Adding zoom on scrollwheel event to Pool demo.

samples/o3d-webgl-samples/pool.html

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 Copyright 2009, Google Inc.
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
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@@ skipping 876 matching lines @@
  * Registers event handlers.
  */
 function registerEventCallbacks() {
   o3djs.event.addEventListener(g_o3dElement, 'mousedown', startDragging);
   o3djs.event.addEventListener(g_o3dElement, 'mousemove', drag);
   o3djs.event.addEventListener(g_o3dElement, 'mouseup', stopDragging);
 
   o3djs.event.addEventListener(g_o3dElement, 'keypress', keyPressed);
   o3djs.event.addEventListener(g_o3dElement, 'keyup', keyUp);
   o3djs.event.addEventListener(g_o3dElement, 'keydown', keyDown);
+
+  o3djs.event.addEventListener(g_o3dElement, 'wheel', scrollWheel);
 }
 
 
 /**
  * Creates the client area.
  */
 function initClient() {
   o3djs.webgl.makeClients(main);
 }
 
@@ skipping 970 matching lines @@
         finishShooting();
       break;
   }
 }
 
 function keyDown(event) {
   switch (event.keyCode) {
   }
 }
 
+function zoomIn() {
+  g_cameraInfo.targetPosition.radius *= 0.9;
+}
+
+function zoomOut() {
+  g_cameraInfo.targetPosition.radius /= 0.9;
+}
+
+function scrollWheel(event) {
+  if (event.deltaY > 0) {
+    zoomIn();
+  } else {
+    zoomOut();
+  }
+}
+
 function keyPressed(event) {
   var keyChar = String.fromCharCode(o3djs.event.getEventKeyChar(event));
   keyChar = keyChar.toLowerCase();
   var identifier = o3djs.event.getKeyIdentifier(event.charCode, event.keyCode);
 
   var spotDelta = 1;
   var cueBall = g_physics.balls[0];
   var x = cueBall.center[0];
   var y = cueBall.center[1];
 
@@ skipping 39 matching lines @@
       if (!g_rolling)
         g_barRoot.visible = true;
       break;
 
     case 't':
       g_cameraInfo.goTo([0, 0, 0], null, null, 100);
       break;
 
     case '=':
     case '+':
-      g_cameraInfo.targetPosition.radius *= 0.9;
+      zoomIn();
       break;
 
     case '-':
     case '_':
-      g_cameraInfo.targetPosition.radius /= 0.9;
+      zoomOut();
       break;
 
     case ' ':
       if (!g_cameraInfo.lookingAt(g_physics.balls[0].center)) {
         g_cameraInfo.zoomToPoint(g_physics.balls[0].center);
         if (!g_rolling)
           g_barRoot.visible = true;
       } else {
         if (g_seriousness > 1) {
           if (!(g_rolling || g_shooting)) {
@@ skipping 193 matching lines @@
   }
 
 </textarea>
 <!-- End of effect -->
 </div>
 
 </body>
 </html>