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Improve simulation code stability

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Mattéo Delabre 4 years ago
parent
commit
5dfa49b75f
Signed by: matteo GPG Key ID: AE3FBD02DC583ABB
  1. 381
      src/tam/simulation.js

381
src/tam/simulation.js

@ -4,188 +4,168 @@ const network = require('./network.json');
const server = 'http://localhost:4321';
const arriveAtStop = (course, stop) =>
class Course
{
course.state = 'stopped';
course.currentStop = stop;
delete course.departureStop;
delete course.arrivalStop;
delete course.arrivalTime;
delete course.traveledDistance;
delete course.speed;
};
const moveToStop = (course, stop, arrivalTime) =>
{
course.state = 'moving';
course.departureStop = course.currentStop;
course.arrivalStop = stop;
course.arrivalTime = arrivalTime;
course.traveledDistance = 0;
course.speed = 0;
delete course.currentStop;
const segment = `${course.departureStop}-${course.arrivalStop}`;
if (!(segment in network.segments))
{
// There is no segment between the two requested stops, jump
// directly to the arrival stop
arriveAtStop(course, course.arrivalStop);
}
else
constructor(data)
{
updateSpeed(course);
this.id = data.id;
this.passings = {};
this.state = null;
// Attributes for the `stopped` state
this.currentStop = null;
// Attributes for the `moving` state
this.departureStop = null;
this.arrivalStop = null;
this.arrivalTime = 0;
this.traveledDistance = 0;
this.speed = 0;
this.position = [0, 0];
this.angle = 0;
}
};
const getCurrentSegment = course =>
{
if (course.state === 'stopped')
get currentSegment()
{
return null;
if (this.state !== 'moving')
{
return undefined;
}
return network.segments[`${this.departureStop}-${this.arrivalStop}`];
}
return network.segments[`${course.departureStop}-${course.arrivalStop}`];
};
updateData(data)
{
this.line = data.line;
this.finalStop = data.finalStop;
Object.assign(this.passings, data.nextPassings);
const updateSpeed = course =>
{
const segment = getCurrentSegment(course);
const length = segment.points[segment.points.length - 1].distance;
const now = Date.now();
const remainingTime = course.arrivalTime - Date.now();
const remainingDistance = length - course.traveledDistance;
// Make sure we’re on the right `stopped`/`moving` state
if (this.state === null)
{
let previousStop = null;
let departureTime = 0;
if (remainingTime <= 0 || remainingDistance <= 0)
{
arriveAtStop(course, course.arrivalStop);
return;
}
let nextStop = null;
let arrivalTime = Infinity;
course.speed = remainingDistance / remainingTime;
};
for (let [stopId, time] of Object.entries(this.passings))
{
if (time > now && time < arrivalTime)
{
nextStop = stopId;
arrivalTime = time;
}
const updateFromTam = async (courses) =>
{
const currentCourses = (await axios.get(`${server}/courses`)).data;
if (time < now && time > departureTime)
{
previousStop = stopId;
departureTime = time;
}
}
for (let [id, course] of Object.entries(currentCourses))
{
// Find out the next stop, ignoring the ones that are in the past
let nextStop = null;
let arrivalTime = null;
if (nextStop === null)
{
return false;
}
for (let {stopId, arrivalTime: time} of course.nextPassings)
{
if (time > Date.now())
if (previousStop === null)
{
// Teleport to the first known stop
this.arriveToStop(nextStop);
}
else
{
nextStop = stopId;
arrivalTime = time;
break;
// Teleport to the first known segment
this.arriveToStop(previousStop);
this.moveToStop(nextStop, arrivalTime);
}
}
if (nextStop === null)
else if (this.state === 'moving')
{
continue;
// Should already be at the next stop
if (this.passings[this.arrivalStop] <= now)
{
this.arriveToStop(this.arrivalStop);
}
// On the right track, update the arrival time
else
{
this.arrivalTime = this.passings[this.arrivalStop];
}
}
// Update an existing course
if (id in courses)
else // this.state === 'stopped'
{
const prev = courses[id];
// Try moving to the next stop
let nextStop = null;
let arrivalTime = Infinity;
if (prev.state === 'stopped')
for (let [stopId, time] of Object.entries(this.passings))
{
if (prev.currentStop !== nextStop)
if (time > now && time < arrivalTime)
{
// Start traveling from the current stop to the next
moveToStop(prev, nextStop, arrivalTime);
nextStop = stopId;
arrivalTime = time;
}
}
else
if (nextStop === null)
{
// Update the ETA if we’re still headed to the same stop
if (prev.arrivalStop === nextStop)
{
prev.arrivalTime = arrivalTime;
updateSpeed(prev);
}
// Otherwise, we missed a stop, try to go directly to the
// next segment
else
{
arriveAtStop(prev, prev.arrivalStop);
moveToStop(prev, nextStop, arrivalTime);
}
// This course is finished
return false;
}
if (nextStop !== this.currentStop)
{
this.moveToStop(nextStop, arrivalTime);
}
}
// Create a new course
else
if (this.state === 'moving')
{
courses[id] = {
id,
line: course.line,
finalStop: course.finalStop,
position: [0, 0],
angle: 0,
};
arriveAtStop(courses[id], nextStop);
this.speed = this.computeTheoreticalSpeed();
}
return true;
}
// Remove stale courses
for (let id of Object.keys(courses))
