Let transform function transform all dimensions it is capable of

changelog/upgrade-notes.md

@@ -1,5 +1,28 @@
 ## Upgrade notes
 
+### v6.15.0
+
+#### Fixed coordinate dimesion handling in `ol/proj`'s `addCoordinateTransforms`
+
+The `forward` and `inverse` functions passed to `addCooordinateTransforms` now receive a coordinate with all dimensions of the original coordinate, not just two. If you previosly had coordinates with more than two dimensions and added a transform like
+```js
+addCoordinateTransforms(
+    'EPSG:4326',
+    new Projection({code: 'latlong', units: 'degrees}),
+    function(coordinate) { return coordinate.reverse(); },
+    function(coordinate) { return coordinate.reverse(); }
+);
+```
+you have to change that to
+```js
+addCoordinateTransforms(
+    'EPSG:4326',
+    new Projection({code: 'latlong', units: 'degrees}),
+    function(coordinate) { return coordinate.slice(0, 2).reverse() },
+    function(coordinate) { return coordinate.slice(0, 2).reverse() }
+);
+```
+
 ### v6.14.0
 
 No special changes are required when upgrading to the 6.14.0 release.

src/ol/proj.js

@@ -340,11 +340,10 @@ export function createTransformFromCoordinateTransform(coordTransform) {
       const dimension = opt_dimension !== undefined ? opt_dimension : 2;
       const output = opt_output !== undefined ? opt_output : new Array(length);
       for (let i = 0; i < length; i += dimension) {
-        const point = coordTransform([input[i], input[i + 1]]);
-        output[i] = point[0];
-        output[i + 1] = point[1];
-        for (let j = dimension - 1; j >= 2; --j) {
-          output[i + j] = input[i + j];
+        const point = coordTransform(input.slice(i, i + dimension));
+        const pointLength = point.length;
+        for (let j = 0, jj = dimension; j < jj; ++j) {
+          output[i + j] = j >= pointLength ? input[i + j] : point[j];
         }
       }
       return output;
@@ -368,7 +367,10 @@ export function createTransformFromCoordinateTransform(coordTransform) {
  * @param {function(import("./coordinate.js").Coordinate): import("./coordinate.js").Coordinate} inverse The inverse transform
  *     function (that is, from the destination projection to the source
  *     projection) that takes a {@link module:ol/coordinate~Coordinate} as argument and returns
- *     the transformed {@link module:ol/coordinate~Coordinate}.
+ *     the transformed {@link module:ol/coordinate~Coordinate}. If the transform function can only
+ *     transform less dimensions than the input coordinate, it is supposeed to return a coordinate
+ *     with only the length it can transform. The other dimensions will be taken unchanged from the
+ *     source.
  * @api
  */
 export function addCoordinateTransforms(source, destination, forward, inverse) {
@@ -706,20 +708,19 @@ export function fromUserResolution(resolution, destProjection) {
  */
 export function createSafeCoordinateTransform(sourceProj, destProj, transform) {
   return function (coord) {
-    let sourceX = coord[0];
-    let sourceY = coord[1];
     let transformed, worldsAway;
     if (sourceProj.canWrapX()) {
       const sourceExtent = sourceProj.getExtent();
       const sourceExtentWidth = getWidth(sourceExtent);
+      coord = coord.slice(0);
       worldsAway = getWorldsAway(coord, sourceProj, sourceExtentWidth);
       if (worldsAway) {
         // Move x to the real world
-        sourceX = sourceX - worldsAway * sourceExtentWidth;
+        coord[0] = coord[0] - worldsAway * sourceExtentWidth;
       }
-      sourceX = clamp(sourceX, sourceExtent[0], sourceExtent[2]);
-      sourceY = clamp(sourceY, sourceExtent[1], sourceExtent[3]);
-      transformed = transform([sourceX, sourceY]);
+      coord[0] = clamp(coord[0], sourceExtent[0], sourceExtent[2]);
+      coord[1] = clamp(coord[1], sourceExtent[1], sourceExtent[3]);
+      transformed = transform(coord);
     } else {
       transformed = transform(coord);
     }

test/node/ol/proj.test.js

@@ -7,6 +7,7 @@ import {HALF_SIZE} from '../../../src/ol/proj/epsg3857.js';
 import {
   METERS_PER_UNIT,
   addCommon,
+  addCoordinateTransforms,
   clearAllProjections,
   clearUserProjection,
   disableCoordinateWarning,
@@ -776,6 +777,26 @@ describe('ol/proj.js', function () {
       expect(got[2]).to.be(3);
     });
 
+    it('transforms a 3d coordinate with 2-dimension transform', function () {
+      const latlon = new Projection({
+        code: 'latlon',
+      });
+      addCoordinateTransforms(
+        'EPSG:4326',
+        latlon,
+        function (coordinate) {
+          return coordinate.slice(0, 2).reverse();
+        },
+        function (coordinate) {
+          return coordinate.slice(0, 2).reverse();
+        }
+      );
+
+      const got = transform([-10, -20, 3], 'EPSG:4326', latlon);
+      expect(got).to.have.length(3);
+      expect(got).to.eql([-20, -10, 3]);
+    });
+
     it('transforms a 4d coordinate', function () {
       const got = transform([-10, -20, 3, 4], 'EPSG:4326', 'EPSG:3857');
       expect(got).to.have.length(4);
@@ -805,6 +826,47 @@ describe('ol/proj.js', function () {
       addCommon();
     });
 
+    it('works with 3d points and proj4 defs for 3d transforms', function () {
+      proj4.defs(
+        'geocent',
+        '+proj=geocent +datum=WGS84 +ellps=WGS84 +units=m +no_defs'
+      );
+      register(proj4);
+
+      const got = transform(
+        [5584000, 2844000, 3448000],
+        'geocent',
+        'EPSG:4326'
+      );
+      expect(got).to.have.length(3);
+      expect(got[0]).to.roughlyEqual(26.990304649234826, 1e-9);
+      expect(got[1]).to.roughlyEqual(28.965718227798618, 1e-9);
+      expect(got[2]).to.roughlyEqual(779337.8584198505, 1e-9);
+
+      delete proj4.defs.geocent;
+      clearAllProjections();
+      addCommon();
+    });
+
+    it('works with 3d points and proj4 defs for 3d transforms with clamped extent', function () {
+      proj4.defs(
+        'geocent',
+        '+proj=geocent +datum=WGS84 +ellps=WGS84 +units=m +no_defs'
+      );
+      register(proj4);
+
+      const got = transform([-7.56234, 38.96618, 0], 'EPSG:4326', 'geocent');
+
+      expect(got).to.have.length(3);
+      expect(got[0]).to.roughlyEqual(4922499, 1);
+      expect(got[1]).to.roughlyEqual(-653508, 1);
+      expect(got[2]).to.roughlyEqual(3989398, 1);
+
+      delete proj4.defs.geocent;
+      clearAllProjections();
+      addCommon();
+    });
+
     it('does not flip axis order', function () {
       proj4.defs('enu', '+proj=longlat');
       proj4.defs('neu', '+proj=longlat +axis=neu');
@@ -812,7 +874,6 @@ describe('ol/proj.js', function () {
 
       const got = transform([1, 2], 'neu', 'enu');
       expect(got).to.eql([1, 2]);
-
       delete proj4.defs.enu;
       delete proj4.defs.neu;
       clearAllProjections();