nc-gpxedit/js/leaflet.geometryutil.js

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// Packaging/modules magic dance.
(function (factory) {
var L;
if (typeof define === 'function' && define.amd) {
// AMD
define(['leaflet'], factory);
} else if (typeof module !== 'undefined') {
// Node/CommonJS
L = require('leaflet');
module.exports = factory(L);
} else {
// Browser globals
if (typeof window.L === 'undefined')
throw 'Leaflet must be loaded first';
factory(window.L);
}
}(function (L) {
"use strict";
L.Polyline._flat = L.Polyline._flat || function (latlngs) {
// true if it's a flat array of latlngs; false if nested
return !L.Util.isArray(latlngs[0]) || (typeof latlngs[0][0] !== 'object' && typeof latlngs[0][0] !== 'undefined');
};
/**
* @fileOverview Leaflet Geometry utilities for distances and linear referencing.
* @name L.GeometryUtil
*/
L.GeometryUtil = L.extend(L.GeometryUtil || {}, {
/**
Shortcut function for planar distance between two {L.LatLng} at current zoom.
@tutorial distance-length
@param {L.Map} map Leaflet map to be used for this method
@param {L.LatLng} latlngA geographical point A
@param {L.LatLng} latlngB geographical point B
@returns {Number} planar distance
*/
distance: function (map, latlngA, latlngB) {
return map.latLngToLayerPoint(latlngA).distanceTo(map.latLngToLayerPoint(latlngB));
},
/**
Shortcut function for planar distance between a {L.LatLng} and a segment (A-B).
@param {L.Map} map Leaflet map to be used for this method
@param {L.LatLng} latlng - The position to search
@param {L.LatLng} latlngA geographical point A of the segment
@param {L.LatLng} latlngB geographical point B of the segment
@returns {Number} planar distance
*/
distanceSegment: function (map, latlng, latlngA, latlngB) {
var p = map.latLngToLayerPoint(latlng),
p1 = map.latLngToLayerPoint(latlngA),
p2 = map.latLngToLayerPoint(latlngB);
return L.LineUtil.pointToSegmentDistance(p, p1, p2);
},
/**
Shortcut function for converting distance to readable distance.
@param {Number} distance distance to be converted
@param {String} unit 'metric' or 'imperial'
@returns {String} in yard or miles
*/
readableDistance: function (distance, unit) {
var isMetric = (unit !== 'imperial'),
distanceStr;
if (isMetric) {
// show metres when distance is < 1km, then show km
if (distance > 1000) {
distanceStr = (distance / 1000).toFixed(2) + ' km';
}
else {
distanceStr = Math.ceil(distance) + ' m';
}
}
else {
distance *= 1.09361;
if (distance > 1760) {
distanceStr = (distance / 1760).toFixed(2) + ' miles';
}
else {
distanceStr = Math.ceil(distance) + ' yd';
}
}
return distanceStr;
},
/**
Returns true if the latlng belongs to segment A-B
@param {L.LatLng} latlng - The position to search
@param {L.LatLng} latlngA geographical point A of the segment
@param {L.LatLng} latlngB geographical point B of the segment
@param {?Number} [tolerance=0.2] tolerance to accept if latlng belongs really
@returns {boolean}
*/
belongsSegment: function(latlng, latlngA, latlngB, tolerance) {
tolerance = tolerance === undefined ? 0.2 : tolerance;
var hypotenuse = latlngA.distanceTo(latlngB),
delta = latlngA.distanceTo(latlng) + latlng.distanceTo(latlngB) - hypotenuse;
return delta/hypotenuse < tolerance;
},
/**
* Returns total length of line
* @tutorial distance-length
*
* @param {L.Polyline|Array<L.Point>|Array<L.LatLng>} coords Set of coordinates
* @returns {Number} Total length (pixels for Point, meters for LatLng)
*/
length: function (coords) {
var accumulated = L.GeometryUtil.accumulatedLengths(coords);
return accumulated.length > 0 ? accumulated[accumulated.length-1] : 0;
},
/**
* Returns a list of accumulated length along a line.
