mapcomplete/Logic/GeoOperations.ts
2021-11-07 16:34:51 +01:00

441 lines
15 KiB
TypeScript

import * as turf from '@turf/turf'
import {BBox} from "./BBox";
export class GeoOperations {
private static readonly _earthRadius = 6378137;
private static readonly _originShift = 2 * Math.PI * GeoOperations._earthRadius / 2;
static surfaceAreaInSqMeters(feature: any) {
return turf.area(feature);
}
/**
* Converts a GeoJson feature to a point GeoJson feature
* @param feature
*/
static centerpoint(feature: any) {
const newFeature = turf.center(feature);
newFeature.properties = feature.properties;
newFeature.id = feature.id;
return newFeature;
}
static centerpointCoordinates(feature: any): [number, number] {
// @ts-ignore
return turf.center(feature).geometry.coordinates;
}
/**
* Returns the distance between the two points in kilometers
* @param lonlat0
* @param lonlat1
*/
static distanceBetween(lonlat0: [number, number], lonlat1: [number, number]) {
return turf.distance(lonlat0, lonlat1)
}
/**
* Calculates the overlap of 'feature' with every other specified feature.
* The features with which 'feature' overlaps, are returned together with their overlap area in m²
*
* If 'feature' is a LineString, the features in which this feature is (partly) embedded is returned, the overlap length in meter is given
* If 'feature' is a Polygon, overlapping points and points within the polygon will be returned
*
* If 'feature' is a point, it will return every feature the point is embedded in. Overlap will be undefined
*
*/
static calculateOverlap(feature: any, otherFeatures: any[]): { feat: any, overlap: number }[] {
const featureBBox = BBox.get(feature);
const result: { feat: any, overlap: number }[] = [];
if (feature.geometry.type === "Point") {
const coor = feature.geometry.coordinates;
for (const otherFeature of otherFeatures) {
if (feature.id !== undefined && feature.id === otherFeature.id) {
continue;
}
if (otherFeature.geometry === undefined) {
console.error("No geometry for feature ", feature)
throw "List of other features contains a feature without geometry an undefined"
}
if (GeoOperations.inside(coor, otherFeature)) {
result.push({feat: otherFeature, overlap: undefined})
}
}
return result;
}
if (feature.geometry.type === "LineString") {
for (const otherFeature of otherFeatures) {
if (feature.id !== undefined && feature.id === otherFeature.id) {
continue;
}
const intersection = this.calculateInstersection(feature, otherFeature, featureBBox)
if (intersection === null) {
continue
}
result.push({feat: otherFeature, overlap: intersection})
}
return result;
}
if (feature.geometry.type === "Polygon" || feature.geometry.type === "MultiPolygon") {
for (const otherFeature of otherFeatures) {
if (feature.id === otherFeature.id) {
continue;
}
if (otherFeature.geometry.type === "Point") {
if (this.inside(otherFeature, feature)) {
result.push({feat: otherFeature, overlap: undefined})
}
continue;
}
// Calculate the surface area of the intersection
const intersection = this.calculateInstersection(feature, otherFeature, featureBBox)
if (intersection === null) {
continue;
}
result.push({feat: otherFeature, overlap: intersection})
}
return result;
}
console.error("Could not correctly calculate the overlap of ", feature, ": unsupported type")
return result;
}
public static inside(pointCoordinate, feature): boolean {
// ray-casting algorithm based on
// http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html
if (feature.geometry.type === "Point") {
return false;
}
if (pointCoordinate.geometry !== undefined) {
pointCoordinate = pointCoordinate.geometry.coordinates
}
if (feature.geometry.type === "MultiPolygon") {
const coordinates = feature.geometry.coordinates[0];
const outerPolygon = coordinates[0];
const inside = GeoOperations.inside(pointCoordinate, {
geometry: {
type: 'Polygon',
coordinates: [outerPolygon]
}
})
if (!inside) {
return false;
}
for (let i = 1; i < coordinates.length; i++) {
const inHole = GeoOperations.inside(pointCoordinate, {
geometry: {
type: 'Polygon',
coordinates: [coordinates[i]]
}
})
if (inHole) {
return false;
}
}
return true;
}
const x: number = pointCoordinate[0];
const y: number = pointCoordinate[1];
for (let i = 0; i < feature.geometry.coordinates.length; i++) {
let poly = feature.geometry.coordinates[i];
let inside = false;
for (let i = 0, j = poly.length - 1; i < poly.length; j = i++) {
const coori = poly[i];
const coorj = poly[j];
const xi = coori[0];
const yi = coori[1];
const xj = coorj[0];
const yj = coorj[1];
const intersect = ((yi > y) != (yj > y))
&& (x < (xj - xi) * (y - yi) / (yj - yi) + xi);
if (intersect) {
inside = !inside;
}
}
if (inside) {
return true;
}
}
return false;
};
static lengthInMeters(feature: any) {
return turf.length(feature) * 1000
}
static buffer(feature: any, bufferSizeInMeter: number) {
return turf.buffer(feature, bufferSizeInMeter / 1000, {
units: 'kilometers'
})
}
static bbox(feature: any) {
const [lon, lat, lon0, lat0] = turf.bbox(feature)
return {
"type": "Feature",
"geometry": {
"type": "LineString",
"coordinates": [
[
lon,
lat
],
[
lon0,
lat
],
[
lon0,
lat0
],
[
lon,
lat0
],
[
lon,
lat
],
]
}
}
}
/**
* Generates the closest point on a way from a given point
*
* The properties object will contain three values:
// - `index`: closest point was found on nth line part,
// - `dist`: distance between pt and the closest point (in kilometer),
// `location`: distance along the line between start (of the line) and the closest point.
