Feature to repeat days with noise on departure (#926)

* Added repeat days with noise function & enum

* Added widgets and controls

* Modified description

* Refactor to have an Option<usize> in signature instead of a whole new similar function

* Added noise parameter + xor random shift + clamped substraction

* Added ref to the XorShiftRng to ScenarioModifiers::apply calls

* Added noise to pushed ScenarioModifier

* Finish up the PR:

- consistently reuse the RNG in the UI like tests/headless
- slight style tweaks

Co-authored-by: Dustin Carlino <dabreegster@gmail.com>

apps/game/src/sandbox/gameplay/play_scenario.rs

@@ -259,12 +259,19 @@ impl EditScenarioModifiers {
                 .build_def(ctx),
         );
         rows.push(Widget::row(vec![
-            Spinner::widget(ctx, "repeat_days", (2, 14), 2_usize, 1),
+            Spinner::widget(ctx, "repeat_days", (2, 14), 2, 1),
             ctx.style()
                 .btn_outline
                 .text("Repeat schedule multiple days")
                 .build_def(ctx),
         ]));
+        rows.push(Widget::row(vec![
+            Spinner::widget(ctx, "repeat_days_noise", (2, 14), 2_usize, 1),
+            ctx.style()
+                .btn_outline
+                .text("Repeat schedule multiple days with +/- 10 minutes of noise")
+                .build_def(ctx),
+        ]));
         rows.push(Widget::horiz_separator(ctx, 1.0));
         rows.push(
             Widget::row(vec![
@@ -361,6 +368,17 @@ impl State<App> for EditScenarioModifiers {
                         self.modifiers.clone(),
                     ));
                 }
+                "Repeat schedule multiple days with +/- 10 minutes of noise" => {
+                    self.modifiers.push(ScenarioModifier::RepeatDaysNoise {
+                        days: self.panel.spinner("repeat_days_noise"),
+                        departure_time_noise: Duration::minutes(10),
+                    });
+                    return Transition::Replace(EditScenarioModifiers::new_state(
+                        ctx,
+                        self.scenario_name.clone(),
+                        self.modifiers.clone(),
+                    ));
+                }
                 x => {
                     if let Some(x) = x.strip_prefix("delete modifier ") {
                         self.modifiers.remove(x.parse::<usize>().unwrap() - 1);

apps/game/src/sandbox/mod.rs

@@ -549,18 +549,22 @@ impl State<App> for SandboxLoader {
                     ctx.loading_screen("instantiate scenario", |_, timer| {
                         app.primary.scenario = Some(scenario.clone());
 
+                        // Use the same RNG as we apply scenario modifiers and instantiate the
+                        // scenario. One unexpected effect will be that parked car seeding (during
+                        // scenario instantiation) may spuriously change if a scenario modifier
+                        // uses the RNG. This is at least consistent with the tests, headless mode,
+                        // and instantiating a scenario from CLI flags.
+                        let mut rng = app.primary.current_flags.sim_flags.make_rng();
+
                         if let GameplayMode::PlayScenario(_, _, ref modifiers) = self.mode {
                             for m in modifiers {
-                                scenario = m.apply(&app.primary.map, scenario);
+                                scenario = m.apply(&app.primary.map, scenario, &mut rng);
                             }
                         }
 
-                        app.primary.sim.instantiate(
-                            &scenario,
-                            &app.primary.map,
-                            &mut app.primary.current_flags.sim_flags.make_rng(),
-                            timer,
-                        );
+                        app.primary
+                            .sim
+                            .instantiate(&scenario, &app.primary.map, &mut rng, timer);
                         app.primary
                             .sim
                             .tiny_step(&app.primary.map, &mut app.primary.sim_cb);
@@ -572,6 +576,8 @@ impl State<App> for SandboxLoader {
                             secondary.sim.instantiate(
                                 &scenario,
                                 &secondary.map,
+                                // Start fresh here. This will match up with the primary sim,
+                                // unless modifiers used the RNG
                                 &mut secondary.current_flags.sim_flags.make_rng(),
                                 timer,
                             );

cli/src/augment_scenario.rs

@@ -29,7 +29,7 @@ pub fn run(
     }
 
     for m in modifiers {
-        scenario = m.apply(&map, scenario);
+        scenario = m.apply(&map, scenario, &mut rng);
     }
 
     if should_delete_cancelled_trips {

headless/src/main.rs

@@ -510,11 +510,11 @@ impl LoadSim {
             map.recalculate_pathfinding_after_edits(timer);
         }
 
