Description
Ken Shoemake's algorithm seems most common one, it also handles 24 different permutations of rotation order. Maybe instead of providing separate functions for euler angles we could adopt that algorithm / codes.
Related implementation (Graphics Gems IV): https://github.com/erich666/GraphicsGems/tree/master/gemsiv/euler_angle
https://github.com/erich666/GraphicsGems/blob/master/gemsiv/euler_angle/EulerAngles.c
It also provides euler to quaternion which is in our TODO list. I hope there is no any LICENSE conflict