Describe how you would adapt the RGB color model in WebGL to allow you to work with an additive color model.

We saw that a fundamental operation in graphics systems is to map a point (x, y) that lies within a clipping rectangle to a point (xs, ys) that lies in the viewport of a window on the screen. Assume that the two rectangles are defined by the viewport specified by

gl.viewport(u, v, w, h);

and a viewing rectangle specified by

Find the mathematical equations that map (x, y) into (xs, ys).