Make the LTN impact prediction work off autogenerated home-to-work scenarios too.

Most of the work is moving proletariat robot to synthpop, so the LTN
crate doesn't depend on sim. That was a refactor that needed to happen
anyway.

Cargo.lock

@@ -2245,6 +2245,8 @@ dependencies = [
  "map_gui",
  "map_model",
  "maplit",
+ "rand",
+ "rand_xorshift",
  "regex",
  "serde",
  "serde_json",

apps/ltn/Cargo.toml

@@ -26,6 +26,8 @@ log = "0.4"
 maplit = "1.0.2"
 map_gui = { path = "../../map_gui" }
 map_model = { path = "../../map_model" }
+rand = "0.8.3"
+rand_xorshift = "0.3.0"
 regex = "1.5.5"
 serde = "1.0.123"
 serde_json = "1.0.61"

apps/ltn/src/browse.rs

@@ -3,7 +3,6 @@ use std::collections::HashSet;
 use abstutil::Counter;
 use geom::Distance;
 use map_gui::tools::{ColorNetwork, DrawRoadLabels};
-use synthpop::Scenario;
 use widgetry::mapspace::{ToggleZoomed, World, WorldOutcome};
 use widgetry::{
     Choice, Color, DrawBaselayer, EventCtx, GeomBatch, GfxCtx, Key, Line, Outcome, Panel, State,
@@ -307,19 +306,10 @@ fn impact_widget(ctx: &EventCtx, app: &App) -> Widget {
 
     if &app.session.impact.map != map_name {
         // Starting from scratch
-        let scenario_name = Scenario::default_scenario_for_map(map_name);
-        if scenario_name == "home_to_work" {
-            return "This city doesn't have travel demand model data available".text_widget(ctx);
-        }
-        let size = abstio::Manifest::load()
-            .get_entry(&abstio::path_scenario(map_name, &scenario_name))
-            .map(|entry| abstutil::prettyprint_bytes(entry.compressed_size_bytes))
-            .unwrap_or_else(|| "???".to_string());
         return Widget::col(vec![
             Text::from_multiline(vec![
                 Line("This will take a moment.").small(),
                 Line("The app may freeze while calculating.").small(),
-                Line(format!("We need to load a {} file", size)).small(),
             ])
             .into_widget(ctx),
             ctx.style().btn_outline.text("Calculate").build_def(ctx),

apps/ltn/src/impact/ui.rs

@@ -1,7 +1,11 @@
 use std::collections::BTreeSet;
 
+use rand::SeedableRng;
+use rand_xorshift::XorShiftRng;
+
 use map_gui::tools::checkbox_per_mode;
 use map_model::{Path, NORMAL_LANE_THICKNESS};
+use synthpop::make::ScenarioGenerator;
 use synthpop::{Scenario, TripMode};
 use widgetry::tools::{FileLoader, PopupMsg};
 use widgetry::{
@@ -25,6 +29,8 @@ impl ShowResults {
         let map_name = app.map.get_name().clone();
         if app.session.impact.map != map_name {
             let scenario_name = Scenario::default_scenario_for_map(&map_name);
+
+            if scenario_name != "home_to_work" {
                 return FileLoader::<App, Scenario>::new_state(
                     ctx,
                     abstio::path_scenario(&map_name, &scenario_name),
@@ -36,6 +42,15 @@ impl ShowResults {
                     }),
                 );
             }
+            ctx.loading_screen("synthesize travel demand model", |ctx, timer| {
+                let scenario = ScenarioGenerator::proletariat_robot(
+                    &app.map,
+                    &mut XorShiftRng::seed_from_u64(42),
+                    timer,
+                );
+                app.session.impact = Impact::from_scenario(ctx, app, scenario, timer);
+            });
+        }
 
         if app.session.impact.change_key != app.session.modal_filters.get_change_key() {
             ctx.loading_screen("recalculate impact", |ctx, timer| {

sim/src/lib.rs

@@ -37,7 +37,7 @@ pub use crate::render::{
 pub use self::analytics::{Analytics, Problem, ProblemType, SlidingWindow, TripPhase};
 pub(crate) use self::events::Event;
 pub use self::events::{AlertLocation, TripPhaseType};
-pub use self::make::{fork_rng, BorderSpawnOverTime, ScenarioGenerator, SimFlags, SpawnOverTime};
+pub use self::make::SimFlags;
 pub(crate) use self::make::{StartTripArgs, TripSpec};
 pub(crate) use self::mechanics::{
     DrivingSimState, IntersectionSimState, ParkingSim, ParkingSimState, WalkingSimState,
@@ -54,6 +54,7 @@ pub use self::sim::{
 pub(crate) use self::transit::TransitSimState;
 pub use self::trips::{CommutersVehiclesCounts, Person, PersonState, TripInfo, TripResult};
 pub(crate) use self::trips::{TripLeg, TripManager};
+pub use synthpop::make::{fork_rng, BorderSpawnOverTime, ScenarioGenerator, SpawnOverTime};
 
