[GEO] Add optional left/right parameter to GeoJSON

This feature adds an optional orientation parameter to the GeoJSON document and geo_shape mapping enabling users to explicitly define how they want Elasticsearch to interpret vertex ordering.  The default uses the right-hand rule (counterclockwise for outer ring, clockwise for inner ring) complying with OGC Simple Feature Access standards. The parameter can be explicitly specified for an entire index using the geo_shape mapping by adding "orientation":{"left"|"right"|"cw"|"ccw"|"clockwise"|"counterclockwise"} and/or overridden on each insert by adding the same parameter to the GeoJSON document.

closes #8764

Author: nknize

docs/reference/mapping/types/geo-shape-type.asciidoc

@@ -11,6 +11,7 @@ You can query documents using this type using
 or <<query-dsl-geo-shape-query,geo_shape
 Query>>.
 
+[[geo-shape-mapping-options]]
 [float]
 ==== Mapping Options
 
@@ -46,6 +47,17 @@ via the mapping API even if you use the precision parameter.
 |`distance_error_pct` |Used as a hint to the PrefixTree about how
 precise it should be. Defaults to 0.025 (2.5%) with 0.5 as the maximum
 supported value.
+
+|`orientation` |Optionally define how to interpret vertex order for
+polygons / multipolygons.  This parameter defines one of two coordinate
+system rules (Right-hand or Left-hand) each of which can be specified in three
+different ways. 1. Right-hand rule (default): `right`, `ccw`, `counterclockwise`,
+2. Left-hand rule: `left`, `cw`, `clockwise`. The default orientation
+(`counterclockwise`) complies with the OGC standard which defines
+outer ring vertices in counterclockwise order with inner ring(s) vertices (holes)
+in clockwise order. Setting this parameter in the geo_shape mapping explicitly
+sets vertex order for the coordinate list of a geo_shape field but can be
+overridden in each individual GeoJSON document.
 |=======================================================================
 
 [float]
@@ -246,7 +258,7 @@ defines the following vertex ordering:
 
 For polygons that do not cross the dateline, vertex order will not matter in
 Elasticsearch. For polygons that do cross the dateline, Elasticsearch requires
-vertex orderinging comply with the OGC specification. Otherwise, an unintended polygon
+vertex ordering to comply with the OGC specification. Otherwise, an unintended polygon
 may be created and unexpected query/filter results will be returned.
 
 The following provides an example of an ambiguous polygon.  Elasticsearch will apply
@@ -265,6 +277,24 @@ OGC standards to eliminate ambiguity resulting in a polygon that crosses the dat
 }
 --------------------------------------------------
 
+An `orientation` parameter can be defined when setting the geo_shape mapping (see <<geo-shape-mapping-options>>). This will define vertex
+order for the coordinate list on the mapped geo_shape field. It can also be overridden on each document.  The following is an example for
+overriding the orientation on a document:
+
+[source,js]
+--------------------------------------------------
+{
+    "location" : {
+        "type" : "polygon",
+        "orientation" : "clockwise",
+        "coordinates" : [
+            [ [-177.0, 10.0], [176.0, 15.0], [172.0, 0.0], [176.0, -15.0], [-177.0, -10.0], [-177.0, 10.0] ],
+            [ [178.2, 8.2], [-178.8, 8.2], [-180.8, -8.8], [178.2, 8.8] ]
+        ]
+    }
+}
+--------------------------------------------------
+
 [float]
 ===== http://www.geojson.org/geojson-spec.html#id5[MultiPoint]
 

src/main/java/org/elasticsearch/common/geo/builders/BasePolygonBuilder.java

@@ -48,6 +48,10 @@ public abstract class BasePolygonBuilder<E extends BasePolygonBuilder<E>> extend
     // List of linear rings defining the holes of the polygon 
     protected final ArrayList<BaseLineStringBuilder<?>> holes = new ArrayList<>();
 
+    public BasePolygonBuilder(Orientation orientation) {
+        super(orientation);
+    }
+
     @SuppressWarnings("unchecked")
     private E thisRef() {
         return (E)this;
@@ -125,9 +129,9 @@ public Coordinate[][][] coordinates() {
 
         Edge[] edges = new Edge[numEdges];
         Edge[] holeComponents = new Edge[holes.size()];
-        int offset = createEdges(0, false, shell, null, edges, 0);
+        int offset = createEdges(0, orientation.getValue(), shell, null, edges, 0);
         for (int i = 0; i < holes.size(); i++) {
-            int length = createEdges(i+1, true, shell, this.holes.get(i), edges, offset);
+            int length = createEdges(i+1, orientation.getValue(), shell, this.holes.get(i), edges, offset);
             holeComponents[i] = edges[offset];
             offset += length;
         }
@@ -453,11 +457,14 @@ private static void connect(Edge in, Edge out) {
         }
     }
 