* @param {L.Polyline|Array<L.Point>|Array<L.LatLng>} coords Set of coordinates
* @returns {Array<Number>} Array of accumulated lengths (pixels for Point, meters for LatLng)
*/
accumulatedLengths: function (coords) {
if (typeof coords.getLatLngs == 'function') {
coords = coords.getLatLngs();
}
if (coords.length === 0)
return [];
var total = 0,
lengths = [0];
for (var i = 0, n = coords.length - 1; i< n; i++) {
total += coords[i].distanceTo(coords[i+1]);
lengths.push(total);
}
return lengths;
},
/**
Returns the closest point of a {L.LatLng} on the segment (A-B)
@tutorial closest
@param {L.Map} map Leaflet map to be used for this method
@param {L.LatLng} latlng - The position to search
@param {L.LatLng} latlngA geographical point A of the segment
@param {L.LatLng} latlngB geographical point B of the segment
@returns {L.LatLng} Closest geographical point
*/
closestOnSegment: function (map, latlng, latlngA, latlngB) {
var maxzoom = map.getMaxZoom();
if (maxzoom === Infinity)
maxzoom = map.getZoom();
var p = map.project(latlng, maxzoom),
p1 = map.project(latlngA, maxzoom),
p2 = map.project(latlngB, maxzoom),
closest = L.LineUtil.closestPointOnSegment(p, p1, p2);
return map.unproject(closest, maxzoom);
},
/**
Returns the closest latlng on layer.
Accept nested arrays
@tutorial closest
@param {L.Map} map Leaflet map to be used for this method
@param {Array<L.LatLng>|Array<Array<L.LatLng>>|L.PolyLine|L.Polygon} layer - Layer that contains the result
@param {L.LatLng} latlng - The position to search
@param {?boolean} [vertices=false] - Whether to restrict to path vertices.
@returns {L.LatLng} Closest geographical point or null if layer param is incorrect
*/
closest: function (map, layer, latlng, vertices) {
var latlngs,
mindist = Infinity,
result = null,
i, n, distance;
if (layer instanceof Array) {
// if layer is Array<Array<T>>
if (layer[0] instanceof Array && typeof layer[0][0] !== 'number') {
// if we have nested arrays, we calc the closest for each array
// recursive
for (var i = 0; i < layer.length; i++) {
var subResult = L.GeometryUtil.closest(map, layer[i], latlng, vertices);
if (subResult.distance < mindist) {
mindist = subResult.distance;
result = subResult;
}
}
return result;
} else if (layer[0] instanceof L.LatLng
|| typeof layer[0][0] === 'number'
|| typeof layer[0].lat === 'number') { // we could have a latlng as [x,y] with x & y numbers or {lat, lng}
layer = L.polyline(layer);
} else {
return result;
}
}
// if we don't have here a Polyline, that means layer is incorrect
// see https://github.com/makinacorpus/Leaflet.GeometryUtil/issues/23
if (! ( layer instanceof L.Polyline ) )
return result;
// deep copy of latlngs
latlngs = JSON.parse(JSON.stringify(layer.getLatLngs().slice(0)));
// add the last segment for L.Polygon
if (layer instanceof L.Polygon) {
// add the last segment for each child that is a nested array
var addLastSegment = function(latlngs) {
if (L.Polyline._flat(latlngs)) {
latlngs.push(latlngs[0]);
} else {
for (var i = 0; i < latlngs.length; i++) {
addLastSegment(latlngs[i]);
}
}
}
addLastSegment(latlngs);
}
// we have a multi polygon / multi polyline / polygon with holes
// use recursive to explore and return the good result
if ( ! L.Polyline._flat(latlngs) ) {
for (var i = 0; i < latlngs.length; i++) {
// if we are at the lower level, and if we have a L.Polygon, we add the last segment
var subResult = L.GeometryUtil.closest(map, latlngs[i], latlng, vertices);
if (subResult.distance < mindist) {
mindist = subResult.distance;
result = subResult;
}
}
return result;
} else {
// Lookup vertices
if (vertices) {
for(i = 0, n = latlngs.length; i < n; i++) {
var ll = latlngs[i];
distance = L.GeometryUtil.distance(map, latlng, ll);
if (distance < mindist) {
mindist = distance;
result = ll;
result.distance = distance;
}
}
return result;
}
// Keep the closest point of all segments
for (i = 0, n = latlngs.length; i < n-1; i++) {
var latlngA = latlngs[i],
latlngB = latlngs[i+1];
distance = L.GeometryUtil.distanceSegment(map, latlng, latlngA, latlngB);
if (distance <= mindist) {
mindist = distance;
result = L.GeometryUtil.closestOnSegment(map, latlng, latlngA, latlngB);
result.distance = distance;
}
}
return result;
}
},
/**
Returns the closest layer to latlng among a list of layers.
