I have multiplied my object coordinates by
the modelview and projection matrices.
What is this perspective divide that I apparently
need to do to convert from Clip Coordinates
to Screen coordinates.
It appears that I must divide x,y,z by w.
but w is 1.0 because I don’t bother setting or
changing it becuase I have no need.
So I won’t have a value between -1 and 1
to convert to screen coordinates.
Please explain how I do this.