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<!--
-->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
  "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>
Compute and Display FPS.
</title>
<style type="text/css">
  html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    border: none;
  }
</style>
<!-- Our javascript code -->
<script type="text/javascript" src="o3djs/base.js"></script>
<script type="text/javascript" id="o3dscript">
o3djs.require('o3djs.util');
o3djs.require('o3djs.math');
o3djs.require('o3djs.rendergraph');
o3djs.require('o3djs.primitives');
o3djs.require('o3djs.material');
o3djs.require('o3djs.fps');

// Events
// Run the init() function once the page has finished loading.
//         unload() when the page is unloaded.
window.onload = init;
window.onunload = unload;

// global variables
var g_o3d;
var g_math;
var g_client;
var g_pack;
var g_viewInfo;
var g_o3dWidth = -1;
var g_o3dHeight = -1;
var g_o3dElement;
var g_clock = 0;
var g_timeMult = 1;
var g_finished = false;  // for selenium testing
var g_eye;
var g_fpsManager;

/**
 * Creates the client area.
 */
function init() {
  o3djs.util.makeClients(initStep2);
}

/**
 * Initializes O3D, loads the effect, and draws the cube.
 * @param {Array} clientElements Array of o3d object elements.
 */
function initStep2(clientElements) {
  // Initialize global variables and libraries.
  g_o3dElement = clientElements[0];
  g_o3d = g_o3dElement.o3d;
  g_math = o3djs.math;
  g_client = g_o3dElement.client;

  // Create a pack to manage our resources/assets
  g_pack = g_client.createPack();

  // Create the render graph for a view.
  g_viewInfo = o3djs.rendergraph.createBasicView(
      g_pack,
      g_client.root,
      g_client.renderGraphRoot);

  // Create an FPS manager.
  g_fpsManager = o3djs.fps.createFPSManager(g_pack,
                                            g_client.width,
                                            g_client.height,
                                            g_client.renderGraphRoot);

  // Create a material.
  var myMaterial = o3djs.material.createMaterialFromFile(
      g_pack,
      'shaders/vertex-color.shader',
      g_viewInfo.performanceDrawList);

  // Draw a cube using the effect we have loaded.
  var myShape = o3djs.primitives.createRainbowCube(g_pack,
                                                   myMaterial,
                                                   0.5);

  // Attach the cube to the root of the transform graph.
  var root = g_client.root;
  root.addShape(myShape);

  // Set the projection and viewProjection matrices based
  // on the o3d plugin size by calling resize().
  resize();

  // Set our render callback for animation.
  // This sets a function to be executed every time a frame is rendered.
  g_client.setRenderCallback(onrender);

  g_finished = true;  // for selenium testing.
}

// Sets the projection matrix based on the size of the plugin.
function resize() {
  var newWidth  = g_client.width;
  var newHeight = g_client.height;

  if (newWidth != g_o3dWidth || newHeight != g_o3dHeight) {
    g_o3dWidth = newWidth;
    g_o3dHeight = newHeight;

    // Set the projection matrix, with a vertical field of view of 45 degrees
    // a near clipping plane of 0.1 and far clipping plane of 100.
    g_viewInfo.drawContext.projection = g_math.matrix4.perspective(
        g_math.degToRad(45),
        g_o3dWidth / g_o3dHeight,
        0.1,
        100);

    g_fpsManager.resize(g_o3dWidth, g_o3dHeight);
  }
}

// Animates the cube.
// This function executes on each frame.
// @param {!o3d.RenderEvent} renderEvent Info about rendering.
function onrender(renderEvent) {
  // Get the number of seconds since the last render.
  var elapsedTime = renderEvent.elapsedTime;

  g_fpsManager.update(renderEvent);

  // Rotate frame rate independently.
  g_clock += 2.0 * elapsedTime * g_timeMult;

  // Eye-position, the position of the camera.
  var eye = [
      0.0 + Math.sin(g_clock) * 1.5,
      1.0,
      0.0 + Math.cos(g_clock) * 1.5
  ];

  var target = [0, 0, 0];
  var up = [0, 1, 0];

  g_viewInfo.drawContext.view = g_math.matrix4.lookAt(eye, target, up);

  resize();
}

/**
 * Removes any callbacks so they don't get called after the page has unloaded.
 */
function unload() {
  if (g_client) {
    g_client.cleanup();
  }
}

</script>
</head>
<body>
<table width="100%" style="height:100%;">
  <tr><td>
<h1>Show FPS</h1>
<p>
This example shows computing and displaying FPS (Frames Per Second)
</p></td></tr>
<tr><td height="100%">
<div id=o3d" style="width: 100%; height: 100%;"></div>
</td></tr></table>
</body>
</html>