forked from MapComplete/MapComplete
		
	
		
			
				
	
	
		
			285 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			TypeScript
		
	
	
	
	
	
			
		
		
	
	
			285 lines
		
	
	
	
		
			11 KiB
		
	
	
	
		
			TypeScript
		
	
	
	
	
	
| import {OsmObject, OsmWay} from "../OsmObject";
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| import {Changes} from "../Changes";
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| import {GeoOperations} from "../../GeoOperations";
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| import OsmChangeAction from "./OsmChangeAction";
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| import {ChangeDescription} from "./ChangeDescription";
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| import RelationSplitHandler from "./RelationSplitHandler";
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| 
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| interface SplitInfo {
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|     originalIndex?: number, // or negative for new elements
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|     lngLat: [number, number],
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|     doSplit: boolean
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| }
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| 
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| export default class SplitAction extends OsmChangeAction {
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|     private readonly wayId: string;
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|     private readonly _splitPointsCoordinates: [number, number] []// lon, lat
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|     private _meta: { theme: string, changeType: "split" };
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|     private _toleranceInMeters: number;
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| 
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|     /**
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|      * Create a changedescription for splitting a point.
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|      * Will attempt to reuse existing points
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|      * @param wayId
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|      * @param splitPointCoordinates: lon, lat
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|      * @param meta
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|      * @param toleranceInMeters: if a splitpoint closer then this amount of meters to an existing point, the existing point will be used to split the line instead of a new point
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|      */
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|     constructor(wayId: string, splitPointCoordinates: [number, number][], meta: {theme: string},  toleranceInMeters = 5) {
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|         super()
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|         this.wayId = wayId;
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|         this._splitPointsCoordinates = splitPointCoordinates
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|         this._toleranceInMeters = toleranceInMeters;
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|         this._meta = {...meta, changeType: "split"};
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|     }
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| 
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|     private static SegmentSplitInfo(splitInfo: SplitInfo[]): SplitInfo[][] {
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|         const wayParts = []
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|         let currentPart = []
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|         for (const splitInfoElement of splitInfo) {
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|             currentPart.push(splitInfoElement)
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| 
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|             if (splitInfoElement.doSplit) {
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|                 // We have to do a split!
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|                 // We add the current index to the currentParts, flush it and add it again
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|                 wayParts.push(currentPart)
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|                 currentPart = [splitInfoElement]
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|             }
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|         }
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|         wayParts.push(currentPart)
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|         return wayParts.filter(wp => wp.length > 0)
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|     }
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| 
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|     async CreateChangeDescriptions(changes: Changes): Promise<ChangeDescription[]> {
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|         const originalElement = <OsmWay> await OsmObject.DownloadObjectAsync(this.wayId)
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|         const originalNodes = originalElement.nodes;
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| 
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|         // First, calculate splitpoints and remove points close to one another
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|         const splitInfo = this.CalculateSplitCoordinates(originalElement, this._toleranceInMeters)
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|         // Now we have a list with e.g. 
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|         // [ { originalIndex: 0}, {originalIndex: 1, doSplit: true}, {originalIndex: 2}, {originalIndex: undefined, doSplit: true}, {originalIndex: 3}]
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| 
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|         // Lets change 'originalIndex' to the actual node id first (or assign a new id if needed):
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|         for (const element of splitInfo) {
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|             if (element.originalIndex >= 0) {
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|                 element.originalIndex = originalElement.nodes[element.originalIndex]
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|             } else {
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|                 element.originalIndex = changes.getNewID();
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|             }
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|         }
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| 
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|         // Next up is creating actual parts from this
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|         const wayParts: SplitInfo[][] = SplitAction.SegmentSplitInfo(splitInfo);
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|         // Allright! At this point, we have our new ways!
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|         // Which one is the longest of them (and can keep the id)?
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| 
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|         let longest = undefined;
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|         for (const wayPart of wayParts) {
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|             if (longest === undefined) {
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|                 longest = wayPart;
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|                 continue
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|             }
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|             if (wayPart.length > longest.length) {
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|                 longest = wayPart
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|             }
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|         }
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| 
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|         const changeDescription: ChangeDescription[] = []
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|         // Let's create the new points as needed
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|         for (const element of splitInfo) {
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|             if (element.originalIndex >= 0) {
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|                 continue;
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|             }
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|             changeDescription.push({
