text: /**********************************************************************
   *
   * GEOS - Geometry Engine Open Source
   * http://geos.osgeo.org
   *
   * Copyright (C) 2005-2006 Refractions Research Inc.
   * Copyright (C) 2001-2002 Vivid Solutions Inc.
   *
   * This is free software; you can redistribute and/or modify it under
   * the terms of the GNU Lesser General Public Licence as published
   * by the Free Software Foundation. 
   * See the COPYING file for more information.
   *
   **********************************************************************/
  
  #ifndef GEOS_OPOVERLAY_H
  #define GEOS_OPOVERLAY_H
  
  namespace geos {
  namespace operation { 
  
  /** \brief
   * Contains classes that perform a topological overlay to compute boolean
   * spatial functions.
   * 
   * The Overlay Algorithm is used in spatial analysis methods for computing
   * set-theoretic operations (boolean combinations) of input {@link Geometry}s.
   * The algorithm for computing the overlay uses the intersection operations
   * supported by topology graphs.
   * To compute an overlay it is necessary to explicitly compute the resultant
   * graph formed by the computed intersections.
   * 
   * The algorithm to compute a set-theoretic spatial analysis method has the
   * following steps:
   * 
   *  - Build topology graphs of the two input geometries.  For each geometry all
   *    self-intersection nodes are computed and added to the graph.
   *  - Compute nodes for all intersections between edges and nodes of the graphs.
   *  - Compute the labeling for the computed nodes by merging the labels from
   *    the input graphs.
   *  - Compute new edges between the compute intersection nodes. 
   *    Label the edges appropriately.
   *  - Build the resultant graph from the new nodes and edges.
   *  - Compute the labeling for isolated components of the graph.  Add the
   *    isolated components to the resultant graph.
   *  - Compute the result of the boolean combination by selecting the node
   *    and edges with the appropriate labels. Polygonize areas and sew linear
   *    geometries together.
   * 
   * <h2>Package Specification</h2>
   * 
   * - Java Topology Suite Technical Specifications
   * - <A HREF="http://www.opengis.org/techno/specs.htm">
   *   OpenGIS Simple Features Specification for SQL</A>
   * 
   */
  namespace overlay { // geos.operation.overlay
  
  } // namespace geos.operation.overlay
  } // namespace geos.operation
  } // namespace geos
  
  #include <geos/operation/overlay/OverlayOp.h>
  //#include <geos/operation/overlay/PolygonBuilder.h>
  //#include <geos/operation/overlay/PointBuilder.h>
  //#include <geos/operation/overlay/LineBuilder.h>
  //#include <geos/operation/overlay/MinimalEdgeRing.h>
  //#include <geos/operation/overlay/MaximalEdgeRing.h>
  //#include <geos/operation/overlay/OverlayNodeFactory.h>
  //#include <geos/operation/overlay/EdgeSetNoder.h>
  //#include <geos/operation/overlay/ElevationMatrix.h>
  
  #endif
  
  