flecs/Chipmunk2D integration examples

This repo contains a number of different ways to use the Chipmunk2D physics library with the flecs ECS library in C++.

• flecs: https://github.com/SanderMertens/flecs
• Chipmunk2D: https://github.com/slembcke/Chipmunk2D

Key details:

• Chipmunk2D uses pointers internally to connect various structures together
• flecs does not currently have support for fixed address components
• flecs components for Chipmunk2D must manage some number of pointers to Chipmunk2D structs, as a result they will be move-only components

Implementation Approaches

• simple struct
  • naive approach
  • 1:1 mapping of one flecs component wrapping one pointer to a Chipmunk2D type (Body wraps struct cpBody *)
  • single helper for implicit conversion from Body to struct cpBody *
  • no allocator call in component
  • destructor handles resource release
  • no templating or inheritance
• std::unique_ptr
  • component is std::unique_ptr<T, TDeleter>
  • custom destructors for each component type
  • using Body = std::unique_ptr<cpBody, BodyDeleter>