IPolygon.hpp

#pragma once
 
#include "DM/config.hpp"
#include "DM/Handle.hpp"
#include "DM/IGeometry.hpp"
#include "DM/IPoint.hpp"
#include "DM/IAddInfo.hpp"
#include "DM/IAddInfoContainer.hpp"
#include "DM/Iterator.hpp"
#include "DM/IAddInfoStatistics.hpp"
 
DM_NAMESPACE_BEGIN
 
/// \brief interface to a 2.5d polygon of arbitrary complexity
/**
  The DM polygon object can handle arbitrary nested polygons (often called multi part polygons). The implementation is based
  on the CGAL nef polygons, a 2d polyhedron representation. Hence, positive regions (=part of the polygon) may contain an arbitrary number of negative 
  regions (=not part of the polygon. also called holes) contains positive regions again and so on defining a hierarchy (=levels of polygons)
  Additionally the number of level 0 polygons (top level hierarchy) is not limited.
 
  Such polygon objects can only be constructed by a corresponding polygon factory object. However, it has to be considered that there are some
  prerequisites regarding the topological correctness of the input data. see the IPolylineFactory for details
 
  The polygon object is structured in a hierarchy and can be traversed with the corresponding part iterators. To identify positive and negative
  region use the  IFace::positveFace member function of the corresponding part object. The part object has no nested parts if the IPart::sizePart
  retruns zero or the distance of the part iterators is empty.
 
  For accessing the points of part object use the corresponding point iterator functions. Note that points of positive regions are sorted 
  counterclockwise and points of negative regions clockwise. 
 
  For listing all polygon points in a non-hierarchical  manner use the point iterator function of the polygon object itself
*/
class DM_API IPolygon : public IGeometry, public IAddInfoContainer
{
public:
  class IFace;
  typedef ConstIterator<IPoint>    const_iterator_point;      ///< Point iterator
  typedef ConstIterator<IFace>     const_iterator_face;       ///< Face iterator
 
  class IFace : public ObjectBase {
  public:
    virtual ~IFace() {}
 
    virtual bool positveFace() const = 0; ///< returns true if part is a positive region (=belongs to polygon) or false otherise
 
    virtual bool isDegenerated() const = 0; ///< flag if the current part is degenerated (2d aera is zero)
 
    virtual int  sizePoint() const = 0; ///< number of points of the outer boundary 
    virtual int  sizePart() const = 0;  ///< number of nested parts
 
    virtual const_iterator_point beginPoint() const = 0;  ///< begin point iterator of outer boundary 
    virtual const_iterator_point endPoint() const = 0;    ///< end point iterator of outer boundary 
 
    virtual const_iterator_face beginPart() const = 0;
    virtual const_iterator_face endPart() const = 0;
  };
 
  IPolygon* clone() const override = 0;
  virtual ~IPolygon() {}
 
  virtual bool isEmpty() const = 0; ///< check if polygon is empty
 
  virtual int sizePoint() const = 0;  ///< number of all points within the polygon
  virtual int sizeFace() const = 0;   ///< number of all faces within the polygon
  virtual int sizePart() const = 0;   ///< number of parts (level-0 faces) of the polygons
 
  virtual const_iterator_point beginPoint() const = 0;
  virtual const_iterator_point endPoint() const = 0;
 
  virtual const_iterator_face beginFace() const = 0;
  virtual const_iterator_face endFace() const = 0;
 
  virtual const_iterator_face beginPart() const = 0;
  virtual const_iterator_face endPart()   const = 0;
 
  virtual double getArea() const = 0; ///< returns the 2d area of the polygon
 
  /// \brief returns the maximum hierarchy depth for this poylgon
  /** If a polygon is empty, then 0 is returned. If the polygon consists of one part or
      spatially separated parts (=positive faces) only, the depth is 1. If parts have one or multiples 
      holes (=negative face) than the depth is 2. If holes contains islands then the depth is 2 and so on.
 
      \param ignorDegeneratedFaces  flag if degenerated faces should be considered or not
      \returns maximum hierarchy depth
  */
  virtual unsigned getMaxDepth(bool ignorDegeneratedFaces=false) const = 0;
 
  /// \brief get add info statistic object for all line points
  virtual AddInfoStatisticsHandle getPointAddInfoStatistics() const = 0;
};
 
typedef Handle< IPolygon > PolygonHandle;
 
DM_NAMESPACE_END