tick(time)
{
if (!(id in currentCourses))
if (this.state === null)
{
delete courses[id];
// Ignore uninitalized courses
}
}
};
const updatePositions = (courses, time) =>
{
for (let [id, course] of Object.entries(courses))
{
if (course.state === 'moving')
else if (this.state === 'moving')
{
// Increase the travelled distance respective to the current speed
const delta = course.speed * time;
// Integrate current speed in travelled distance
const delta = this.speed * time;
const segment = getCurrentSegment(course);
const segment = this.currentSegment;
const length = segment.points[segment.points.length - 1].distance;
this.traveledDistance += delta;
if (course.traveledDistance + delta >= length)
{
course.traveledDistance = length;
}
else
if (this.traveledDistance >= length)
{
course.traveledDistance += delta;
this.arriveToStop(this.arrivalStop);
return;
}
// Recompute updated position
const departureStop = network.stops[course.departureStop];
const arrivalStop = network.stops[course.arrivalStop];
const departureStop = network.stops[this.departureStop];
const arrivalStop = network.stops[this.arrivalStop];
const nextNodeIndex = segment.points.findIndex(
({distance}) => distance >= course.traveledDistance);
({distance}) => distance >= this.traveledDistance);
if (nextNodeIndex === 0)
{
course.position = {
lat: departureStop.lat,
lon: departureStop.lon
};
}
else if (nextNodeIndex === -1)
{
course.position = {
lat: arrivalStop.lat,
lon: arrivalStop.lon
};
this.position = turf.toMercator([
departureStop.lon,
departureStop.lat
]);
}
else
{
@ -202,33 +182,148 @@ const updatePositions = (courses, time) =>
nextNode.lat
]);
const curLength = course.traveledDistance
const curLength = this.traveledDistance
- previousNode.distance;
const totalLength = nextNode.distance
- previousNode.distance;
const t = curLength / totalLength;
course.position = [
this.position = [
t * nextPoint[0] + (1 - t) * previousPoint[0],
t * nextPoint[1] + (1 - t) * previousPoint[1],
];
course.angle = Math.atan2(
this.angle = Math.atan2(
previousPoint[1] - nextPoint[1],
nextPoint[0] - previousPoint[0],
);
}
}
else
else // this.state === 'stopped'
{
const currentNode = network.stops[course.currentStop];
const currentNode = network.stops[this.currentStop];
course.position = turf.toMercator([
this.position = turf.toMercator([
currentNode.lon,
currentNode.lat
]);
}
}
/**
* Transition this course to a state where it has arrived to a stop.
*
* @param stop Identifier for the stop to which the course arrives.
*/
arriveToStop(stop)
{
this.state = 'stopped';
this.currentStop = stop;
this.position = turf.toMercator([
network.stops[this.currentStop].lon,
network.stops[this.currentStop].lat,
]);
}
/**
* Transition this course to a state where it is moving to a stop.
*
* @param stop Next stop for this course.
* @param arrivalTime Planned arrival time to that stop.
*/
moveToStop(stop, arrivalTime)
{
this.state = 'moving';
this.departureStop = this.currentStop;
this.arrivalStop = stop;
this.arrivalTime = arrivalTime;
this.traveledDistance = 0;
this.speed = 0;
this.position = turf.toMercator([
network.stops[this.departureStop].lon,
network.stops[this.departureStop].lat,
]);
console.log(`Course ${this.id} leaving stop ${this.currentStop} \
with initial speed ${this.computeTheoreticalSpeed() * 3600} km/h`);
if (this.currentSegment === undefined)
{
console.error(`Course ${this.id} is on an undefined segment from \
stop ${this.departureStop} to stop ${this.arrivalStop}`);
}
}
/**
* Compute the speed that needs to be maintained to arrive on time.
*/
computeTheoreticalSpeed()
{
if (this.state !== 'moving')
{
return 0;
}
const segment = this.currentSegment;
const length = segment.points[segment.points.length - 1].distance;
const remainingTime = this.arrivalTime - Date.now();
const remainingDistance = length - this.traveledDistance;
if (remainingDistance <= 0)
{
return 0;
}
else if (remainingTime <= 0)
{
// We’re late, go to maximum speed
return 50 / 3600; // 50 km/h
}
else
{
return remainingDistance / remainingTime;
}
}
}
const updateData = async (courses) =>
{
const dataset = (await axios.get(`${server}/courses`)).data;
// Update or create new courses
for (let [id, data] of Object.entries(dataset))
{
if (id in courses)
{
courses[id].updateData(data);
}
else
{
courses[id] = new Course(data);
if (!courses[id].updateData(data))
{
console.info(`Ignoring course ${id} which is outdated.`);
}
}
}
// Remove stale courses
for (let id of Object.keys(courses))
{
if (!(id in dataset))
{
delete courses[id];
}
}
};
const tick = (courses, time) =>
{
for (let course of Object.values(courses))
{
course.tick(time);
}
};
const start = () =>
@ -244,12 +339,12 @@ const start = () =>
if (lastUpdate === null || lastUpdate + 5000 <= now)
{
lastUpdate = now;
updateFromTam(courses);
updateData(courses);
}
const time = lastFrame === null ? 0 : now - lastFrame;
lastFrame = now;
updatePositions(courses, time);
tick(courses, time);
};
return {courses, update};

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