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       1                 :            : /***************************************************************************
       2                 :            :                          qgsellipse.h
       3                 :            :                          --------------
       4                 :            :     begin                : March 2017
       5                 :            :     copyright            : (C) 2017 by Loîc Bartoletti
       6                 :            :     email                : lbartoletti at tuxfamily dot org
       7                 :            :  ***************************************************************************/
       8                 :            : 
       9                 :            : /***************************************************************************
      10                 :            :  *                                                                         *
      11                 :            :  *   This program is free software; you can redistribute it and/or modify  *
      12                 :            :  *   it under the terms of the GNU General Public License as published by  *
      13                 :            :  *   the Free Software Foundation; either version 2 of the License, or     *
      14                 :            :  *   (at your option) any later version.                                   *
      15                 :            :  *                                                                         *
      16                 :            :  ***************************************************************************/
      17                 :            : 
      18                 :            : #ifndef QGSELLIPSE_H
      19                 :            : #define QGSELLIPSE_H
      20                 :            : 
      21                 :            : #include <QString>
      22                 :            : 
      23                 :            : #include "qgis_core.h"
      24                 :            : #include "qgspoint.h"
      25                 :            : #include "qgspolygon.h"
      26                 :            : #include "qgslinestring.h"
      27                 :            : #include "qgsrectangle.h"
      28                 :            : 
      29                 :            : /**
      30                 :            :  * \ingroup core
      31                 :            :  * \class QgsEllipse
      32                 :            :  * \brief Ellipse geometry type.
      33                 :            :  *
      34                 :            :  * An ellipse is defined by a center point with a semi-major axis, a semi-minor axis and an azimuth.
      35                 :            :  * The azimuth is the north angle to the first quadrant (always oriented on the semi-major axis), in degrees. By default, the semi-major axis is oriented to the east (90 degrees).
      36                 :            :  * The semi-minor axis is always smaller than the semi-major axis. If it is set larger, it will be swapped and the azimuth will increase by 90 degrees.
      37                 :            :  * \since QGIS 3.0
      38                 :            :  */
      39                 :        161 : class CORE_EXPORT QgsEllipse
      40                 :            : {
      41                 :            : 
      42                 :            :   public:
      43                 :            : 
      44                 :            :     /**
      45                 :            :      * Constructor for QgsEllipse.
      46                 :            :      */
      47                 :         30 :     QgsEllipse() SIP_HOLDGIL = default;
      48                 :            : 
      49                 :        425 :     virtual ~QgsEllipse() = default;
      50                 :            : 
      51                 :            :     /**
      52                 :            :      * Constructs an ellipse by defining all the members.
      53                 :            :      * \param center The center of the ellipse.
      54                 :            :      * \param semiMajorAxis Semi-major axis of the ellipse.
      55                 :            :      * \param semiMinorAxis Semi-minor axis of the ellipse.
      56                 :            :      * \param azimuth Angle in degrees started from the North to the first quadrant.
      57                 :            :      */
      58                 :            :     QgsEllipse( const QgsPoint &center, double semiMajorAxis, double semiMinorAxis, double azimuth = 90 ) SIP_HOLDGIL;
      59                 :            : 
      60                 :            :     /**
      61                 :            :      * Constructs an ellipse by foci (\a pt1 and \a pt2) and a point \a pt3.
      62                 :            :      * The center point can have m value which is the result from the midpoint
      63                 :            :      * operation between \a pt1 and \a pt2. Z dimension is also supported and
      64                 :            :      * is retrieved from the first 3D point amongst \a pt1 and \a pt2.
      65                 :            :      * Axes are calculated from the 2D distance with the third point \a pt3.
      66                 :            :      * The azimuth is the angle between \a pt1 and \a pt2.
      67                 :            :      * \param pt1 First focus.
      68                 :            :      * \param pt2 Second focus.
      69                 :            :      * \param pt3 A point to calculate the axes.
      70                 :            :      */
      71                 :            :     static QgsEllipse fromFoci( const QgsPoint &pt1, const QgsPoint &pt2, const QgsPoint &pt3 ) SIP_HOLDGIL;
      72                 :            : 
      73                 :            :     /**
      74                 :            :      * Constructs an ellipse by an extent (aka bounding box / QgsRectangle).
      75                 :            :      * The center point can have m value which is the result from the midpoint
      76                 :            :      * operation between \a pt1 and \a pt2. Z dimension is also supported and
      77                 :            :      * is retrieved from the first 3D point amongst \a pt1 and \a pt2.
      78                 :            :      * Axes are calculated from the 2D distance between \a pt1 and \a pt2.
      79                 :            :      * The azimuth always takes the default value.
      80                 :            :      * \param pt1 First corner.
      81                 :            :      * \param pt2 Second corner.
