Refactoring the project

For the past few months, I've managed to make a prototype which is capable for rendering 3D models and having a free camera exploring the game world. But I thought the code base was a little messy and there're lots of coupling between classes, so I plan to rebuild the whole project while sticking to some better design patterns. So this is the last picture before refactoring.

The most significant change was encapsulating the game engine into a DLL and thus separating the engine from the sandbox (or playground, whatever). And I want the engine to be more ground-up by creating more interface abstract classes rather than straight into implementing them (I realized that is a better practice). Which also allows me to integrate other rendering APIs afterwards (e.g. OpenGL, Vulkan, etc.). The refactor branch is available at here: https://github.com/tkchanat/VISEngine/tree/dev/refactor