Leaflet coordinates helper

0main.js

const L = require('./leaflet-0.5.0-coord-part')

const simpleCrs = L.Util.extend({}, L.CRS, {
    code                : 'simple',
    projection          : L.Projection.LonLat,
    transformation      : new L.Transformation(1,0,-1,0)
})

console.log(
  L.CRS.EPSG3857.pointToLatLng(
    simpleCrs.latLngToPoint({
        "lat": -0.6068115234375,
        "lng": 0.82440185546875
    }, 1), 1))

leaflet-0.5.0-coord-part.js

/*
 Leaflet, a JavaScript library for mobile-friendly interactive maps. http://leafletjs.com
 (c) 2010-2013, Vladimir Agafonkin, CloudMade
*/
/*
 * Leaflet coordinates helper
 * Mofified for NodeJS
 */

var L, originalL;

if (typeof exports !== undefined + '') {
	L = exports;
} else {
	originalL = window.L;
	L = {};

	L.noConflict = function () {
		window.L = originalL;
		return this;
	};

	window.L = L;
}

L.version = '0.5.1';


/*
 * L.Util contains various utility functions used throughout Leaflet code.
 */

L.Util = {
	extend: function (dest) { // (Object[, Object, ...]) ->
		var sources = Array.prototype.slice.call(arguments, 1),
		    i, j, len, src;

		for (j = 0, len = sources.length; j < len; j++) {
			src = sources[j] || {};
			for (i in src) {
				if (src.hasOwnProperty(i)) {
					dest[i] = src[i];
				}
			}
		}
		return dest;
	},

	bind: function (fn, obj) { // (Function, Object) -> Function
		var args = arguments.length > 2 ? Array.prototype.slice.call(arguments, 2) : null;
		return function () {
			return fn.apply(obj, args || arguments);
		};
	},

	stamp: (function () {
		var lastId = 0, key = '_leaflet_id';
		return function (/*Object*/ obj) {
			obj[key] = obj[key] || ++lastId;
			return obj[key];
		};
	}()),

	limitExecByInterval: function (fn, time, context) {
		var lock, execOnUnlock;

		return function wrapperFn() {
			var args = arguments;

			if (lock) {
				execOnUnlock = true;
				return;
			}

			lock = true;

			setTimeout(function () {
				lock = false;

				if (execOnUnlock) {
					wrapperFn.apply(context, args);
					execOnUnlock = false;
				}
			}, time);

			fn.apply(context, args);
		};
	},

	falseFn: function () {
		return false;
	},

	formatNum: function (num, digits) {
		var pow = Math.pow(10, digits || 5);
		return Math.round(num * pow) / pow;
	},

	splitWords: function (str) {
		return str.replace(/^\s+|\s+$/g, '').split(/\s+/);
	},

	setOptions: function (obj, options) {
		obj.options = L.extend({}, obj.options, options);
		return obj.options;
	},

	getParamString: function (obj, existingUrl) {
		var params = [];
		for (var i in obj) {
			if (obj.hasOwnProperty(i)) {
				params.push(i + '=' + obj[i]);
			}
		}
		return ((!existingUrl || existingUrl.indexOf('?') === -1) ? '?' : '&') + params.join('&');
	},

	template: function (str, data) {
		return str.replace(/\{ *([\w_]+) *\}/g, function (str, key) {
			var value = data[key];
			if (!data.hasOwnProperty(key)) {
				throw new Error('No value provided for variable ' + str);
			}
			return value;
		});
	},

	isArray: function (obj) {
		return (Object.prototype.toString.call(obj) === '[object Array]');
	},

	emptyImageUrl: 'data:image/gif;base64,R0lGODlhAQABAAD/ACwAAAAAAQABAAACADs='
};


// shortcuts for most used utility functions
L.extend = L.Util.extend;
L.bind = L.Util.bind;
L.stamp = L.Util.stamp;
L.setOptions = L.Util.setOptions;


/*
 * L.Point represents a point with x and y coordinates.
 */

L.Point = function (/*Number*/ x, /*Number*/ y, /*Boolean*/ round) {
	this.x = (round ? Math.round(x) : x);
	this.y = (round ? Math.round(y) : y);
};

L.Point.prototype = {

	clone: function () {
		return new L.Point(this.x, this.y);
	},

	// non-destructive, returns a new point
	add: function (point) {
		return this.clone()._add(L.point(point));
	},

	// destructive, used directly for performance in situations where it's safe to modify existing point
	_add: function (point) {
		this.x += point.x;
		this.y += point.y;
		return this;
	},

	subtract: function (point) {
		return this.clone()._subtract(L.point(point));
	},