+        let mut rng = XorShiftRng::seed_from_u64(self.rng_seed);
         for m in &self.modifiers {
-            scenario = m.apply(&map, scenario);
+            scenario = m.apply(&map, scenario, &mut rng);
         }
 
-        let mut rng = XorShiftRng::seed_from_u64(self.rng_seed);
         let mut sim = Sim::new(&map, self.opts.clone());
         sim.instantiate(&scenario, &map, &mut rng, timer);
 

sim/src/make/load.rs

@@ -108,7 +108,7 @@ impl SimFlags {
             let map = Map::load_synchronously(scenario.map_name.path(), timer);
 
             for m in &self.scenario_modifiers {
-                scenario = m.apply(&map, scenario);
+                scenario = m.apply(&map, scenario, &mut rng);
             }
 
             if opts.run_name == "unnamed" {

synthpop/Cargo.toml

@@ -10,4 +10,6 @@ anyhow = "1.0.38"
 geom = { path = "../geom" }
 log = "0.4.14"
 map_model = { path = "../map_model" }
+rand = "0.8.5"
+rand_xorshift = "0.3.0"
 serde = "1.0.123"

synthpop/src/modifier.rs

@@ -1,5 +1,9 @@
+extern crate rand;
+
 use std::collections::BTreeSet;
 
+use rand::Rng;
+use rand_xorshift::XorShiftRng;
 use serde::{Deserialize, Serialize};
 
 use abstutil::Timer;
@@ -12,6 +16,10 @@ use crate::{Scenario, TripMode};
 #[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Serialize, Deserialize)]
 pub enum ScenarioModifier {
     RepeatDays(usize),
+    RepeatDaysNoise {
+        days: usize,
+        departure_time_noise: Duration,
+    },
     ChangeMode {
         pct_ppl: usize,
         departure_filter: (Time, Time),
@@ -26,9 +34,13 @@ pub enum ScenarioModifier {
 impl ScenarioModifier {
     /// If this modifies scenario_name, then that means prebaked results don't match up and
     /// shouldn't be used.
-    pub fn apply(&self, map: &Map, mut s: Scenario) -> Scenario {
+    pub fn apply(&self, map: &Map, mut s: Scenario, rng: &mut XorShiftRng) -> Scenario {
         match self {
-            ScenarioModifier::RepeatDays(n) => repeat_days(s, *n),
+            ScenarioModifier::RepeatDays(n) => repeat_days(s, *n, None, rng),
+            ScenarioModifier::RepeatDaysNoise {
+                days,
+                departure_time_noise,
+            } => repeat_days(s, *days, Some(*departure_time_noise), rng),
             ScenarioModifier::ChangeMode {
                 pct_ppl,
                 departure_filter,
@@ -90,6 +102,13 @@ impl ScenarioModifier {
     pub fn describe(&self) -> String {
         match self {
             ScenarioModifier::RepeatDays(n) => format!("repeat the entire day {} times", n),
+            ScenarioModifier::RepeatDaysNoise {
+                days,
+                departure_time_noise,
+            } => format!(
+                "repeat the entire day {} times with +/- {} noise on each departure",
+                days, departure_time_noise
+            ),
             ScenarioModifier::ChangeMode {
                 pct_ppl,
                 to_mode,
@@ -117,7 +136,12 @@ impl ScenarioModifier {
 //
 // The bigger problem is that any people that seem to require multiple cars... will wind up
 // needing LOTS of cars.
-fn repeat_days(mut s: Scenario, days: usize) -> Scenario {
+fn repeat_days(
+    mut s: Scenario,
+    days: usize,
+    noise: Option<Duration>,
+    rng: &mut XorShiftRng,
+) -> Scenario {
     s.scenario_name = format!("{} (repeated {} days)", s.scenario_name, days);
     for person in &mut s.people {
         let mut trips = Vec::new();
@@ -126,6 +150,13 @@ fn repeat_days(mut s: Scenario, days: usize) -> Scenario {
             for trip in &person.trips {
                 let mut new = trip.clone();
                 new.depart += offset;
+                if let Some(noise_v) = noise {
+                    // + or - noise_v
+                    let noise_rnd = Duration::seconds(
+                        rng.gen_range((0.0)..=(2.0 * noise_v.inner_seconds() as f64)),
+                    ) - noise_v;
+                    new.depart = new.depart.clamped_sub(noise_rnd);
+                }
                 new.modified = true;
                 trips.push(new);
             }