src/core/qgsgeometry.h

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/***************************************************************************
  qgsgeometry.h - Geometry (stored as Open Geospatial Consortium WKB)
  -------------------------------------------------------------------
Date                 : 02 May 2005
Copyright            : (C) 2005 by Brendan Morley
email                : morb at ozemail dot com dot au
 ***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/
/* $Id$ */

#ifndef QGSGEOMETRY_H
#define QGSGEOMETRY_H

#include <QString>
#include <QVector>

#include "qgis.h"

#include <geos_c.h>

#if defined(GEOS_VERSION_MAJOR) && (GEOS_VERSION_MAJOR<3)
#define GEOSGeometry struct GEOSGeom_t
#define GEOSCoordSequence struct GEOSCoordSeq_t
#endif

#include "qgspoint.h"
#include "qgscoordinatetransform.h"

typedef QVector<QgsPoint> QgsPolyline;

typedef QVector<QgsPolyline> QgsPolygon;

typedef QVector<QgsPoint> QgsMultiPoint;

typedef QVector<QgsPolyline> QgsMultiPolyline;

typedef QVector<QgsPolygon> QgsMultiPolygon;

class QgsRectangle;

class CORE_EXPORT QgsGeometry
{
  public:
    QgsGeometry();

    QgsGeometry( QgsGeometry const & );

    QgsGeometry & operator=( QgsGeometry const & rhs );

    ~QgsGeometry();

    static QgsGeometry* fromWkt( QString wkt );

    static QgsGeometry* fromPoint( const QgsPoint& point );
    static QgsGeometry* fromMultiPoint( const QgsMultiPoint& multipoint );
    static QgsGeometry* fromPolyline( const QgsPolyline& polyline );
    static QgsGeometry* fromMultiPolyline( const QgsMultiPolyline& multiline );
    static QgsGeometry* fromPolygon( const QgsPolygon& polygon );
    static QgsGeometry* fromMultiPolygon( const QgsMultiPolygon& multipoly );
    static QgsGeometry* fromRect( const QgsRectangle& rect );
    void fromGeos( GEOSGeometry* geos );
    void fromWkb( unsigned char * wkb, size_t length );

    unsigned char * asWkb();

    size_t wkbSize();

    GEOSGeometry* asGeos();

    QGis::WkbType wkbType();

    QGis::GeometryType type();

    bool isMultipart();

    bool isGeosEqual( QgsGeometry & );

    bool isGeosValid();

    bool isGeosEmpty();

    double area();

    double length();

    double distance( QgsGeometry& geom );

    QgsPoint closestVertex( const QgsPoint& point, int& atVertex, int& beforeVertex, int& afterVertex, double& sqrDist );


    void adjacentVertices( int atVertex, int& beforeVertex, int& afterVertex );


    bool insertVertex( double x, double y, int beforeVertex );

    bool moveVertex( double x, double y, int atVertex );

    bool deleteVertex( int atVertex );

    QgsPoint vertexAt( int atVertex );

    double sqrDistToVertexAt( QgsPoint& point, int atVertex );

    double closestVertexWithContext( const QgsPoint& point, int& atVertex );

    double closestSegmentWithContext( const QgsPoint& point, QgsPoint& minDistPoint, int& beforeVertex );

    int addRing( const QList<QgsPoint>& ring );

    int addIsland( const QList<QgsPoint>& ring );

    int translate( double dx, double dy );

    int transform( const QgsCoordinateTransform& ct );

    int splitGeometry( const QList<QgsPoint>& splitLine,
                       QList<QgsGeometry*>&newGeometries,
                       bool topological,
                       QList<QgsPoint> &topologyTestPoints );

    int reshapeGeometry( const QList<QgsPoint>& reshapeWithLine );

    int makeDifference( QgsGeometry* other );

    QgsRectangle boundingBox();

    bool intersects( const QgsRectangle& r );

    bool intersects( QgsGeometry* geometry );

    bool contains( QgsPoint* p );

    bool contains( QgsGeometry* geometry );

    bool disjoint( QgsGeometry* geometry );

    bool equals( QgsGeometry* geometry );

    bool touches( QgsGeometry* geometry );

    bool overlaps( QgsGeometry* geometry );

    bool within( QgsGeometry* geometry );

    bool crosses( QgsGeometry* geometry );

