How can we treat the touchpad like a touchscreen?

I want to use only tablet apps eventually on my ubuntu machine, but its hard to find out where i should change the OS so that i may use my macbook's touchpad as a direct touch surface. My goal is to make this a 2 part touch/screen, rather than touching directly on the screen.

When i open the settings for the touchpad, it has no setting to treat the device as a drawing surface, like how the drawing tablets work.