Merge pull request #2345 from Leaflet/geodesic

Better geodesy handling
Leaflet · Jan 3, 2014 · b01126d · b01126d
2 parents d1bc836 + ae8bc57
commit b01126d
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Showing 21 changed files with 148 additions and 134 deletions.
diff --git a/build/build.js b/build/build.js
@@ -143,7 +143,7 @@ exports.build = function (callback, version, compsBase32, buildName) {
 	});
 };
 
-exports.test = function(callback) {
+exports.test = function(complete, fail) {
 	var karma = require('karma'),
 	    testConfig = {configFile : __dirname + '/../spec/karma.conf.js'};
 
@@ -182,7 +182,9 @@ exports.test = function(callback) {
 	karma.server.start(testConfig, function(exitCode) {
 		if (!exitCode) {
 			console.log('\tTests ran successfully.\n');
+			complete();
+		} else {
+			process.exit(exitCode);
 		}
-		callback();
 	});
 };
diff --git a/build/deps.js b/build/deps.js
@@ -15,6 +15,7 @@ var deps = {
 		      'geo/projection/Projection.SphericalMercator.js',
 		      'geo/crs/CRS.js',
 		      'geo/crs/CRS.Simple.js',
+		      'geo/crs/CRS.Earth.js',
 		      'geo/crs/CRS.EPSG3857.js',
 		      'geo/crs/CRS.EPSG4326.js',
 		      'map/Map.js',

diff --git a/debug/map/simple-proj.html b/debug/map/simple-proj.html
@@ -52,6 +52,8 @@
 
 		map.addLayer(grid);
 
+		L.circle([0, 0], 100, {color: 'red'}).addTo(map);
+
 	</script>
 </body>
 </html>
diff --git a/spec/suites/geo/CRSSpec.js b/spec/suites/geo/CRSSpec.js
@@ -24,8 +24,8 @@ describe("CRS.EPSG3857", function () {
 	describe("project", function () {
 		it('projects geo coords into meter coords correctly', function () {
 			expect(crs.project(new L.LatLng(50, 30))).near(new L.Point(3339584.7238, 6446275.84102));
-			expect(crs.project(new L.LatLng(90, 180))).near(new L.Point(20037508.34279, 20037508.34278));
-			expect(crs.project(new L.LatLng(-90, -180))).near(new L.Point(-20037508.34279, -20037508.34278));
+			expect(crs.project(new L.LatLng(85.0511287798, 180))).near(new L.Point(20037508.34279, 20037508.34278));
+			expect(crs.project(new L.LatLng(-85.0511287798, -180))).near(new L.Point(-20037508.34279, -20037508.34278));
 		});
 	});
 

diff --git a/spec/suites/geo/ProjectionSpec.js b/spec/suites/geo/ProjectionSpec.js
@@ -8,11 +8,11 @@ describe("Projection.Mercator", function () {
 		});
 
 		it("projects the northeast corner of the world", function () {
-			expect(p.project(new L.LatLng(90, 180))).near(new L.Point(20037508, 20037508));
+			expect(p.project(new L.LatLng(85.0840591556, 180))).near(new L.Point(20037508, 20037508));
 		});
 
 		it("projects the southwest corner of the world", function () {
-			expect(p.project(new L.LatLng(-90, -180))).near(new L.Point(-20037508, -20037508));
+			expect(p.project(new L.LatLng(-85.0840591556, -180))).near(new L.Point(-20037508, -20037508));
 		});
 
 		it("projects other points", function () {
@@ -56,11 +56,11 @@ describe("Projection.SphericalMercator", function () {
 		});
 
 		it("projects the northeast corner of the world", function () {
-			expect(p.project(new L.LatLng(90, 180))).near(new L.Point(20037508, 20037508));
+			expect(p.project(new L.LatLng(85.0511287798, 180))).near(new L.Point(20037508, 20037508));
 		});
 
 		it("projects the southwest corner of the world", function () {
-			expect(p.project(new L.LatLng(-90, -180))).near(new L.Point(-20037508, -20037508));
+			expect(p.project(new L.LatLng(-85.0511287798, -180))).near(new L.Point(-20037508, -20037508));
 		});
 
 		it("projects other points", function () {

diff --git a/spec/suites/layer/vector/CircleSpec.js b/spec/suites/layer/vector/CircleSpec.js
@@ -1,17 +1,18 @@
 describe('Circle', function () {
 	describe('#getBounds', function () {
 