    QgsGeometry* buffer( double distance, int segments );

    QgsGeometry* simplify( double tolerance );

    QgsGeometry* centroid();

    QgsGeometry* convexHull();

    QgsGeometry* intersection( QgsGeometry* geometry );

    QgsGeometry* combine( QgsGeometry* geometry );

    QgsGeometry* difference( QgsGeometry* geometry );

    QgsGeometry* symDifference( QgsGeometry* geometry );

    QString exportToWkt();

    /* Accessor functions for getting geometry data */

    QgsPoint asPoint();

    QgsPolyline asPolyline();

    QgsPolygon asPolygon();

    QgsMultiPoint asMultiPoint();

    QgsMultiPolyline asMultiPolyline();

    QgsMultiPolygon asMultiPolygon();

    QList<QgsGeometry*> asGeometryCollection();

    bool deleteRing( int ringNum, int partNum = 0 );

    bool deletePart( int partNum );

    bool convertToMultiType();

    int avoidIntersections();


    class Error
    {
        QString message;
        QgsPoint location;
        bool hasLocation;
      public:
        Error( QString m ) : message( m ), hasLocation( false ) {}
        Error( QString m, QgsPoint p ) : message( m ), location( p ), hasLocation( true ) {}

        QString what() { return message; };
        QgsPoint where() { return location; }
        bool hasWhere() { return hasLocation; }
    };

    void validateGeometry( QList<Error> &errors );

    static void validatePolyline( QList<Error> &errors, int i, QgsPolyline polyline, bool ring = false );
    static void validatePolygon( QList<Error> &errors, int i, const QgsPolygon &polygon );

  private:
    // Private variables

    // All of these are mutable since there may be on-the-fly
    // conversions between WKB, GEOS and Wkt;
    // However the intent is the const functions do not
    // semantically change the value that this object represents.

    unsigned char * mGeometry;

    size_t mGeometrySize;

    GEOSGeometry* mGeos;

    bool mDirtyWkb;

    bool mDirtyGeos;


    // Private functions

    bool exportWkbToGeos();

    bool exportGeosToWkb();

    bool insertVertex( double x, double y,
                       int beforeVertex,
                       const GEOSCoordSequence*  old_sequence,
                       GEOSCoordSequence** new_sequence );

    void translateVertex( int& wkbPosition, double dx, double dy, bool hasZValue );

    void transformVertex( int& wkbPosition, const QgsCoordinateTransform& ct, bool hasZValue );

    //helper functions for geometry splitting

    int splitLinearGeometry( GEOSGeometry *splitLine, QList<QgsGeometry*>& newGeometries );
    int splitPolygonGeometry( GEOSGeometry *splitLine, QList<QgsGeometry*>& newGeometries );
    int topologicalTestPointsSplit( const GEOSGeometry* splitLine, QList<QgsPoint>& testPoints ) const;

    static GEOSGeometry* reshapeLine( const GEOSGeometry* origLine, const GEOSGeometry* reshapeLineGeos );

    static GEOSGeometry* reshapePolygon( const GEOSGeometry* polygon, const GEOSGeometry* reshapeLineGeos );

    static GEOSGeometry* nodeGeometries( const GEOSGeometry *splitLine, const GEOSGeometry *poly );

    static int lineContainedInLine( const GEOSGeometry* line1, const GEOSGeometry* line2 );

    static int pointContainedInLine( const GEOSGeometry* point, const GEOSGeometry* line );

    static bool geomInDegrees( const GEOSGeometry* geom );

    int numberOfGeometries( GEOSGeometry* g ) const;

    int mergeGeometriesMultiTypeSplit( QVector<GEOSGeometry*>& splitResult );

    QgsPoint asPoint( unsigned char*& ptr, bool hasZValue );

    QgsPolyline asPolyline( unsigned char*& ptr, bool hasZValue );

    QgsPolygon asPolygon( unsigned char*& ptr, bool hasZValue );

    static void checkRingIntersections( QList<Error> &errors,
                                        int p0, int i0, const QgsPolyline &ring0,
                                        int p1, int i1, const QgsPolyline &ring1 );

    static bool geosRelOp( char( *op )( const GEOSGeometry*, const GEOSGeometry * ),
                           QgsGeometry *a, QgsGeometry *b );


    static int refcount;
}; // class QgsGeometry

#endif