include/geos/noding/OrientedCoordinateArray.h

   1 /**********************************************************************
   2  *
   3  * GEOS - Geometry Engine Open Source
   4  * http://geos.osgeo.org
   5  *
   6  * Copyright (C) 2009    Sandro Santilli <strk@keybit.net>
   7  *
   8  * This is free software; you can redistribute and/or modify it under
   9  * the terms of the GNU Lesser General Public Licence as published
  10  * by the Free Software Foundation.
  11  * See the COPYING file for more information.
  12  *
  13  **********************************************************************
  14  *
  15  * Last port: noding/OrientedCoordinateArray.java rev. 1.1 (JTS-1.9)
  16  *
  17  **********************************************************************/
  18
  19 #ifndef GEOS_NODING_ORIENTEDCOORDINATEARRAY_H
  20 #define GEOS_NODING_ORIENTEDCOORDINATEARRAY_H
  21
  22 #include <geos/export.h>
  23
  24 //#include <vector>
  25 //#include <iostream>
  26
  27 //#include <geos/inline.h>
  28
  29 // Forward declarations
  30 namespace geos {
  31         namespace geom {
  32                 class CoordinateSequence;
  33         }
  34         namespace noding {
  35                 //class SegmentString;
  36         }
  37 }
  38
  39 namespace geos {
  40 namespace noding { // geos.noding
  41
  42 /** \brief
  43  * Allows comparing {@link geom::CoordinateSequence}s
  44  * in an orientation-independent way.
  45  */
  46 class GEOS_DLL OrientedCoordinateArray
  47 {
  48 public:
  49
  50         /**
  51          * Creates a new {@link OrientedCoordinateArray}
  52          * for the given {@link geom::CoordinateSequence}.
  53          *
  54          * @param pts the coordinates to orient
  55          */
  56         OrientedCoordinateArray(const geom::CoordinateSequence& pts)
  57                 :
  58                 pts(pts),
  59                 orientationVar(orientation(pts))
  60         {
  61         }
  62
  63         /** \brief
  64          * Compares two {@link OrientedCoordinateArray}s for their
  65          * relative order
  66          *
  67          * @return -1 this one is smaller
  68          * @return 0 the two objects are equal
  69          * @return 1 this one is greater
  70          *
  71          * In JTS, this is used automatically by ordered lists.
  72          * In C++, operator< would be used instead....
  73          */
  74         int compareTo(const OrientedCoordinateArray& o1) const;
  75
  76
  77 private:
  78
  79         static int compareOriented(const geom::CoordinateSequence& pts1,
  80                                      bool orientation1,
  81                                      const geom::CoordinateSequence& pts2,
  82                                      bool orientation2);
  83
  84
  85         /**
  86          * Computes the canonical orientation for a coordinate array.
  87          *
  88          * @param pts the array to test
  89          * @return <code>true</code> if the points are oriented forwards
  90          * @return <code>false</code if the points are oriented in reverse
  91          */
  92         static bool orientation(const geom::CoordinateSequence& pts);
  93
  94         /// Externally owned
  95         const geom::CoordinateSequence& pts;
  96
  97         bool orientationVar;
  98
  99     // Declare type as noncopyable
 100     OrientedCoordinateArray(const OrientedCoordinateArray& other);
 101     OrientedCoordinateArray& operator=(const OrientedCoordinateArray& rhs);
 102 };
 103
 104 } // namespace geos.noding
 105 } // namespace geos
 106
 107
 108 #endif // GEOS_NODING_ORIENTEDCOORDINATEARRAY_H
 109