-		var circle;
+		var map, circle;
 
 		beforeEach(function () {
-			circle = L.circle([50, 30], 200);
+			map = L.map(document.createElement('div')).setView([0, 0], 4);
+			circle = L.circle([50, 30], 200).addTo(map);
 		});
 
 		it('returns bounds', function () {
 			var bounds = circle.getBounds();
 
-			expect(bounds.getSouthWest().equals([49.998203369, 29.997204939])).to.be.ok();
-			expect(bounds.getNorthEast().equals([50.001796631, 30.002795061])).to.be.ok();
+			expect(bounds.getSouthWest()).nearLatLng(new L.LatLng(49.94347, 29.91211));
+			expect(bounds.getNorthEast()).nearLatLng(new L.LatLng(50.05646, 30.08789));
 		});
 	});
 });
diff --git a/src/control/Control.Scale.js b/src/control/Control.Scale.js
@@ -38,23 +38,21 @@ L.Control.Scale = L.Control.extend({
 	},
 
 	_update: function () {
-		var bounds = this._map.getBounds(),
-		    centerLat = bounds.getCenter().lat,
-		    halfWorldMeters = 6378137 * Math.PI * Math.cos(centerLat * Math.PI / 180),
-		    dist = halfWorldMeters * (bounds.getEast() - bounds.getWest()) / 180,
+		var map = this._map,
+		    y = map.getSize().y / 2;
 
-		    size = this._map.getSize(),
-		    options = this.options,
-		    maxMeters = size.x > 0 ? dist * (options.maxWidth / size.x) : 0;
+		var maxMeters = L.CRS.Earth.distance(
+				map.containerPointToLatLng([0, y]),
+				map.containerPointToLatLng([this.options.maxWidth, y]));
 
-		this._updateScales(options, maxMeters);
+		this._updateScales(maxMeters);
 	},
 
-	_updateScales: function (options, maxMeters) {
-		if (options.metric && maxMeters) {
+	_updateScales: function (maxMeters) {
+		if (this.options.metric && maxMeters) {
 			this._updateMetric(maxMeters);
 		}
-		if (options.imperial && maxMeters) {
+		if (this.options.imperial && maxMeters) {
 			this._updateImperial(maxMeters);
 		}
 	},

diff --git a/src/geo/LatLng.js b/src/geo/LatLng.js
@@ -34,23 +34,8 @@ L.LatLng.prototype = {
 		        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) {
-		other = L.latLng(other);
-
-		var R = 6378137, // earth radius in meters
-		    rad = Math.PI / 180,
-		    dLat = (other.lat - this.lat) * rad,
-		    dLon = (other.lng - this.lng) * rad,
-		    lat1 = this.lat * rad,
-		    lat2 = other.lat * rad,
-		    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));
+		return L.CRS.Earth.distance(this, L.latLng(other));
 	}
 };
 

diff --git a/src/geo/crs/CRS.EPSG3395.js b/src/geo/crs/CRS.EPSG3395.js
@@ -2,18 +2,12 @@
  * L.CRS.EPSG3857 (World Mercator) CRS implementation.
  */
 
