qgsgeometryutils.h

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/***************************************************************************
                        qgsgeometryutils.h
  -------------------------------------------------------------------
Date                 : 21 Nov 2014
Copyright            : (C) 2014 by Marco Hugentobler
email                : marco.hugentobler at sourcepole dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSGEOMETRYUTILS_H
#define QGSGEOMETRYUTILS_H

#include "qgspointv2.h"
#include <limits>

class QgsLineStringV2;

class CORE_EXPORT QgsGeometryUtils
{
  public:

    static QList<QgsLineStringV2*> extractLineStrings( const QgsAbstractGeometryV2* geom );

    static QgsPointV2 closestVertex( const QgsAbstractGeometryV2& geom, const QgsPointV2& pt, QgsVertexId& id );

    static double distanceToVertex( const QgsAbstractGeometryV2& geom, const QgsVertexId& id );

    static bool verticesAtDistance( const QgsAbstractGeometryV2& geometry,
                                    double distance,
                                    QgsVertexId& previousVertex,
                                    QgsVertexId& nextVertex );

    static void adjacentVertices( const QgsAbstractGeometryV2& geom, QgsVertexId atVertex, QgsVertexId& beforeVertex, QgsVertexId& afterVertex );

    static double sqrDistance2D( const QgsPointV2& pt1, const QgsPointV2& pt2 );

    static double sqrDistToLine( double ptX, double ptY, double x1, double y1, double x2, double y2, double& minDistX, double& minDistY, double epsilon );

    static bool lineIntersection( const QgsPointV2& p1, QgsVector v, const QgsPointV2& q1, QgsVector w, QgsPointV2& inter );

    static bool segmentIntersection( const QgsPointV2 &p1, const QgsPointV2 &p2, const QgsPointV2 &q1, const QgsPointV2 &q2, QgsPointV2& inter, double tolerance );

    static QgsPointV2 projPointOnSegment( const QgsPointV2& p, const QgsPointV2& s1, const QgsPointV2& s2 )
    {
      double nx = s2.y() - s1.y();
      double ny = -( s2.x() - s1.x() );
      double t = ( p.x() * ny - p.y() * nx - s1.x() * ny + s1.y() * nx ) / (( s2.x() - s1.x() ) * ny - ( s2.y() - s1.y() ) * nx );
      return t < 0. ? s1 : t > 1. ? s2 : QgsPointV2( s1.x() + ( s2.x() - s1.x() ) * t, s1.y() + ( s2.y() - s1.y() ) * t );
    }

    struct SelfIntersection
    {
      int segment1;
      int segment2;
      QgsPointV2 point;
    };

    static QList<SelfIntersection> getSelfIntersections( const QgsAbstractGeometryV2* geom, int part, int ring, double tolerance );

    static double leftOfLine( double x, double y, double x1, double y1, double x2, double y2 );

    static QgsPointV2 pointOnLineWithDistance( const QgsPointV2& startPoint, const QgsPointV2& directionPoint, double distance );

    static double ccwAngle( double dy, double dx );

    static void circleCenterRadius( const QgsPointV2& pt1, const QgsPointV2& pt2, const QgsPointV2& pt3, double& radius,
                                    double& centerX, double& centerY );

    static bool circleClockwise( double angle1, double angle2, double angle3 );

    static bool circleAngleBetween( double angle, double angle1, double angle2, bool clockwise );

    static bool angleOnCircle( double angle, double angle1, double angle2, double angle3 );

    static double circleLength( double x1, double y1, double x2, double y2, double x3, double y3 );

    static double sweepAngle( double centerX, double centerY, double x1, double y1, double x2, double y2, double x3, double y3 );

    static bool segmentMidPoint( const QgsPointV2& p1, const QgsPointV2& p2, QgsPointV2& result, double radius, const QgsPointV2& mousePos );

    static double circleTangentDirection( const QgsPointV2& tangentPoint, const QgsPointV2& cp1, const QgsPointV2& cp2, const QgsPointV2& cp3 );

    static QgsPointSequenceV2 pointsFromWKT( const QString& wktCoordinateList, bool is3D, bool isMeasure );
    static void pointsToWKB( QgsWkbPtr &wkb, const QgsPointSequenceV2 &points, bool is3D, bool isMeasure );
    static QString pointsToWKT( const QgsPointSequenceV2 &points, int precision, bool is3D, bool isMeasure );
    static QDomElement pointsToGML2( const QgsPointSequenceV2 &points, QDomDocument &doc, int precision, const QString& ns );
    static QDomElement pointsToGML3( const QgsPointSequenceV2 &points, QDomDocument &doc, int precision, const QString& ns, bool is3D );
    static QString pointsToJSON( const QgsPointSequenceV2 &points, int precision );

    static double normalizedAngle( double angle );

    static double lineAngle( double x1, double y1, double x2, double y2 );

    static double linePerpendicularAngle( double x1, double y1, double x2, double y2 );

    static double averageAngle( double x1, double y1, double x2, double y2, double x3, double y3 );

    static double averageAngle( double a1, double a2 );

    static QPair<QgsWKBTypes::Type, QString> wktReadBlock( const QString& wkt );

    static QStringList wktGetChildBlocks( const QString& wkt , const QString &defaultType = "" );

    enum componentType
    {
      VERTEX,
      RING,
      PART
    };

    template<class T> static double closestSegmentFromComponents( T& container, componentType ctype, const QgsPointV2& pt, QgsPointV2& segmentPt,  QgsVertexId& vertexAfter, bool* leftOf, double epsilon )
    {
      double minDist = std::numeric_limits<double>::max();
      double minDistSegmentX = 0.0, minDistSegmentY = 0.0;
      QgsVertexId minDistVertexAfter;
      bool minDistLeftOf = false;
      double sqrDist = 0.0;
      int vertexOffset = 0;
      int ringOffset = 0;
      int partOffset = 0;

      for ( int i = 0; i < container.size(); ++i )
      {
        sqrDist = container.at( i )->closestSegment( pt, segmentPt, vertexAfter, leftOf, epsilon );
        if ( sqrDist >= 0 && sqrDist < minDist )
        {
          minDist = sqrDist;
          minDistSegmentX = segmentPt.x();
          minDistSegmentY = segmentPt.y();
          minDistVertexAfter = vertexAfter;
          minDistVertexAfter.vertex = vertexAfter.vertex + vertexOffset;
          minDistVertexAfter.part = vertexAfter.part + partOffset;
          minDistVertexAfter.ring = vertexAfter.ring + ringOffset;
          if ( leftOf )
          {
            minDistLeftOf = *leftOf;
          }
        }

        if ( ctype == VERTEX )
        {
          //-1 because compoundcurve counts duplicated vertices of neighbour curves as one node
          vertexOffset += container.at( i )->nCoordinates() - 1;
        }
        else if ( ctype == RING )
        {
          ringOffset += 1;
        }
        else if ( ctype == PART )
        {
          partOffset += 1;
        }
      }

      if ( minDist == std::numeric_limits<double>::max() )
        return -1;  // error: no segments

      segmentPt.setX( minDistSegmentX );
      segmentPt.setY( minDistSegmentY );
      vertexAfter = minDistVertexAfter;
      if ( leftOf )
      {
        *leftOf = minDistLeftOf;
      }
      return minDist;
    }
};

#endif // QGSGEOMETRYUTILS_H