Help please: methods to measure visible game space

is there a direct way to instantly ask the GE to tell how many blender units are visible on x and y? I’m hoping to get it for a python script.

Could you give us a bit more information please?

Is this a 2d game, where there is a set x and y distance that does not change?

Is this a 3d game where you want the x and y distances where the view field intersects some object / plane / end of the camera’s clipping distance?

it’s a 3D game, this is an overlay scene for the menu and mouse pointer, I’m trying to find how many blender units are visible side to side and up to down as I would go further away from the screen. the idea is to try to match an object in the actual 3D space of the main scene, with the mouse pointer location on the screen.