Show a diversion score

a-b-street · Dec 4, 2023 · e62892d · e62892d
1 parent 5ccfeba
commit e62892d
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Showing 2 changed files with 40 additions and 4 deletions.
diff --git a/backend/src/route.rs b/backend/src/route.rs
@@ -1,7 +1,7 @@
 use anyhow::{bail, Result};
 use fast_paths::{FastGraph, InputGraph};
-use geo::HaversineLength;
-use geojson::GeoJson;
+use geo::{HaversineLength, LineString};
+use geojson::FeatureCollection;
 use rstar::primitives::GeomWithData;
 use rstar::RTree;
 
@@ -50,7 +50,7 @@ fn build_closest_intersection(
     RTree::bulk_load(points)
 }
 
-pub fn do_route(map: &mut MapModel, req: CompareRouteRequest) -> Result<GeoJson> {
+pub fn do_route(map: &mut MapModel, req: CompareRouteRequest) -> Result<FeatureCollection> {
     let start = map
         .closest_intersection
         .nearest_neighbor(&[req.x1, req.y1])
@@ -66,13 +66,31 @@ pub fn do_route(map: &mut MapModel, req: CompareRouteRequest) -> Result<GeoJson>
     }
     if let Some(path) = map.path_calc.calc_path(&map.ch, start, end) {
         let mut features = Vec::new();
+        let mut route_length = 0.0;
         for pair in path.get_nodes().windows(2) {
             let i1 = map.node_map.translate_id(pair[0]);
             let i2 = map.node_map.translate_id(pair[1]);
             let road = map.find_edge(i1, i2);
             features.push(road.to_gj());
+            route_length += road.linestring.haversine_length();
         }
-        return Ok(GeoJson::from(features));
+        let direct_length = LineString::new(vec![
+            map.intersections[map.node_map.translate_id(start).0]
+                .point
+                .into(),
+            map.intersections[map.node_map.translate_id(end).0]
+                .point
+                .into(),
+        ])
+        .haversine_length();
+        return Ok(FeatureCollection {
+            features,
+            bbox: None,
+            foreign_members: Some(serde_json::json!({
+                "direct_length": direct_length,
+                "route_length": route_length,
+            }).as_object().unwrap().clone()),
+        });
     }
     bail!("No path");
 }
diff --git a/web/src/Directions.svelte b/web/src/Directions.svelte
@@ -3,6 +3,19 @@
 
   export let route_gj;
 
+  function levelChanges(gj) {
+    let count = 0;
+    // No windows(2)?
+    for (let i = 0; i < gj.features.length - 1; i++) {
+      let l1 = route_gj.features[i].properties.layer ?? "0";
+      let l2 = route_gj.features[i + 1].properties.layer ?? "0";
+      if (l1 != l2) {
+        count++;
+      }
+    }
+    return count;
+  }
+
   function step(f) {
     classifyStep(f);
     let props = f.properties;
@@ -16,6 +29,11 @@
   }
 </script>
 
+<p>
+  Crow-flies {route_gj.direct_length.toFixed(0)} vs actual {route_gj.route_length.toFixed(0)}:
+  <b>{(route_gj.route_length / route_gj.direct_length).toFixed(1)}</b>
+</p>
+<p>{levelChanges(route_gj)} changes in level</p>
 <ol>
   {#each route_gj.features as f}
     <li><a href={f.properties.way} target="_blank">{@html step(f)}</a></li>