First working version of snapping to already existing ways from the add-UI (still too slow though), partial fix of #436

Logic/Osm/Actions/CreateNewNodeAction.ts

@@ -3,6 +3,8 @@ import OsmChangeAction from "./OsmChangeAction";
 import {Changes} from "../Changes";
 import {ChangeDescription} from "./ChangeDescription";
 import {And} from "../../Tags/And";
+import {OsmWay} from "../OsmObject";
+import {GeoOperations} from "../../GeoOperations";
 
 export default class CreateNewNodeAction extends OsmChangeAction {
 
@@ -10,13 +12,20 @@ export default class CreateNewNodeAction extends OsmChangeAction {
     private readonly _lat: number;
     private readonly _lon: number;
 
-    public newElementId : string = undefined
-    
-    constructor(basicTags: Tag[], lat: number, lon: number) {
+    public newElementId: string = undefined
+    private readonly _snapOnto: OsmWay;
+    private readonly _reusePointDistance: number;
+
+    constructor(basicTags: Tag[], lat: number, lon: number, options?: { snapOnto: OsmWay, reusePointWithinMeters?: number }) {
         super()
         this._basicTags = basicTags;
         this._lat = lat;
         this._lon = lon;
+        if(lat === undefined || lon === undefined){
+            throw "Lat or lon are undefined!"
+        }
+        this._snapOnto = options?.snapOnto;
+        this._reusePointDistance = options.reusePointWithinMeters ?? 1
     }
 
     CreateChangeDescriptions(changes: Changes): ChangeDescription[] {
@@ -24,7 +33,7 @@ export default class CreateNewNodeAction extends OsmChangeAction {
         const properties = {
             id: "node/" + id
         }
-        this.newElementId = "node/"+id
+        this.newElementId = "node/" + id
         for (const kv of this._basicTags) {
             if (typeof kv.value !== "string") {
                 throw "Invalid value: don't use a regex in a preset"
@@ -32,16 +41,68 @@ export default class CreateNewNodeAction extends OsmChangeAction {
             properties[kv.key] = kv.value;
         }
 
-        return [{
+        const newPointChange: ChangeDescription = {
             tags: new And(this._basicTags).asChange(properties),
             type: "node",
             id: id,
-            changes:{
+            changes: {
                 lat: this._lat,
                 lon: this._lon
             }
-        }]
+        }
+        if (this._snapOnto === undefined) {
+            return [newPointChange]
+        }
 
+
+        // Project the point onto the way
+
+        const geojson = this._snapOnto.asGeoJson()
+        const projected = GeoOperations.nearestPoint(geojson, [this._lon, this._lat])
+        const index = projected.properties.index
+        // We check that it isn't close to an already existing point
+        let reusedPointId = undefined;
+        const prev = <[number, number]>geojson.geometry.coordinates[index]
+        if (GeoOperations.distanceBetween(prev, <[number, number]>projected.geometry.coordinates) * 1000 < this._reusePointDistance) {
+            // We reuse this point instead!
+            reusedPointId = this._snapOnto.nodes[index]
+        }
+        const next = <[number, number]>geojson.geometry.coordinates[index + 1]
+        if (GeoOperations.distanceBetween(next, <[number, number]>projected.geometry.coordinates) * 1000 < this._reusePointDistance) {
+            // We reuse this point instead!
+            reusedPointId = this._snapOnto.nodes[index + 1]
+        }
+        if (reusedPointId !== undefined) {
+            console.log("Reusing an existing point:", reusedPointId)
+            this.newElementId = "node/" + reusedPointId
+
+            return [{
+                tags: new And(this._basicTags).asChange(properties),
+                type: "node",
+                id: reusedPointId
+            }]
+        }
+        
+        const locations = [...this._snapOnto.coordinates]
+        locations.forEach(coor => coor.reverse())
+        console.log("Locations are: ", locations)
+        const ids = [...this._snapOnto.nodes]
+        
+        locations.splice(index + 1, 0, [this._lon, this._lat])
+        ids.splice(index + 1, 0, id)
+        
+        // Allright, we have to insert a new point in the way
+        return [
+            newPointChange,
+            {
+                type:"way",
+                id: this._snapOnto.id,
+                changes: {
+                    locations: locations,
+                    nodes: ids
+                }
+            }
+        ]
     }