/********************************************************************** * * GEOS - Geometry Engine Open Source * http://geos.osgeo.org * * Copyright (C) 2021 Paul Ramsey * Copyright (C) 2021 Martin Davis * * 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. * **********************************************************************/ #pragma once #include #include // Forward declarations namespace geos { namespace geom { class Coordinate; } } namespace geos { // geos. namespace operation { // geos.operation namespace valid { // geos.operation.valid using geos::geom::Coordinate; class GEOS_DLL PolygonNode { private: /** * Tests if an edge p is between edges e0 and e1, * where the edges all originate at a common origin. * The "inside" of e0 and e1 is the arc which does not include the origin. * The edges are assumed to be distinct (non-collinear). * * @param origin the origin * @param p the destination point of edge p * @param e0 the destination point of edge e0 * @param e1 the destination point of edge e1 * @return true if p is between e0 and e1 */ static bool isBetween(const Coordinate* origin, const Coordinate* p, const Coordinate* e0, const Coordinate* e1); /** * Tests if the angle with the origin of a vector P is greater than that of the * vector Q. * * @param origin the origin of the vectors * @param p the endpoint of the vector P * @param q the endpoint of the vector Q * @return true if vector P has angle greater than Q */ static bool isAngleGreater(const Coordinate* origin, const Coordinate* p, const Coordinate* q); static int quadrant(const Coordinate* origin, const Coordinate* p); public: /** * Check if the edges at a node between two rings (or one ring) cross. * The node is topologically valid if the ring edges do not cross. * This function assumes that the edges are not collinear. * * @param nodePt the node location * @param a0 the previous edge endpoint in a ring * @param a1 the next edge endpoint in a ring * @param b0 the previous edge endpoint in the other ring * @param b1 the next edge endpoint in the other ring * @return true if the edges cross at the node */ static bool isCrossing(const Coordinate* nodePt, const Coordinate* a0, const Coordinate* a1, const Coordinate* b0, const Coordinate* b1); /** * Tests whether an edge node-b lies in the interior or exterior * of a corner of a ring given by a0-node-a1. * The ring interior is assumed to be on the right of the corner (a CW ring). * The edge must not be collinear with the corner segments. * * @param nodePt the node location * @param a0 the first vertex of the corner * @param a1 the second vertex of the corner * @param b the destination vertex of the edge * @return true if the edge is interior to the ring corner */ static bool isInteriorSegment(const Coordinate* nodePt, const Coordinate* a0, const Coordinate* a1, const Coordinate* b); }; } // namespace geos.operation.valid } // namespace geos.operation } // namespace geos