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Spherical Radius is used in Spherical Mercator

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This commit is contained in:
Calvin Metcalf 2013-10-03 13:08:19 -04:00 committed by Vladimir Agafonkin
parent 6f1784fc9a
commit 87520df2e2
2 changed files with 53 additions and 5 deletions
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48
spec/suites/geo/ProjectionSpec.js
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@ -46,3 +46,51 @@ describe("Projection.Mercator", function () {
});
});
});
describe("Projection.SphericalMercator", function() {
var p = L.Projection.SphericalMercator;
describe("#project", function() {
it("projects a center point", function() {
//edge cases
expect(p.project(new L.LatLng(0, 0))).near(new L.Point(0, 0));
});
it("projects the northeast corner of the world", function() {
expect(p.project(new L.LatLng(90, 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));
});
it("projects other points", function() {
expect(p.project(new L.LatLng(50, 30))).near(new L.Point(3339584, 6446275));
// from https://github.com/Leaflet/Leaflet/issues/1578
expect(p.project(new L.LatLng(51.9371170300465, 80.11230468750001)))
.near(new L.Point(8918060.96409, 6788763.38325));
});
});
describe("#unproject", function() {
function pr(point) {
return p.project(p.unproject(point));
}
it("unprojects a center point", function() {
expect(pr(new L.Point(0, 0))).near(new L.Point(0, 0));
});
it("unprojects pi points", function() {
expect(pr(new L.Point(-Math.PI, Math.PI))).near(new L.Point(-Math.PI, Math.PI));
expect(pr(new L.Point(-Math.PI, -Math.PI))).near(new L.Point(-Math.PI, -Math.PI));
expect(pr(new L.Point(0.523598775598, 1.010683188683))).near(new L.Point(0.523598775598, 1.010683188683));
});
it('unprojects other points', function () {
// from https://github.com/Leaflet/Leaflet/issues/1578
expect(pr(new L.Point(8918060.964088084, 6755099.410887127)));
});
});
});

10
src/geo/projection/Projection.SphericalMercator.js
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@ -4,23 +4,23 @@
L.Projection.SphericalMercator = {
MAX_LATITUDE: 85.0511287798,
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),
x = latlng.lng * d,
x = latlng.lng * d * this.R_MAJOR,
y = lat * d;
y = Math.log(Math.tan((Math.PI / 4) + (y / 2)));
y *= this.R_MAJOR;
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;
lng = point.x * d / this.R_MAJOR,
lat = (2 * Math.atan(Math.exp(point.y / this.R_MAJOR)) - (Math.PI / 2)) * d;
return new L.LatLng(lat, lng);
}