feat(rust/sedona-proj): Let ST_Transform() handle 3D coordinates

c/sedona-proj/src/proj.rs

@@ -371,6 +371,17 @@ impl Proj {
         Ok((xyzt_out.0, xyzt_out.1))
     }
 
+    /// Transform XYZ coordinates
+    pub(crate) fn transform_xyz(
+        &mut self,
+        point: (f64, f64, f64),
+    ) -> Result<(f64, f64, f64), SedonaProjError> {
+        // Filling extra dimensions with zeroes is what PostGIS does
+        let xyzt = (point.0, point.1, point.2, 0.0);
+        let xyzt_out = self.transform(xyzt)?;
+        Ok((xyzt_out.0, xyzt_out.1, xyzt_out.2))
+    }
+
     /// Transform XYZT coordinates
     pub(crate) fn transform(
         &mut self,

c/sedona-proj/src/transform.rs

@@ -228,6 +228,18 @@ impl CrsTransform for ProjTransform {
         coord.1 = res.1;
         Ok(())
     }
+
+    fn transform_coord_3d(&self, coord: &mut (f64, f64, f64)) -> Result<(), SedonaGeometryError> {
+        let res = self.proj.borrow_mut().transform_xyz(*coord).map_err(|e| {
+            SedonaGeometryError::Invalid(format!(
+                "PROJ coordinate transformation failed with error: {e}"
+            ))
+        })?;
+        coord.0 = res.0;
+        coord.1 = res.1;
+        coord.2 = res.2;
+        Ok(())
+    }
 }
 
 #[cfg(test)]

python/sedonadb/tests/functions/test_transforms.py

@@ -31,6 +31,16 @@ def test_st_transform(eng):
     )
 
 
+@pytest.mark.parametrize("eng", [SedonaDB, PostGIS])
+def test_st_transform_3d(eng):
+    eng = eng.create_or_skip()
+    eng.assert_query_result(
+        "SELECT ST_Transform(ST_GeomFromText('POINT Z (1 1 1)'), 'EPSG:4979', 'EPSG:4978')",
+        "POINT Z (6376201.805927448 111297.016517882 110568.792276973)",
+        wkt_precision=9,
+    )
+
+
 @pytest.mark.parametrize("eng", [SedonaDB, PostGIS])
 @pytest.mark.parametrize(
     ("geom", "srid", "expected_srid"),