In traffic=none mode, allow recording (most of) the manually specified

trips as a Scenario to later re-run. This is useful for quickly defining
"test cases" for development, and it's a start to a UI for letting
players specify (and eventually share) traffic patterns they define.

game/src/sandbox/gameplay/freeform.rs

@@ -1,7 +1,7 @@
 use crate::app::{App, ShowEverything};
 use crate::common::{CityPicker, CommonState};
 use crate::edit::EditMode;
-use crate::game::{ChooseSomething, State, Transition};
+use crate::game::{ChooseSomething, PopupMsg, PromptInput, State, Transition};
 use crate::helpers::{nice_map_name, ID};
 use crate::sandbox::gameplay::{GameplayMode, GameplayState};
 use crate::sandbox::SandboxControls;
@@ -72,6 +72,32 @@ impl GameplayState for Freeform {
                     GameplayMode::Freeform(abstutil::path_map(app.primary.map.get_name())),
                 ))),
                 "Start a new trip" => Some(Transition::Push(AgentSpawner::new(ctx, None))),
+                "Record trips as a scenario" => Some(Transition::Push(PromptInput::new(
+                    ctx,
+                    "Name this scenario",
+                    Box::new(|name, ctx, app| {
+                        if abstutil::file_exists(abstutil::path_scenario(
+                            app.primary.map.get_name(),
+                            &name,
+                        )) {
+                            Transition::Push(PopupMsg::new(
+                                ctx,
+                                "Error",
+                                vec![format!(
+                                    "A scenario called \"{}\" already exists, please pick another \
+                                     name",
+                                    name
+                                )],
+                            ))
+                        } else {
+                            app.primary
+                                .sim
+                                .generate_scenario(&app.primary.map, name)
+                                .save();
+                            Transition::Pop
+                        }
+                    }),
+                ))),
                 _ => unreachable!(),
             },
             _ => None,
@@ -99,9 +125,11 @@ fn make_top_center(ctx: &mut EventCtx, app: &App) -> Composite {
             Btn::svg_def("system/assets/tools/edit_map.svg").build(ctx, "edit map", lctrl(Key::E)),
         ])
         .centered(),
-        Btn::text_fg("Start a new trip")
-            .build_def(ctx, None)
-            .centered_horiz(),
+        Widget::row(vec![
+            Btn::text_fg("Start a new trip").build_def(ctx, None),
+            Btn::text_fg("Record trips as a scenario").build_def(ctx, None),
+        ])
+        .centered(),
         Text::from_all(vec![
             Line("Select an intersection and press "),
             Line(Key::Z.describe()).fg(ctx.style().hotkey_color),

sim/src/sim.rs

@@ -3,9 +3,9 @@ use crate::{
     AgentID, AgentType, AlertLocation, Analytics, CarID, Command, CreateCar, DrawCarInput,
     DrawPedCrowdInput, DrawPedestrianInput, DrivingSimState, Event, GetDrawAgents,
     IntersectionSimState, OrigPersonID, PandemicModel, ParkedCar, ParkingSimState, ParkingSpot,
-    PedestrianID, Person, PersonID, PersonState, Router, Scheduler, SidewalkPOI, SidewalkSpot,
-    TransitSimState, TripID, TripInfo, TripManager, TripPhaseType, TripResult, TripSpawner,
-    UnzoomedAgent, Vehicle, VehicleSpec, VehicleType, WalkingSimState, BUS_LENGTH,
+    PedestrianID, Person, PersonID, PersonState, Router, Scenario, Scheduler, SidewalkPOI,
+    SidewalkSpot, TransitSimState, TripID, TripInfo, TripManager, TripPhaseType, TripResult,
+    TripSpawner, UnzoomedAgent, Vehicle, VehicleSpec, VehicleType, WalkingSimState, BUS_LENGTH,
     LIGHT_RAIL_LENGTH, MIN_CAR_LENGTH, SPAWN_DIST,
 };
 use abstutil::{prettyprint_usize, serialized_size_bytes, Counter, Parallelism, Timer};
@@ -1192,6 +1192,10 @@ impl Sim {
     ) -> &Vec<(PedestrianID, BusRouteID, Option<BusStopID>, Time)> {
         self.transit.get_people_waiting_at_stop(at)
     }
+
+    pub fn generate_scenario(&self, map: &Map, name: String) -> Scenario {
+        self.trips.generate_scenario(map, name)
+    }
 }
 
 // Invasive debugging

sim/src/trips.rs

@@ -1,8 +1,9 @@
 use crate::{
     AgentID, AgentType, AlertLocation, CarID, Command, CreateCar, CreatePedestrian, DrivingGoal,
-    Event, OffMapLocation, OrigPersonID, ParkedCar, ParkingSimState, ParkingSpot, PedestrianID,
-    PersonID, Scheduler, SidewalkPOI, SidewalkSpot, TransitSimState, TripID, TripPhaseType,
-    TripSpec, Vehicle, VehicleSpec, VehicleType, WalkingSimState,
+    Event, IndividTrip, OffMapLocation, OrigPersonID, ParkedCar, ParkingSimState, ParkingSpot,
+    PedestrianID, PersonID, PersonSpec, Scenario, Scheduler, SidewalkPOI, SidewalkSpot, SpawnTrip,
+    TransitSimState, TripID, TripPhaseType, TripSpec, Vehicle, VehicleSpec, VehicleType,
+    WalkingSimState,
 };
 use abstutil::{deserialize_btreemap, serialize_btreemap, Counter};
 use geom::{Duration, Speed, Time};
@@ -1326,6 +1327,35 @@ impl TripManager {
         times.sort();
         times
     }
+
+    // TODO This could be lossy. There are a few layers in spawning trips, and things like
+    // spawn_agents_around reach into one of the middle layers directly. So here in TripManager, we
+    // might not have retained enough state to create a proper scenario. But this should work
+    // reasonably for most cases.
+    pub fn generate_scenario(&self, map: &Map, name: String) -> Scenario {
+        let mut scenario = Scenario::empty(map, &name);
+        for p in &self.people {
+            scenario.people.push(PersonSpec {
+                id: p.id,
+                orig_id: p.orig_id,
+                trips: p
+                    .trips
+                    .iter()
+                    .filter_map(|t| {
+                        let trip = &self.trips[t.0];
+                        SpawnTrip::new(
+                            trip.info.start.clone(),
+                            trip.info.end.clone(),
+                            trip.info.mode,
+                            map,
+                        )
+                        .map(|spawn| IndividTrip::new(trip.info.departure, spawn))
+                    })
+                    .collect(),
+            });
+        }
+        scenario
+    }
 }
 
 #[derive(Serialize, Deserialize, PartialEq, Debug, Clone)]