Glflare

An example of how to do lensflares using OpenGL that I found on the net.
.. Spot / Up Rough

/* This source code is based on Direct3D-based code written by Stephen
   Coy of Microsoft.  All credit for the original implementation of the
   idea should go to Stephen.  While I referenced Stephen's code during
   the writing of my code, my code was completely written by me from
   scratch.  The algorithms are basically the same to ease critical
   comparison of the OpenGL and Direct3D versions.  */

/* The image files used by this program are derived from images
   developed by Microsoft. */