@tutorial closest
@param {L.Map} map Leaflet map to be used for this method
@param {Array<L.ILayer>} layers Set of layers
@param {L.LatLng} latlng - The position to search
@returns {object} ``{layer, latlng, distance}`` or ``null`` if list is empty;
*/
closestLayer: function (map, layers, latlng) {
var mindist = Infinity,
result = null,
ll = null,
distance = Infinity;
for (var i = 0, n = layers.length; i < n; i++) {
var layer = layers[i];
if (layer instanceof L.LayerGroup) {
// recursive
var subResult = L.GeometryUtil.closestLayer(map, layer.getLayers(), latlng);
if (subResult.distance < mindist) {
mindist = subResult.distance;
result = subResult;
}
} else {
// Single dimension, snap on points, else snap on closest
if (typeof layer.getLatLng == 'function') {
ll = layer.getLatLng();
distance = L.GeometryUtil.distance(map, latlng, ll);
}
else {
ll = L.GeometryUtil.closest(map, layer, latlng);
if (ll) distance = ll.distance; // Can return null if layer has no points.
}
if (distance < mindist) {
mindist = distance;
result = {layer: layer, latlng: ll, distance: distance};
}
}
}
return result;
},
/**
Returns the n closest layers to latlng among a list of input layers.
@param {L.Map} map - Leaflet map to be used for this method
@param {Array<L.ILayer>} layers - Set of layers
@param {L.LatLng} latlng - The position to search
@param {?Number} [n=layers.length] - the expected number of output layers.
@returns {Array<object>} an array of objects ``{layer, latlng, distance}`` or ``null`` if the input is invalid (empty list or negative n)
*/
nClosestLayers: function (map, layers, latlng, n) {
n = typeof n === 'number' ? n : layers.length;
if (n < 1 || layers.length < 1) {
return null;
}
var results = [];
var distance, ll;
for (var i = 0, m = layers.length; i < m; i++) {
var layer = layers[i];
if (layer instanceof L.LayerGroup) {
// recursive
var subResult = L.GeometryUtil.closestLayer(map, layer.getLayers(), latlng);
results.push(subResult)
} else {
// Single dimension, snap on points, else snap on closest
if (typeof layer.getLatLng == 'function') {
ll = layer.getLatLng();
distance = L.GeometryUtil.distance(map, latlng, ll);
}
else {
ll = L.GeometryUtil.closest(map, layer, latlng);
if (ll) distance = ll.distance; // Can return null if layer has no points.
}
results.push({layer: layer, latlng: ll, distance: distance})
}
}
results.sort(function(a, b) {
return a.distance - b.distance;
});
if (results.length > n) {
return results.slice(0, n);
} else {
return results;
}
},
/**
* Returns all layers within a radius of the given position, in an ascending order of distance.
@param {L.Map} map Leaflet map to be used for this method
@param {Array<ILayer>} layers - A list of layers.
@param {L.LatLng} latlng - The position to search
@param {?Number} [radius=Infinity] - Search radius in pixels
@return {object[]} an array of objects including layer within the radius, closest latlng, and distance
*/
layersWithin: function(map, layers, latlng, radius) {
radius = typeof radius == 'number' ? radius : Infinity;
var results = [];
var ll = null;
var distance = 0;
for (var i = 0, n = layers.length; i < n; i++) {
var layer = layers[i];
if (typeof layer.getLatLng == 'function') {
ll = layer.getLatLng();
distance = L.GeometryUtil.distance(map, latlng, ll);
}
else {
ll = L.GeometryUtil.closest(map, layer, latlng);
if (ll) distance = ll.distance; // Can return null if layer has no points.
}
if (ll && distance < radius) {
results.push({layer: layer, latlng: ll, distance: distance});
}
}
var sortedResults = results.sort(function(a, b) {
return a.distance - b.distance;
});
return sortedResults;
},
/**
Returns the closest position from specified {LatLng} among specified layers,
with a maximum tolerance in pixels, providing snapping behaviour.
