GEOS 3.3.1
CascadedUnion.h
00001 /**********************************************************************
00002  * $Id$
00003  *
00004  * GEOS - Geometry Engine Open Source
00005  * http://trac.osgeo.org/geos
00006  *
00007  * Copyright (C) 2011 Sandro Santilli <strk@keybit.net>
00008  *
00009  * This is free software; you can redistribute and/or modify it under
00010  * the terms of the GNU Lesser General Public Licence as published
00011  * by the Free Software Foundation. 
00012  * See the COPYING file for more information.
00013  *
00014  **********************************************************************
00015  *
00016  * Last port: ORIGINAL WORK, generalization of CascadedPolygonUnion
00017  *
00018  **********************************************************************/
00019 
00020 #ifndef GEOS_OP_UNION_CASCADEDUNION_H
00021 #define GEOS_OP_UNION_CASCADEDUNION_H
00022 
00023 #include <geos/export.h>
00024 
00025 #include <vector>
00026 #include <algorithm>
00027 
00028 #include "GeometryListHolder.h"
00029 
00030 // Forward declarations
00031 namespace geos {
00032     namespace geom {
00033         class GeometryFactory;
00034         class Geometry;
00035         class Geometry;
00036         class Envelope;
00037     }
00038     namespace index {
00039         namespace strtree {
00040             class ItemsList;
00041         }
00042     }
00043 }
00044 
00045 namespace geos {
00046 namespace operation { // geos::operation
00047 namespace geounion {  // geos::operation::geounion
00048 
00056 class GEOS_DLL CascadedUnion 
00057 {
00058 private:
00059     const std::vector<geom::Geometry*>* inputGeoms;
00060     geom::GeometryFactory const* geomFactory;
00061 
00069     static int const STRTREE_NODE_CAPACITY = 4;
00070 
00071 public:
00072     CascadedUnion();
00073 
00080     static geom::Geometry* Union(std::vector<geom::Geometry*>* geoms);
00081 
00089     template <class T>
00090     static geom::Geometry* Union(T start, T end)
00091     {
00092       std::vector<geom::Geometry*> polys;
00093       for (T i=start; i!=end; ++i) {
00094         const geom::Geometry* p = dynamic_cast<const geom::Geometry*>(*i);
00095         polys.push_back(const_cast<geom::Geometry*>(p));
00096       }
00097       return Union(&polys);
00098     }
00099 
00107     CascadedUnion(const std::vector<geom::Geometry*>* geoms)
00108       : inputGeoms(geoms),
00109         geomFactory(NULL)
00110     {}
00111 
00118     geom::Geometry* Union();
00119 
00120 private:
00121     geom::Geometry* unionTree(index::strtree::ItemsList* geomTree);
00122 
00128     geom::Geometry* binaryUnion(GeometryListHolder* geoms);
00129 
00139     geom::Geometry* binaryUnion(GeometryListHolder* geoms, std::size_t start, 
00140         std::size_t end);
00141 
00149     GeometryListHolder* reduceToGeometries(index::strtree::ItemsList* geomTree);
00150 
00160     geom::Geometry* unionSafe(geom::Geometry* g0, geom::Geometry* g1);
00161 
00162     geom::Geometry* unionOptimized(geom::Geometry* g0, geom::Geometry* g1);
00163 
00180     geom::Geometry* unionUsingEnvelopeIntersection(geom::Geometry* g0, 
00181         geom::Geometry* g1, geom::Envelope const& common);
00182 
00183     geom::Geometry* extractByEnvelope(geom::Envelope const& env, 
00184         geom::Geometry* geom, std::vector<geom::Geometry*>& disjointGeoms);
00185 
00193     static geom::Geometry* unionActual(geom::Geometry* g0, geom::Geometry* g1);
00194 };
00195 
00196 } // namespace geos::operation::union
00197 } // namespace geos::operation
00198 } // namespace geos
00199 
00200 #endif