[SEDONA-483] [SEDONA-491] Implement ST_IsPolygonCCW and ST_ForcePolygonCCW

common/src/main/java/org/apache/sedona/common/Functions.java

@@ -26,6 +26,7 @@
 import org.apache.sedona.common.utils.H3Utils;
 import org.apache.sedona.common.utils.S2Utils;
 import org.locationtech.jts.algorithm.MinimumBoundingCircle;
+import org.locationtech.jts.algorithm.Orientation;
 import org.locationtech.jts.algorithm.hull.ConcaveHull;
 import org.locationtech.jts.geom.*;
 import org.locationtech.jts.geom.impl.CoordinateArraySequence;
@@ -816,6 +817,92 @@ public static double lineLocatePoint(Geometry geom, Geometry point)
         return indexedLine.indexOf(point.getCoordinate()) / length;
     }
 
+    /**
+     * Forces a Polygon/MultiPolygon to use counter-clockwise orientation for the exterior ring and a clockwise for the interior ring(s).
+     * @param geom
+     * @return a counter-clockwise orientated (Multi)Polygon
+     */
+    public static Geometry forcePolygonCCW(Geometry geom) {
+        if (isPolygonCCW(geom)) {
+            return geom;
+        }
+
+        if (geom instanceof Polygon) {
+            return transformCCW((Polygon) geom);
+
+        } else if (geom instanceof MultiPolygon) {
+            List<Polygon> polygons = new ArrayList<>();
+            for (int i = 0; i < geom.getNumGeometries(); i++) {
+                Polygon polygon = (Polygon) geom.getGeometryN(i);
+                polygons.add((Polygon) transformCCW(polygon));
+            }
+
+            return new GeometryFactory().createMultiPolygon(polygons.toArray(new Polygon[0]));
+
+        }
+        // Non-polygonal geometries are returned unchanged
+        return geom;
+    }
+
+    private static Geometry transformCCW(Polygon polygon) {
+        LinearRing exteriorRing = polygon.getExteriorRing();
+        LinearRing exteriorRingEnforced = transformCCW(exteriorRing, true);
+
+        List<LinearRing> interiorRings = new ArrayList<>();
+        for (int i = 0; i < polygon.getNumInteriorRing(); i++) {
+            interiorRings.add(transformCCW(polygon.getInteriorRingN(i), false));
+        }
+
+        return new GeometryFactory(polygon.getPrecisionModel(), polygon.getSRID())
+                .createPolygon(exteriorRingEnforced, interiorRings.toArray(new LinearRing[0]));
+    }
+
+    private static LinearRing transformCCW(LinearRing ring, boolean isExteriorRing) {
+        boolean isRingCounterClockwise = Orientation.isCCW(ring.getCoordinateSequence());
+
+        LinearRing enforcedRing;
+        if (isExteriorRing) {
+            enforcedRing = isRingCounterClockwise ? (LinearRing) ring.copy() : ring.reverse();
+        } else {
+            enforcedRing = isRingCounterClockwise ? ring.reverse() : (LinearRing) ring.copy();
+        }
+        return enforcedRing;
+    }
+
+    /**
+     * This function accepts Polygon and MultiPolygon, if any other type is provided then it will return false.
+     * If the exterior ring is counter-clockwise and the interior ring(s) are clockwise then returns true, otherwise false.
+     * @param geom Polygon or MultiPolygon
+     * @return
+     */
+    public static boolean isPolygonCCW(Geometry geom) {
+        if (geom instanceof MultiPolygon) {
+            MultiPolygon multiPolygon = (MultiPolygon) geom;
+
+            boolean arePolygonsCCW = checkIfPolygonCCW(((Polygon) multiPolygon.getGeometryN(0)));
+            for (int i = 1; i < multiPolygon.getNumGeometries(); i++) {
+                arePolygonsCCW = arePolygonsCCW && checkIfPolygonCCW((Polygon) multiPolygon.getGeometryN(i));
+            }
+            return arePolygonsCCW;
+        } else if (geom instanceof Polygon) {
+            return checkIfPolygonCCW((Polygon) geom);
+        }
+        // False for remaining geometry types
+        return false;
+    }
+
+    private static boolean checkIfPolygonCCW(Polygon geom) {
+        LinearRing exteriorRing = geom.getExteriorRing();
+        boolean isExteriorRingCCW = Orientation.isCCW(exteriorRing.getCoordinateSequence());
+
+        boolean isInteriorRingCCW = !Orientation.isCCW(geom.getInteriorRingN(0).getCoordinateSequence());
+        for (int i = 1; i < geom.getNumInteriorRing(); i++) {
+            isInteriorRingCCW = isInteriorRingCCW && !Orientation.isCCW(geom.getInteriorRingN(i).getCoordinateSequence());
+        }
+
+        return isExteriorRingCCW && isInteriorRingCCW;
+    }
+
     public static Geometry difference(Geometry leftGeometry, Geometry rightGeometry) {
         boolean isIntersects = leftGeometry.intersects(rightGeometry);
         if (!isIntersects) {

