Add an API for the Xi'an group to get agent positions

book/src/api.md

@@ -43,6 +43,8 @@ are missing, etc. A summary of the commands available so far:
     mode, duration of trip in seconds). The mode is either a string like "Walk"
     or "Drive", or null if the trip was aborted (due to a simulation bug or
     disconnected map).
+  - **GET /data/get-agent-positions**: Returns a JSON list of all active agents.
+    Vehicle type (or pedestrian), person ID, and position is included.
 
 ## Related tools
 

headless/examples/python_client.py

@@ -25,6 +25,13 @@ def main():
     print('Baseline: {} finished trips, total of {} seconds'.format(len(trips1), sum(trips1.values())))
     print()
 
+    # Find the average position of all active pedestrians
+    agents = [x['pos'] for x in requests.get(api + '/data/get-agent-positions').json()['agents'] if x['vehicle_type'] is None]
+    avg_lon = sum([x['longitude'] for x in agents]) / len(agents)
+    avg_lat = sum([x['latitude'] for x in agents]) / len(agents)
+    print('Average position of all active pedestrians: {}, {}'.format(avg_lon, avg_lat))
+    print()
+
     # Modify one traffic signal, doubling the duration of its second phase
     print('Modify a traffic signal')
     ts = requests.get(api + '/traffic-signals/get', params={'id': 67}).json()
@@ -91,11 +98,7 @@ def stringify_direction(direxn):
 
 
 def stringify_road(directed_road):
-    if directed_road['forwards']:
-        direxn = 'fwd'
-    else:
-        direxn = 'back'
-    return 'Road #{} ({})'.format(directed_road['id'], direxn)
+    return 'Road #{} ({})'.format(directed_road['id'], directed_road['dir'])
 
 
 if __name__ == '__main__':

headless/src/main.rs

@@ -10,11 +10,13 @@
 // ... huge JSON blob
 
 use abstutil::{serialize_btreemap, CmdArgs, Timer};
-use geom::{Duration, Time};
+use geom::{Duration, LonLat, Time};
 use hyper::{Body, Request, Response, Server};
 use map_model::{CompressedTurnGroupID, ControlTrafficSignal, IntersectionID, Map, TurnGroupID};
 use serde::Serialize;
-use sim::{AlertHandler, Sim, SimFlags, SimOptions, TripID, TripMode};
+use sim::{
+    AlertHandler, GetDrawAgents, PersonID, Sim, SimFlags, SimOptions, TripID, TripMode, VehicleType,
+};
 use std::collections::{BTreeMap, HashMap};
 use std::convert::TryFrom;
 use std::error::Error;
@@ -176,6 +178,17 @@ fn handle_command(
         "/data/get-finished-trips" => Ok(abstutil::to_json(&FinishedTrips {
             trips: sim.get_analytics().finished_trips.clone(),
         })),
+        "/data/get-agent-positions" => Ok(abstutil::to_json(&AgentPositions {
+            agents: sim
+                .get_unzoomed_agents(map)
+                .into_iter()
+                .map(|a| AgentPosition {
+                    vehicle_type: a.vehicle_type,
+                    pos: a.pos.to_gps(map.get_gps_bounds()),
+                    person: a.person,
+                })
+                .collect(),
+        })),
         _ => Err("Unknown command".into()),
     }
 }
@@ -200,3 +213,17 @@ struct Throughput {
     #[serde(serialize_with = "serialize_btreemap")]
     per_direction: BTreeMap<TurnGroupID, usize>,
 }
+
+#[derive(Serialize)]
+struct AgentPositions {
+    agents: Vec<AgentPosition>,
+}
+
+#[derive(Serialize)]
+struct AgentPosition {
+    // None for pedestrians
+    vehicle_type: Option<VehicleType>,
+    pos: LonLat,
+    // None for buses
+    person: Option<PersonID>,
+}