A Games/3d oriented lisp

Thoughts about the desirable properties of a Lisp optimised for fast 3d games use.

1. Generational and/or incremental garbage collection.



Incremental means gc collection can be time-bounded; generational will be more effective in culling short lived, small objects, and give us cache wins. Allocation should be trivial as possible.



2. Native vector, matrix and quaternion types that map to SIMD



De riguer for fast 3d operations: an inline assembler build into the language, coupled with macro expansion would probably mean that these not be coded



3. Hashtables



Too useful for lots of things



4. Property lists



Ditto: perfect for game AI



5. Simple function call syntax



CL's function call syntax is relatively complicated and makes optimisation harder.



6. Fast single dimensional arrays



A neccesity.



7. Unhygenic macros



A big system can be build from a relatively small one via CL-style macro-expansion..



8. Readtable



Ideal for rolling gustom syntax. CL's readtable has too many characters reserved. We need to keep ours free



9. Optional compile-time type declarations



Enables an optimiser to do a better job, and keeps more unboxed values arond



10. Integrated shader compiler



Shaders are just too useful not to have: an embedded lisp style shader with macroexpansion facilities would help a great deal.




11. Sockets



Needed for multiplayer games, and editors that run alongside the game



12. Good FFI - to bind to c/c++ libraries



A lot of exisiting code is in C - eg OpenGL



13. Fast, streamable file I/O library



Streaming in new data as the game runs is very important for large worlds.



14. Heaps



We will need to allocate hunks of memory for talking to 'C' libraries and just because we can? Not sure about this one



15. Datatypes /library specifically for geometry - flexible mesh loading/compilation



We will need acres of geometry, as usual..



16. Datatypes / library specifically for texture and image processing



And acres of texture maps, etc applied to them



17. Datatypes / library for spatial structures: quadrees, bsp trees, octtrees, r-trees



Good Scene management requires these



18. Aggressive optimization: register colouring, scheduling, peephole..etc



Goes without saying

That will do for now..;-)