common/src/test/java/org/apache/sedona/common/FunctionsTest.java

@@ -689,6 +689,53 @@ public void geometricMedian() throws Exception {
         assertEquals(0, expected.compareTo(actual, COORDINATE_SEQUENCE_COMPARATOR));
     }
 
+    @Test
+    public void testForcePolygonCCW() throws ParseException {
+        Geometry polyCW = Constructors.geomFromWKT("POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))", 0);
+        String actual = Functions.asWKT(Functions.forcePolygonCCW(polyCW));
+        String expected = "POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))";
+        assertEquals(expected, actual);
+
+        // both exterior ring and interior ring are counter-clockwise
+        polyCW = Constructors.geomFromWKT("POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))", 0);
+        actual = Functions.asWKT(Functions.forcePolygonCCW(polyCW));
+        expected = "POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))";
+        assertEquals(expected, actual);
+
+        Geometry mPoly = Constructors.geomFromWKT("MULTIPOLYGON (((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20)), ((40 40, 45 30, 20 45, 40 40)))", 0);
+        actual = Functions.asWKT(Functions.forcePolygonCCW(mPoly));
+        expected = "MULTIPOLYGON (((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20)), ((40 40, 20 45, 45 30, 40 40)))";
+        assertEquals(expected, actual);
+
+        mPoly = Constructors.geomFromWKT("MULTIPOLYGON (((0 0, 0 10, 10 10, 10 0, 0 0), (2 2, 8 2, 8 8, 2 8, 2 2), (4 4, 6 4, 6 6, 4 6, 4 4), (6 6, 8 6, 8 8, 6 8, 6 6), (3 3, 4 3, 4 4, 3 4, 3 3), (5 5, 6 5, 6 6, 5 6, 5 5), (7 7, 8 7, 8 8, 7 8, 7 7)))", 0);
+        actual = Functions.asWKT(Functions.forcePolygonCCW(mPoly));
+        expected = "MULTIPOLYGON (((0 0, 10 0, 10 10, 0 10, 0 0), (2 2, 2 8, 8 8, 8 2, 2 2), (4 4, 4 6, 6 6, 6 4, 4 4), (6 6, 6 8, 8 8, 8 6, 6 6), (3 3, 3 4, 4 4, 4 3, 3 3), (5 5, 5 6, 6 6, 6 5, 5 5), (7 7, 7 8, 8 8, 8 7, 7 7)))";
+        assertEquals(expected, actual);
+
+        Geometry nonPoly = Constructors.geomFromWKT("POINT (45 20)", 0);
+        actual = Functions.asWKT(Functions.forcePolygonCCW(nonPoly));
+        expected = Functions.asWKT(nonPoly);
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    public void testIsPolygonCCW() throws ParseException {
+        Geometry polyCCW = Constructors.geomFromWKT("POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35),(30 20, 20 15, 20 25, 30 20))", 0);
+        assertTrue(Functions.isPolygonCCW(polyCCW));
+
+        Geometry polyCW = Constructors.geomFromWKT("POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))", 0);
+        assertFalse(Functions.isPolygonCCW(polyCW));
+
+        Geometry mPoly = Constructors.geomFromWKT("MULTIPOLYGON (((0 0, 10 0, 10 10, 0 10, 0 0), (2 2, 2 8, 8 8, 8 2, 2 2), (4 4, 4 6, 6 6, 6 4, 4 4), (6 6, 6 8, 8 8, 8 6, 6 6), (3 3, 3 4, 4 4, 4 3, 3 3), (5 5, 5 6, 6 6, 6 5, 5 5), (7 7, 7 8, 8 8, 8 7, 7 7)))", 0);
+        assertTrue(Functions.isPolygonCCW(mPoly));
+
+        Geometry point = Constructors.geomFromWKT("POINT (45 20)", 0);
+        assertFalse(Functions.isPolygonCCW(point));
+
+        Geometry lineClosed = Constructors.geomFromWKT("LINESTRING (30 20, 20 25, 20 15, 30 20)", 0);
+        assertFalse(Functions.isPolygonCCW(lineClosed));
+    }
+
     @Test
     public void geometricMedianTolerance() throws Exception {
         MultiPoint multiPoint = GEOMETRY_FACTORY.createMultiPointFromCoords(