	_subtract: function (point) {
		this.x -= point.x;
		this.y -= point.y;
		return this;
	},

	divideBy: function (num) {
		return this.clone()._divideBy(num);
	},

	_divideBy: function (num) {
		this.x /= num;
		this.y /= num;
		return this;
	},

	multiplyBy: function (num) {
		return this.clone()._multiplyBy(num);
	},

	_multiplyBy: function (num) {
		this.x *= num;
		this.y *= num;
		return this;
	},

	round: function () {
		return this.clone()._round();
	},

	_round: function () {
		this.x = Math.round(this.x);
		this.y = Math.round(this.y);
		return this;
	},

	floor: function () {
		return this.clone()._floor();
	},

	_floor: function () {
		this.x = Math.floor(this.x);
		this.y = Math.floor(this.y);
		return this;
	},

	distanceTo: function (point) {
		point = L.point(point);

		var x = point.x - this.x,
		    y = point.y - this.y;

		return Math.sqrt(x * x + y * y);
	},

	equals: function (point) {
		return point.x === this.x &&
		       point.y === this.y;
	},

	toString: function () {
		return 'Point(' +
		        L.Util.formatNum(this.x) + ', ' +
		        L.Util.formatNum(this.y) + ')';
	}
};

L.point = function (x, y, round) {
	if (x instanceof L.Point) {
		return x;
	}
	if (L.Util.isArray(x)) {
		return new L.Point(x[0], x[1]);
	}
	if (isNaN(x)) {
		return x;
	}
	return new L.Point(x, y, round);
};


/*
 * L.Bounds represents a rectangular area on the screen in pixel coordinates.
 */

L.Bounds = function (a, b) { //(Point, Point) or Point[]
	if (!a) { return; }

	var points = b ? [a, b] : a;

	for (var i = 0, len = points.length; i < len; i++) {
		this.extend(points[i]);
	}
};

L.Bounds.prototype = {
	// extend the bounds to contain the given point
	extend: function (point) { // (Point)
		point = L.point(point);

		if (!this.min && !this.max) {
			this.min = point.clone();
			this.max = point.clone();
		} else {
			this.min.x = Math.min(point.x, this.min.x);
			this.max.x = Math.max(point.x, this.max.x);
			this.min.y = Math.min(point.y, this.min.y);
			this.max.y = Math.max(point.y, this.max.y);
		}
		return this;
	},

	getCenter: function (round) { // (Boolean) -> Point
		return new L.Point(
		        (this.min.x + this.max.x) / 2,
		        (this.min.y + this.max.y) / 2, round);
	},

	getBottomLeft: function () { // -> Point
		return new L.Point(this.min.x, this.max.y);
	},

	getTopRight: function () { // -> Point
		return new L.Point(this.max.x, this.min.y);
	},

	getSize: function () {
		return this.max.subtract(this.min);
	},

	contains: function (obj) { // (Bounds) or (Point) -> Boolean
		var min, max;

		if (typeof obj[0] === 'number' || obj instanceof L.Point) {
			obj = L.point(obj);
		} else {
			obj = L.bounds(obj);
		}

		if (obj instanceof L.Bounds) {
			min = obj.min;
			max = obj.max;
		} else {
			min = max = obj;
		}

		return (min.x >= this.min.x) &&
		       (max.x <= this.max.x) &&
		       (min.y >= this.min.y) &&
		       (max.y <= this.max.y);
	},

	intersects: function (bounds) { // (Bounds) -> Boolean
		bounds = L.bounds(bounds);

		var min = this.min,
		    max = this.max,
		    min2 = bounds.min,
		    max2 = bounds.max,
		    xIntersects = (max2.x >= min.x) && (min2.x <= max.x),
		    yIntersects = (max2.y >= min.y) && (min2.y <= max.y);

		return xIntersects && yIntersects;
	},

	isValid: function () {
		return !!(this.min && this.max);
	}
};

L.bounds = function (a, b) { // (Bounds) or (Point, Point) or (Point[])
	if (!a || a instanceof L.Bounds) {
		return a;
	}
	return new L.Bounds(a, b);
};


/*
 * L.Transformation is an utility class to perform simple point transformations through a 2d-matrix.
 */

L.Transformation = function (a, b, c, d) {
	this._a = a;
	this._b = b;
	this._c = c;
	this._d = d;
};

L.Transformation.prototype = {
	transform: function (point, scale) { // (Point, Number) -> Point
		return this._transform(point.clone(), scale);
	},