@tutorial closest
@param {L.Map} map Leaflet map to be used for this method
@param {Array<ILayer>} layers - A list of layers to snap on.
@param {L.LatLng} latlng - The position to snap
@param {?Number} [tolerance=Infinity] - Maximum number of pixels.
@param {?boolean} [withVertices=true] - Snap to layers vertices or segment points (not only vertex)
@returns {object} with snapped {LatLng} and snapped {Layer} or null if tolerance exceeded.
*/
closestLayerSnap: function (map, layers, latlng, tolerance, withVertices) {
tolerance = typeof tolerance == 'number' ? tolerance : Infinity;
withVertices = typeof withVertices == 'boolean' ? withVertices : true;
var result = L.GeometryUtil.closestLayer(map, layers, latlng);
if (!result || result.distance > tolerance)
return null;
// If snapped layer is linear, try to snap on vertices (extremities and middle points)
if (withVertices && typeof result.layer.getLatLngs == 'function') {
var closest = L.GeometryUtil.closest(map, result.layer, result.latlng, true);
if (closest.distance < tolerance) {
result.latlng = closest;
result.distance = L.GeometryUtil.distance(map, closest, latlng);
}
}
return result;
},
/**
Returns the Point located on a segment at the specified ratio of the segment length.
@param {L.Point} pA coordinates of point A
@param {L.Point} pB coordinates of point B
@param {Number} the length ratio, expressed as a decimal between 0 and 1, inclusive.
@returns {L.Point} the interpolated point.
*/
interpolateOnPointSegment: function (pA, pB, ratio) {
return L.point(
(pA.x * (1 - ratio)) + (ratio * pB.x),
(pA.y * (1 - ratio)) + (ratio * pB.y)
);
},
/**
Returns the coordinate of the point located on a line at the specified ratio of the line length.
@param {L.Map} map Leaflet map to be used for this method
@param {Array<L.LatLng>|L.PolyLine} latlngs Set of geographical points
@param {Number} ratio the length ratio, expressed as a decimal between 0 and 1, inclusive
@returns {Object} an object with latLng ({LatLng}) and predecessor ({Number}), the index of the preceding vertex in the Polyline
(-1 if the interpolated point is the first vertex)
*/
interpolateOnLine: function (map, latLngs, ratio) {
latLngs = (latLngs instanceof L.Polyline) ? latLngs.getLatLngs() : latLngs;
var n = latLngs.length;
if (n < 2) {
return null;
}
// ensure the ratio is between 0 and 1;
ratio = Math.max(Math.min(ratio, 1), 0);
if (ratio === 0) {
return {
latLng: latLngs[0] instanceof L.LatLng ? latLngs[0] : L.latLng(latLngs[0]),
predecessor: -1
};
}
if (ratio == 1) {
return {
latLng: latLngs[latLngs.length -1] instanceof L.LatLng ? latLngs[latLngs.length -1] : L.latLng(latLngs[latLngs.length -1]),
predecessor: latLngs.length - 2
};
}
// project the LatLngs as Points,
// and compute total planar length of the line at max precision
var maxzoom = map.getMaxZoom();
if (maxzoom === Infinity)
maxzoom = map.getZoom();
var pts = [];
var lineLength = 0;
for(var i = 0; i < n; i++) {
pts[i] = map.project(latLngs[i], maxzoom);
if(i > 0)
lineLength += pts[i-1].distanceTo(pts[i]);
}
var ratioDist = lineLength * ratio;
var a = pts[0],
b = pts[1],
distA = 0,
distB = a.distanceTo(b);
// follow the line segments [ab], adding lengths,
// until we find the segment where the points should lie on
var index = 1;
for (; index < n && distB < ratioDist; index++) {
a = b;
distA = distB;
b = pts[index];
distB += a.distanceTo(b);
}
// compute the ratio relative to the segment [ab]
var segmentRatio = ((distB - distA) !== 0) ? ((ratioDist - distA) / (distB - distA)) : 0;
var interpolatedPoint = L.GeometryUtil.interpolateOnPointSegment(a, b, segmentRatio);
return {
latLng: map.unproject(interpolatedPoint, maxzoom),
predecessor: index-2
};
},
/**
Returns a float between 0 and 1 representing the location of the
closest point on polyline to the given latlng, as a fraction of total line length.
