Stencil Shadows for 1.3 - missing gl_func.h

Has anyone gotten the stencil shadows resource ported to the current version of TGE? It appears that there were quite a few changes from the earlier version, especially in the platformwin32 directory (missing gl_func.h, wingl.cc very different).
Where should I put the gl_func.h changes? Any general strategies I can try on missing files/functions?