This code example shows how to build oblique parallel projection matrices.  Two are
presented: the one described in the text, and a 45 degree cabinet matrix, which 
foreshortens distances parallel to the projection plane to half their length.

Projection code can be found in Game.cpp.

Controls
--------
ESC: quit
W,S: move near plane out and in
E,D: move far plane out and in
I,K: move view window up and down
J,L: move view window left and right
P: switch projections
SPACE: reset transforms