-L.CRS.EPSG3395 = L.extend({}, L.CRS, {
+L.CRS.EPSG3395 = L.extend({}, L.CRS.Earth, {
 	code: 'EPSG:3395',
-
 	projection: L.Projection.Mercator,
 
 	transformation: (function () {
-		var m = L.Projection.Mercator,
-		    r = m.R_MAJOR,
-		    scale = 0.5 / (Math.PI * r);
-
+		var scale = 0.5 / (Math.PI * L.Projection.Mercator.R);
 		return new L.Transformation(scale, 0.5, -scale, 0.5);
-	}()),
-
-	wrapLng: [-180, 180]
+	}())
 });
diff --git a/src/geo/crs/CRS.EPSG3857.js b/src/geo/crs/CRS.EPSG3857.js
@@ -2,17 +2,14 @@
  * 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, {
+L.CRS.EPSG3857 = L.extend({}, L.CRS.Earth, {
 	code: 'EPSG:3857',
-
 	projection: L.Projection.SphericalMercator,
 
 	transformation: (function () {
 		var scale = 0.5 / (Math.PI * L.Projection.SphericalMercator.R);
 		return new L.Transformation(scale, 0.5, -scale, 0.5);
-	}()),
-
-	wrapLng: [-180, 180]
+	}())
 });
 
 L.CRS.EPSG900913 = L.extend({}, L.CRS.EPSG3857, {

diff --git a/src/geo/crs/CRS.EPSG4326.js b/src/geo/crs/CRS.EPSG4326.js
@@ -2,11 +2,8 @@
  * L.CRS.EPSG4326 is a CRS popular among advanced GIS specialists.
  */
 
-L.CRS.EPSG4326 = L.extend({}, L.CRS, {
+L.CRS.EPSG4326 = L.extend({}, L.CRS.Earth, {
 	code: 'EPSG:4326',
-
 	projection: L.Projection.LonLat,
-	transformation: new L.Transformation(1 / 180, 1, -1 / 180, 0.5),
-
-	wrapLng: [-180, 180]
+	transformation: new L.Transformation(1 / 180, 1, -1 / 180, 0.5)
 });
diff --git a/src/geo/crs/CRS.Earth.js b/src/geo/crs/CRS.Earth.js
@@ -0,0 +1,19 @@
+/*
+ * L.CRS.Earth is the base class for all CRS representing Earth.
+ */
+
+L.CRS.Earth = L.extend({}, L.CRS, {
+	wrapLng: [-180, 180],
+
+	R: 6378137,
+
+	// distane between two geographical points using spherical law of cosines approximation
+	distance: function (latlng1, latlng2) {
+		var rad = Math.PI / 180,
+		    lat1 = latlng1.lat * rad,
+		    lat2 = latlng2.lat * rad;
+
+		return this.R * Math.acos(Math.sin(lat1) * Math.sin(lat2) +
+				Math.cos(lat1) * Math.cos(lat2) * Math.cos((latlng2.lng - latlng1.lng) * rad));
+	}
+});
diff --git a/src/geo/crs/CRS.Simple.js b/src/geo/crs/CRS.Simple.js
@@ -10,5 +10,12 @@ L.CRS.Simple = L.extend({}, L.CRS, {
 		return Math.pow(2, zoom);
 	},
 
+	distance: function (latlng1, latlng2) {
+		var dx = latlng2.lng - latlng1.lng,
+		    dy = latlng2.lat - latlng1.lat;
+
+		return Math.sqrt(dx * dx + dy * dy);
+	},
+
 	infinite: true
 });
diff --git a/src/geo/projection/Projection.Mercator.js b/src/geo/projection/Projection.Mercator.js
@@ -4,55 +4,40 @@
  */
 
