To address your last question, those appear to be screen coordinates which are given in (X,Y,Z) from -1 to 1. Y is the depth and I think in this case would always be 1. X/Z are vertical and horizontal screen coordinates where 0,0 is the center and -1,1 represent the minima and maxima of the window.
I was looking at this answer, and it might be of value to you.