Add largest empty circle method to Geometry. (#78)

Author: jericks

doc/api/geom/geometry.rst

@@ -281,9 +281,10 @@ Common Geometry Methods
     Tests if this geometry is within the other geometry.  This is the
     inverse of :func:`contains`.
 
+.. function:: Geometry.getLargestEmptyCircle
 
+    :arg config: :`Object` tolerance property defaults to 1.0
+    :returns: :class:`geom.Geometry`
 
-
-
-
+    Get the largest empty circle in this Geometry.
 

src/main/java/org/geoscript/js/geom/Geometry.java

@@ -6,6 +6,7 @@
 import java.util.List;
 import java.util.Objects;
 
+import org.locationtech.jts.algorithm.construct.LargestEmptyCircle;
 import org.locationtech.jts.algorithm.construct.MaximumInscribedCircle;
 import org.locationtech.jts.densify.Densifier;
 import org.geoscript.js.GeoObject;
@@ -370,6 +371,16 @@ public ScriptableObject createDelaunayTriangles(boolean isConforming) {
         return triangles;
     }
 
+    @JSFunction
+    public Geometry getLargestEmptyCircle(NativeObject config) {
+        double tolerance = getDouble(config.getOrDefault("tolerance", 1.0));
+        LargestEmptyCircle algorithm = new LargestEmptyCircle(getGeometry(), tolerance);
+        return (Geometry) GeometryWrapper.wrap(
+            getParentScope(),
+            algorithm.getCenter().buffer(algorithm.getRadiusLine().getLength())
+        );
+    }
+
     @JSFunction
     public String getGeometryType() {
         return geometry.getGeometryType();

src/test/resources/org/geoscript/js/tests/geoscript/test_geom.js

@@ -176,6 +176,20 @@ exports["test: create random points"] = function() {
 
 }
 
+exports["test: largest empty circle"] = function() {
+
+    var geom = new GEOM.Polygon([[
+        [-122.38855361938475, 47.5805786829606], [-122.38636493682861, 47.5783206388176],
+        [-122.38700866699219, 47.5750491969984], [-122.38177299499512, 47.57502024527343],
+        [-122.38481998443604, 47.5780600889959], [-122.38151550292969, 47.5805786829606],
+        [-122.38855361938475, 47.5805786829606]
+    ]]);
+    ASSERT.ok(geom instanceof GEOM.Polygon);
+    var circle = geom.getLargestEmptyCircle({tolerance: 1.0});
+    ASSERT.ok(circle instanceof GEOM.Polygon);
+
+}
+
 exports["test: create conforming delaunay triangles"] = function() {
 
     var geom = GEOM.Point([1,1]).buffer(50)