Entity Component System (ECS)

https://www.richardlord.net/blog/ecs/why-use-an-entity-framework.html

https://www.david-colson.com/2020/02/09/making-a-simple-ecs.html

• Very thorough, shows both a sparse and a compact version
• Explains Unity’s DOTS, a variant of ECS using archetypes

https://hacksoflife.blogspot.com/2021/02/making-soa-tollerable.html?m=1

• ECS
• struct of arrays
• SIMD

https://kyren.github.io/2018/09/14/rustconf-talk.html

• Long intro to ECS (Rust colored)
• Generational entity indices

Design for ECS in V

https://claude.ai/share/23d77773-bd59-4fff-9868-1fa6b935c4bb

• hot / high performance vs cold path split using embedded struct
• fixed-size arrays
• generational allocation of slots

ECS design

• components known at compile time

  • Placement { Position, Rotation }
  • Movement {Velocity, Angular Velocity }
  • Mesh
  • Texture(s)
  • ClosestCamera

• Array of entities

  • Each entity has a bitmask describing which components are associated with it

• Systems

  • Each system processes all entities with a specific set of Components Examples:
    • Physics requires Placement and Movement
    • Render requires Placement, Mesh and Texture
    • LOD requires ClosestCamera and Mesh

See also

• Data Oriented Design :https://vimeo.com/649009599
• Zig struct of arrays : https://andreashohmann.com/zig-struct-of-arrays/