Improve simulation code stability
This commit is contained in:
		
							parent
							
								
									91d6771f5e
								
							
						
					
					
						commit
						5dfa49b75f
					
				|  | @ -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)) | ||||
|     constructor(data) | ||||
|     { | ||||
|         // There is no segment between the two requested stops, jump
 | ||||
|         // directly to the arrival stop
 | ||||
|         arriveAtStop(course, course.arrivalStop); | ||||
|     } | ||||
|     else | ||||
|     { | ||||
|         updateSpeed(course); | ||||
|     } | ||||
| }; | ||||
|         this.id = data.id; | ||||
|         this.passings = {}; | ||||
|         this.state = null; | ||||
| 
 | ||||
| const getCurrentSegment = course => | ||||
| { | ||||
|     if (course.state === 'stopped') | ||||
|     { | ||||
|         return 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; | ||||
|     } | ||||
| 
 | ||||
|     return network.segments[`${course.departureStop}-${course.arrivalStop}`]; | ||||
| }; | ||||
| 
 | ||||
| const updateSpeed = course => | ||||
| { | ||||
|     const segment = getCurrentSegment(course); | ||||
|     const length = segment.points[segment.points.length - 1].distance; | ||||
| 
 | ||||
|     const remainingTime = course.arrivalTime - Date.now(); | ||||
|     const remainingDistance = length - course.traveledDistance; | ||||
| 
 | ||||
|     if (remainingTime <= 0 || remainingDistance <= 0) | ||||
|     get currentSegment() | ||||
|     { | ||||
|         arriveAtStop(course, course.arrivalStop); | ||||
|         return; | ||||
|     } | ||||
| 
 | ||||
|     course.speed = remainingDistance / remainingTime; | ||||
| }; | ||||
| 
 | ||||
| const updateFromTam = async (courses) => | ||||
| { | ||||
|     const currentCourses = (await axios.get(`${server}/courses`)).data; | ||||
| 
 | ||||
|     for (let [id, course] of Object.entries(currentCourses)) | ||||
|     { | ||||
|         // Find out the next stop, ignoring the ones that are in the past
 | ||||
|         let nextStop = null; | ||||
|         let arrivalTime = null; | ||||
| 
 | ||||
|         for (let {stopId, arrivalTime: time} of course.nextPassings) | ||||
|         if (this.state !== 'moving') | ||||
|         { | ||||
|             if (time > Date.now()) | ||||
|             { | ||||
|                 nextStop = stopId; | ||||
|                 arrivalTime = time; | ||||
|                 break; | ||||
|             } | ||||
|             return undefined; | ||||
|         } | ||||
| 
 | ||||
|         if (nextStop === null) | ||||
|         { | ||||
|             continue; | ||||
|         } | ||||
|         return network.segments[`${this.departureStop}-${this.arrivalStop}`]; | ||||
|     } | ||||
| 
 | ||||
|         // Update an existing course
 | ||||
|         if (id in courses) | ||||
|         { | ||||
|             const prev = courses[id]; | ||||
|     updateData(data) | ||||
|     { | ||||
|         this.line = data.line; | ||||
|         this.finalStop = data.finalStop; | ||||
|         Object.assign(this.passings, data.nextPassings); | ||||
| 
 | ||||
|             if (prev.state === 'stopped') | ||||
|         const now = Date.now(); | ||||
| 
 | ||||
|         // Make sure we’re on the right `stopped`/`moving` state
 | ||||
|         if (this.state === null) | ||||
|         { | ||||
|             let previousStop = null; | ||||
|             let departureTime = 0; | ||||
| 
 | ||||
|             let nextStop = null; | ||||
|             let arrivalTime = Infinity; | ||||
| 
 | ||||
|             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; | ||||
|                 } | ||||
| 
 | ||||
|                 if (time < now && time > departureTime) | ||||
|                 { | ||||
|                     previousStop = stopId; | ||||
|                     departureTime = time; | ||||
|                 } | ||||
|             } | ||||
| 
 | ||||
|             if (nextStop === null) | ||||
|             { | ||||
|                 return false; | ||||
|             } | ||||
| 
 | ||||
|             if (previousStop === null) | ||||
|             { | ||||
|                 // Teleport to the first known stop
 | ||||
|                 this.arriveToStop(nextStop); | ||||
|             } | ||||
|             else | ||||
|             { | ||||
|                 // 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); | ||||
|                 } | ||||
|                 // Teleport to the first known segment
 | ||||
|                 this.arriveToStop(previousStop); | ||||
|                 this.moveToStop(nextStop, arrivalTime); | ||||
|             } | ||||
|         } | ||||
|         // Create a new course
 | ||||
|         else | ||||
|         else if (this.state === 'moving') | ||||
|         { | ||||
|             courses[id] = { | ||||
|                 id, | ||||
|                 line: course.line, | ||||
|                 finalStop: course.finalStop, | ||||
|                 position: [0, 0], | ||||
|                 angle: 0, | ||||
|             }; | ||||
| 
 | ||||
|             arriveAtStop(courses[id], nextStop); | ||||
|             // 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]; | ||||
|             } | ||||
|         } | ||||
|         else // this.state === 'stopped'
 | ||||
|         { | ||||
|             // Try moving to the next stop
 | ||||
|             let nextStop = null; | ||||
|             let arrivalTime = Infinity; | ||||
| 
 | ||||
|             for (let [stopId, time] of Object.entries(this.passings)) | ||||
|             { | ||||
|                 if (time > now && time < arrivalTime) | ||||
|                 { | ||||
|                     nextStop = stopId; | ||||
|                     arrivalTime = time; | ||||
|                 } | ||||
|             } | ||||
| 
 | ||||
|             if (nextStop === null) | ||||
|             { | ||||
|                 // This course is finished
 | ||||
|                 return false; | ||||
|             } | ||||
| 
 | ||||
|             if (nextStop !== this.currentStop) | ||||
|             { | ||||
|                 this.moveToStop(nextStop, arrivalTime); | ||||
|             } | ||||
|         } | ||||
| 
 | ||||
|         if (this.state === 'moving') | ||||
|         { | ||||
|             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) | ||||
|             if (this.traveledDistance >= length) | ||||
|             { | ||||
|                 course.traveledDistance = length; | ||||
|             } | ||||
|             else | ||||
|             { | ||||
|                 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}; | ||||
|  |  | |||
		Loading…
	
		Reference in New Issue