* @param way The road on which you want to find a point
* @param point Point defined as [lon, lat]
*/
public static nearestPoint(way, point: [number, number]) {
if (way.geometry.type === "Polygon") {
way = {...way}
way.geometry = {...way.geometry}
way.geometry.type = "LineString"
way.geometry.coordinates = way.geometry.coordinates[0]
}
return turf.nearestPointOnLine(way, point, {units: "kilometers"});
}
public static toCSV(features: any[]): string {
const headerValuesSeen = new Set<string>();
const headerValuesOrdered: string[] = []
function addH(key) {
if (!headerValuesSeen.has(key)) {
headerValuesSeen.add(key)
headerValuesOrdered.push(key)
}
}
addH("_lat")
addH("_lon")
const lines: string[] = []
for (const feature of features) {
const properties = feature.properties;
for (const key in properties) {
if (!properties.hasOwnProperty(key)) {
continue;
}
addH(key)
}
}
headerValuesOrdered.sort()
for (const feature of features) {
const properties = feature.properties;
let line = ""
for (const key of headerValuesOrdered) {
const value = properties[key]
if (value === undefined) {
line += ","
} else {
line += JSON.stringify(value) + ","
}
}
lines.push(line)
}
return headerValuesOrdered.map(v => JSON.stringify(v)).join(",") + "\n" + lines.join("\n")
}
//Converts given lat/lon in WGS84 Datum to XY in Spherical Mercator EPSG:900913
public static ConvertWgs84To900913(lonLat: [number, number]): [number, number] {
const lon = lonLat[0];
const lat = lonLat[1];
const x = lon * GeoOperations._originShift / 180;
let y = Math.log(Math.tan((90 + lat) * Math.PI / 360)) / (Math.PI / 180);
y = y * GeoOperations._originShift / 180;
return [x, y];
}
//Converts XY point from (Spherical) Web Mercator EPSG:3785 (unofficially EPSG:900913) to lat/lon in WGS84 Datum
public static Convert900913ToWgs84(lonLat: [number, number]): [number, number] {
const lon = lonLat[0]
const lat = lonLat[1]
const x = 180 * lon / GeoOperations._originShift;
let y = 180 * lat / GeoOperations._originShift;
y = 180 / Math.PI * (2 * Math.atan(Math.exp(y * Math.PI / 180)) - Math.PI / 2);
return [x, y];
}
public static GeoJsonToWGS84(geojson) {
return turf.toWgs84(geojson)
}
/**
* Tries to remove points which do not contribute much to the general outline.
* Points for which the angle is ~ 180° are removed
* @param coordinates
* @constructor
*/
public static SimplifyCoordinates(coordinates: [number, number][]) {
const newCoordinates = []
for (let i = 1; i < coordinates.length - 1; i++) {
const coordinate = coordinates[i];
const prev = coordinates[i - 1]
const next = coordinates[i + 1]
const b0 = turf.bearing(prev, coordinate, {final: true})
const b1 = turf.bearing(coordinate, next)
const diff = Math.abs(b1 - b0)
if (diff < 2) {
continue
}
newCoordinates.push(coordinate)
}
return newCoordinates
}
/**
* Calculates the intersection between two features.
* Returns the length if intersecting a linestring and a (multi)polygon (in meters), returns a surface area (in m²) if intersecting two (multi)polygons
* Returns 0 if both are linestrings
* Returns null if the features are not intersecting
*/
private static calculateInstersection(feature, otherFeature, featureBBox: BBox, otherFeatureBBox?: BBox): number {
try {
if (feature.geometry.type === "LineString") {
otherFeatureBBox = otherFeatureBBox ?? BBox.get(otherFeature);
const overlaps = featureBBox.overlapsWith(otherFeatureBBox)
if (!overlaps) {
return null;
}
// Calculate the length of the intersection
let intersectionPoints = turf.lineIntersect(feature, otherFeature);
if (intersectionPoints.features.length == 0) {
// No intersections.
// If one point is inside of the polygon, all points are
const coors = feature.geometry.coordinates;
const startCoor = coors[0]
if (this.inside(startCoor, otherFeature)) {
return this.lengthInMeters(feature)
}
return null;
}
let intersectionPointsArray = intersectionPoints.features.map(d => {
return d.geometry.coordinates
});
if (otherFeature.geometry.type === "LineString") {
if (intersectionPointsArray.length > 0) {
return 0
}
return null;
}
if (intersectionPointsArray.length == 1) {
// We need to add the start- or endpoint of the current feature, depending on which one is embedded
const coors = feature.geometry.coordinates;
const startCoor = coors[0]
if (this.inside(startCoor, otherFeature)) {
// The startpoint is embedded
intersectionPointsArray.push(startCoor)
} else {
intersectionPointsArray.push(coors[coors.length - 1])
}
}
let intersection = turf.lineSlice(turf.point(intersectionPointsArray[0]), turf.point(intersectionPointsArray[1]), feature);
if (intersection == null) {
return null;
}
const intersectionSize = turf.length(intersection); // in km
return intersectionSize * 1000
}
if (feature.geometry.type === "Polygon" || feature.geometry.type === "MultiPolygon") {
const otherFeatureBBox = BBox.get(otherFeature);
const overlaps = featureBBox.overlapsWith(otherFeatureBBox)
if (!overlaps) {
return null;
}
if (otherFeature.geometry.type === "LineString") {
return this.calculateInstersection(otherFeature, feature, otherFeatureBBox, featureBBox)
}
const intersection = turf.intersect(feature, otherFeature);
if (intersection == null) {
return null;
}
return turf.area(intersection); // in m²
}
} catch (exception) {
console.warn("EXCEPTION CAUGHT WHILE INTERSECTING: ", exception);
return undefined
}
return undefined;
}
}