- fix for [#18867] getScreenRay error
... the Vector wasn't been added to KX_Camera origin. Therefore the Ray was always casted to the wrong coordinate when camera wasn't in [0,0,0] (where is obviously was in my tests :)
- making the input parameter compatible with Blender/BGE window coordinate system (Top-Bottom).
... that will break scripts done in 2.49. Since this feature was added only in 2.49 that fix is OK. (and the fix is ridiculous.
Note:
the input parameter is normalized. That means it runs from 0.0 to 1.0. Some users found it confusing, but it allows to make a game compatible with multiple desktop resolutions.a