They were returning TOUCH_INVALID_TEXCOORD for num <= idx <= 15 in detection events which were not touch events. That is incorrect.
Now it correctly returns:
- ZERO_VECTOR when idx < 0 or idx > 15 or the event is known not to be a detection event.
- TOUCH_INVALID_TEXCOORD when idx == 0 and the event is known to be a detection event that is not a touch event.
- Raises ELSLCantCompute otherwise.