After we compiled and installed libg3d under windows/cygwin, the next step would be to port something which needs it. An "easy" target was s3d because I have write permissions to all repositories and can fix problems very fast.

I assume that you didn't remove anything after installing libg3d but we still need cmake, font-bitstream-vera-ttf and a self compiled version of SDL for cygwin.

Run cmake in your s3d clone/checkout with cmake . -DHAVE_SHM=0 -DCMAKE_INSTALL_PREFIX=/usr/ && make install to get a working s3d installation cygwin. We need to disable SHM to fix a "bad syscall" when there is no ipcserver running (and sun, moon, earth, .. aren't aligned).

If you get an error that _glEnd can not be found then remove libGL-devel or rename /usr/include/GL/gl.h to /usr/include/GL/gl.h.bak. We must use gl.h from /usr/include/w32api/GL/ because it uses another symbol mangling than the version from libGL-devel and we must use the native opengl32.dll to be compatible with SDL (which is a no-cygwin dll).

To proof that it works take a look at the running cat example.