text: <!--
  Copyright (c) 2012 Cameron Adams. All rights reserved.
  Copyright (c) 2012 Code Aurora Forum. All rights reserved.
  Copyright (C) 2013 Google Inc. All rights reserved.
  
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  modification, are permitted provided that the following conditions are
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      * 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
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      * Neither the name of Code Aurora Forum Inc., Google Inc. nor the
  names of its 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.
  
  This test is based on code written by Cameron Adams and imported from
    http://themaninblue.com/experiment/AnimationBenchmark/html
  -->
  
  <!doctype html>
  <head>
  <title>Benchmark - Balls Animation using HTML5 Canvas</title>
  <style>
  html {
      height: 100%;
  }
  
  body {
      width: 100%;
      height: 100%;
      overflow: hidden;
      margin: 0;
      padding: 0;
  }
  
  span {
      position: absolute;
      width: 12px;
      height: 12px;
      border-radius: 6px;
  }
  </style>
  <script src="resources/perf_test_helper.js"></script>
  <script>
  var measurementReady = false;
  var stageWidth = 600;
  var stageHeight = 600;
  var maxParticles = 2500;
  var minVelocity = 50;
  var maxVelocity = 500;
  var particleRadius = 6;
  var colors = ["#cc0000", "#ffcc00", "#aaff00", "#0099cc", "#194c99", "#661999"];
  
  var canvas;
  var context;
  var testRunning = true;
  var particles = [];
  var prevTime;
  
  window.onload = function () {
      // Prepare the canvas.
      canvas = document.querySelector('canvas');
      canvas.width = stageWidth;
      canvas.height = stageHeight;
      context = canvas.getContext('2d');
  
      // Create the particles
      for (var i = 0; i < maxParticles; i++)
          particles.push(new Particle());
  
      // Start the animation
      prevTime = performance.now();
      animate();
      measurementReady = true;
  }
  
  function animate()
  {
      var currTime = performance.now();
      var timeDelta = currTime - prevTime;
  
      context.clearRect(0, 0, stageWidth, stageHeight);
  
      // Draw each particle
      for (var particle in particles)
          particles[particle].draw(timeDelta);
  
      prevTime = currTime;
  
      if (testRunning)
          requestAnimationFrame(animate);
  }
  
  function Particle()
  {
      var angle = Math.PI * 2 * PerfTestHelper.random();
      var velocity = minVelocity + ((maxVelocity - minVelocity) * PerfTestHelper.random());
      var x = stageWidth / 2 - particleRadius;
      var y = stageHeight / 2 - particleRadius;
      var dx = Math.cos(angle) * velocity;
      var dy = Math.sin(angle) * velocity;
  
      // Set colour of element
      var color = colors[Math.floor(PerfTestHelper.random() * colors.length)];
  
      function draw(timeDelta)
      {
          var timeDeltaSeconds = timeDelta / 1000;
          var testX = x + (dx * timeDeltaSeconds);
          var testY = y + (dy * timeDeltaSeconds);
  
          if (testX < 0 || testX > stageWidth) {
              dx = -dx;
              x += dx;
          } else {
              x = testX;
          }
          if (testY < 0 || testY > stageHeight) {
              dy = -dy;
              y += dy;
          } else {
              y = testY;
          }
  
          context.fillStyle = color;
          context.beginPath();
          context.arc(x, y, particleRadius, 0, Math.PI * 2);
          context.fill();
      }
  
      this.draw = draw;
  }
  </script>
  </head>
  <canvas></canvas>
  </html>
  