Don't erase modal filters when switching neighborhoods

game/src/app.rs

@@ -1,5 +1,5 @@
 use std::cell::RefCell;
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, BTreeSet};
 
 use anyhow::Result;
 use maplit::btreemap;
@@ -14,7 +14,7 @@ use map_gui::render::{unzoomed_agent_radius, AgentCache, DrawMap, DrawOptions, R
 use map_gui::tools::CameraState;
 use map_gui::ID;
 use map_model::AreaType;
-use map_model::{BufferType, IntersectionID, LaneType, Map, Traversable};
+use map_model::{BufferType, IntersectionID, LaneType, Map, RoadID, Traversable};
 use sim::{AgentID, Analytics, Scenario, Sim, SimCallback, SimFlags, VehicleType};
 use widgetry::mapspace::ToggleZoomed;
 use widgetry::{Cached, Canvas, EventCtx, GfxCtx, Prerender, SharedAppState, State};
@@ -756,6 +756,9 @@ pub struct SessionState {
     pub ungap_current_trip_name: Option<String>,
     // Map and edit change key
     pub mode_shift: Cached<(MapName, usize), crate::ungap::ModeShiftData>,
+
+    // Specific to LTN
+    pub modal_filters: BTreeSet<RoadID>,
 }
 
 impl SessionState {
@@ -778,6 +781,8 @@ impl SessionState {
             routing_preferences: crate::ungap::RoutingPreferences::default(),
             ungap_current_trip_name: None,
             mode_shift: Cached::new(),
+
+            modal_filters: BTreeSet::new(),
         }
     }
 }

game/src/ltn/mod.rs

@@ -17,8 +17,8 @@ struct Neighborhood {
     perimeter: BTreeSet<RoadID>,
     borders: BTreeSet<IntersectionID>,
 
-    // The cells change as a result of modal filters
-    modal_filters: BTreeSet<RoadID>,
+    // The cells change as a result of modal filters, which're stored for all neighborhoods in
+    // app.session.
     cells: Vec<BTreeSet<RoadID>>,
 
     fade_irrelevant: Drawable,
@@ -26,21 +26,15 @@ struct Neighborhood {
 }
 
 impl Neighborhood {
-    fn new(
-        ctx: &EventCtx,
-        app: &App,
-        orig_perimeter: Perimeter,
-        modal_filters: BTreeSet<RoadID>,
-    ) -> Neighborhood {
+    fn new(ctx: &EventCtx, app: &App, orig_perimeter: Perimeter) -> Neighborhood {
         let map = &app.primary.map;
 
-        let cells = find_cells(map, &orig_perimeter, &modal_filters);
+        let cells = find_cells(map, &orig_perimeter, &app.session.modal_filters);
         let mut n = Neighborhood {
             orig_perimeter,
             perimeter: BTreeSet::new(),
             borders: BTreeSet::new(),
 
-            modal_filters,
             cells,
 
             fade_irrelevant: Drawable::empty(ctx),
@@ -77,7 +71,11 @@ impl Neighborhood {
         n.fade_irrelevant = GeomBatch::from(vec![(app.cs.fade_map_dark, fade_area)]).upload(ctx);
 
         let mut batch = GeomBatch::new();
-        for r in &n.modal_filters {
+        for r in &app.session.modal_filters {
+            if !n.orig_perimeter.interior.contains(r) {
+                continue;
+            }
+
             let road = map.get_r(*r);
             // If this road touches a border, place it closer to that intersection. If it's an
             // inner neighborhood split, then stick to the middle of that road.

game/src/ltn/viewer.rs

@@ -1,5 +1,3 @@
-use std::collections::BTreeSet;
-
 use geom::Distance;
 use map_gui::tools::{CityPicker, DrawRoadLabels};
 use map_model::{Block, RoadID};
@@ -43,8 +41,7 @@ impl Viewer {
         .aligned(HorizontalAlignment::Left, VerticalAlignment::Top)
         .build(ctx);
 
-        let modal_filters = BTreeSet::new();
-        let neighborhood = Neighborhood::new(ctx, app, block.perimeter.clone(), modal_filters);
+        let neighborhood = Neighborhood::new(ctx, app, block.perimeter.clone());
 
         let mut label_roads = neighborhood.perimeter.clone();
         label_roads.extend(neighborhood.orig_perimeter.interior.clone());
@@ -82,19 +79,15 @@ impl State<App> for Viewer {
 
         match self.world.event(ctx) {
             WorldOutcome::ClickedObject(Obj::InteriorRoad(r)) => {
-                if self.neighborhood.modal_filters.contains(&r) {
-                    self.neighborhood.modal_filters.remove(&r);
+                if app.session.modal_filters.contains(&r) {
+                    app.session.modal_filters.remove(&r);
                 } else {
-                    self.neighborhood.modal_filters.insert(r);
+                    app.session.modal_filters.insert(r);
                 }
                 // TODO The cell coloring changes quite spuriously just by toggling a filter, even
                 // when it doesn't matter
-                self.neighborhood = Neighborhood::new(
-                    ctx,
-                    app,
-                    self.neighborhood.orig_perimeter.clone(),
-                    std::mem::take(&mut self.neighborhood.modal_filters),
-                );
+                self.neighborhood =
+                    Neighborhood::new(ctx, app, self.neighborhood.orig_perimeter.clone());
                 self.world = make_world(ctx, app, &self.neighborhood);
             }
             _ => {}