1 files changed, 10 insertions, 8 deletions

diff --git a/js/lib/drawing/world.js b/js/lib/drawing/world.js
index 9e502c3e..4b117242 100755
--- a/js/lib/drawing/world.js
+++ b/js/lib/drawing/world.js
@@ -17,7 +17,7 @@ var worldCounter = 0;
 // Class GLWorld
 //      Manages display in a canvas
 ///////////////////////////////////////////////////////////////////////
-var World = function GLWorld( canvas, use3D ) {
+var World = function GLWorld( canvas, use3D, preserveDrawingBuffer ) {
     ///////////////////////////////////////////////////////////////////////
     // Instance variables
     ///////////////////////////////////////////////////////////////////////
@@ -30,7 +30,11 @@ var World = function GLWorld( canvas, use3D ) {
 
     this._canvas = canvas;
         if (this._useWebGL) {
-                this._glContext = canvas.getContext("experimental-webgl");
+        if(preserveDrawingBuffer) {
+            this._glContext = canvas.getContext("experimental-webgl", {preserveDrawingBuffer: true});
+        } else {
+                    this._glContext = canvas.getContext("experimental-webgl");
+        }
     } else {
                 this._2DContext = canvas.getContext( "2d" );
     }
@@ -347,20 +351,18 @@ var World = function GLWorld( canvas, use3D ) {
                 return false;
         };
 
-        this.generateUniqueNodeID = function()
-        {
+        this.generateUniqueNodeID = function() {
                 var str = "" + this._nodeCounter;
                 this._nodeCounter++;
                 return str;
-        }
+        };
 
     
     // start RDGE passing your runtime object, and false to indicate we don't need a an initialization state
     // in the case of a procedurally built scene an init state is not needed for loading data
         if (this._useWebGL) {
                 rdgeStarted = true;
-                var id = this._canvas.getAttribute( "data-RDGE-id" ); 
-                this._canvas.rdgeid = id;
+                this._canvas.rdgeid = this._canvas.getAttribute( "data-RDGE-id" );
                 g_Engine.registerCanvas(this._canvas, this);
                 RDGEStart( this._canvas );
                 this._canvas.task.stop()
@@ -680,7 +682,7 @@ World.prototype.render = function() {
                 var root = this.getGeomRoot();
                 this.hRender( root );
         } else {
-                g_Engine.setContext( this._canvas.rdgeId );
+                g_Engine.setContext( this._canvas.rdgeid );
                 //this.draw();
                 this.restartRenderLoop();
         }