 mod analytics;
 mod events;

sim/src/make/mod.rs

@@ -1,20 +1,7 @@
 //! Everything needed to setup a simulation.
-//! <https://a-b-street.github.io/docs/tech/trafficsim/travel_demand.html> for context.
 
-use rand::{RngCore, SeedableRng};
-use rand_xorshift::XorShiftRng;
-
-pub use self::generator::{BorderSpawnOverTime, ScenarioGenerator, SpawnOverTime};
 pub use self::load::SimFlags;
 pub(crate) use self::spawner::{StartTripArgs, TripSpec};
 
-mod activity_model;
-mod generator;
 mod load;
 mod spawner;
-
-/// Need to explain this trick -- basically keeps consistency between two different simulations when
-/// each one might make slightly different sequences of calls to the RNG.
-pub fn fork_rng(base_rng: &mut XorShiftRng) -> XorShiftRng {
-    XorShiftRng::seed_from_u64(base_rng.next_u64())
-}

sim/src/sim/scenario.rs

@@ -7,9 +7,9 @@ use rand_xorshift::XorShiftRng;
 use abstutil::{prettyprint_usize, Counter, Timer};
 use geom::{Distance, Speed};
 use map_model::{BuildingID, Map, OffstreetParking, RoadID};
+use synthpop::make::fork_rng;
 use synthpop::{PersonSpec, Scenario, TripEndpoint, TripMode};
 
-use crate::make::fork_rng;
 use crate::{
     ParkingSpot, Sim, StartTripArgs, TripInfo, Vehicle, VehicleSpec, VehicleType, BIKE_LENGTH,
     MAX_CAR_LENGTH, MIN_CAR_LENGTH,

synthpop/src/lib.rs

@@ -26,6 +26,7 @@ mod borders;
 mod counts;
 mod endpoint;
 mod external;
+pub mod make;
 mod modifier;
 mod scenario;
 

synthpop/src/make/activity_model.rs

@@ -11,10 +11,10 @@ use rand_xorshift::XorShiftRng;
 use abstutil::{prettyprint_usize, Timer};
 use geom::{Distance, Duration, Time};
 use map_model::{BuildingID, BuildingType, Map, PathConstraints, PathRequest};
-use synthpop::{IndividTrip, PersonSpec, Scenario, TripEndpoint, TripMode, TripPurpose};
 
-use crate::make::fork_rng;
-use crate::ScenarioGenerator;
+use crate::{IndividTrip, PersonSpec, Scenario, TripEndpoint, TripMode, TripPurpose};
+
+use crate::make::{fork_rng, ScenarioGenerator};
 
 impl ScenarioGenerator {
     /// Designed in https://github.com/a-b-street/abstreet/issues/154

synthpop/src/make/generator.rs

@@ -11,7 +11,8 @@ use serde::{Deserialize, Serialize};
 use abstutil::Timer;
 use geom::{Duration, Time};
 use map_model::{IntersectionID, Map};
-use synthpop::{IndividTrip, PersonSpec, Scenario, TripEndpoint, TripMode, TripPurpose};
+
+use crate::{IndividTrip, PersonSpec, Scenario, TripEndpoint, TripMode, TripPurpose};
 
 // TODO This can be simplified dramatically.
 

synthpop/src/make/mod.rs

@@ -0,0 +1,15 @@
+//! <https://a-b-street.github.io/docs/tech/trafficsim/travel_demand.html> for context.
+
+use rand::{RngCore, SeedableRng};
+use rand_xorshift::XorShiftRng;
+
+pub use self::generator::{BorderSpawnOverTime, ScenarioGenerator, SpawnOverTime};
+
+mod activity_model;
+mod generator;
+
+/// Need to explain this trick -- basically keeps consistency between two different simulations when
+/// each one might make slightly different sequences of calls to the RNG.
+pub fn fork_rng(base_rng: &mut XorShiftRng) -> XorShiftRng {
+    XorShiftRng::seed_from_u64(base_rng.next_u64())
+}