 L.Projection.Mercator = {
-	MAX_LATITUDE: 85.0840591556,
-
+	R: 6378137,
 	R_MINOR: 6356752.314245179,
-	R_MAJOR: 6378137,
 
 	bounds: L.bounds([-20037508.34279, -15496570.73972], [20037508.34279, 18764656.23138]),
 
 	project: function (latlng) {
 		var d = Math.PI / 180,
-		    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 = -r * Math.log(ts);
-
-		return new L.Point(x, y);
+		    r = this.R,
+		    y = latlng.lat * d,
+		    tmp = this.R_MINOR / r,
+		    e = Math.sqrt(1 - tmp * tmp),
+		    con = e * Math.sin(y);
+
+		var ts = Math.tan(Math.PI / 4 - y / 2) / Math.pow((1 - con) / (1 + con), e / 2);
+		y = -r * Math.log(Math.max(ts, 1E-10));
+
+		return new L.Point(latlng.lng * d * r, y);
 	},
 
 	unproject: function (point) {
 		var d = 180 / Math.PI,
-		    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 / r),
-		    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;
+		    r = this.R,
+		    tmp = this.R_MINOR / r,
+		    e = Math.sqrt(1 - tmp * tmp),
+		    ts = Math.exp(-point.y / r),
+		    phi = Math.PI / 2 - 2 * Math.atan(ts);
+
+		for (var i = 0, dphi = 0.1, con; i < 15 && Math.abs(dphi) > 1e-7; i++) {
+			con = e * Math.sin(phi);
+			con = Math.pow((1 - con) / (1 + con), e / 2);
+			dphi = Math.PI / 2 - 2 * Math.atan(ts * con) - phi;
 			phi += dphi;
 		}
 
-		return new L.LatLng(phi * d, lng);
+		return new L.LatLng(phi * d, point.x * d / r);
 	}
 };
diff --git a/src/geo/projection/Projection.SphericalMercator.js b/src/geo/projection/Projection.SphericalMercator.js
@@ -4,27 +4,24 @@
 
 L.Projection.SphericalMercator = {
 
-	MAX_LATITUDE: 85.0511287798,
-
 	R: 6378137,
 
 	project: function (latlng) {
 		var d = Math.PI / 180,
-		    max = this.MAX_LATITUDE,
-		    x = this.R * latlng.lng * d,
-		    y = Math.max(Math.min(max, latlng.lat), -max) * d;
-
-		y = this.R * Math.log(Math.tan((Math.PI / 4) + (y / 2)));
+		    max = 1 - 1E-15,
+		    sin = Math.max(Math.min(Math.sin(latlng.lat * d), max), -max);
 
-		return new L.Point(x, y);
+		return new L.Point(
+				this.R * latlng.lng * d,
+				this.R * Math.log((1 + sin) / (1 - sin)) / 2);
 	},
 
 	unproject: function (point) {
-		var d = 180 / Math.PI,
-		    lng = point.x * d / this.R,
-		    lat = (2 * Math.atan(Math.exp(point.y / this.R)) - (Math.PI / 2)) * d;
+		var d = 180 / Math.PI;
 
-		return new L.LatLng(lat, lng);
+		return new L.LatLng(
+			(2 * Math.atan(Math.exp(point.y / this.R)) - (Math.PI / 2)) * d,
+			point.x * d / this.R);
 	},
 
 	bounds: (function () {

diff --git a/src/layer/vector/Canvas.js b/src/layer/vector/Canvas.js
@@ -129,10 +129,21 @@ L.Canvas = L.Renderer.extend({
 		if (layer._empty()) { return; }
 
 		var p = layer._point,
-		    ctx = this._ctx;
+		    ctx = this._ctx,
+		    r = layer._radius,
+		    s = (layer._radiusY || r) / r;
+
+		if (s !== 1) {
+			ctx.save();
+			ctx.scale(1, s);
+		}
 
 		ctx.beginPath();
-		ctx.arc(p.x, p.y, layer._radius, 0, Math.PI * 2, false);
+		ctx.arc(p.x, p.y / s, r, 0, Math.PI * 2, false);
+
+		if (s !== 1) {
+			ctx.restore();
+		}
 
 		this._fillStroke(ctx, layer);
 	},