move initialization of buffer
move initialization of buffer

Float32Array and Uint16Array are not available in many browsers.
Do not mention them before we are sure the browser supports
WebGL. Fixes WebGL support detection in IE and other browsers
without WebGL

Traksewt/pv,yuhangwang/pv,biasmv/pv,CyrusBiotechnology/pv,CyrusBiotechnology/pv,yuhangwang/pv,Traksewt/pv,biasmv/pv,Traksewt/pv,biasmv/pv,biasmv/pv,CyrusBiotechnology/pv,yuhangwang/pv,CyrusBiotechnology/pv,yuhangwang/pv,Traksewt/pv