docs/api/flink/Function.md

@@ -1221,6 +1221,26 @@ Output:
 LINESTRING EMPTY
 ```
 
+## ST_ForcePolygonCCW
+
+Introduction: For (Multi)Polygon geometries, this function sets the exterior ring orientation to counter-clockwise and interior rings to clockwise orientation. Non-polygonal geometries are returned unchanged.
+
+Format: `ST_ForcePolygonCCW(geom: Geometry)`
+
+Since: `v1.6.0`
+
+SQL Example:
+
+```sql
+SELECT ST_AsText(ST_ForcePolygonCCW(ST_GeomFromText('POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))')))
+```
+
+Output:
+
+```
+POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))
+```
+
 ## ST_FrechetDistance
 
 Introduction: Computes and returns discrete [Frechet Distance](https://en.wikipedia.org/wiki/Fr%C3%A9chet_distance) between the given two geometries,
@@ -1630,6 +1650,26 @@ Output:
 false
 ```
 
+## ST_IsPolygonCCW
+
+Introduction: Returns true if all polygonal components in the input geometry have their exterior rings oriented counter-clockwise and interior rings oriented clockwise.
+
+Format: `ST_IsPolygonCCW(geom: Geometry)`
+
+Since: `v1.6.0`
+
+SQL Example:
+
+```sql
+SELECT ST_IsPolygonCCW(ST_GeomFromWKT('POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))'))
+```
+
+Output:
+
+```
+true
+```
+
 ## ST_IsRing
 
 Introduction: RETURN true if LINESTRING is ST_IsClosed and ST_IsSimple.

docs/api/snowflake/vector-data/Function.md

@@ -942,6 +942,24 @@ Input: `LINESTRING EMPTY`
 
 Output: `LINESTRING EMPTY`
 
+## ST_ForcePolygonCCW
+
+Introduction: For (Multi)Polygon geometries, this function sets the exterior ring orientation to counter-clockwise and interior rings to clockwise orientation. Non-polygonal geometries are returned unchanged.
+
+Format: `ST_ForcePolygonCCW(geom: Geometry)`
+
+SQL Example:
+
+```sql
+SELECT ST_AsText(ST_ForcePolygonCCW(ST_GeomFromText('POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))')))
+```
+
+Output:
+
+```
+POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))
+```
+
 ## ST_FrechetDistance
 
 Introduction: Computes and returns discrete [Frechet Distance](https://en.wikipedia.org/wiki/Fr%C3%A9chet_distance) between the given two geometries,
@@ -1168,6 +1186,24 @@ SELECT ST_IsEmpty(polygondf.countyshape)
 FROM polygondf
 ```
 
+## ST_IsPolygonCCW
+
+Introduction: Returns true if all polygonal components in the input geometry have their exterior rings oriented counter-clockwise and interior rings oriented clockwise.
+
+Format: `ST_IsPolygonCCW(geom: Geometry)`
+
+SQL Example:
+
+```sql
+SELECT ST_IsPolygonCCW(ST_GeomFromWKT('POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))'))
+```
+
+Output:
+
+```
+true
+```
+
 ## ST_IsRing
 
 Introduction: RETURN true if LINESTRING is ST_IsClosed and ST_IsSimple.

docs/api/sql/Function.md

@@ -1228,6 +1228,26 @@ Output:
 LINESTRING EMPTY
 ```
 
+## ST_ForcePolygonCCW
+
+Introduction: For (Multi)Polygon geometries, this function sets the exterior ring orientation to counter-clockwise and interior rings to clockwise orientation. Non-polygonal geometries are returned unchanged.
+
+Format: `ST_ForcePolygonCCW(geom: Geometry)`
+
+Since: `v1.6.0`
+
+SQL Example:
+
+```sql
+SELECT ST_AsText(ST_ForcePolygonCCW(ST_GeomFromText('POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))')))
+```
+
+Output:
+
+```
+POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))
+```
+
 ## ST_FrechetDistance
 
