be able to launch DES model on any lane

docs/TODO_game.md

@@ -43,9 +43,9 @@
 
 ## Discrete-event model
 
+- Make cars cover an entire lane, even when it's short
 - try real distance over time ;) but does it make intersection calculation extremely hard?
 - avoid impossible accel/deaccel
-- Make cars cover an entire lane, even when it's short
 - Handle lead car being faster
 - The speed stated in the middle of intervals is clearly wrong for the follower car
 

editor/src/plugins/sim/des_model.rs

@@ -7,13 +7,14 @@ use sim::{CarID, CarState, DrawCarInput, VehicleType};
 const FOLLOWING_DISTANCE: Distance = Distance::const_meters(1.0);
 
 pub struct World {
+    lane: LaneID,
     leader: Car,
     follower: Car,
 }
 
 impl World {
-    pub fn new(map: &Map) -> World {
-        let lane = map.get_l(LaneID(1250));
+    pub fn new(l: LaneID, map: &Map) -> World {
+        let lane = map.get_l(l);
         let speed_limit = map.get_parent(lane.id).get_speed_limit();
 
         let mut leader = Car {
@@ -74,21 +75,25 @@ impl World {
 
         leader.validate();
         follower.validate();
-        World { leader, follower }
+        World {
+            leader,
+            follower,
+            lane: l,
+        }
     }
 
     pub fn get_draw_cars(&self, time: Duration, map: &Map) -> Vec<DrawCarInput> {
         let mut draw = Vec::new();
         for car in vec![&self.leader, &self.follower] {
             if let Some((d, _)) = car.dist_at(time) {
-                draw.push(draw_car(car, d, map));
+                draw.push(car.get_draw_car(d, map.get_l(self.lane)));
             }
         }
         draw
     }
 
     pub fn draw_tooltips(&self, g: &mut GfxCtx, ctx: &DrawCtx, time: Duration) {
-        let lane = ctx.map.get_l(LaneID(1250));
+        let lane = ctx.map.get_l(self.lane);
 
         for car in vec![&self.leader, &self.follower] {
             if let Some((d, idx)) = car.dist_at(time) {
@@ -106,24 +111,6 @@ impl World {
     }
 }
 
-fn draw_car(car: &Car, front: Distance, map: &Map) -> DrawCarInput {
-    let lane = map.get_l(LaneID(1250));
-
-    DrawCarInput {
-        id: car.id,
-        waiting_for_turn: None,
-        stopping_trace: None,
-        state: car.state,
-        vehicle_type: VehicleType::Car,
-        on: Traversable::Lane(lane.id),
-        body: lane
-            .lane_center_pts
-            .slice(front - car.car_length, front)
-            .unwrap()
-            .0,
-    }
-}
-
 #[derive(Debug)]
 struct Interval {
     start_dist: Distance,
@@ -474,6 +461,22 @@ impl Car {
         assert_eq!(speed, Speed::ZERO);
         self.next_state(Distance::ZERO, Speed::ZERO, time);
     }
+
+    fn get_draw_car(&self, front: Distance, lane: &Lane) -> DrawCarInput {
+        DrawCarInput {
+            id: self.id,
+            waiting_for_turn: None,
+            stopping_trace: None,
+            state: self.state,
+            vehicle_type: VehicleType::Car,
+            on: Traversable::Lane(lane.id),
+            body: lane
+                .lane_center_pts
+                .slice(front - self.car_length, front)
+                .unwrap()
+                .0,
+        }
+    }
 }
 
 fn overlap<A: PartialOrd>((a_start, a_end): (A, A), (b_start, b_end): (A, A)) -> bool {

editor/src/plugins/sim/simple_model.rs

@@ -1,7 +1,7 @@
-use crate::objects::DrawCtx;
+use crate::objects::{DrawCtx, ID};
 use crate::plugins::sim::des_model;
 use crate::plugins::{BlockingPlugin, PluginCtx};
-use ezgui::{EventLoopMode, GfxCtx};
+use ezgui::{EventLoopMode, GfxCtx, Key};
 use map_model::{Map, Traversable};
 use sim::{CarID, DrawCarInput, DrawPedestrianInput, GetDrawAgents, PedestrianID, Tick};
 
@@ -20,13 +20,17 @@ pub struct SimpleModelController {
 
 impl SimpleModelController {
     pub fn new(ctx: &mut PluginCtx) -> Option<SimpleModelController> {
-        if ctx.input.action_chosen("start simple model") {
-            return Some(SimpleModelController {
-                current_tick: Tick::zero(),
-                world: des_model::World::new(&ctx.primary.map),
-                mode: AutoMode::Off,
-                show_tooltips: false,
-            });
+        if let Some(ID::Lane(id)) = ctx.primary.current_selection {
+            if ctx.primary.map.get_l(id).is_driving()
+                && ctx.input.contextual_action(Key::C, "start simple model")
+            {
+                return Some(SimpleModelController {
+                    current_tick: Tick::zero(),
+                    world: des_model::World::new(id, &ctx.primary.map),
+                    mode: AutoMode::Off,
+                    show_tooltips: false,
+                });
+            }
         }
         None
     }

editor/src/ui.rs

@@ -75,7 +75,6 @@ impl<S: UIState> GUI<RenderingHints> for UI<S> {
                     (Some(Key::D), "diff all A/B trips"),
                     (Some(Key::S), "seed the sim with agents"),
                     (Some(Key::LeftAlt), "swap the primary/secondary sim"),
-                    (Some(Key::C), "start simple model"),
                 ],
             ),
             Folder::new(