TODO - Refactoring

easier way to define magic tuneable constants
- and maybe to recalculate fixedish things if they change?

Map layer

pt2d resolution
- handle turns with 0 geometry first.
  - maybe Traversable having helpers is also bad. if it can fail for zero-geom turns.
  - these seem to exist in the first place due to intersections that ought to be merged! argh.
- savestating test should work now!
- make sure display is always just 2 decimal places... should be though.
- FP math still sucky... debug a polyline, look at the deltas.
- get rid of HashablePt2D?
then my own physics types
maybe also the time to split into different lane types? what's similar/not between them?
- graph querying?
- rendering (and other UI/editor interactions)?
- sim state?
- Sidewalk, Parking, Street
make synthetic use raw stuff directly?
- lonlat vs pt is annoying; have to use bounds to balloon to world at least once

consider refactoring car/ped sim
- basic structure with actions, react, stepping is same. SimQueue, lookahead, can goto? differs.
detangle sim managers... but first, figure out how to capture stacktraces
- 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
- https://en.wikipedia.org/wiki/File:A_Call_Graph_generated_by_pycallgraph.png
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