remove disconnected roads from raw map later, not in convert_osm. that way, if MapFixes disconnect anything, it gets removed later

convert_osm/src/lib.rs

@@ -1,7 +1,6 @@
 mod clip;
 mod neighborhoods;
 mod osm;
-mod remove_disconnected;
 mod split_ways;
 
 use abstutil::{prettyprint_usize, Timer};
@@ -55,7 +54,6 @@ pub fn convert(flags: &Flags, timer: &mut abstutil::Timer) -> raw_data::Map {
     let mut map =
         split_ways::split_up_roads(osm::extract_osm(&flags.osm, &flags.clip, timer), timer);
     clip::clip_map(&mut map, timer);
-    remove_disconnected::remove_disconnected_roads(&mut map, timer);
     check_orig_ids(&map);
 
     if flags.fast_dev {

docs/articles/map/article.md

@@ -122,12 +122,6 @@ it only takes a few seconds to load a serialized map.
     to preserve lots of out-of-bounds geometry.
   - Area polygons are intersected with the boundary polygon using the `clipping`
     crate
-- `remove_disconnected.rs`: Remove disconnected roads
-  - Just floodfill from some road, assuming all roads are bidirectional, to get
-    different partitions.
-  - Remove roads from all but the largest partition
-  - Also remove cul-de-sacs (roads that begin and end at the same intersection),
-    because they mess up parking hints and pathfinding.
 - `lib.rs`: Apply parking hints from a King County GIS blockface dataset
   - Match each blockface to the nearest edge of a road
   - Interpret the metadata to assign on-street parking there or not
@@ -148,6 +142,12 @@ The remainder of map construction is done in the `map_model` crate, driven by
 the `precompute.sh` script. There are two awkwardly named intermediate phases
 before the final Map: InitialMap and HalfMap.
 
+- `make/remove_disconnected.rs`: Remove disconnected roads
+  - Just floodfill from some road, assuming all roads are bidirectional, to get
+    different partitions.
+  - Remove roads from all but the largest partition
+  - Also remove cul-de-sacs (roads that begin and end at the same intersection),
+    because they mess up parking hints and pathfinding.
 - `make/initial/mod.rs` and `make/initial/lane_specs.rs`: Interpret OSM tags and
   parking hints to figure out what lanes are on each side of each road, also
   figuring out the total width of the road.

map_model/src/make/mod.rs

@@ -3,6 +3,7 @@ mod bus_stops;
 mod half_map;
 mod initial;
 mod parking_blackholes;
+mod remove_disconnected;
 mod sidewalk_finder;
 mod turns;
 
@@ -12,4 +13,5 @@ pub use self::half_map::make_half_map;
 pub use self::initial::lane_specs::{get_lane_types, RoadSpec};
 pub use self::initial::{Hint, Hints, InitialMap};
 pub use self::parking_blackholes::redirect_parking_blackholes;
+pub use self::remove_disconnected::remove_disconnected_roads;
 pub use self::turns::make_all_turns;

map_model/src/make/remove_disconnected.rs

@@ -1,5 +1,5 @@
+use crate::raw_data;
 use abstutil::{retain_btreemap, MultiMap, Timer};
-use map_model::raw_data;
 use std::collections::HashSet;
 
 pub fn remove_disconnected_roads(map: &mut raw_data::Map, timer: &mut Timer) {

map_model/src/map.rs

@@ -53,6 +53,8 @@ impl Map {
     pub fn new(path: &str, timer: &mut Timer) -> Result<Map, io::Error> {
         let mut data: raw_data::Map = abstutil::read_binary(path, timer)?;
         data.apply_fixes(&raw_data::MapFixes::load(), timer);
+        // Do this after applying fixes, which might split off pieces of the map.
+        make::remove_disconnected_roads(&mut data, timer);
         Ok(Map::create_from_raw(abstutil::basename(path), data, timer))
     }
 

map_model/src/raw_data.rs

@@ -166,6 +166,7 @@ pub struct Area {
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq)]
 pub struct OriginalRoad {
     // This is needed to distinguish cul-de-sacs.
+    // ... which is a bit weird, because we remove those in a later stage anyway.
     // TODO Maybe replace pt1 and pt2 with OSM node IDs? OSM node IDs may change over time
     // upstream, but as long as everything is internally consistent within A/B Street...
     pub osm_way_id: i64,