The code below has a different behaviour depending on wether WebGL is activated or not. The browser with WebGL is centering the content whereas without WebGL it’s not because visibleOrigin is always at 0.0,0.0.
Also the following piece of code that can be found in the framework examples:
//show Information to user
alert(“Browser doesn’t support WebGL”);
Is not doing anything when you are using a browser without WebGL.