      82                 :            :      */
      83                 :            :     static QgsEllipse fromExtent( const QgsPoint &pt1, const QgsPoint &pt2 ) SIP_HOLDGIL;
      84                 :            : 
      85                 :            :     /**
      86                 :            :      * Constructs an ellipse by a center point and a another point.
      87                 :            :      * The center point keeps m value from \a ptc. Z dimension is also
      88                 :            :      * supported and is retrieved from the first 3D point amongst \a ptc and
      89                 :            :      * \a pt1.
      90                 :            :      * Axes are calculated from the 2D distance between \a ptc and \a pt1.
      91                 :            :      * The azimuth always takes the default value.
      92                 :            :      * \param ptc Center point.
      93                 :            :      * \param pt1 First point.
      94                 :            :      */
      95                 :            :     static QgsEllipse fromCenterPoint( const QgsPoint &ptc, const QgsPoint &pt1 ) SIP_HOLDGIL;
      96                 :            : 
      97                 :            :     /**
      98                 :            :      * Constructs an ellipse by a central point and two other points.
      99                 :            :      * The center point keeps m value from \a ptc. Z dimension is also
     100                 :            :      * supported and is retrieved from the first 3D point amongst \a ptc,
     101                 :            :      * \a pt1 and \a pt2.
     102                 :            :      * Axes are calculated from the 2D distance between \a ptc and \a pt1 and \a pt2.
     103                 :            :      * The azimuth is the angle between \a ptc and \a pt1.
     104                 :            :      * \param ptc Center point.
     105                 :            :      * \param pt1 First point.
     106                 :            :      * \param pt2 Second point.
     107                 :            :      */
     108                 :            :     static QgsEllipse fromCenter2Points( const QgsPoint &ptc, const QgsPoint &pt1, const QgsPoint &pt2 ) SIP_HOLDGIL;
     109                 :            : 
     110                 :            :     virtual bool operator ==( const QgsEllipse &elp ) const;
     111                 :            :     virtual bool operator !=( const QgsEllipse &elp ) const;
     112                 :            : 
     113                 :            :     //! An ellipse is empty if axes are equal to 0
     114                 :            :     virtual bool isEmpty() const SIP_HOLDGIL;
     115                 :            : 
     116                 :            :     /**
     117                 :            :      * Returns the center point.
     118                 :            :      * \see setCenter()
     119                 :            :      * \see rcenter()
     120                 :            :      */
     121                 :         74 :     QgsPoint center() const SIP_HOLDGIL {return mCenter; }
     122                 :            : 
     123                 :            :     /**
     124                 :            :      * Returns the semi-major axis.
     125                 :            :      * \see setSemiMajorAxis()
     126                 :            :      */
     127                 :         11 :     double semiMajorAxis() const SIP_HOLDGIL {return mSemiMajorAxis; }
     128                 :            : 
     129                 :            :     /**
     130                 :            :      * Returns the semi-minor axis.
     131                 :            :      * \see setSemiMinorAxis()
     132                 :            :      */
     133                 :         10 :     double semiMinorAxis() const SIP_HOLDGIL {return mSemiMinorAxis; }
     134                 :            : 
     135                 :            :     /**
     136                 :            :      * Returns the azimuth.
     137                 :            :      * \see setAzimuth()
     138                 :            :      */
     139                 :          9 :     double azimuth() const SIP_HOLDGIL {return mAzimuth; }
     140                 :            : 
     141                 :            :     /**
     142                 :            :      * Returns a reference to the center point of this ellipse.
     143                 :            :      * Using a reference makes it possible to directly manipulate center in place.
     144                 :            :      * \see center()
     145                 :            :      * \see setCenter()
     146                 :            :      * \note not available in Python bindings
     147                 :            :      */
     148                 :          4 :     QgsPoint &rcenter() SIP_SKIP { return mCenter; }
     149                 :            : 
     150                 :            :     /**
     151                 :            :      * Sets the center point.
     152                 :            :      * \see center()
     153                 :            :      * \see rcenter()
     154                 :            :      */
     155                 :          2 :     void setCenter( const QgsPoint &center ) SIP_HOLDGIL {mCenter = center; }
     156                 :            : 
     157                 :            :     /**
     158                 :            :      * Sets the semi-major axis.
     159                 :            :      * \see semiMajorAxis()
     160                 :            :      */
     161                 :            :     virtual void setSemiMajorAxis( double semiMajorAxis ) SIP_HOLDGIL;
     162                 :            : 
     163                 :            :     /**
     164                 :            :      * Sets the semi-minor axis.
     165                 :            :      * \see semiMinorAxis()
     166                 :            :      */
     167                 :            :     virtual void setSemiMinorAxis( double semiMinorAxis ) SIP_HOLDGIL;
     168                 :            : 
     169                 :            :     /**
     170                 :            :      * Sets the azimuth (orientation).
