/********************************************************************** * * GEOS - Geometry Engine Open Source * http://geos.osgeo.org * * Copyright (C) 2006 Refractions Research 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. * ********************************************************************** * * Last port: noding/snapround/SimpleSnapRounder.java r320 (JTS-1.12) * **********************************************************************/ #ifndef GEOS_NODING_SNAPROUND_SIMPLESNAPROUNDER_H #define GEOS_NODING_SNAPROUND_SIMPLESNAPROUNDER_H #include #include #include #include // for inheritance #include // for composition #include // for use in vector #include // for inlines (should drop) // Forward declarations namespace geos { namespace geom { //class PrecisionModel; } namespace algorithm { class LineIntersector; } namespace noding { class SegmentString; class NodedSegmentString; namespace snapround { class HotPixel; } } } namespace geos { namespace noding { // geos::noding namespace snapround { // geos::noding::snapround /** \brief * Uses Snap Rounding to compute a rounded, * fully noded arrangement from a set of {@link SegmentString}s. * * Implements the Snap Rounding technique described in * Hobby, Guibas & Marimont, and Goodrich et al. * Snap Rounding assumes that all vertices lie on a uniform grid * (hence the precision model of the input must be fixed precision, * and all the input vertices must be rounded to that precision). * * This implementation uses simple iteration over the line segments. * * This is not the most efficient approach for large sets of segments. * * This implementation appears to be fully robust using an integer * precision model. * It will function with non-integer precision models, but the * results are not 100% guaranteed to be correctly noded. * */ class GEOS_DLL SimpleSnapRounder: public Noder { // implements NoderIface public: SimpleSnapRounder(const geom::PrecisionModel& newPm); std::vector* getNodedSubstrings() const; void computeNodes(std::vector* inputSegmentStrings); void add(const SegmentString* segStr); /** * Computes nodes introduced as a result of * snapping segments to vertices of other segments * * @param edges the list of segment strings to snap together. * Must be NodedSegmentString or an assertion will fail. */ void computeVertexSnaps(const std::vector& edges); private: const geom::PrecisionModel& pm; algorithm::LineIntersector li; double scaleFactor; std::vector* nodedSegStrings; void checkCorrectness(std::vector& inputSegmentStrings); void snapRound(std::vector* segStrings, algorithm::LineIntersector& li); /** * Computes all interior intersections in the vector * of SegmentString, and fill the given vector * with their Coordinates. * * Does NOT node the segStrings. * * @param segStrings a vector of const Coordinates for the intersections * @param li the algorithm::LineIntersector to use * @param ret the vector to push intersection Coordinates to */ void findInteriorIntersections(std::vector& segStrings, algorithm::LineIntersector& li, std::vector& ret); /** \brief * Computes nodes introduced as a result of snapping segments to * snap points (hot pixels) * @param li */ void computeSnaps(const std::vector& segStrings, std::vector& snapPts); void computeSnaps(NodedSegmentString* ss, std::vector& snapPts); /** \brief * Performs a brute-force comparison of every segment in each * {@link SegmentString}. * This has n^2 performance. */ void computeVertexSnaps(NodedSegmentString* e0, NodedSegmentString* e1); // Declare type as noncopyable SimpleSnapRounder(const SimpleSnapRounder& other); SimpleSnapRounder& operator=(const SimpleSnapRounder& rhs); }; } // namespace geos::noding::snapround } // namespace geos::noding } // namespace geos #endif // GEOS_NODING_SNAPROUND_SIMPLESNAPROUNDER_H