Merge pull request #3371 from Leaflet/polyline-getcenter

Fix Polyline.getCenter returning undefined with very small line
This commit is contained in:
Vladimir Agafonkin 2015-04-12 13:23:16 +03:00
commit a9f7cb9060
2 changed files with 43 additions and 0 deletions

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@ -52,4 +52,40 @@ describe('Polyline', function () {
expect(polyline._latlngs).to.eql([L.latLng([1, 2]), L.latLng([7, 8]), L.latLng([5, 6])]); expect(polyline._latlngs).to.eql([L.latLng([1, 2]), L.latLng([7, 8]), L.latLng([5, 6])]);
}); });
}); });
describe('#getCenter', function () {
it('should compute center of a big flat line on equator', function () {
var polyline = new L.Polyline([[0, 0], [0, 90]]).addTo(map);
expect(polyline.getCenter()).to.eql(L.latLng([0, 45]));
});
it('should compute center of a big flat line close to the pole', function () {
var polyline = new L.Polyline([[80, 0], [80, 90]]).addTo(map);
expect(polyline.getCenter()).to.be.nearLatLng(L.latLng([80, 45]), 1e-2);
});
it('should compute center of a big diagonal line', function () {
var polyline = new L.Polyline([[0, 0], [80, 80]]).addTo(map);
expect(polyline.getCenter()).to.be.nearLatLng(L.latLng([57, 40]), 1);
});
it('should compute center of a diagonal line close to the pole', function () {
var polyline = new L.Polyline([[70, 70], [84, 84]]).addTo(map);
expect(polyline.getCenter()).to.be.nearLatLng(L.latLng([79, 77]), 1);
});
it('should compute center of a big multiline', function () {
var polyline = new L.Polyline([[10, -80], [0, 0], [0, 10], [10, 90]]).addTo(map);
expect(polyline.getCenter()).to.be.nearLatLng(L.latLng([0, 5]), 1);
});
it('should compute center of a small flat line', function () {
var polyline = new L.Polyline([[0, 0], [0, 0.090]]).addTo(map);
map.setZoom(0); // Make the line disappear in screen;
expect(polyline.getCenter()).to.be.nearLatLng(L.latLng([0, 0]), 1e-2);
});
});
}); });

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@ -74,12 +74,19 @@ L.Polyline = L.Path.extend({
points = this._rings[0], points = this._rings[0],
len = points.length; len = points.length;
if (!len) { return null; }
// polyline centroid algorithm; only uses the first ring if there are multiple // polyline centroid algorithm; only uses the first ring if there are multiple
for (i = 0, halfDist = 0; i < len - 1; i++) { for (i = 0, halfDist = 0; i < len - 1; i++) {
halfDist += points[i].distanceTo(points[i + 1]) / 2; halfDist += points[i].distanceTo(points[i + 1]) / 2;
} }
// The line is so small in the current view that all points are on the same pixel.
if (halfDist === 0) {
return this._map.layerPointToLatLng(points[0]);
}
for (i = 0, dist = 0; i < len - 1; i++) { for (i = 0, dist = 0; i < len - 1; i++) {
p1 = points[i]; p1 = points[i];
p2 = points[i + 1]; p2 = points[i + 1];