Load simulation in front

src/front/index.js

@@ -1,7 +1,4 @@
 require('regenerator-runtime/runtime');
 
 const {createMap} = require('./map');
-
-require('../tam/simulation');
-
 createMap(/* map = */ 'map');

src/front/map.js

@@ -21,6 +21,7 @@ const color = require('color');
 const mapboxToken = `pk.eyJ1IjoibWF0dGVvZGVsYWJyZSIsImEiOiJja2NxaTUyMmUwcmFhMn\
 h0NmFsdzQ3emxqIn0.cyxF0h36emIMTk3cc4VqUw`;
 
+const simulation = require('../tam/simulation');
 const network = require('../tam/network.json');
 
 const getRouteColors = routes =>
@@ -39,7 +40,7 @@ const getRouteColors = routes =>
     return ['#FFFFFF'];
 };
 
-const makeDataSources = async () =>
+const makeDataSources = () =>
 {
     const segmentsSource = new VectorSource();
     const stopsSource = new VectorSource();
@@ -101,7 +102,7 @@ const stopsStyle = feature => new Style({
     }),
 });
 
-const createMap = async (target) =>
+const createMap = target =>
 {
     // Map background
     const backgroundSource = new XYZSource({
@@ -116,8 +117,8 @@ const createMap = async (target) =>
         source: backgroundSource,
     });
 
-    // Data overlay
+    // Static data overlay
-    const {segmentsSource, stopsSource} = await makeDataSources();
+    const {segmentsSource, stopsSource} = makeDataSources();
 
     const segmentsBorderLayer = new VectorLayer({
         source: segmentsSource,
@@ -144,6 +145,63 @@ const createMap = async (target) =>
         updateWhileAnimating: true,
     });
 
+    // Dynamic data overlay
+    const coursesSource = new VectorSource();
+
+    const onFrame = courses =>
+    {
+        // Remove stale courses
+        for (let feature of coursesSource.getFeatures())
+        {
+            if (!(feature.getId() in courses))
+            {
+                coursesSource.removeFeature(feature);
+            }
+        }
+
+        // Add new courses or update existing courses
+        const newFeatures = [];
+
+        for (let [courseId, course] of Object.entries(courses))
+        {
+            if ('position' in course)
+            {
+                const feature = coursesSource.getFeatureById(courseId);
+                const coords = proj.fromLonLat([
+                    course.position.lon,
+                    course.position.lat
+                ]);
+
+                if (feature === null)
+                {
+                    const feature = new Feature({
+                        colors: ['#FF0000'],
+                        geometry: new Point(coords)
+                    });
+
+                    feature.setId(courseId);
+                    newFeatures.push(feature);
+                }
+                else
+                {
+                    feature.getGeometry().setCoordinates(coords);
+                }
+            }
+        }
+
+        coursesSource.addFeatures(newFeatures);
+    };
+
+    simulation.run(onFrame);
+
+    const coursesLayer = new VectorLayer({
+        source: coursesSource,
+        style: stopsStyle,
+
+        updateWhileInteracting: true,
+        updateWhileAnimating: true,
+    });
+
     // Setup map
     const map = new Map({
         target,
@@ -152,6 +210,7 @@ const createMap = async (target) =>
             segmentsBorderLayer,
             segmentsInnerLayer,
             stopsLayer,
+            coursesLayer,
         ],
         view: new View({
             center: proj.fromLonLat([3.88, 43.605]),

src/tam/simulation.js

@@ -149,6 +149,7 @@ const updatePositions = (courses, time) =>
     {
         if (course.state === 'moving')
         {
+            // Increase the travelled distance respective to the current speed
             const delta = course.speed * time;
 
             const segment = getCurrentSegment(course);
@@ -162,20 +163,66 @@ const updatePositions = (courses, time) =>
             {
                 course.traveledDistance += delta;
             }
+
+            // Recompute updated position
+            const departureStop = network.stops[course.departureStop];
+            const arrivalStop = network.stops[course.arrivalStop];
+            const nextNodeIndex = segment.points.findIndex(
+                ({distance}) => distance >= course.traveledDistance);
+
+            if (nextNodeIndex === 0)
+            {
+                course.position = {
+                    lat: departureStop.lat,
+                    lon: departureStop.lon
+                };
+            }
+            else if (nextNodeIndex === -1)
+            {
+                course.position = {
+                    lat: arrivalStop.lat,
+                    lon: arrivalStop.lon
+                };
+            }
+            else
+            {
+                const previousNode = segment.points[nextNodeIndex - 1];
+                const nextNode = segment.points[nextNodeIndex];
+
+                const curLength = course.traveledDistance
+                    - previousNode.distance;
+                const totalLength = nextNode.distance
+                    - previousNode.distance;
+                const progression = curLength / totalLength;
+
+                course.position = {
+                    lat: progression * nextNode.lat
+                        + (1 - progression) * previousNode.lat,
+                    lon: progression * nextNode.lon
+                        + (1 - progression) * previousNode.lon,
+                };
+            }
+        }
+        else
+        {
+            const currentStop = network.stops[course.currentStop];
+            course.position = {
+                lat: currentStop.lat,
+                lon: currentStop.lon,
+            };
         }
     }
 };
 
+const run = callback =>
+{
     const courses = {};
     let lastFrame = null;
     let lastUpdate = null;
 
-const loop = now =>
+    const loop = () =>
     {
-    const time = lastFrame === null ? 0 : now - lastFrame;
+        const now = Date.now();
-
-    lastFrame = now;
-    updatePositions(courses, time);
 
         if (lastUpdate === null || lastUpdate + 5000 <= now)
         {
@@ -183,7 +230,15 @@ const loop = now =>
             updateFromTam(courses);
         }
 
-    requestAnimationFrame(loop);
+        const time = lastFrame === null ? 0 : now - lastFrame;
+        lastFrame = now;
+        updatePositions(courses, time);
+
+        callback(courses);
     };
 
-requestAnimationFrame(loop);
+    const interval = setInterval(loop, 24);
+    return () => clearInterval(interval);
+};
+
+exports.run = run;