LayerServer: fix some bugs in build_db-script, decode MVT-tilesource for more features

src/Logic/FeatureSource/TiledFeatureSource/LineSourceMerger.ts

@@ -0,0 +1,80 @@
+import { FeatureSourceForTile } from "../FeatureSource"
+import { Store } from "../../UIEventSource"
+import { BBox } from "../../BBox"
+import { Utils } from "../../../Utils"
+import { Feature, LineString, MultiLineString, Position } from "geojson"
+import { Tiles } from "../../../Models/TileRange"
+import { GeoOperations } from "../../GeoOperations"
+import DynamicTileSource from "./DynamicTileSource"
+
+/**
+ * The PolygonSourceMerger receives various small pieces of bigger polygons and stitches them together.
+ * This is used to reconstruct polygons of vector tiles
+ */
+export class LineSourceMerger extends DynamicTileSource<FeatureSourceForTile> {
+    private readonly _zoomlevel: Store<number>
+
+    constructor(
+        zoomlevel: Store<number>,
+        minzoom: number,
+        constructSource: (tileIndex: number) => FeatureSourceForTile,
+        mapProperties: {
+            bounds: Store<BBox>
+            zoom: Store<number>
+        },
+        options?: {
+            isActive?: Store<boolean>
+        },
+    ) {
+        super(zoomlevel, minzoom, constructSource, mapProperties, options)
+        this._zoomlevel = zoomlevel
+    }
+
+    protected addDataFromSources(sources: FeatureSourceForTile[]) {
+        sources = Utils.NoNull(sources)
+        const all: Map<string, Feature<MultiLineString>> = new Map()
+        const currentZoom = this._zoomlevel?.data ?? 0
+        for (const source of sources) {
+            if(source.z != currentZoom){
+                continue
+            }
+            const bboxCoors = Tiles.tile_bounds_lon_lat(source.z, source.x, source.y)
+            const bboxGeo = new BBox(bboxCoors).asGeoJson({})
+            for (const f of source.features.data) {
+                const id = f.properties.id
+                const coordinates : Position[][] = []
+                if(f.geometry.type === "LineString"){
+                    coordinates.push(f.geometry.coordinates)
+                }else if(f.geometry.type === "MultiLineString"){
+                    coordinates.push(...f.geometry.coordinates)
+                }else {
+                    console.error("Invalid geometry type:", f.geometry.type)
+                    continue
+                }
+                const oldV = all.get(id)
+                if(!oldV){
+
+                all.set(id, {
+                    type: "Feature",
+                    properties: f.properties,
+                    geometry:{
+                        type:"MultiLineString",
+                        coordinates
+                    }
+                })
+                    continue
+                }
+                oldV.geometry.coordinates.push(...coordinates)
+            }
+        }
+
+        const keys = Array.from(all.keys())
+        for (const key of keys) {
+            all.set(key, <any> GeoOperations.attemptLinearize(<Feature<MultiLineString>>all.get(key)))
+        }
+        const newList = Array.from(all.values())
+        this.features.setData(newList)
+        this._featuresById.setData(all)
+    }
+
+}