(opposite of L.GeometryUtil.interpolateOnLine())
@param {L.Map} map Leaflet map to be used for this method
@param {L.PolyLine} polyline Polyline on which the latlng will be search
@param {L.LatLng} latlng The position to search
@returns {Number} Float between 0 and 1
*/
locateOnLine: function (map, polyline, latlng) {
var latlngs = polyline.getLatLngs();
if (latlng.equals(latlngs[0]))
return 0.0;
if (latlng.equals(latlngs[latlngs.length-1]))
return 1.0;
var point = L.GeometryUtil.closest(map, polyline, latlng, false),
lengths = L.GeometryUtil.accumulatedLengths(latlngs),
total_length = lengths[lengths.length-1],
portion = 0,
found = false;
for (var i=0, n = latlngs.length-1; i < n; i++) {
var l1 = latlngs[i],
l2 = latlngs[i+1];
portion = lengths[i];
if (L.GeometryUtil.belongsSegment(point, l1, l2)) {
portion += l1.distanceTo(point);
found = true;
break;
}
}
if (!found) {
throw "Could not interpolate " + latlng.toString() + " within " + polyline.toString();
}
return portion / total_length;
},
/**
Returns a clone with reversed coordinates.
@param {L.PolyLine} polyline polyline to reverse
@returns {L.PolyLine} polyline reversed
*/
reverse: function (polyline) {
return L.polyline(polyline.getLatLngs().slice(0).reverse());
},
/**
Returns a sub-part of the polyline, from start to end.
If start is superior to end, returns extraction from inverted line.
@param {L.Map} map Leaflet map to be used for this method
@param {L.PolyLine} polyline Polyline on which will be extracted the sub-part
@param {Number} start ratio, expressed as a decimal between 0 and 1, inclusive
@param {Number} end ratio, expressed as a decimal between 0 and 1, inclusive
@returns {Array<L.LatLng>} new polyline
*/
extract: function (map, polyline, start, end) {
if (start > end) {
return L.GeometryUtil.extract(map, L.GeometryUtil.reverse(polyline), 1.0-start, 1.0-end);
}
// Bound start and end to [0-1]
start = Math.max(Math.min(start, 1), 0);
end = Math.max(Math.min(end, 1), 0);
var latlngs = polyline.getLatLngs(),
startpoint = L.GeometryUtil.interpolateOnLine(map, polyline, start),
endpoint = L.GeometryUtil.interpolateOnLine(map, polyline, end);
// Return single point if start == end
if (start == end) {
var point = L.GeometryUtil.interpolateOnLine(map, polyline, end);
return [point.latLng];
}
// Array.slice() works indexes at 0
if (startpoint.predecessor == -1)
startpoint.predecessor = 0;
if (endpoint.predecessor == -1)
endpoint.predecessor = 0;
var result = latlngs.slice(startpoint.predecessor+1, endpoint.predecessor+1);
result.unshift(startpoint.latLng);
result.push(endpoint.latLng);
return result;
},
/**
Returns true if first polyline ends where other second starts.
@param {L.PolyLine} polyline First polyline
@param {L.PolyLine} other Second polyline
@returns {bool}
*/
isBefore: function (polyline, other) {
if (!other) return false;
var lla = polyline.getLatLngs(),
llb = other.getLatLngs();
return (lla[lla.length-1]).equals(llb[0]);
},
/**
Returns true if first polyline starts where second ends.
@param {L.PolyLine} polyline First polyline
@param {L.PolyLine} other Second polyline
@returns {bool}
*/
isAfter: function (polyline, other) {
if (!other) return false;
var lla = polyline.getLatLngs(),
llb = other.getLatLngs();
return (lla[0]).equals(llb[llb.length-1]);
},
/**
Returns true if first polyline starts where second ends or start.
@param {L.PolyLine} polyline First polyline
@param {L.PolyLine} other Second polyline
@returns {bool}
*/
startsAtExtremity: function (polyline, other) {
if (!other) return false;
var lla = polyline.getLatLngs(),
llb = other.getLatLngs(),
start = lla[0];
return start.equals(llb[0]) || start.equals(llb[llb.length-1]);
},
/**
Returns horizontal angle in degres between two points.
