Fixes Ticket #2517.
Increase performance by fetching only the necessary points. 1097 → 917 decicyles.
Call NEXT() only once since it got slower due to the overflow condition introduced in 91b46145. interp_trilinear: 1462 → 1280 decicycles interp_tetrahedral: 1188 → 1097 decicycles Tested on a Core2, GCC 4.8.
91b46145
Fixes part of Ticket #2517.