	// destructive transform (faster)
	_transform: function (point, scale) {
		scale = scale || 1;
		point.x = scale * (this._a * point.x + this._b);
		point.y = scale * (this._c * point.y + this._d);
		return point;
	},

	untransform: function (point, scale) {
		scale = scale || 1;
		return new L.Point(
		        (point.x / scale - this._b) / this._a,
		        (point.y / scale - this._d) / this._c);
	}
};


/*
 * L.LatLng represents a geographical point with latitude and longitude coordinates.
 */

L.LatLng = function (rawLat, rawLng) { // (Number, Number)
	var lat = parseFloat(rawLat),
	    lng = parseFloat(rawLng);

	if (isNaN(lat) || isNaN(lng)) {
		throw new Error('Invalid LatLng object: (' + rawLat + ', ' + rawLng + ')');
	}

	this.lat = lat;
	this.lng = lng;
};

L.extend(L.LatLng, {
	DEG_TO_RAD: Math.PI / 180,
	RAD_TO_DEG: 180 / Math.PI,
	MAX_MARGIN: 1.0E-9 // max margin of error for the "equals" check
});

L.LatLng.prototype = {
	equals: function (obj) { // (LatLng) -> Boolean
		if (!obj) { return false; }

		obj = L.latLng(obj);

		var margin = Math.max(
		        Math.abs(this.lat - obj.lat),
		        Math.abs(this.lng - obj.lng));

		return margin <= L.LatLng.MAX_MARGIN;
	},

	toString: function (precision) { // (Number) -> String
		return 'LatLng(' +
		        L.Util.formatNum(this.lat, precision) + ', ' +
		        L.Util.formatNum(this.lng, precision) + ')';
	},

	// Haversine distance formula, see http://en.wikipedia.org/wiki/Haversine_formula
	// TODO move to projection code, LatLng shouldn't know about Earth
	distanceTo: function (other) { // (LatLng) -> Number
		other = L.latLng(other);

		var R = 6378137, // earth radius in meters
		    d2r = L.LatLng.DEG_TO_RAD,
		    dLat = (other.lat - this.lat) * d2r,
		    dLon = (other.lng - this.lng) * d2r,
		    lat1 = this.lat * d2r,
		    lat2 = other.lat * d2r,
		    sin1 = Math.sin(dLat / 2),
		    sin2 = Math.sin(dLon / 2);

		var a = sin1 * sin1 + sin2 * sin2 * Math.cos(lat1) * Math.cos(lat2);

		return R * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
	},

	wrap: function (a, b) { // (Number, Number) -> LatLng
		var lng = this.lng;

		a = a || -180;
		b = b ||  180;

		lng = (lng + b) % (b - a) + (lng < a || lng === b ? b : a);

		return new L.LatLng(this.lat, lng);
	}
};

L.latLng = function (a, b) { // (LatLng) or ([Number, Number]) or (Number, Number)
	if (a instanceof L.LatLng) {
		return a;
	}
	if (L.Util.isArray(a)) {
		return new L.LatLng(a[0], a[1]);
	}
	if (isNaN(a)) {
		return a;
	}
	return new L.LatLng(a, b);
};



/*
 * L.LatLngBounds represents a rectangular area on the map in geographical coordinates.
 */

L.LatLngBounds = function (southWest, northEast) { // (LatLng, LatLng) or (LatLng[])
	if (!southWest) { return; }

	var latlngs = northEast ? [southWest, northEast] : southWest;

	for (var i = 0, len = latlngs.length; i < len; i++) {
		this.extend(latlngs[i]);
	}
};

L.LatLngBounds.prototype = {
	// extend the bounds to contain the given point or bounds
	extend: function (obj) { // (LatLng) or (LatLngBounds)
		if (typeof obj[0] === 'number' || typeof obj[0] === 'string' || obj instanceof L.LatLng) {
			obj = L.latLng(obj);
		} else {
			obj = L.latLngBounds(obj);
		}

		if (obj instanceof L.LatLng) {
			if (!this._southWest && !this._northEast) {
				this._southWest = new L.LatLng(obj.lat, obj.lng);
				this._northEast = new L.LatLng(obj.lat, obj.lng);
			} else {
				this._southWest.lat = Math.min(obj.lat, this._southWest.lat);
				this._southWest.lng = Math.min(obj.lng, this._southWest.lng);

				this._northEast.lat = Math.max(obj.lat, this._northEast.lat);
				this._northEast.lng = Math.max(obj.lng, this._northEast.lng);
			}
		} else if (obj instanceof L.LatLngBounds) {
			this.extend(obj._southWest);
			this.extend(obj._northEast);
		}
		return this;
	},

