Any code in lib/ shouldn't have to care about doing this.
Any required setup must be done in the GR C++ part
Do you mean in xxx_sink_c_impl, or are you thinking that GR would do it in it's initial GUI setup?
Also using a magic 'USING_GLEW' that must somehow be setup manually is
not acceptable. Need some CMake logic to detect when this is required and automatically set it up.
Sure. I don't disagree, but I'm not sure what other configurations would require Glew, so since I couldn't vouch for anything but Win10-64/MSVC, I left it as a manual option that can then be specified on the CMake command line (which is what my build scripts are doing now). If you can point in to what configurations overall would need this, then happy to submit a new change.
Geof