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|                 type: "node",
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|                 id: element.originalIndex,
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|                 changes: {
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|                     lon: element.lngLat[0],
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|                     lat: element.lngLat[1]
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|                 },
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|                 meta: this._meta
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|             })
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|         }
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| 
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|         // The ids of all the ways (including the original)
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|         const allWayIdsInOrder: number[] = []
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| 
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|         const allWaysNodesInOrder: number[][] = []
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|         // Lets create OsmWays based on them
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|         for (const wayPart of wayParts) {
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| 
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|             let isOriginal = wayPart === longest
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|             if (isOriginal) {
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|                 // We change the actual element!
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|                 const nodeIds = wayPart.map(p => p.originalIndex)
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|                 changeDescription.push({
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|                     type: "way",
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|                     id: originalElement.id,
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|                     changes: {
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|                         coordinates: wayPart.map(p => p.lngLat),
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|                         nodes: nodeIds
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|                     },
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|                     meta: this._meta
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|                 })
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|                 allWayIdsInOrder.push(originalElement.id)
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|                 allWaysNodesInOrder.push(nodeIds)
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|             } else {
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|                 let id = changes.getNewID();
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|                 // Copy the tags from the original object onto the new
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|                 const kv = []
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|                 for (const k in originalElement.tags) {
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|                     if (!originalElement.tags.hasOwnProperty(k)) {
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|                         continue
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|                     }
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|                     if (k.startsWith("_") || k === "id") {
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|                         continue;
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|                     }
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|                     kv.push({k: k, v: originalElement.tags[k]})
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|                 }
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|                 const nodeIds = wayPart.map(p => p.originalIndex)
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|                 changeDescription.push({
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|                     type: "way",
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|                     id: id,
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|                     tags: kv,
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|                     changes: {
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|                         coordinates: wayPart.map(p => p.lngLat),
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|                         nodes: nodeIds
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|                     },
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|                     meta: this._meta
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|                 })
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| 
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|                 allWayIdsInOrder.push(id)
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|                 allWaysNodesInOrder.push(nodeIds)
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|             }
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|         }
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| 
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|         // At last, we still have to check that we aren't part of a relation...
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|         // At least, the order of the ways is identical, so we can keep the same roles
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|         const relations = await OsmObject.DownloadReferencingRelations(this.wayId)
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|         for (const relation of relations) {
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|             const changDescrs = await new RelationSplitHandler({
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|                 relation: relation,
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|                 allWayIdsInOrder: allWayIdsInOrder,
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|                 originalNodes: originalNodes,
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|                 allWaysNodesInOrder: allWaysNodesInOrder,
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|                 originalWayId: originalElement.id,
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|             }, this._meta.theme).CreateChangeDescriptions(changes)
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|             changeDescription.push(...changDescrs)
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|         }
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| 
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|         // And we have our objects!
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|         // Time to upload
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| 
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|         return changeDescription
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|     }
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| 
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|     /**
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|      * Calculates the actual points to split
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|      * If another point is closer then ~5m, we reuse that point
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|      */
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|     private CalculateSplitCoordinates(osmWay: OsmWay, toleranceInM = 5): SplitInfo[] {
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|         const wayGeoJson = osmWay.asGeoJson()
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|         // Should be [lon, lat][]
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|         const originalPoints : [number, number][] = osmWay.coordinates.map(c => [c[1], c[0]])
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|         const allPoints: {
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|             // lon, lat
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|             coordinates: [number, number],
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|             isSplitPoint: boolean,
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|             originalIndex?: number, // Original index
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|             dist: number, // Distance from the nearest point on the original line
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|             location: number // Distance from the start of the way
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|         }[] = this._splitPointsCoordinates.map(c => {
