Plumb through the study area boundary

Author: dabreegster

.gitignore

@@ -1,5 +1,6 @@
 *.swp
 target/
 node_modules/
-# Local symlink to avoid hitting od2net.org
+# Local symlinks to avoid hitting od2net.org
 web/public/osm
+web/public/boundaries

backend/src/auto_boundaries.rs

@@ -51,8 +51,7 @@ impl MapModel {
             severances.push(linestring.clone());
         }
 
-        // TODO The boundary is imprecise, messing this process up
-        for polygon in split_polygon(self.boundary_polygon.clone(), severances) {
+        for polygon in split_polygon(self.mercator.to_mercator(&self.boundary_wgs84), severances) {
             let mut f = self.mercator.to_wgs84_gj(&polygon);
             f.set_property("kind", "area");
             features.push(f);

backend/src/lib.rs

@@ -45,14 +45,21 @@ pub struct LTN {
 impl LTN {
     /// Call with bytes of an osm.pbf or osm.xml string
     #[wasm_bindgen(constructor)]
-    pub fn new(input_bytes: &[u8], study_area_name: Option<String>) -> Result<LTN, JsValue> {
+    pub fn new(
+        input_bytes: &[u8],
+        boundary_input: JsValue,
+        study_area_name: Option<String>,
+    ) -> Result<LTN, JsValue> {
         // Panics shouldn't happen, but if they do, console.log them.
         console_error_panic_hook::set_once();
         START.call_once(|| {
             console_log::init_with_level(log::Level::Info).unwrap();
         });
 
-        let map = MapModel::new(input_bytes, study_area_name).map_err(err_to_js)?;
+        let boundary: Feature = serde_wasm_bindgen::from_value(boundary_input)?;
+        let polygon = boundary.try_into().map_err(err_to_js)?;
+
+        let map = MapModel::new(input_bytes, polygon, study_area_name).map_err(err_to_js)?;
         Ok(LTN {
             map,
             neighbourhood: None,

backend/src/map_model.rs

@@ -6,7 +6,7 @@ use geo::{
     Closest, ClosestPoint, Coord, Euclidean, Length, Line, LineInterpolatePoint, LineLocatePoint,
     LineString, Point, Polygon,
 };
-use geojson::{Feature, FeatureCollection, GeoJson};
+use geojson::{Feature, FeatureCollection, GeoJson, Geometry};
 use rstar::{primitives::GeomWithData, RTree, AABB};
 use serde::Serialize;
 use utils::{Mercator, Tags};
@@ -20,7 +20,7 @@ pub struct MapModel {
     // All geometry stored in worldspace, including rtrees
     pub mercator: Mercator,
     pub study_area_name: Option<String>,
-    pub boundary_polygon: Polygon,
+    pub boundary_wgs84: Polygon,
     pub closest_road: RTree<GeomWithData<LineString, RoadID>>,
 
     // Only those acting as severances; above or belowground don't count
@@ -87,8 +87,12 @@ pub struct Intersection {
 
 impl MapModel {
     /// Call with bytes of an osm.pbf or osm.xml string
-    pub fn new(input_bytes: &[u8], study_area_name: Option<String>) -> Result<MapModel> {
-        crate::scrape::scrape_osm(input_bytes, study_area_name)
+    pub fn new(
+        input_bytes: &[u8],
+        boundary_wgs84: Polygon,
+        study_area_name: Option<String>,
+    ) -> Result<MapModel> {
+        crate::scrape::scrape_osm(input_bytes, boundary_wgs84, study_area_name)
     }
 
     pub fn get_r(&self, r: RoadID) -> &Road {
@@ -355,7 +359,7 @@ impl MapModel {
 
         gj.features.extend(self.boundaries.values().cloned());
 
-        let mut f = self.mercator.to_wgs84_gj(&self.boundary_polygon);
+        let mut f = Feature::from(Geometry::from(&self.boundary_wgs84));
         f.set_property("kind", "study_area_boundary");
         gj.features.push(f);
 
@@ -486,7 +490,6 @@ impl MapModel {
 
     /// Return a polygon covering the world, minus a hole for the boundary, in WGS84
     pub fn invert_boundary(&self) -> Polygon {
-        let (boundary, _) = self.mercator.to_wgs84(&self.boundary_polygon).into_inner();
         Polygon::new(
             LineString::from(vec![
                 (180.0, 90.0),
@@ -495,7 +498,7 @@ impl MapModel {
                 (180.0, -90.0),
                 (180.0, 90.0),
             ]),
-            vec![boundary],
+            vec![self.boundary_wgs84.exterior().clone()],
         )
     }
 

backend/src/scrape.rs

@@ -1,14 +1,18 @@
 use std::collections::{BTreeMap, BTreeSet, HashMap};
 
 use anyhow::Result;
-use geo::{Coord, LineString};
+use geo::{Coord, LineString, Polygon};
 use osm_reader::{Element, NodeID};
 use rstar::{primitives::GeomWithData, RTree};
 use utils::Tags;
 
 use crate::{Direction, FilterKind, Intersection, IntersectionID, MapModel, Road, RoadID, Router};
 
