Fix nearest points types

src/allCFunctions.mjs

@@ -724,22 +724,22 @@ export function initCFunctions (config = {}) {
 
   /**
  * Compute the nearest points between two geometries.
- * @param {string} g1 - A JSON string representing a GEOSGeometry object
- * @param {string} g2 - A JSON string representing a GEOSGeometry object
- * @returns {string} A JSON string representing a GEOSGeometry object containing two points, or null on exception
+ * @param {number} g1 - A pointer to a GEOSGeometry object.
+ * @param {number} g2 - A pointer to a GEOSGeometry object.
+ * @returns {number} A pointer to a GEOSCoordSequence object containing two points, or null on exception.
  * @alias module:geos
   */
   geos.GEOSNearestPoints = null
 
   /**
  * Returns a GEOSCoordSequence of the nearest points between two geometries.
  * @param {number} handle - A pointer to the GEOS context handle.
- * @param {string} g1 - The first geometry as a WKT string.
- * @param {string} g2 - The second geometry as a WKT string.
- * @returns {string} A WKT string representing the GEOSCoordSequence of the nearest points.
+ * @param {number} g1 - A pointer to a GEOSGeometry object.
+ * @param {number} g2 - A pointer to a GEOSGeometry object.
+ * @returns {number} A pointer to a GEOSCoordSequence object containing two points, or null on exception.
  * @alias module:geos
   */
-  geos.GEOSNearestPoints_r = Module.cwrap('GEOSNearestPoints_r', 'string', ['number', 'string', 'string'])
+  geos.GEOSNearestPoints_r = Module.cwrap('GEOSNearestPoints_r', 'number', ['number', 'number', 'number'])
 
   /**
  * Returns a GEOSGeometry from a Well-Known Text (WKT) representation.

test/tests/GEOSNearestPoints.spec.mjs

@@ -0,0 +1,125 @@
+// This test is based on the following GEOS CAPI test:
+// https://github.com/libgeos/geos/blob/3.12.0/tests/unit/capi/GEOSNearestPointsTest.cpp
+import test from 'tape'
+import initGeosJs from '../../build/package/geos.esm.js'
+
+const geos = await initGeosJs()
+
+const checkNearestPoints = (t, wkt1, wkt2, x1, y1, x2, y2) => {
+  const wkt1Size = wkt1.length + 1
+  const wkt1Ptr = geos.Module._malloc(wkt1Size)
+  geos.Module.stringToUTF8(wkt1, wkt1Ptr, wkt1Size)
+  const geom1_ = geos.GEOSGeomFromWKT(wkt1Ptr)
+  geos.Module._free(wkt1Ptr)
+  t.ok(geom1_ !== null)
+
+  const wkt2Size = wkt2.length + 1
+  const wkt2Ptr = geos.Module._malloc(wkt2Size)
+  geos.Module.stringToUTF8(wkt2, wkt2Ptr, wkt2Size)
+  const geom2_ = geos.GEOSGeomFromWKT(wkt2Ptr)
+  geos.Module._free(wkt2Ptr)
+  t.ok(geom2_ !== null)
+  const coords_ = geos.GEOSNearestPoints(geom1_, geom2_)
+
+  const sizePtr = geos.Module._malloc(4)
+  geos.GEOSCoordSeq_getSize(coords_, sizePtr)
+  const size = geos.Module.getValue(sizePtr, 'i32')
+  geos.Module._free(sizePtr)
+  t.equal(size, 2, 'CoordSeq size')
+
+  const oxPtr = geos.Module._malloc(8)
+  const oyPtr = geos.Module._malloc(8)
+
+  // Point in geom1_
+  geos.GEOSCoordSeq_getOrdinate(coords_, 0, 0, oxPtr)
+  geos.GEOSCoordSeq_getOrdinate(coords_, 0, 1, oyPtr)
+  let ox = geos.Module.getValue(oxPtr, 'double')
+  let oy = geos.Module.getValue(oyPtr, 'double')
+  t.equal(ox, x1, 'P1 x')
+  t.equal(oy, y1, 'P1 y')
+
+  // Point in geom1_
+  geos.GEOSCoordSeq_getOrdinate(coords_, 1, 0, oxPtr)
+  geos.GEOSCoordSeq_getOrdinate(coords_, 1, 1, oyPtr)
+  ox = geos.Module.getValue(oxPtr, 'double')
+  oy = geos.Module.getValue(oyPtr, 'double')
+  t.equal(ox, x2, 'P2 x')
+  t.equal(oy, y2, 'P2 y')
+
+  geos.Module._free(oxPtr)
+  geos.Module._free(oyPtr)
+
+  geos.GEOSCoordSeq_destroy(coords_)
+}
+
+const checkNearestPointsNull = (t, wkt1, wkt2) => {
+  const wkt1Size = wkt1.length + 1
+  const wkt1Ptr = geos.Module._malloc(wkt1Size)
+  geos.Module.stringToUTF8(wkt1, wkt1Ptr, wkt1Size)
+  const geom1_ = geos.GEOSGeomFromWKT(wkt1Ptr)
+  t.ok(geom1_ !== 0)
+  const wkt2Size = wkt2.length + 1
+  const wkt2Ptr = geos.Module._malloc(wkt2Size)
+  geos.Module.stringToUTF8(wkt1, wkt2Ptr, wkt2Size)
+  const geom2_ = geos.GEOSGeomFromWKT(wkt2Ptr)
+  t.ok(geom2_ !== 0)
+  const coords_ = geos.GEOSNearestPoints(geom1_, geom2_)
+
+  t.ok(coords_ === 0)
+}
+
+test('1', (t) => {
+  checkNearestPointsNull(t, 'POLYGON EMPTY', 'POLYGON EMPTY')
+  t.end()
+})
+
+test('2', (t) => {
+  checkNearestPoints(
+    t,
+    'POLYGON((1 1,1 5,5 5,5 1,1 1))',
+    'POLYGON((8 8, 9 9, 9 10, 8 8))',
+    5, 5, 8, 8
+  )
+  t.end()
+})
+
+test('3', (t) => {
+  checkNearestPoints(
+    t,
+    'POLYGON((1 1,1 5,5 5,5 1,1 1))',
+    'POINT(2 2)',
+    2, 2, 2, 2
+  )
+  t.end()
+})
+
+test('4', (t) => {
+  checkNearestPoints(
+    t,
+    'LINESTRING(1 5,5 5,5 1,1 1)',
+    'POINT(2 2)',
+    2, 1, 2, 2
+  )
+  t.end()
+})
+
+test('5', (t) => {
+  checkNearestPoints(
+    t,
+    'LINESTRING(0 0,10 10)',
+    'LINESTRING(0 10,10 0)',
+    5, 5, 5, 5
+  )
+  t.end()
+})
+
+test('6', (t) => {
+  checkNearestPoints(
+    t,
+    'POLYGON((0 0,10 0,10 10,0 10,0 0))',
+    'LINESTRING(8 5,12 5)',
+    /* But could also be the intersection point... */
+    8, 5, 8, 5
+  )
+  t.end()
+})