Add direction:centerpoint as calculated tag; improve typing of geoOperations.ts

Logic/GeoOperations.ts

@@ -13,7 +13,7 @@ import {
     Polygon,
     Properties,
 } from "@turf/turf"
-import {GeoJSON, LineString} from "geojson";
+import {GeoJSON, LineString, Point} from "geojson";
 
 export class GeoOperations {
     private static readonly _earthRadius = 6378137
@@ -27,8 +27,8 @@ export class GeoOperations {
      * Converts a GeoJson feature to a point GeoJson feature
      * @param feature
      */
-    static centerpoint(feature: any) {
+    static centerpoint(feature: any): Feature<Point> {
-        const newFeature = turf.center(feature)
+        const newFeature : Feature<Point> = turf.center(feature)
         newFeature.properties = feature.properties
         newFeature.id = feature.id
         return newFeature

Logic/SimpleMetaTagger.ts

@@ -9,6 +9,7 @@ import LayerConfig from "../Models/ThemeConfig/LayerConfig"
 import { CountryCoder } from "latlon2country"
 import Constants from "../Models/Constants"
 import { TagUtils } from "./Tags/TagUtils"
+import {Feature, LineString} from "geojson";
 
 export class SimpleMetaTagger {
     public readonly keys: string[]
@@ -420,6 +421,38 @@ export default class SimpleMetaTaggers {
             return true
         }
     )
+
+    private static directionCenterpoint = new SimpleMetaTagger(
+        {
+            keys:["_direction:centerpoint"],
+            isLazy: true,
+            doc: "_direction:centerpoint is the direction of the linestring (in degrees) if one were standing at the projected centerpoint."
+        },
+        (feature: Feature) => {
+            if(feature.geometry.type !== "LineString"){
+                return false
+            }
+
+            const ls = <Feature<LineString>> feature;
+
+            Object.defineProperty(feature.properties, "_direction:centerpoint", {
+                enumerable: false,
+                configurable: true,
+                get: () => {
+                    const centroid = GeoOperations.centerpoint(feature)
+                    const projected = GeoOperations.nearestPoint(ls, <[number,number]> centroid.geometry.coordinates)
+                    const nextPoint = ls.geometry.coordinates[projected.properties.index + 1]
+                    const bearing = GeoOperations.bearing(projected.geometry.coordinates, nextPoint)
+                    delete feature.properties["_direction:centerpoint"]
+                    feature.properties["_direction:centerpoint"] = bearing
+                    return bearing
+                },
+            })
+
+            return true
+        }
+    )
+
     private static currentTime = new SimpleMetaTagger(
         {
             keys: ["_now:date", "_now:datetime", "_loaded:date", "_loaded:_datetime"],
@@ -457,6 +490,7 @@ export default class SimpleMetaTaggers {
         SimpleMetaTaggers.country,
         SimpleMetaTaggers.isOpen,
         SimpleMetaTaggers.directionSimplified,
+        SimpleMetaTaggers.directionCenterpoint,
         SimpleMetaTaggers.currentTime,
         SimpleMetaTaggers.objectMetaInfo,
         SimpleMetaTaggers.noBothButLeftRight,