@param {L.Point} a Coordinates of point A
@param {L.Point} b Coordinates of point B
@returns {Number} horizontal angle
*/
computeAngle: function(a, b) {
return (Math.atan2(b.y - a.y, b.x - a.x) * 180 / Math.PI);
},
/**
Returns slope (Ax+B) between two points.
@param {L.Point} a Coordinates of point A
@param {L.Point} b Coordinates of point B
@returns {Object} with ``a`` and ``b`` properties.
*/
computeSlope: function(a, b) {
var s = (b.y - a.y) / (b.x - a.x),
o = a.y - (s * a.x);
return {'a': s, 'b': o};
},
/**
Returns LatLng of rotated point around specified LatLng center.
@param {L.LatLng} latlngPoint: point to rotate
@param {double} angleDeg: angle to rotate in degrees
@param {L.LatLng} latlngCenter: center of rotation
@returns {L.LatLng} rotated point
*/
rotatePoint: function(map, latlngPoint, angleDeg, latlngCenter) {
var maxzoom = map.getMaxZoom();
if (maxzoom === Infinity)
maxzoom = map.getZoom();
var angleRad = angleDeg*Math.PI/180,
pPoint = map.project(latlngPoint, maxzoom),
pCenter = map.project(latlngCenter, maxzoom),
x2 = Math.cos(angleRad)*(pPoint.x-pCenter.x) - Math.sin(angleRad)*(pPoint.y-pCenter.y) + pCenter.x,
y2 = Math.sin(angleRad)*(pPoint.x-pCenter.x) + Math.cos(angleRad)*(pPoint.y-pCenter.y) + pCenter.y;
return map.unproject(new L.Point(x2,y2), maxzoom);
},
/**
Returns the bearing in degrees clockwise from north (0 degrees)
from the first L.LatLng to the second, at the first LatLng
@param {L.LatLng} latlng1: origin point of the bearing
@param {L.LatLng} latlng2: destination point of the bearing
@returns {float} degrees clockwise from north.
*/
bearing: function(latlng1, latlng2) {
var rad = Math.PI / 180,
lat1 = latlng1.lat * rad,
lat2 = latlng2.lat * rad,
lon1 = latlng1.lng * rad,
lon2 = latlng2.lng * rad,
y = Math.sin(lon2 - lon1) * Math.cos(lat2),
x = Math.cos(lat1) * Math.sin(lat2) -
Math.sin(lat1) * Math.cos(lat2) * Math.cos(lon2 - lon1);
var bearing = ((Math.atan2(y, x) * 180 / Math.PI) + 360) % 360;
return bearing >= 180 ? bearing-360 : bearing;
},
/**
Returns the point that is a distance and heading away from
the given origin point.
@param {L.LatLng} latlng: origin point
@param {float}: heading in degrees, clockwise from 0 degrees north.
@param {float}: distance in meters
@returns {L.latLng} the destination point.
Many thanks to Chris Veness at http://www.movable-type.co.uk/scripts/latlong.html
for a great reference and examples.
*/
destination: function(latlng, heading, distance) {
heading = (heading + 360) % 360;
var rad = Math.PI / 180,
radInv = 180 / Math.PI,
R = 6378137, // approximation of Earth's radius
lon1 = latlng.lng * rad,
lat1 = latlng.lat * rad,
rheading = heading * rad,
sinLat1 = Math.sin(lat1),
cosLat1 = Math.cos(lat1),
cosDistR = Math.cos(distance / R),
sinDistR = Math.sin(distance / R),
lat2 = Math.asin(sinLat1 * cosDistR + cosLat1 *
sinDistR * Math.cos(rheading)),
lon2 = lon1 + Math.atan2(Math.sin(rheading) * sinDistR *
cosLat1, cosDistR - sinLat1 * Math.sin(lat2));
lon2 = lon2 * radInv;
lon2 = lon2 > 180 ? lon2 - 360 : lon2 < -180 ? lon2 + 360 : lon2;
return L.latLng([lat2 * radInv, lon2]);
}
});
return L.GeometryUtil;
}));