CleverRaven/Cataclysm-DDA — pull request #4509 by kevingranade (2013-11-20 01:44:45+00:00)
Title: Track player position and stopupdating scent when the player hasn't moved for a while.

Like it says on the tin, once 100 turns or so have passed, the scent cloud is going to have stabilized, no need to keep running the diffusion simulation.