	// extend the bounds by a percentage
	pad: function (bufferRatio) { // (Number) -> LatLngBounds
		var sw = this._southWest,
		    ne = this._northEast,
		    heightBuffer = Math.abs(sw.lat - ne.lat) * bufferRatio,
		    widthBuffer = Math.abs(sw.lng - ne.lng) * bufferRatio;

		return new L.LatLngBounds(
		        new L.LatLng(sw.lat - heightBuffer, sw.lng - widthBuffer),
		        new L.LatLng(ne.lat + heightBuffer, ne.lng + widthBuffer));
	},

	getCenter: function () { // -> LatLng
		return new L.LatLng(
		        (this._southWest.lat + this._northEast.lat) / 2,
		        (this._southWest.lng + this._northEast.lng) / 2);
	},

	getSouthWest: function () {
		return this._southWest;
	},

	getNorthEast: function () {
		return this._northEast;
	},

	getNorthWest: function () {
		return new L.LatLng(this._northEast.lat, this._southWest.lng);
	},

	getSouthEast: function () {
		return new L.LatLng(this._southWest.lat, this._northEast.lng);
	},

	contains: function (obj) { // (LatLngBounds) or (LatLng) -> Boolean
		if (typeof obj[0] === 'number' || obj instanceof L.LatLng) {
			obj = L.latLng(obj);
		} else {
			obj = L.latLngBounds(obj);
		}

		var sw = this._southWest,
		    ne = this._northEast,
		    sw2, ne2;

		if (obj instanceof L.LatLngBounds) {
			sw2 = obj.getSouthWest();
			ne2 = obj.getNorthEast();
		} else {
			sw2 = ne2 = obj;
		}

		return (sw2.lat >= sw.lat) && (ne2.lat <= ne.lat) &&
		       (sw2.lng >= sw.lng) && (ne2.lng <= ne.lng);
	},

	intersects: function (bounds) { // (LatLngBounds)
		bounds = L.latLngBounds(bounds);

		var sw = this._southWest,
		    ne = this._northEast,
		    sw2 = bounds.getSouthWest(),
		    ne2 = bounds.getNorthEast(),

		    latIntersects = (ne2.lat >= sw.lat) && (sw2.lat <= ne.lat),
		    lngIntersects = (ne2.lng >= sw.lng) && (sw2.lng <= ne.lng);

		return latIntersects && lngIntersects;
	},

	toBBoxString: function () {
		var sw = this._southWest,
		    ne = this._northEast;

		return [sw.lng, sw.lat, ne.lng, ne.lat].join(',');
	},

	equals: function (bounds) { // (LatLngBounds)
		if (!bounds) { return false; }

		bounds = L.latLngBounds(bounds);

		return this._southWest.equals(bounds.getSouthWest()) &&
		       this._northEast.equals(bounds.getNorthEast());
	},

	isValid: function () {
		return !!(this._southWest && this._northEast);
	}
};

//TODO International date line?

L.latLngBounds = function (a, b) { // (LatLngBounds) or (LatLng, LatLng)
	if (!a || a instanceof L.LatLngBounds) {
		return a;
	}
	return new L.LatLngBounds(a, b);
};


/*
 * L.Projection contains various geographical projections used by CRS classes.
 */

L.Projection = {};


/*
 * Spherical Mercator is the most popular map projection, used by EPSG:3857 CRS used by default.
 */

L.Projection.SphericalMercator = {
	MAX_LATITUDE: 85.0511287798,

	project: function (latlng) { // (LatLng) -> Point
		var d = L.LatLng.DEG_TO_RAD,
		    max = this.MAX_LATITUDE,
		    lat = Math.max(Math.min(max, latlng.lat), -max),
		    x = latlng.lng * d,
		    y = lat * d;

		y = Math.log(Math.tan((Math.PI / 4) + (y / 2)));

		return new L.Point(x, y);
	},

	unproject: function (point) { // (Point, Boolean) -> LatLng
		var d = L.LatLng.RAD_TO_DEG,
		    lng = point.x * d,
		    lat = (2 * Math.atan(Math.exp(point.y)) - (Math.PI / 2)) * d;

		return new L.LatLng(lat, lng);
	}
};


/*
 * Simple equirectangular (Plate Carree) projection, used by CRS like EPSG:4326 and Simple.
 */

L.Projection.LonLat = {
	project: function (latlng) {
		return new L.Point(latlng.lng, latlng.lat);
	},

	unproject: function (point) {
		return new L.LatLng(point.y, point.x);
	}
};


/*
 * L.CRS is a base object for all defined CRS (Coordinate Reference Systems) in Leaflet.
 */

