Caused by 5f6e94ca58
When there are more than 2^16 points, the GPU index buffer code tries
to compress the indices to uint16 because we passed the incorrect max
index. In general that optimization just isn't worth the complexity
of precalculating the max index in this situation. There are other
potential optimizations here that would be vastly more helpful.
So just pass INT_MAX to disable the compression.
2a8da4c1fa