Improve cage tool algorithm to benefit from threading
Submitted by Jehan
I have not made any accurate time measurement because the slowness is obvious. Using a same big image, the cage tool is painfully slow when multi-threaded compared to single-threaded.
So multi-threading is currently disabled on this GEGL operation (see commits 87aaf576 and f28cb1c5). This report is a reminder of this so that we reenable it after some algorithm improvements. See also bug 787663.
Version: git master