[Wine] Question about gamma changing...

[doh123]

I need to know exactly how Wine tells the X server to change gamma settings... so gamma controls in games can work.  Basically I need to know.. when a game has like a gamma adjust bar, and it moves... what specifically happens behind the scenes.

I need to know this because right now Xquartz on Mac OS X does not support doing this at all, and I'd like to be able to add that ability into it... but I do not know how it works.