     171                 :            :      * \see azimuth()
     172                 :            :      */
     173                 :            :     void setAzimuth( double azimuth ) SIP_HOLDGIL;
     174                 :            : 
     175                 :            :     /**
     176                 :            :      * The distance between the center and each foci.
     177                 :            :      * \see fromFoci()
     178                 :            :      * \see foci()
     179                 :            :      * \return The distance between the center and each foci.
     180                 :            :      */
     181                 :            :     virtual double focusDistance() const SIP_HOLDGIL;
     182                 :            : 
     183                 :            :     /**
     184                 :            :      * Two foci of the ellipse. The axes are oriented by the azimuth and are on the semi-major axis.
     185                 :            :      * \see fromFoci()
     186                 :            :      * \see focusDistance()
     187                 :            :      * \return the two foci.
     188                 :            :      */
     189                 :            :     virtual QVector<QgsPoint> foci() const;
     190                 :            : 
     191                 :            :     /**
     192                 :            :      * The eccentricity of the ellipse.
     193                 :            :      * nan is returned if the ellipse is empty.
     194                 :            :      */
     195                 :            :     virtual double eccentricity() const SIP_HOLDGIL;
     196                 :            :     //! The area of the ellipse.
     197                 :            :     virtual double area() const SIP_HOLDGIL;
     198                 :            :     //! The circumference of the ellipse using first approximation of Ramanujan.
     199                 :            :     virtual double perimeter() const SIP_HOLDGIL;
     200                 :            : 
     201                 :            :     /**
     202                 :            :      * The four quadrants of the ellipse.
     203                 :            :      * They are oriented and started always from semi-major axis.
     204                 :            :      * \return quadrants defined by four points.
     205                 :            :      */
     206                 :            :     virtual QVector<QgsPoint> quadrant() const;
     207                 :            : 
     208                 :            :     /**
     209                 :            :      * Returns a list of points with segmentation from \a segments.
     210                 :            :      * \param segments Number of segments used to segment geometry.
     211                 :            :      */
     212                 :            :     virtual QgsPointSequence points( unsigned int segments = 36 ) const;
     213                 :            : 
     214                 :            :     /**
     215                 :            :      * Returns a segmented polygon.
     216                 :            :      * \param segments Number of segments used to segment geometry.
     217                 :            :      */
     218                 :            :     virtual QgsPolygon *toPolygon( unsigned int segments = 36 ) const SIP_FACTORY;
     219                 :            : 
     220                 :            :     /**
     221                 :            :      * Returns a segmented linestring.
     222                 :            :      * \param segments Number of segments used to segment geometry.
     223                 :            :      */
     224                 :            :     virtual QgsLineString *toLineString( unsigned int segments = 36 ) const SIP_FACTORY;
     225                 :            :     //virtual QgsCurvePolygon toCurvePolygon() const;
     226                 :            : 
     227                 :            :     /**
     228                 :            :      * Returns the oriented minimal bounding box for the ellipse.
     229                 :            :      */
     230                 :            :     virtual QgsPolygon *orientedBoundingBox() const SIP_FACTORY;
     231                 :            : 
     232                 :            :     /**
     233                 :            :      * Returns the minimal bounding box for the ellipse.
     234                 :            :      */
     235                 :            :     virtual QgsRectangle boundingBox() const;
     236                 :            : 
     237                 :            :     /**
     238                 :            :      * returns a string representation of the ellipse.
     239                 :            :      * Members will be truncated to the specified precision.
     240                 :            :      */
     241                 :            :     virtual QString toString( int pointPrecision = 17, int axisPrecision = 17, int azimuthPrecision = 2 ) const;
     242                 :            : 
     243                 :            : #ifdef SIP_RUN
     244                 :            :     SIP_PYOBJECT __repr__();
     245                 :            :     % MethodCode
     246                 :            :     QString str = QStringLiteral( "<QgsEllipse: %1>" ).arg( sipCpp->toString() );
     247                 :            :     sipRes = PyUnicode_FromString( str.toUtf8().constData() );
     248                 :            :     % End
     249                 :            : #endif
     250                 :            : 
     251                 :            :   protected:
     252                 :            :     QgsPoint mCenter;
     253                 :         30 :     double mSemiMajorAxis = 0.0;
     254                 :         30 :     double mSemiMinorAxis = 0.0;
     255                 :         30 :     double mAzimuth = 90.0;
     256                 :            : 
     257                 :            :   private:
     258                 :            :     //! The semi-minor axis is always smaller than the semi-major axis. If it is set larger, it will be swapped and the azimuth will increase by 90 degrees.
     259                 :            :     void normalizeAxis();
     260                 :            : };
     261                 :            : 
     262                 :            : #endif // QGSELLIPSE_H