message: on reflection, this should never be null!
diff: @@ -83,7 +83,7 @@ export default class TextureManager
  // if the location is undefined then this may have been called by n event.
  // this being the case the texture may already be bound to a slot. As a texture can only be bound once
  // we need to find its current location if it exists.
  - if (location == null)
  + if (location === undefined)
  {
  location = 0;
  