v0.2.55..v0.2.56 changeset AlphaShape.h

diff --git a/hoot-core/src/main/cpp/hoot/core/algorithms/alpha-shape/AlphaShape.h b/hoot-core/src/main/cpp/hoot/core/algorithms/alpha-shape/AlphaShape.h
index e451509..2e72662 100644
--- a/hoot-core/src/main/cpp/hoot/core/algorithms/alpha-shape/AlphaShape.h
+++ b/hoot-core/src/main/cpp/hoot/core/algorithms/alpha-shape/AlphaShape.h
@@ -28,11 +28,15 @@
 #ifndef __ALPHASHAPE_H__
 #define __ALPHASHAPE_H__
 
-// Geos
+// GEOS
 #include <geos/geom/Geometry.h>
 #include <geos/geom/MultiPolygon.h>
 #include <geos/geom/Polygon.h>
 
+// GDAL
+#include <ogr_core.h>
+class OGRSpatialReference;
+
 // Qt
 #include <QString>
 
@@ -58,9 +62,12 @@ class OsmMap;
 class Way;
 
 /**
- * Technically a Alpha complex, not an Alpha Shape, but the literature seems to alternate between
- * the terms.
+ * Representation of an Alpha Shape. Technically an Alpha complex, not an Alpha Shape, but the
+ * literature seems to alternate between the terms.
  *
+ * https://github.com/ngageoint/hootenanny/files/595246/Hootenanny.-.Alpha.Shape.2013-03-07.pptx
+ * https://github.com/ngageoint/hootenanny/blob/master/docs/algorithms/AlphaShape.asciidoc
+ * https://github.com/ngageoint/hootenanny/wiki/files/2010-B-01-AlphaShapes.pdf
  */
 class AlphaShape
 {
@@ -70,44 +77,68 @@ public:
 
   static int logWarnCount;
 
+  /**
+   * Constructor
+   *
+   * @param alpha tuning parameter which determines the makeup of the output shape
+   */
   AlphaShape(double alpha);
 
+  /**
+   * Converts this shape to a GEOS geometry
+   *
+   * @return a GEOS geometry
+   */
   std::shared_ptr<geos::geom::Geometry> toGeometry();
 
+  /**
+   * Inserts points which are used to build the shape
+   *
+   * @param points a collection of points
+   */
   void insert(const std::vector<std::pair<double, double>>& points);
 
+  /**
+   * Returns a string representation of the shape
+   *
+   * @return a string
+   */
   QString toString();
 
-  std::shared_ptr<OsmMap> toOsmMap();
-
+  /**
+   * Returns the length of the longest face edge used to create the shape
+   *
+   * @return a length
+   */
   double getLongestFaceEdge() const { return _longestFaceEdge; }
 
 private:
 
+  friend class AlphaShapeTest;
+
+  // tuning parameter which determines the makeup of the output shape
   double _alpha;
 
+  // size of the longest face edge
   mutable double _longestFaceEdge;
 
+  // main data structures used to calculate the shape
   std::shared_ptr<Tgs::DelaunayTriangulation> _pDelauneyTriangles;
   std::set<std::pair<double, double>> _outsidePoint;
 
   std::shared_ptr<geos::geom::Polygon> _convertFaceToPolygon(const Tgs::Face& face) const;
 
-  // The root group represents empty space
-  // first level children represent filled space
-  // second level children are empty
-  // third filled
-  // etc, alternating at each level between filled and empty
-  std::shared_ptr<OsmMap> _groupFaces();
-
+  /*
+   * Returns true if the face is on the boundary of the triangulation
+   */
   bool _isBoundary(const Tgs::Edge& e) const;
 
-  /**
+  /*
    * Returns true if the face is inside an alpha shape.
    */
-  bool _isInside(const Tgs::Face &face) const;
+  bool _isInside(const Tgs::Face& face) const;
 
-  /**
+  /*
    * Returns true if this edge is part of the artificial outer bounds of the triangulation.
    */
   bool _isOutsideEdge(const Tgs::Edge& e) const;
@@ -116,6 +147,8 @@ private:
 
   std::shared_ptr<geos::geom::Geometry> _validateGeometry(
     const std::shared_ptr<geos::geom::Geometry>& g);
+
+  std::shared_ptr<OsmMap> _toOsmMap();
 };
 
 }