When using the default make file I was unable to build the example for Ubuntu, there were unresolved references and other issues. I separated out that I know works under Ubuntu and made the appropriate source code changes to link correctly to the OpenGL libs and source includes.
The original makefile should still be useful for Mac.
Provisional undefined NULL fix.
Finding header files fixed.
Fixed core source files and wrote a new makefile for Ubuntu.
Fully separated out the linux and Mac makefiles.
Restored Mac functionality for original makefile.
Restored forced exit if original make file run on Linux instead of Mac.
It would be better to tell the compiler that the include directory is in its set of include paths, rather than all the conditional includes with relative file paths. That makes the files unduly complex, I think.
Sure, I'll look into correcting that.
Simplified cyclone core file inclusion.
Simplified platform-specific OpenGL header inclusion for demo files.
All updated and generally improved as per your requirements.
Thank you so much for sticking with this and making these changes. I'm merging now.
No problem at all. Thank you for the great book and the merge!