L.CRS = {
	latLngToPoint: function (latlng, zoom) { // (LatLng, Number) -> Point
		var projectedPoint = this.projection.project(latlng),
		    scale = this.scale(zoom);

		return this.transformation._transform(projectedPoint, scale);
	},

	pointToLatLng: function (point, zoom) { // (Point, Number[, Boolean]) -> LatLng
		var scale = this.scale(zoom),
		    untransformedPoint = this.transformation.untransform(point, scale);

		return this.projection.unproject(untransformedPoint);
	},

	project: function (latlng) {
		return this.projection.project(latlng);
	},

	scale: function (zoom) {
		return 256 * Math.pow(2, zoom);
	}
};


/*
 * A simple CRS that can be used for flat non-Earth maps like panoramas or game maps.
 */

L.CRS.Simple = L.extend({}, L.CRS, {
	projection: L.Projection.LonLat,
	transformation: new L.Transformation(1, 0, -1, 0),

	scale: function (zoom) {
		return Math.pow(2, zoom);
	}
});


/*
 * L.CRS.EPSG3857 (Spherical Mercator) is the most common CRS for web mapping
 * and is used by Leaflet by default.
 */

L.CRS.EPSG3857 = L.extend({}, L.CRS, {
	code: 'EPSG:3857',

	projection: L.Projection.SphericalMercator,
	transformation: new L.Transformation(0.5 / Math.PI, 0.5, -0.5 / Math.PI, 0.5),

	project: function (latlng) { // (LatLng) -> Point
		var projectedPoint = this.projection.project(latlng),
		    earthRadius = 6378137;
		return projectedPoint.multiplyBy(earthRadius);
	}
});

L.CRS.EPSG900913 = L.extend({}, L.CRS.EPSG3857, {
	code: 'EPSG:900913'
});


/*
 * L.CRS.EPSG4326 is a CRS popular among advanced GIS specialists.
 */

L.CRS.EPSG4326 = L.extend({}, L.CRS, {
	code: 'EPSG:4326',

	projection: L.Projection.LonLat,
	transformation: new L.Transformation(1 / 360, 0.5, -1 / 360, 0.5)
});




/*
 * Mercator projection that takes into account that the Earth is not a perfect sphere.
 * Less popular than spherical mercator; used by projections like EPSG:3395.
 */

L.Projection.Mercator = {
	MAX_LATITUDE: 85.0840591556,

	R_MINOR: 6356752.3142,
	R_MAJOR: 6378137,

	project: function (latlng) { // (LatLng) -> Point
		var d = L.LatLng.DEG_TO_RAD,
		    max = this.MAX_LATITUDE,
		    lat = Math.max(Math.min(max, latlng.lat), -max),
		    r = this.R_MAJOR,
		    r2 = this.R_MINOR,
		    x = latlng.lng * d * r,
		    y = lat * d,
		    tmp = r2 / r,
		    eccent = Math.sqrt(1.0 - tmp * tmp),
		    con = eccent * Math.sin(y);

		con = Math.pow((1 - con) / (1 + con), eccent * 0.5);

		var ts = Math.tan(0.5 * ((Math.PI * 0.5) - y)) / con;
		y = -r2 * Math.log(ts);

		return new L.Point(x, y);
	},

	unproject: function (point) { // (Point, Boolean) -> LatLng
		var d = L.LatLng.RAD_TO_DEG,
		    r = this.R_MAJOR,
		    r2 = this.R_MINOR,
		    lng = point.x * d / r,
		    tmp = r2 / r,
		    eccent = Math.sqrt(1 - (tmp * tmp)),
		    ts = Math.exp(- point.y / r2),
		    phi = (Math.PI / 2) - 2 * Math.atan(ts),
		    numIter = 15,
		    tol = 1e-7,
		    i = numIter,
		    dphi = 0.1,
		    con;

		while ((Math.abs(dphi) > tol) && (--i > 0)) {
			con = eccent * Math.sin(phi);
			dphi = (Math.PI / 2) - 2 * Math.atan(ts *
			            Math.pow((1.0 - con) / (1.0 + con), 0.5 * eccent)) - phi;
			phi += dphi;
		}

		return new L.LatLng(phi * d, lng);
	}
};



L.CRS.EPSG3395 = L.extend({}, L.CRS, {
	code: 'EPSG:3395',

	projection: L.Projection.Mercator,

	transformation: (function () {
		var m = L.Projection.Mercator,
		    r = m.R_MAJOR,
		    r2 = m.R_MINOR;

		return new L.Transformation(0.5 / (Math.PI * r), 0.5, -0.5 / (Math.PI * r2), 0.5);
	}())
});