereffect</strong></span>
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$image</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$effect</code></span>
)</div>
<p class="para rdfs-comment">
Set the alpha blending flag to use layering effects.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.imagelayereffect-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<code class="parameter">
image</code></dt>
<dd>
<p class="para">An image resource, returned by one of the image creation functions,
such as <span class="function"><a href="function.imagecreatetruecolor.html" class="function">imagecreatetruecolor()</a></span>.</p></dd>
<dt>
<code class="parameter">effect</code></dt>
<dd>
<p class="para">
One of the following constants:
<dl>
<dt>
<strong><code>IMG_EFFECT_REPLACE</code></strong></dt>
<dd>
<span class="simpara">
Use pixel replacement (equivalent of passing <strong><code>TRUE</code></strong> to
<span class="function"><a href="function.imagealphablending.html" class="function">imagealphablending()</a></span>)
</span>
</dd>
<dt>
<strong><code>IMG_EFFECT_ALPHABLEND</code></strong></dt>
<dd>
<span class="simpara">
Use normal pixel blending (equivalent of passing <strong><code>FALSE</code></strong> to
<span class="function"><a href="function.imagealphablending.html" class="function">imagealphablending()</a></span>)
</span>
</dd>
<dt>
<strong><code>IMG_EFFECT_NORMAL</code></strong></dt>
<dd>
<span class="simpara">
Same as <strong><code>IMG_EFFECT_ALPHABLEND</code></strong>.
</span>
</dd>
<dt>
<strong><code>IMG_EFFECT_OVERLAY</code></strong></dt>
<dd>
<span class="simpara">
Overlay has the effect that black background pixels will remain
black, white background pixels will remain white, but grey
background pixels will take the colour of the foreground pixel.
</span>
</dd>
<dt>
<strong><code>IMG_EFFECT_MULTIPLY</code></strong></dt>
<dd>
<span class="simpara">
Overlays with a multiply effect.
</span>
</dd>
</dl>
</p>
</dd>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.imagelayereffect-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.imagelayereffect-changelog">
<h3 class="title">Changelog</h3>
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>7.2.0</td>
<td>
Added <strong><code>IMG_EFFECT_MULTIPLY</code></strong> (requires system libgd >=
2.1.1 or the bundled libgd).
</td>
</tr>
</tbody>
</table>
</div>
<div class="refsect1 examples" id="refsect1-function.imagelayereffect-examples">
<h3 class="title">Examples</h3>
<div class="example" id="example-3825">
<p><strong>Example #1 <span class="function"><strong>imagelayereffect()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// Setup an image<br /></span><span style="color: #0000BB">$im </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecreatetruecolor</span><span style="color: #007700">(</span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Set a background<br /></span><span style="color: #0000BB">imagefilledrectangle</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">imagecolorallocate</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">220</span><span style="color: #007700">, </span><span style="color: #0000BB">220</span><span style="color: #007700">, </span><span style="color: #0000BB">220</span><span style="color: #007700">));<br /><br /></span><span style="color: #FF8000">// Apply the overlay alpha blending flag<br /></span><span style="color: #0000BB">imagelayereffect</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">IMG_EFFECT_OVERLAY</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Draw two grey ellipses<br /></span><span style="color: #0000BB">imagefilledellipse</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">50</span><span style="color: #007700">, </span><span style="color: #0000BB">50</span><span style="color: #007700">, </span><span style="color: #0000BB">40</span><span style="color: #007700">, </span><span style="color: #0000BB">40</span><span style="color: #007700">, </span><span style="color: #0000BB">imagecolorallocate</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">255</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">imagefilledellipse</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">50</span><span style="color: #007700">, </span><span style="color: #0000BB">50</span><span style="color: #007700">, </span><span style="color: #0000BB">50</span><span style="color: #007700">, </span><span style="color: #0000BB">80</span><span style="color: #007700">, </span><span style="color: #0000BB">imagecolorallocate</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">255</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">imagefilledellipse</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">50</span><span style="color: #007700">, </span><span style="color: #0000BB">50</span><span style="color: #007700">, </span><span style="color: #0000BB">80</span><span style="color: #007700">, </span><span style="color: #0000BB">50</span><span style="color: #007700">, </span><span style="color: #0000BB">imagecolorallocate</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">255</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">));<br /><br /></span><span style="color: #FF8000">// Output<br /></span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Content-type: image/png'</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">imagepng</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">imagedestroy</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></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="images/21009b70229598c6a80eef8b45bf282b-imagelayereffect.png" alt="Output of example : imagelayereffect()" width="100" height="100" />
</div>
</div>
</div>
</div>
<div class="refsect1 notes" id="refsect1-function.imagelayereffect-notes">
<h3 class="title">Notes</h3>
<p class="simpara">
Before PHP 5.5.0, this function is only available if PHP is compiled with the
bundled version of the GD library.
</p>
</div>
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