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  <!--
  O3D Tutorial B3
  
  In this tutorial, we show how to use textures in o3d.
  -->
  <!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>
  Tutorial B3: Textures
  </title>
  <script type="text/javascript" src="o3djs/base.js"></script>
  <script type="text/javascript">
  o3djs.require('o3djs.util');
  o3djs.require('o3djs.math');
  o3djs.require('o3djs.rendergraph');
  o3djs.require('o3djs.primitives');
  o3djs.require('o3djs.effect');
  o3djs.require('o3djs.io');
  
  // Events
  // Run the init() once the page has finished loading.
  window.onload = init;
  
  // global variables
  var g_o3d;
  var g_math;
  var g_client;
  var g_pack;
  var g_viewInfo;
  var g_finished = false;  // for selenium testing
  
  
Creates the client area.

  
  function init() {
    o3djs.util.makeClients(initStep2);
  }
  
  
Initializes O3D, loads the effect, and draws the quad.
parameter: {Array} clientElements Array of o3d object elements.

  
  function initStep2(clientElements) {
    // Initialize global variables and libraries.
    var o3dElement = clientElements[0];
    g_o3d = o3dElement.o3d;
    g_math = o3djs.math;
    g_client = 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);
  
    // Setup an orthographic projection
    g_viewInfo.drawContext.projection = g_math.matrix4.orthographic(
      -g_client.width * 0.5,
      g_client.width * 0.5,
      -g_client.height * 0.5,
      g_client.height * 0.5,
      0.1,
      1000);
  
    // move the camera above the origin looking down.
    g_viewInfo.drawContext.view = g_math.matrix4.lookAt(
        [0, 500, 0], // eye
        [0, 0, 0],   // target
        [0, 0, -1]); // up
  
    // Create and load the effect.
    var effect = g_pack.createObject('Effect');
    o3djs.effect.loadEffect(effect, 'shaders/texture-only.shader');
  
    // Create a Material for the effect.
    var myMaterial = g_pack.createObject('Material');
  
    // Set the material's drawList
    myMaterial.drawList = g_viewInfo.performanceDrawList;
  
    // Apply our effect to this material.
    myMaterial.effect = effect;
  
    // Create the params the effect needs on the material.
    effect.createUniformParameters(myMaterial);
  
    // Create a quad.
    var myShape = o3djs.primitives.createPlane(g_pack,
                                               myMaterial,
                                               300,  // width
                                               300,  // height
                                               1,    // quads across
                                               1);   // quads down
  
    // Get the material's sampler parameter
    var sampler_param = myMaterial.getParam('texSampler0');
    var sampler = g_pack.createObject('Sampler');
    sampler_param.value = sampler;
  
    // Load our texture. This happens asynchronously.
    var url = o3djs.util.getCurrentURI() + 'assets/texture_b3.jpg';
    o3djs.io.loadTexture(g_pack, url, function(texture, exception) {
      if (exception) {
        alert(exception);
      } else {
        sampler.texture = texture;
        // adjust the scale of our transform to match the aspect ratio of
        // the texture. Of course we could also have waited until now to build
        // our plane and set its width and height to match instead of scaling
        // here.
        var textureWidth = texture.width;
        var textureHeight = texture.height;
        var hScale = 1;
        var vScale = 1;
        if (textureWidth > textureHeight) {
          vScale = textureHeight / textureWidth;
        } else if (textureHeight > textureWidth) {
          hScale = textureWidth / textureHeight;
        }
        // We now attach our quad to the root of the transform graph.
        // We do this after the texture has loaded, otherwise we'd be attempting
        // to display something invalid.
        var root = g_client.root;
        root.addShape(myShape);
        root.scale(hScale, 1, vScale);
  
        g_finished = true;  // for selenium testing.
      }
    });
  }
  </script>
  </head>
  <body>
  <h1>Simple texturing</h1>
  This tutorial shows how we use textures in O3D.
  <br/>
  
  <!-- Start of O3D plugin -->
  <div id="o3d" style="width: 600px; height: 600px"></div>
  <!-- End of O3D plugin -->
  </body>
  </html>
  


(C) Æliens 20/2/2008

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