abstreet/docs/TODO_phase3.md

# TODO for Phase 3 (Simulation)

## cars

- features
	- different lookahead reaction times
	- figure out lanechanging (and turns that dont make sense)

- code cleanup
	- figure out responsibility btwn agents and managers, then fix up visibility
	- things like ParkingSimState have so many methods -- some are only
	  meant for spawner, or driving/walking to query. separate out some
          traits.
	- on a lane vs turn permeates so many places

- better visualization
	- draw moving / blocked colors (gradually more red as they wait longer)
	- make lookahead buffer follow the shape of the road and extend into other lanes and stuff
	- render cars with textures?

- reversible sim

- be careful
	- could see if we ever have a lookahead constraint to deaccel more than
	  what we're capable of. it might mask problems. but since things like
          accel_to_stop_in_dist don't have a careful notion of how much time will pass,
          they recommend big rates sometimes.
	- no way for an agent to request a turn and ASAP have it granted. are there cases where they might slow down unnecessarily?

## bikes

- model bikes as slow cars

## pedestrians

- render overlapping peds reasonably

## General

- savestating a sim has nondet output due to hashes; switching to btree is kind of weird
	- consider overriding encoding for TurnID and such, instead of remembering to stick maps everywhere
- diffing two sim states is tedious no matter what; is there a nice macro-driven deep equals we could do instead?
	- will need programmatic diffs later for pointing out changes to players in A/B tests
- consider refactoring car/ped sim
	- basic structure with actions, react, stepping is same. SimQueue, lookahead, can goto? differs.

- handle map borders
	- manually mark them?
	- be able to start/end trips there
	- start to model demand data with manually selecting a source/dest area

- figure out how to capture stacktraces kinda optionally
	- manual call at a fxn to dump its stacktrace somewhere (to a file? ideally shared global state to dedupe stuff)
	- macro to insert a call at the beginning of a fxn
	- macro to apply a macro to all fxns in an impl
	- then i can manually edit a few places when I want to gather data