[jitter] Drawing in jit.window for reactable-like surface

I am currently in the final stages of building a reactable-like surface with a friend/fellow student @ calarts for an installation in 3 weeks.  Right now I wrote a patch that downloads/updates a particular weather map from the web ever hour.  This will be projected onto the table, and as you move the fiducial/object along the map, the X/Y data will be used as control data in reaktor (being sent via OSC).  The max patch is also determining the RGB value of the map, directly underneath where the object is, and this is also being sent to Reaktor, where it is converted into a number between 0.-1.0 to be used as other control data.  To keep this on my particular question, I wont go into what all the xy and rgb/other control data does, but if you ask me/email me, id be happy to go into more detail.

HERE IS MY QUESTION :)

Right now I have max pull the image from online, send it to a jit.window (fullscreen).  I'd like to be able to trace my reactable fiducial and overlay that path over the map being projected by max.

It would be like, tracing a mouse cursor along a computer screen and overlaying it on top of the background image (my map).  When I place the object on the table (IE mouse click down), it would start tracking/following its movement with a line and when the object was removed/picked up from the table (IE mouse click-release) it would erase the path.

I have been researching this for 2 days with no luck-- playing with every object from jit.sketch, jit.gl.render...etc

I saw some stuff online suggesting using jit.chromakey and luminance, but I couldn't get them to work either.

I understand this might be a little hard to grasp being that most people dont have reactable like interfaces, but if we can figure out a way to do this with a mouse, simply trace mouse movements over a projected image which updates every hour, I can translate the mouse data to my reactable fiducial data easily i think.

Thanks a lot!

Jordan