 Introduction: Computes and returns discrete [Frechet Distance](https://en.wikipedia.org/wiki/Fr%C3%A9chet_distance) between the given two geometries,
@@ -1638,6 +1658,26 @@ Output:
 false
 ```
 
+## ST_IsPolygonCCW
+
+Introduction: Returns true if all polygonal components in the input geometry have their exterior rings oriented counter-clockwise and interior rings oriented clockwise.
+
+Format: `ST_IsPolygonCCW(geom: Geometry)`
+
+Since: `v1.6.0`
+
+SQL Example:
+
+```sql
+SELECT ST_IsPolygonCCW(ST_GeomFromWKT('POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))'))
+```
+
+Output:
+
+```
+true
+```
+
 ## ST_IsRing
 
 Introduction: RETURN true if LINESTRING is ST_IsClosed and ST_IsSimple.

flink/src/main/java/org/apache/sedona/flink/Catalog.java

@@ -140,6 +140,8 @@ public static UserDefinedFunction[] getFuncs() {
                 new Functions.ST_NumPoints(),
                 new Functions.ST_Force3D(),
                 new Functions.ST_NRings(),
+                new Functions.ST_IsPolygonCCW(),
+                new Functions.ST_ForcePolygonCCW(),
                 new Functions.ST_Translate(),
                 new Functions.ST_VoronoiPolygons(),
                 new Functions.ST_FrechetDistance(),

flink/src/main/java/org/apache/sedona/flink/expressions/Functions.java

@@ -1007,6 +1007,22 @@ public int eval(@DataTypeHint(value = "RAW", bridgedTo = org.locationtech.jts.ge
         }
     }
 
+    public static class ST_ForcePolygonCCW extends ScalarFunction {
+        @DataTypeHint(value = "RAW", bridgedTo = org.locationtech.jts.geom.Geometry.class)
+        public Geometry eval(@DataTypeHint(value = "RAW", bridgedTo = org.locationtech.jts.geom.Geometry.class) Object o) {
+            Geometry geometry = (Geometry) o;
+            return org.apache.sedona.common.Functions.forcePolygonCCW(geometry);
+        }
+    }
+
+    public static class ST_IsPolygonCCW extends ScalarFunction {
+        @DataTypeHint("Boolean")
+        public boolean eval(@DataTypeHint(value = "RAW", bridgedTo = org.locationtech.jts.geom.Geometry.class) Object o) {
+            Geometry geom = (Geometry) o;
+            return org.apache.sedona.common.Functions.isPolygonCCW(geom);
+        }
+    }
+
     public static class ST_Translate extends ScalarFunction {
         @DataTypeHint(value = "RAW", bridgedTo = org.locationtech.jts.geom.Geometry.class)
         public Geometry eval(@DataTypeHint(value = "RAW", bridgedTo = org.locationtech.jts.geom.Geometry.class) Object o,

flink/src/test/java/org/apache/sedona/flink/FunctionTest.java

@@ -1195,6 +1195,25 @@ public void testNRings() {
         assertEquals(expected, actual);
     }
 
+    @Test
+    public void testForcePolygonCCW() {
+        Table polyTable = tableEnv.sqlQuery("SELECT ST_ForcePolygonCCW(ST_GeomFromWKT('POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))')) AS polyCW");
+        String actual = (String) first(polyTable.select(call(Functions.ST_AsText.class.getSimpleName(), $("polyCW")))).getField(0);
+        String expected = "POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))";
+        assertEquals(expected, actual);
+    }
+
+    @Test
+    public void testIsPolygonCCW() {
+        Table polyTable = tableEnv.sqlQuery("SELECT ST_GeomFromWKT('POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35),(30 20, 20 15, 20 25, 30 20))') AS polyCCW");
+        boolean actual = (boolean) first(polyTable.select(call(Functions.ST_IsPolygonCCW.class.getSimpleName(), $("polyCCW")))).getField(0);
+        assertTrue(actual);
+
+        polyTable = tableEnv.sqlQuery("SELECT ST_GeomFromWKT('POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))') AS polyCW");
+        actual = (boolean) first(polyTable.select(call(Functions.ST_IsPolygonCCW.class.getSimpleName(), $("polyCW")))).getField(0);
+        assertFalse(actual);
+    }
+
     @Test
     public void testTranslate() {
         Table polyTable = tableEnv.sqlQuery("SELECT ST_Translate(ST_GeomFromWKT('POLYGON ((1 0, 1 1, 2 1, 2 0, 1 0))'), 2, 5)" + "AS " + polygonColNames[0]);