-pub fn scrape_osm(input_bytes: &[u8], study_area_name: Option<String>) -> Result<MapModel> {
+pub fn scrape_osm(
+    input_bytes: &[u8],
+    boundary_wgs84: Polygon,
+    study_area_name: Option<String>,
+) -> Result<MapModel> {
     info!("Parsing {} bytes of OSM data", input_bytes.len());
     // This doesn't use osm2graph's helper, because it needs to scrape more things from OSM
     let mut node_mapping = HashMap::new();
@@ -142,7 +146,7 @@ pub fn scrape_osm(input_bytes: &[u8], study_area_name: Option<String>) -> Result
         roads,
         intersections,
         mercator: graph.mercator,
-        boundary_polygon: graph.boundary_polygon,
+        boundary_wgs84,
         study_area_name,
         closest_road,
 

backend/src/tests.rs

@@ -1,6 +1,6 @@
 use anyhow::Result;
 use geo::Polygon;
-use geojson::FeatureCollection;
+use geojson::{Feature, FeatureCollection};
 
 use crate::{MapModel, Neighbourhood};
 
@@ -34,7 +34,13 @@ fn test_example(study_area_name: &str, savefile_name: &str, neighbourhood_name:
 // TODO web/public/osm must be symlinked to local PBF copies
 fn get_gj(study_area_name: &str, savefile_name: &str, neighbourhood_name: &str) -> Result<String> {
     let input_bytes = std::fs::read(format!("../web/public/osm/{study_area_name}.pbf"))?;
-    let mut map = MapModel::new(&input_bytes, Some(study_area_name.to_string()))?;
+    let boundary: Feature = std::fs::read_to_string(format!(
+        "../web/public/boundaries/{study_area_name}.geojson"
+    ))?
+    .parse()?;
+    let polygon = boundary.try_into()?;
+
+    let mut map = MapModel::new(&input_bytes, polygon, Some(study_area_name.to_string()))?;
 
     let savefile: FeatureCollection =
         std::fs::read_to_string(format!("../tests/{savefile_name}.geojson"))?.parse()?;

web/package-lock.json

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import type { Feature, Polygon } from "geojson";
   import { LTN } from "backend";
   import { onMount } from "svelte";
   import { Loading } from "svelte-utils";
@@ -30,10 +31,14 @@
     exampleAreas = await resp.json();
   });
 
-  function gotXml(e: CustomEvent<string>) {
+  function gotXml(e: CustomEvent<{ xml: string; boundary: Feature<Polygon> }>) {
     loading = "Loading OSM";
     try {
-      $app = new LTN(new TextEncoder().encode(e.detail), undefined);
+      $app = new LTN(
+        new TextEncoder().encode(e.detail.xml),
+        e.detail.boundary,
+        undefined,
+      );
       $projectName = `ltn_${newProjectName}`;
       afterProjectLoaded();
       // No savefile to load. Create it immediately with just the boundary

web/src/title/NewProjectMode.svelte

@@ -1,7 +1,7 @@
 import { get } from "svelte/store";
 import { LngLat } from "maplibre-gl";
 import { LTN } from "backend";
-import type { Feature } from "geojson";
+import type { Feature, Polygon } from "geojson";
 import { overpassQueryForPolygon } from "svelte-utils/overpass";
 import { RouteTool } from "route-snapper-ts";
 import {
@@ -28,10 +28,16 @@ export async function loadFromLocalStorage(key: string) {
     let gj = JSON.parse(window.localStorage.getItem(key)!);
 
     console.time("get OSM input");
-    let buffer = await getOsmInput(gj);
+    let [buffer, boundary] = await getOsmInput(gj);
     console.timeEnd("get OSM input");
     console.time("load");
-    app.set(new LTN(new Uint8Array(buffer), gj.study_area_name || undefined));
+    app.set(
+      new LTN(
+        new Uint8Array(buffer),
+        boundary,
+        gj.study_area_name || undefined,
+      ),
+    );
     // TODO Rename savefile -> project? Or combine this call with the constructor?
     get(app)!.loadSavefile(gj);
     console.timeEnd("load");
@@ -43,24 +49,32 @@ export async function loadFromLocalStorage(key: string) {
   }
 }
 
-// Either from a pre-hosted pbf file or from Overpass
-async function getOsmInput(gj: any): Promise<ArrayBuffer> {
+// Returns OSM input and the boundary polygon, either from a pre-hosted pbf
+// file or from Overpass.
+async function getOsmInput(gj: any): Promise<[ArrayBuffer, Feature<Polygon>]> {
   if (gj.study_area_name) {
-    let url = get(useLocalVite)
+    let url1 = get(useLocalVite)
       ? `/osm/${gj.study_area_name}.pbf`
       : `https://assets.od2net.org/severance_pbfs/${gj.study_area_name}.pbf`;
-    console.log(`Grabbing ${url}`);
-    let resp = await fetch(url);
-    let bytes = await resp.arrayBuffer();
-    return bytes;
+    console.log(`Grabbing ${url1}`);
+    let resp1 = await fetch(url1);
+    let bytes = await resp1.arrayBuffer();
+
+    let url2 = get(useLocalVite)
+      ? `/boundaries/${gj.study_area_name}.geojson`
+      : `https://assets.od2net.org/boundaries/${gj.study_area_name}.geojson`;
+    let resp2 = await fetch(url2);
+    let boundary = await resp2.json();
+
+    return [bytes, boundary];
   } else {
     console.log(`Grabbing from Overpass`);
     let study_area_boundary = gj.features.find(
       (f: Feature) => f.properties!.kind == "study_area_boundary",
     )!;
     let resp = await fetch(overpassQueryForPolygon(study_area_boundary));
     let bytes = await resp.arrayBuffer();
-    return bytes;
+    return [bytes, study_area_boundary];
   }
 }