diff --git a/src/ol/coordinate.js b/src/ol/coordinate.js index ec9d2a101b..29048f173a 100644 --- a/src/ol/coordinate.js +++ b/src/ol/coordinate.js @@ -410,17 +410,22 @@ export function toStringXY(coordinate, opt_fractionDigits) { * @return {Coordinate} The coordinate within the real world extent. */ export function wrapX(coordinate, projection) { - const projectionExtent = projection.getExtent(); - if ( - projection.canWrapX() && - (coordinate[0] < projectionExtent[0] || - coordinate[0] >= projectionExtent[2]) - ) { - const worldWidth = getWidth(projectionExtent); - const worldsAway = Math.floor( - (coordinate[0] - projectionExtent[0]) / worldWidth - ); - coordinate[0] -= worldsAway * worldWidth; + const worldsAway = getWorldsAway(coordinate, projection); + if (worldsAway) { + coordinate[0] -= worldsAway * getWidth(projection.getExtent()); } return coordinate; } + +export function getWorldsAway(coordinate, projection) { + const projectionExtent = projection.getExtent(); + let worldsAway = 0; + if ( + projection.canWrapX() && + (coordinate[0] < projectionExtent[0] || coordinate[0] > projectionExtent[2]) + ) { + const worldWidth = getWidth(projectionExtent); + worldsAway = Math.floor((coordinate[0] - projectionExtent[0]) / worldWidth); + } + return worldsAway; +} diff --git a/src/ol/proj.js b/src/ol/proj.js index ed4e1e00b4..29f51cd817 100644 --- a/src/ol/proj.js +++ b/src/ol/proj.js @@ -71,9 +71,10 @@ import { clear as clearTransformFuncs, get as getTransformFunc, } from './proj/transforms.js'; -import {applyTransform} from './extent.js'; +import {applyTransform, getWidth} from './extent.js'; +import {clamp, modulo} from './math.js'; import {getDistance} from './sphere.js'; -import {modulo} from './math.js'; +import {getWorldsAway} from './coordinate.js'; /** * A projection as {@link module:ol/proj/Projection}, SRS identifier @@ -625,6 +626,55 @@ export function fromUserExtent(extent, destProjection) { return transformExtent(extent, userProjection, destProjection); } +/** + * Creates a safe coordinate transform function from a coordinate transform function. + * "Safe" means that it can handle wrapping of x-coordinates for global projections, + * and that coordinates exceeding the projection validity extent's range will be + * clamped to the validity range. + * @param {Projection} sourceProj Source projection. + * @param {Projection} destProj Destination projection. + * @param {function(import("./coordinate.js").Coordinate): import("./coordinate.js").Coordinate} forward Transform function (source to destiation). + * @param {function(import("./coordinate.js").Coordinate): import("./coordinate.js").Coordinate} inverse Transform function (destiation to source). + * @return {function(import("./coordinate.js").Coordinate): import("./coordinate.js").Coordinate} Safe transform function (source to destiation). + */ +export function createSafeCoordinateTransform( + sourceProj, + destProj, + forward, + inverse +) { + return function (coord) { + const worldsAway = getWorldsAway(coord, sourceProj); + const sourceExtent = sourceProj.getExtent(); + const destExtent = destProj.getExtent(); + let clampBottom, clampTop; + if (destExtent) { + const clampBottomLeft = inverse(destExtent.slice(0, 2)); + const clampTopRight = inverse(destExtent.slice(2, 4)); + clampBottom = isNaN(clampBottomLeft[1]) + ? sourceExtent + ? sourceExtent[1] + : undefined + : clampBottomLeft[1]; + clampTop = isNaN(clampTopRight[1]) + ? sourceExtent + ? sourceExtent[3] + : undefined + : clampTopRight[1]; + } + const transformed = sourceExtent + ? forward([ + coord[0] - worldsAway * getWidth(sourceExtent), + clampTop ? clamp(coord[1], clampBottom, clampTop) : coord[1], + ]) + : forward(coord); + if (worldsAway && destProj.canWrapX()) { + transformed[0] += worldsAway * getWidth(destProj.getExtent()); + } + return transformed; + }; +} + /** * Add transforms to and from EPSG:4326 and EPSG:3857. This function is called * by when this module is executed and should only need to be called again after diff --git a/src/ol/proj/proj4.js b/src/ol/proj/proj4.js index ca7c17cc35..f4fb255074 100644 --- a/src/ol/proj/proj4.js +++ b/src/ol/proj/proj4.js @@ -6,6 +6,7 @@ import { addCoordinateTransforms, addEquivalentProjections, addProjection, + createSafeCoordinateTransform, get, } from '../proj.js'; import {assign} from '../obj.js'; @@ -60,8 +61,18 @@ export function register(proj4) { addCoordinateTransforms( proj1, proj2, - transform.forward, - transform.inverse + createSafeCoordinateTransform( + proj1, + proj2, + transform.forward, + transform.inverse + ), + createSafeCoordinateTransform( + proj2, + proj1, + transform.inverse, + transform.forward + ) ); } } diff --git a/test/spec/ol/proj.test.js b/test/spec/ol/proj.test.js index 4d9592267e..bc5990256b 100644 --- a/test/spec/ol/proj.test.js +++ b/test/spec/ol/proj.test.js @@ -560,6 +560,25 @@ describe('ol.proj', function () { }); expect(getProjection('EPSG:4326')).to.equal(epsg4326); }); + + it('uses safe transform functions', function () { + register(proj4); + const wgs84 = getProjection('WGS84'); + const epsg4326 = getProjection('EPSG:4326'); + wgs84.setExtent(epsg4326.getExtent()); + wgs84.setGlobal(true); + const google = getProjection('GOOGLE'); + const epsg3857 = getProjection('EPSG:3857'); + google.setExtent(epsg3857.getExtent()); + google.setGlobal(true); + const coord = [-190, 90]; + const transformed = transform(coord, wgs84, google); + expect(transformed).to.eql(transform(coord, epsg4326, epsg3857)); + const got = transform(transformed, google, wgs84); + const expected = transform(transformed, epsg3857, epsg4326); + expect(got[0]).to.roughlyEqual(expected[0], 1e-9); + expect(got[1]).to.roughlyEqual(expected[1], 1e-9); + }); }); describe('ol.proj.getTransformFromProjections()', function () {