It seems that TwoKsLine is giving unstable behaviour in !655 (merged). This MR fixes an outstanding issue in the line which may solve that.
- Compare all tracks in the vertices (one such comparison was missing).
Separately, a couple of fixes are included:
- Use float numerals instead of doubles.
threadIdx.ywas being used - this would have led to a race condition, but luckily parallelism in lines only pan the X dimension. It now uses a sequential iteration instead.