The vocabulary types everything else shares.
Header-only, no dependency. Whatever two libraries need to agree on before they can talk to each other.
Vector2.hpp/Vector3.hpp/Vector4.hpp,Matrix.hpp,Quaternion.hppColor.hpp,Shape.hpp—Line<T>,Triangle<T>Type.hpp—OS, and the aliases used across the engineConstants.hpp,Lambdify.hpp,std.hpp