RayCasting v.05 - the Map

RayCasting v0.5 implements ray casting up to a map (not the 3D) by using NumPy to avoid looping the rays one by one. The user can steer the "viewer" on a map using cursor keys and see how the rays (field of vision) is formed. (Inspired by raytomely's project: https://www.pygame.org/project/3919 - check it out, too.) Next version will implement the 3D view.