collecting notes on modeling lanes

TODO.md

@@ -44,18 +44,8 @@
 	- look for current stop sign priorities
 		- https://gis-kingcounty.opendata.arcgis.com/datasets/traffic-signs--sign-point/
 
-- roads -> lanes
-	- driving lanes
-	- parking
-	- sidewalks
-	- bike lanes
-
-	- in an experimental branch...
-		- make map_model create several "roads" per road proto
-		- add an enum type and an index-from-center
-		- plumb through in all layers
-		- rename these lanes
-		- only have cars on the driving lanes
+- multiple lanes
+	- prep: make DrawRoad depend on GeomRoad, dont percolate onewayness around as much
 
 ## Code cleanup
 

docs/lanes.md

@@ -2,16 +2,35 @@
 
 It's time to model more things:
 
+- multiple driving lanes, with possibly individual turn restrictions
+- dedicated bus lanes
 - lanes with parked cars
 - bike lanes
 - sidewalks
 
-These have a geometric aspect (which seems similar / derivable the same way as
-roads) and a graph / usage aspect.
+Each lane needs some geometry:
 
-Where should the expansion of roads into lanes happen? In the initial map
-conversion, adding an index and type to the current road proto? Or better, in
-map_model::new, to defer it a bit.
+- center lines to draw agents on
+	- for sidewalks, use center line to to draw agents on the left and right sides?
+- polygons to draw the lane and mouseover
 
-And actually, there isn't really much use in having roads and lanes. Get rid of
-the concept of road after the proto.
+Open questions:
+
+- Can we assume all lanes are the same width?
+	- Seems wrong for many sidewalks especially
+	- Could be wrong for bike lanes, but could just assume it's a bike lane with a buffer
+- Some lanes are immutable
+	- Sidewalks can't be changed to other types; they're raised with a curb
+
+Some modeling questions:
+
+- Where should expansion of roads into lanes happen?
+	- initial OSM conversion, adding more stuff to the proto?
+	- initial map_model::new loading, at least for development convenience
+		- same reason that turns aren't (yet) serialized
+- Is it useful to model the entire road?
+	- the parent/child relation may be hard to maintain
+	- but lanes need to know their siblings
+	- maintaining directional sanity could be useful
+	- what's the UI for changing lane types?
+	- it's a bit arbitrary which lane should draw the yellow center lines