Mapping screen for mouse

[justsomeguy]

Interesting but for a _MouseZone function I would want to see if mouse or mouse click is in a given rectangle.

You are assigning "colors" to boxes. Color is just a 32 bit value, what you do with said value is up to you. In this case I'm using that value to specify regions on the screen that overlay the buttons or whatever I'm interested in clicking. Using POINT command is just an easy way of retrieving that value for a given X,Y coordinate.

As long as your "color" is unique, you should be able discern which "zone" your mouse is on based upon what "color" you assigned it when you drew the boxes on the hidden screen.

If zones overlap, what color would that be? 

It would be the same if you drew a box on top of another box. The second would overwrite the first.