Vulkan & C++17 based Scene Graph Project

The **include/vsg/maths** header directory contains the vector, matrix classes and maths functions. The interface and conventions are kept the same as GLSL so C++ usage can be kept consistent with shaders usage.

The vector and maths classes are simple types, do not subclass from vsg::Object, so should be treated like ints, floats etc. The memory storage used aligns with the types expected by Vulkan so can be used directly for uniform, vertex and image data.

- include/vsg/maths/vec2.h - template class for 2d vectors, provides vsg::vec2 (float), vsg::dvec2 (double) versions.
- include/vsg/maths/vec3.h - template class for 3d vectors, provides vsg::vec3 (float), vsg::dvec3 (double) versions.
- include/vsg/maths/vec4.h - template class for 4d vectors, provides vsg::vec4 (float), vsg::dvec4 (double) versions.

- include/vsg/maths/mat4.h - template class for 4x4 matrix, providing vsg::mat4 (float) and vsg::dmat4 (double) versions.

- include/vsg/maths/transform.h - provides a range of convenience functions for creation of matrices and operations on matrices and vector.