Module map_model::make::initial::geometry

OSM describes roads as center-lines that intersect. Turn these into road and intersection polygons roughly by

1. treating the road as a PolyLine with a width, so that it has a left and right edge
2. finding the places where the edges of different roads intersect
3. "Trimming back" the center lines to avoid the overlap
4. Producing a polygon for the intersection itsef

Structs

Piece

Constants

DEGENERATE_INTERSECTION_HALF_LENGTH

Functions

close_off_polygon
deadend
generalized_trim_back
intersection_polygon	Also returns a list of labeled polygons for debugging.
on_off_ramp