webcomponentsjs/src/ShadowDOM/wrappers/WebGLRenderingContext.js

/**
 * @license
 * Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
 * This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
 * The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
 * The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
 * Code distributed by Google as part of the polymer project is also
 * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
 */

(function(scope) {
  'use strict';

  var mixin = scope.mixin;
  var registerWrapper = scope.registerWrapper;
  var setWrapper = scope.setWrapper;
  var unsafeUnwrap = scope.unsafeUnwrap;
  var unwrapIfNeeded = scope.unwrapIfNeeded;
  var wrap = scope.wrap;

  var OriginalWebGLRenderingContext = window.WebGLRenderingContext;

  // IE10 does not have WebGL.
  if (!OriginalWebGLRenderingContext)
    return;

  function WebGLRenderingContext(impl) {
    setWrapper(impl, this);
  }

  mixin(WebGLRenderingContext.prototype, {
    get canvas() {
      return wrap(unsafeUnwrap(this).canvas);
    },

    texImage2D: function() {
      arguments[5] = unwrapIfNeeded(arguments[5]);
      unsafeUnwrap(this).texImage2D.apply(unsafeUnwrap(this), arguments);
    },

    texSubImage2D: function() {
      arguments[6] = unwrapIfNeeded(arguments[6]);
      unsafeUnwrap(this).texSubImage2D.apply(unsafeUnwrap(this), arguments);
    }
  });

  // Blink/WebKit has broken DOM bindings. Usually we would create an instance
  // of the object and pass it into registerWrapper as a "blueprint" but
  // creating WebGL contexts is expensive and might fail so we use a dummy
  // object with dummy instance properties for these broken browsers.
  var instanceProperties = /WebKit/.test(navigator.userAgent) ?
      {drawingBufferHeight: null, drawingBufferWidth: null} : {};

  registerWrapper(OriginalWebGLRenderingContext, WebGLRenderingContext,
      instanceProperties);

  scope.wrappers.WebGLRenderingContext = WebGLRenderingContext;
})(window.ShadowDOMPolyfill);