<Math> header undefines macros

[Teskann]

Hello,

I would like to spot an issue regarding the include file:
https://github.com/openscenegraph/OpenSceneGraph/blob/2e4ae2ea94595995c1fc56860051410b0c0be605/include/osg/Math#L25C1-L34C35

Indeed, you undefine some macros, so that you can use PI, PI_2, PI_4 identifiers for your constants.

This is a bug source. These #undef directives might cause conflicts with third party code that would be included before osg (read more).
I suggest you rename your pi constants with another case, (as recommended in CPP core guidelines) and remove the #undef directives to avoid potentially interfering with user code.

Cheers,

[robertosfield]

I don't recall the original reasons but the OSG has had a looong life and tricks like these were likely essential to handle some problem compile/header/platform combinations. The OSG is in maintenance mode so we aren't chasing the perfect way.

For any modern application work please don't use the OSG, use a modern API like the OSG's successor the VuklanSceneGraph.