Cooling with Grackle

Hi,

I am planning to start soon to work on the cooling with the grackle library. If I have well understood, you are currently using a very simple constant cooling right?

Currently in Gear (improved Gadget-2), we have two different implementations. The first one is using a precomputed cooling from a table and the second quickly computes on the fly the cooling (slow down of about 20% in Gear). I am thinking about trying to implement the second one, is it fine with you? @matthieu @yvesrevaz