ashatora/openlayers
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Fix scale line for EPSG:4326 maps

Browse Source
This commit is contained in:
Andreas Hocevar
2017-08-07 18:16:40 -06:00
parent ac13dbccf1
commit 388e2a93cb
4 changed files with 83 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
src/ol/control/scaleline.js
View File

@@ -168,17 +168,22 @@ ol.control.ScaleLine.prototype.updateElement_ = function() {
var center = viewState.center;
var projection = viewState.projection;
var metersPerUnit = projection.getMetersPerUnit();
var units = this.getUnits();
var pointResolutionUnits = units == ol.control.ScaleLineUnits.DEGREES ?
ol.proj.Units.DEGREES :
ol.proj.Units.METERS;
var pointResolution =
ol.proj.getPointResolution(projection, viewState.resolution, center) *
metersPerUnit;
ol.proj.getPointResolution(projection, viewState.resolution, center, pointResolutionUnits);
var nominalCount = this.minWidth_ * pointResolution;
var suffix = '';
var units = this.getUnits();
if (units == ol.control.ScaleLineUnits.DEGREES) {
var metersPerDegree = ol.proj.METERS_PER_UNIT[ol.proj.Units.DEGREES];
if (projection.getUnits() == ol.proj.Units.DEGREES) {
nominalCount *= metersPerDegree;
} else {
pointResolution /= metersPerDegree;
}
if (nominalCount < metersPerDegree / 60) {
suffix = '\u2033'; // seconds
pointResolution *= 3600;

12
src/ol/proj.js
View File

@@ -63,10 +63,12 @@ if (ol.ENABLE_PROJ4JS) {
* @param {ol.ProjectionLike} projection The projection.
* @param {number} resolution Nominal resolution in projection units.
* @param {ol.Coordinate} point Point to find adjusted resolution at.
* @return {number} Point resolution at point in projection units.
* @param {ol.proj.Units=} opt_units Units to get the point resolution in.
* Default is the projection's units.
* @return {number} Point resolution.
* @api
*/
ol.proj.getPointResolution = function(projection, resolution, point) {
ol.proj.getPointResolution = function(projection, resolution, point, opt_units) {
projection = ol.proj.get(projection);
var pointResolution;
var getter = projection.getPointResolutionFunc();
@@ -74,7 +76,7 @@ ol.proj.getPointResolution = function(projection, resolution, point) {
pointResolution = getter(resolution, point);
} else {
var units = projection.getUnits();
if (units == ol.proj.Units.DEGREES) {
if (units == ol.proj.Units.DEGREES && !opt_units || opt_units == ol.proj.Units.DEGREES) {
pointResolution = resolution;
} else {
// Estimate point resolution by transforming the center pixel to EPSG:4326,
@@ -93,7 +95,9 @@ ol.proj.getPointResolution = function(projection, resolution, point) {
var height = ol.proj.AUTHALIC_SPHERE_.haversineDistance(
vertices.slice(4, 6), vertices.slice(6, 8));
pointResolution = (width + height) / 2;
var metersPerUnit = projection.getMetersPerUnit();
var metersPerUnit = opt_units ?
ol.proj.Units.METERS_PER_UNIT[opt_units] :
projection.getMetersPerUnit();
if (metersPerUnit !== undefined) {
pointResolution /= metersPerUnit;
}

38
test/spec/ol/control/scaleline.test.js
View File

@@ -262,6 +262,44 @@ describe('ol.control.ScaleLine', function() {
});
});
describe('latitude may affect scale line in EPSG:4326', function() {
it('is rendered differently at different latitudes for metric', function() {
var ctrl = new ol.control.ScaleLine();
ctrl.setMap(map);
map.setView(new ol.View({
center: ol.proj.fromLonLat([7, 0]),
zoom: 2,
projection: 'EPSG:4326'
}));
map.renderSync();
var innerHtml0 = ctrl.element_.innerHTML;
map.getView().setCenter([7, 52]);
map.renderSync();
var innerHtml52 = ctrl.element_.innerHTML;
expect(innerHtml0).to.not.be(innerHtml52);
});
it('is rendered the same at different latitudes for degrees', function() {
var ctrl = new ol.control.ScaleLine({
units: 'degrees'
});
ctrl.setMap(map);
map.setView(new ol.View({
center: ol.proj.fromLonLat([7, 0]),
zoom: 2,
projection: 'EPSG:4326'
}));
map.renderSync();
var innerHtml0 = ctrl.element_.innerHTML;
map.getView().setCenter([7, 52]);
map.renderSync();
var innerHtml52 = ctrl.element_.innerHTML;
expect(innerHtml0).to.be(innerHtml52);
});
});
describe('zoom affects the scaleline', function() {
var currentZoom;
var ctrl;

27
test/spec/ol/proj/index.test.js
View File

@@ -212,6 +212,33 @@ describe('ol.proj', function() {
});
describe('getPointResolution()', function() {
it('returns the correct point resolution for EPSG:4326', function() {
var pointResolution = ol.proj.getPointResolution('EPSG:4326', 1, [0, 0]);
expect (pointResolution).to.be(1);
pointResolution = ol.proj.getPointResolution('EPSG:4326', 1, [0, 52]);
expect (pointResolution).to.be(1);
});
it('returns the correct point resolution for EPSG:4326 with custom units', function() {
var pointResolution = ol.proj.getPointResolution('EPSG:4326', 1, [0, 0], 'm');
expect (pointResolution).to.roughlyEqual(111194.874284, 1e-5);
pointResolution = ol.proj.getPointResolution('EPSG:4326', 1, [0, 52], 'm');
expect (pointResolution).to.roughlyEqual(89826.367538, 1e-5);
});
it('returns the correct point resolution for EPSG:3857', function() {
var pointResolution = ol.proj.getPointResolution('EPSG:3857', 1, [0, 0]);
expect (pointResolution).to.be(1);
pointResolution = ol.proj.getPointResolution('EPSG:3857', 1, ol.proj.fromLonLat([0, 52]));
expect (pointResolution).to.roughlyEqual(0.615661, 1e-5);
});
it('returns the correct point resolution for EPSG:3857 with custom units', function() {
var pointResolution = ol.proj.getPointResolution('EPSG:3857', 1, [0, 0], 'degrees');
expect (pointResolution).to.be(1);
pointResolution = ol.proj.getPointResolution('EPSG:4326', 1, ol.proj.fromLonLat([0, 52]), 'degrees');
expect (pointResolution).to.be(1);
});
});
describe('Proj4js integration', function() {
var proj4 = window.proj4;