---
title: CanvasRenderingContext2D.globalCompositeOperation
slug: Web/API/CanvasRenderingContext2D/globalCompositeOperation
tags:
  - API
  - Blending
  - Canvas
  - CanvasRenderingContext2D
  - Compositie
  - Onderdeel
  - Referentie
translation_of: Web/API/CanvasRenderingContext2D/globalCompositeOperation
---
<div>{{APIRef}}</div>

<p>De <code><strong>CanvasRenderingContext2D</strong></code><strong><code>.globalCompositeOperation</code></strong>onderdeel van de Canvas 2D API verandert het type van renderen van nieuwe figuren. Hierbij is type een string die de nieuwe rendermodus geeft.</p>

<p>Bekijk ook het hoofdstuk <a href="/en-US/docs/Web/API/Canvas_API/Tutorial/Compositing">Compositing</a> in de <a href="/en-US/docs/Web/API/Canvas_API/Tutorial">Canvas Tutorial</a>.</p>

<h2 id="Syntax">Syntax</h2>

<pre class="syntaxbox"><var><em>ctx</em>.globalCompositeOperation = type;</var></pre>

<h3 id="Types">Types</h3>

<p>{{EmbedLiveSample("Compositing_example", 750, 7300, "" ,"Web/API/Canvas_API/Tutorial/Compositing/Example")}}</p>

<h2 id="Examples">Examples</h2>

<h3 id="Using_the_globalAlpha_property" name="Using_the_globalAlpha_property"><code>globalCompositeOperation</code> gebruiken</h3>

<p>Dit is maar een klein stukje code die de <code>globalCompositeOperation</code> property gebruikt om twee rechthoeken te tekenen die elkaar erbuiten houden waar ze overlappen.</p>

<h4 id="HTML">HTML</h4>

<pre class="brush: html">&lt;canvas id="canvas"&gt;&lt;/canvas&gt;
</pre>

<h4 id="JavaScript">JavaScript</h4>

<pre class="brush: js; highlight[4]">var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');

ctx.globalCompositeOperation = 'xor';

ctx.fillStyle = 'blue';
ctx.fillRect(10, 10, 100, 100);

ctx.fillStyle = 'red';
ctx.fillRect(50, 50, 100, 100);
</pre>

<p>Bewerk de code hieronder en zie de veranderingen:</p>

<div class="hidden">
<h6 id="Playable_code" name="Playable_code">Speelcode</h6>

<pre class="brush: html">&lt;canvas id="canvas" width="400" height="200" class="playable-canvas"&gt;&lt;/canvas&gt;
&lt;div class="playable-buttons"&gt;
  &lt;input id="edit" type="button" value="Edit" /&gt;
  &lt;input id="reset" type="button" value="Reset" /&gt;
&lt;/div&gt;
&lt;textarea id="code" class="playable-code" style="height:120px;"&gt;
ctx.globalCompositeOperation = 'xor';

ctx.fillStyle = 'blue';
ctx.fillRect(10, 10, 100, 100);

ctx.fillStyle = 'red';
ctx.fillRect(50, 50, 100, 100);&lt;/textarea&gt;
</pre>

<pre class="brush: js">var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
var textarea = document.getElementById('code');
var reset = document.getElementById('reset');
var edit = document.getElementById('edit');
var code = textarea.value;

function drawCanvas() {
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  eval(textarea.value);
}

reset.addEventListener('click', function() {
  textarea.value = code;
  drawCanvas();
});

edit.addEventListener('click', function() {
  textarea.focus();
})

textarea.addEventListener('input', drawCanvas);
window.addEventListener('load', drawCanvas);
</pre>
</div>

<p>{{ EmbedLiveSample('Playable_code', 700, 380) }}</p>

<h2 id="Specificaties">Specificaties</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specificatie</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('HTML WHATWG', "scripting.html#dom-context-2d-globalcompositeoperation", "CanvasRenderingContext2D.globalCompositeOperation")}}</td>
   <td>{{Spec2('HTML WHATWG')}}</td>
   <td> </td>
  </tr>
  <tr>
   <td>{{SpecName('Compositing')}}</td>
   <td>{{Spec2('Compositing')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="Browserondersteuning">Browserondersteuning</h2>

<p>{{CompatibilityTable}}</p>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Edge</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari</th>
  </tr>
  <tr>
   <td>Standaard</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
  <tr>
   <td>Blendmodus</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{ CompatGeckoDesktop("20") }}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Android Webview</th>
   <th>Edge</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
   <th>Chrome for Android</th>
  </tr>
  <tr>
   <td>Standaard</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
  <tr>
   <td>Blendmodus</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{ CompatGeckoMobile("20") }}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="WebKitBlink-specifieke_opmerkingen">WebKit/Blink-specifieke opmerkingen</h2>

<ul>
 <li>In WebKit- and Blink-gebaseerde Browsers, is een niet-standaard en afgewezen functie <code>ctx.setCompositeOperation()</code> gebruikt voor deze operatie.</li>
 <li>Ondersteuning "plus-darker" en "darker" zijn verwijderd in Chrome 48. Ontwikkelaars zoeken een vervanging die "darken" moet gebruiken.</li>
</ul>

<h2 id="Gecko-specifieke_opmerkingen">Gecko-specifieke opmerkingen</h2>

<ul>
 <li>Een vroege Canvas-specificatie draft heeft de waarde "darker", maar Firefox verwijderde ondersteuning voor "darker" in versie 4 ({{bug(571532)}}). Bekijk ook <a href="http://dropshado.ws/post/77229081704/firefox-doesnt-support-canvas-composite-darker">deze blogpost</a> die de <code>difference</code> value aanraad om een gelijk effect als "darker" te maken.</li>
</ul>

<h2 id="Bekijk_ook">Bekijk ook</h2>

<ul>
 <li>De interface die het definieert: {{domxref("CanvasRenderingContext2D")}}</li>
 <li>{{domxref("CanvasRenderingContext2D.globalAlpha")}}</li>
</ul>