What is the easiest way to calculate the field of view from the projection matrix gl_cpara?
I am trying to draw a scene using gl_cpara as my projection matrix ( I am not switching to
orthographic). I am displaying my video texture on a polygon which will be display just in front of
the far plane of my scene. To determine the correct size of the polygon, so my image fill the far
plane, I need to calculate the field of view from the projection matrix gl_cpara.
I searched the list archive but could not find any clear answer.
o Alexandre Gillet email: gillet@s ..........
/ The Scripps Research Institute,
o Dept. Molecular Biology, MB-5,
\ 10550 North Torrey Pines Road,
o La Jolla, CA 92037-1000, USA.
/ tel: (858) 784-2053
o fax: (858) 784-2860