three.js/manual/examples/resources/threejs-utils.js

/*
 * Copyright 2012, Gregg Tavares.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Gregg Tavares. nor the names of his
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* global define */

(function(root, factory) {  // eslint-disable-line
  if (typeof define === 'function' && define.amd) {
    // AMD. Register as an anonymous module.
    define([], function() {
      return factory.call(root);
    });
  } else {
    // Browser globals
    root.threejsUtils = factory.call(root);
  }
}(this, function() {
  'use strict';  // eslint-disable-line

  /** @module threejs-utils */

  /**
   * Resize a canvas to match the size its displayed.
   * @param {HTMLCanvasElement} canvas The canvas to resize.
   * @param {number} [multiplier] amount to multiply by.
   *    Pass in window.devicePixelRatio for native pixels.
   * @return {boolean} true if the canvas was resized.
   * @memberOf module:webgl-utils
   */
  function resizeCanvasToDisplaySize(canvas, multiplier) {
    multiplier = multiplier || 1;
    const width  = canvas.clientWidth  * multiplier | 0;
    const height = canvas.clientHeight * multiplier | 0;
    if (canvas.width !== width ||  canvas.height !== height) {
      canvas.width  = width;
      canvas.height = height;
      return true;
    }
    return false;
  }

  return {
    resizeCanvasToDisplaySize: resizeCanvasToDisplaySize,
  };

}));