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

Handle view projections crossing dateline

Browse Source 
Use custom toLonLat transform to return wrapped longitudes for extents if view projection crosses the dateline.
Enhance the validation for center and extents to avoid proj4 errors.
This commit is contained in:
mike-000
2020-02-24 21:53:53 +00:00
committed by GitHub
parent 6ae6d0b835
commit 737f3a5066
1 changed files with 53 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

71
src/ol/layer/Graticule.js
View File

@@ -12,10 +12,18 @@ import VectorSource from '../source/Vector.js';
import {
equivalent as equivalentProjection,
get as getProjection,
getTransform,
transformExtent
getTransform
} from '../proj.js';
import {getCenter, getHeight, getWidth, intersects, equals, getIntersection, isEmpty} from '../extent.js';
import {
applyTransform,
equals,
getCenter,
getHeight,
getIntersection,
getWidth,
intersects,
isEmpty
} from '../extent.js';
import {clamp} from '../math.js';
import Style from '../style/Style.js';
import Feature from '../Feature.js';
@@ -665,24 +673,30 @@ class Graticule extends VectorLayer {
return;
}
const centerLonLat = this.toLonLatTransform_(center);
const validCenter = [
clamp(center[0], this.minLonP_, this.maxLonP_),
clamp(center[1], this.minLatP_, this.maxLatP_)
];
const centerLonLat = this.toLonLatTransform_(validCenter);
let centerLon = centerLonLat[0];
let centerLat = centerLonLat[1];
const maxLines = this.maxLines_;
let cnt, idx, lat, lon;
let validExtent = [
Math.max(extent[0], this.minLonP_),
Math.max(extent[1], this.minLatP_),
Math.min(extent[2], this.maxLonP_),
Math.min(extent[3], this.maxLatP_)
clamp(extent[0], this.minLonP_, this.maxLonP_),
clamp(extent[1], this.minLatP_, this.maxLatP_),
clamp(extent[2], this.minLonP_, this.maxLonP_),
clamp(extent[3], this.minLatP_, this.maxLatP_)
];
validExtent = transformExtent(validExtent, this.projection_, 'EPSG:4326', 8);
const maxLat = validExtent[3];
const maxLon = validExtent[2];
const minLat = validExtent[1];
const minLon = validExtent[0];
validExtent = applyTransform(validExtent, this.toLonLatTransform_, undefined, 8);
const maxLat = Math.min(validExtent[3], this.maxLat_);
const maxLon = Math.min(validExtent[2], this.maxLon_);
const minLat = Math.max(validExtent[1], this.minLat_);
const minLon = Math.max(validExtent[0], this.minLon_);
// Create meridians
@@ -897,22 +911,43 @@ class Graticule extends VectorLayer {
const epsg4326Projection = getProjection('EPSG:4326');
const worldExtent = projection.getWorldExtent();
const worldExtentP = transformExtent(worldExtent, epsg4326Projection, projection, 8);
this.maxLat_ = worldExtent[3];
this.maxLon_ = worldExtent[2];
this.minLat_ = worldExtent[1];
this.minLon_ = worldExtent[0];
const toLonLatTransform = getTransform(projection, epsg4326Projection);
if (this.minLon_ < this.maxLon_) {
this.toLonLatTransform_ = toLonLatTransform;
} else {
const split = this.minLon_ + this.maxLon_ / 2;
this.maxLon_ += 360;
this.toLonLatTransform_ = function(coordinates, opt_output, opt_dimension) {
const dimension = opt_dimension || 2;
const lonLatCoordinates = toLonLatTransform(coordinates, opt_output, dimension);
for (let i = 0, l = lonLatCoordinates.length; i < l; i += dimension) {
if (lonLatCoordinates[i] < split) {
lonLatCoordinates[i] += 360;
}
}
return lonLatCoordinates;
};
}
this.fromLonLatTransform_ = getTransform(epsg4326Projection, projection);
const worldExtentP = applyTransform(
[this.minLon_, this.minLat_, this.maxLon_, this.maxLat_],
this.fromLonLatTransform_,
undefined,
8
);
this.maxLatP_ = worldExtentP[3];
this.maxLonP_ = worldExtentP[2];
this.minLatP_ = worldExtentP[1];
this.minLonP_ = worldExtentP[0];
this.fromLonLatTransform_ = getTransform(epsg4326Projection, projection);
this.toLonLatTransform_ = getTransform(projection, epsg4326Projection);
this.projectionCenterLonLat_ = this.toLonLatTransform_(getCenter(projection.getExtent()));
this.projection_ = projection;