Work on mouse selection in options menu

src/Dodge/Base/Coordinate.hs

@@ -22,6 +22,8 @@ import Geometry
 {- | Transform world coordinates to scaled screen coordinates.
  - These have to be scaled according to the size of the window to get actual screen positions.
  - This allows for line thicknesses etc to correspond to pixel sizes.
+ - I believe the resulting point is the number of pixels from the center of
+ - the screen, I am not sure how rounding affects this though.
 -}
 worldPosToScreen :: Camera -> Point2 -> Point2
 worldPosToScreen cam =