-    private static int createEdges(int component, boolean direction, BaseLineStringBuilder<?> shell, BaseLineStringBuilder<?> hole,
+    private static int createEdges(int component, boolean orientation, BaseLineStringBuilder<?> shell,
+                                   BaseLineStringBuilder<?> hole,
                                    Edge[] edges, int offset) {
+        // inner rings (holes) have an opposite direction than the outer rings
+        boolean direction = (component != 0) ? !orientation : orientation;
         // set the points array accordingly (shell or hole)
         Coordinate[] points = (hole != null) ? hole.coordinates(false) : shell.coordinates(false);
-        Edge.ring(component, direction, shell, points, 0, edges, offset, points.length-1);
+        Edge.ring(component, direction, orientation, shell, points, 0, edges, offset, points.length-1);
         return points.length-1;
     }
 

src/main/java/org/elasticsearch/common/geo/builders/EnvelopeBuilder.java

@@ -32,6 +32,14 @@ public class EnvelopeBuilder extends ShapeBuilder {
     protected Coordinate topLeft;
     protected Coordinate bottomRight;
 
+    public EnvelopeBuilder() {
+        this(Orientation.RIGHT);
+    }
+
+    public EnvelopeBuilder(Orientation orientation) {
+        super(orientation);
+    }
+
     public EnvelopeBuilder topLeft(Coordinate topLeft) {
         this.topLeft = topLeft;
         return this;

src/main/java/org/elasticsearch/common/geo/builders/GeometryCollectionBuilder.java

@@ -33,6 +33,14 @@ public class GeometryCollectionBuilder extends ShapeBuilder {
 
     protected final ArrayList<ShapeBuilder> shapes = new ArrayList<>();
 
+    public GeometryCollectionBuilder() {
+        this(Orientation.RIGHT);
+    }
+
+    public GeometryCollectionBuilder(Orientation orientation) {
+        super(orientation);
+    }
+
     public GeometryCollectionBuilder shape(ShapeBuilder shape) {
         this.shapes.add(shape);
         return this;

src/main/java/org/elasticsearch/common/geo/builders/MultiPolygonBuilder.java

@@ -35,13 +35,25 @@ public class MultiPolygonBuilder extends ShapeBuilder {
 
     protected final ArrayList<BasePolygonBuilder<?>> polygons = new ArrayList<>();
 
+    public MultiPolygonBuilder() {
+        this(Orientation.RIGHT);
+    }
+
+    public MultiPolygonBuilder(Orientation orientation) {
+        super(orientation);
+    }
+
     public MultiPolygonBuilder polygon(BasePolygonBuilder<?> polygon) {
         this.polygons.add(polygon);
         return this;
     }
 
     public InternalPolygonBuilder polygon() {
-        InternalPolygonBuilder polygon = new InternalPolygonBuilder(this);
+        return polygon(Orientation.RIGHT);
+    }
+
+    public InternalPolygonBuilder polygon(Orientation orientation) {
+        InternalPolygonBuilder polygon = new InternalPolygonBuilder(this, orientation);
         this.polygon(polygon);
         return polygon;
     }
@@ -92,8 +104,8 @@ public static class InternalPolygonBuilder extends BasePolygonBuilder<InternalPo
 
         private final MultiPolygonBuilder collection;
 
-        private InternalPolygonBuilder(MultiPolygonBuilder collection) {
-            super();
+        private InternalPolygonBuilder(MultiPolygonBuilder collection, Orientation orientation) {
+            super(orientation);
             this.collection = collection;
             this.shell = new Ring<>(this);
         }

src/main/java/org/elasticsearch/common/geo/builders/PolygonBuilder.java

@@ -26,11 +26,15 @@
 public class PolygonBuilder extends BasePolygonBuilder<PolygonBuilder> {
 
     public PolygonBuilder() {
-        this(new ArrayList<Coordinate>());
+        this(new ArrayList<Coordinate>(), Orientation.RIGHT);
     }
 
-    protected PolygonBuilder(ArrayList<Coordinate> points) {
-        super();
+    public PolygonBuilder(Orientation orientation) {
+        this(new ArrayList<Coordinate>(), orientation);
+    }
+
+    protected PolygonBuilder(ArrayList<Coordinate> points, Orientation orientation) {
+        super(orientation);
         this.shell = new Ring<>(this, points);
     }