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|             // From the turf.js docs:
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|             // The properties object will contain three values: 
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|             // - `index`: closest point was found on nth line part,
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|             // - `dist`: distance between pt and the closest point, 
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|             // `location`: distance along the line between start and the closest point.
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|             let projected = GeoOperations.nearestPoint(wayGeoJson, c)
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|             // c is lon lat
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|             return ({
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|                 coordinates: c,
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|                 isSplitPoint: true,
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|                 dist: projected.properties.dist,
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|                 location: projected.properties.location
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|             });
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|         })
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| 
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|         // We have a bunch of coordinates here: [ [lon, lon], [lat, lon], ...] ...
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|         // We project them onto the line (which should yield pretty much the same point and add them to allPoints
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|         for (let i = 0; i < originalPoints.length; i++) {
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|             let originalPoint = originalPoints[i];
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|             let projected = GeoOperations.nearestPoint(wayGeoJson, originalPoint)
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|             allPoints.push({
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|                 coordinates: originalPoint,
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|                 isSplitPoint: false,
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|                 location: projected.properties.location,
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|                 originalIndex: i,
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|                 dist: projected.properties.dist
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|             })
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|         }
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|         // At this point, we have a list of both the split point and the old points, with some properties to discriminate between them
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|         // We sort this list so that the new points are at the same location
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|         allPoints.sort((a, b) => a.location - b.location)
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| 
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| 
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|         for (let i = allPoints.length - 2; i >= 1; i--) {
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|             // We 'merge' points with already existing nodes if they are close enough to avoid closeby elements
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| 
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|             // Note the loop bounds: we skip the first two and last two elements:
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|             // The first and last element are always part of the original way and should be kept
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|             // Furthermore, we run in reverse order as we'll delete elements on the go
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| 
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|             const point = allPoints[i]
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|             if (point.originalIndex !== undefined) {
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|                 // We keep the original points
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|                 continue
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|             }
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|          
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|             // At this point, 'dist' told us the point is pretty close to an already existing point.
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|             // Lets see which (already existing) point is closer and mark it as splitpoint
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|             const nextPoint = allPoints[i + 1]
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|             const prevPoint = allPoints[i - 1]
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|             const distToNext = nextPoint.location - point.location
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|             const distToPrev = point.location - prevPoint.location
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|             
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|             if(distToNext * 1000 > toleranceInM && distToPrev * 1000 > toleranceInM){
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|                 // Both are too far away to mark them as the split point
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|                 continue;
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|             }
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|             
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|             let closest = nextPoint
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|             if (distToNext > distToPrev) {
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|                 closest = prevPoint
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|             }
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|             // Ok, we have a closest point!
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|             if(closest.originalIndex === 0 || closest.originalIndex === originalPoints.length){
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|                 // We can not split on the first or last points...
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|                 continue
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|             }
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|             closest.isSplitPoint = true;
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|             allPoints.splice(i, 1)
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| 
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|         }
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| 
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|         const splitInfo: SplitInfo[] = []
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|         let nextId = -1 // Note: these IDs are overwritten later on, no need to use a global counter here
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| 
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|         for (const p of allPoints) {
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|             let index = p.originalIndex
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|             if (index === undefined) {
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|                 index = nextId;
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|                 nextId--;
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|             }
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|             const splitInfoElement = {
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|                 originalIndex: index,
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|                 lngLat: p.coordinates,
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|                 doSplit: p.isSplitPoint
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|             }
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|             splitInfo.push(splitInfoElement)
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|         }
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| 
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|         return splitInfo
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|     }
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| 
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| 
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| }
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