Halfedge Class Reference

This class encapsulate a halfedge over a window manifold. More...

#include <Manifold_2.h>

Collaboration diagram for Halfedge:

Public Member Functions
	Halfedge ()
	Halfedge (const Pane_manifold_2 *pm, Edge_ID e, Access_Mode mode)
	Construct a Halfedge object from a pane manifold and its edge ID. More...
Halfedge	opposite () const
	Get the ID of the opposite edge of a given edge. More...
Halfedge	prev () const
	Get the previous halfedge of its owner element. More...
Halfedge	next () const
	Get the next halfedge of its owner element. More...
Node	origin () const
	Obtain the (primary copy of the) origin of the edge. More...
Node	destination () const
	Obtain the (primary copy of the) destination of the edge. More...
bool	is_border () const
	Is the edge a border edge? More...
bool	is_physical_border () const
	Is the edge on the physical boundary? More...
Vector_3< Real >	tangent () const
	Get the tangent of the given halfedge. More...
Vector_3< Real >	normal () const
	Get the normal of the incident facet. More...
Vector_3< Real >	deformed_normal (const COM::Attribute *disp) const
	Get the normal of the deformed shape (coordinates plus given displacements) of the incident facet of the halfedge. More...
void	edge_center (Point_3< Real > &mid) const
	Get the edge center of the given halfedge. More...
void	face_center (Point_3< Real > &cnt) const
	Get the face center of the incident face of a given halfedge. More...
template<class Value >
void	edge_average (const COM::Attribute *attr, Value &val) const
	Get the avarage value of the nodes of a given halfedge. More...
template<class Value >
void	face_average (const COM::Attribute *attr, Value &val) const
	Get the average value of the nodes of the incident face of a given halfedge. More...
double	dihedral_angle () const
	Return the dihedral angle at the edge. More...
const Pane_manifold_2 *	pane_manifold () const
	Obtain the pane manifold that owns the edge. More...
const COM::Pane *	pane () const
	Obtain the owner Pane_manifold_2 of the node. More...
Edge_ID	id () const
	Obtain the ID of the edge. More...
const void *	addr (const COM::Attribute *attr) const
	Obtain the address of an attribute associated with its bounded element. More...
const COM::Attribute *	attr (const COM::Attribute *a) const
	Obtain the attribute on the parent pane of the node. More...
bool	operator== (const Halfedge &h) const
	Are two halfedges the same? More...
bool	operator!= (const Halfedge &h) const
	Are two halfedges different? More...
bool	operator< (const Halfedge &h) const
	Does the current halfedge has a smaller ID then the given one? More...

Protected Attributes
const Pane_manifold_2 *	_pm
Edge_ID	_eID
Access_Mode	_mode

Detailed Description

This class encapsulate a halfedge over a window manifold.

Definition at line 446 of file Manifold_2.h.

Constructor & Destructor Documentation

Halfedge ( )

inline

Definition at line 448 of file Manifold_2.h.

: _pm(NULL) {}

Halfedge ( const Pane_manifold_2 *  pm, Edge_ID  e, Access_Mode  mode  )

inline

Construct a Halfedge object from a pane manifold and its edge ID.

Definition at line 450 of file Manifold_2.h.

    : _pm( pm), _eID( e), _mode(mode) {}

Member Function Documentation

const void * addr

(

const COM::Attribute *

attr

)

const

Obtain the address of an attribute associated with its bounded element.

Note: This function can be slow O(1) if the attribute is not on the current pane, and is even slower (O(log(#panes)) if not owned by the owner window of the pane.

Definition at line 1215 of file Manifold_2.C.

References _eID, _pm, attr(), COM_assertion, COM_assertion_msg, COM_get_sizeof(), is_border(), and Simple_manifold_2::pane().

                                                       {
  COM_assertion( !is_border());
  COM_assertion_msg( a, "Unexpected NULL pointer");
  COM_assertion_msg( a->is_elemental(), "Expect a element-centered attribute");

  const COM::Attribute *attr;

  const COM::Pane *pn = _pm->pane();
  int pid = pn->id();
  if ( a->pane()->id() == pid) 
    attr = a;
  else {
    if ( a->window() != pn->window()) {
      pn = &a->window()->pane( pid);
      COM_assertion_msg( pn, "Pane does not exist");
    }
    attr=pn->attribute( a->id());
    COM_assertion_msg( attr, "Attribute does not exist");
  }

  return ((const char*)attr->pointer()) +
    COM_get_sizeof( attr->data_type(), attr->stride()*(_eID.eid()-1));
}

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const COM::Attribute* attr ( const COM::Attribute *  a ) const

inline

Obtain the attribute on the parent pane of the node.

Definition at line 556 of file Manifold_2.h.

References _pm, COM_assertion_msg, and Simple_manifold_2::pane().

Referenced by addr().

                                                         { 
    COM_assertion_msg( a, "Unexpected NULL pointer");
    return a->window()->pane( _pm->pane()->id()).attribute(a->id()); 
  }

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Vector_3< Real > deformed_normal

(

const COM::Attribute *

disp

)

const

Get the normal of the deformed shape (coordinates plus given displacements) of the incident facet of the halfedge.

Definition at line 1290 of file Manifold_2.C.

References get_deformed_normal().

                                                 {
  return get_deformed_normal( *this, Vector_2<Real>( 0.5, 0.5), disp);
}

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Node destination ( ) const

inline

Obtain the (primary copy of the) destination of the edge.

Definition at line 472 of file Manifold_2.h.

References _eID, _mode, _pm, Simple_manifold_2::get_destination(), and Pane_manifold_2::get_primary().

Referenced by edge_average(), and tangent().

  { return _pm->get_primary( _pm->get_destination( _eID), _mode); }

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double dihedral_angle

(

)

const

Return the dihedral angle at the edge.

If the edge is a border edge, then return pi.

If the edge is a border edge, then return pi. Note that this must be called after update_bd_normals has been called.

Definition at line 1297 of file Manifold_2.C.

References cimg_library::acos(), is_physical_border(), normal(), opposite(), pi, and sqrt().

                                      {
  const double pi=3.14159265358979;
  if ( is_physical_border()) return pi;

  Halfedge hopp = opposite();
  if ( hopp.is_physical_border()) return pi;

  Vector_3<Real> normals[2] = { normal(), hopp.normal() };

  double cos_a = normals[0]*normals[1] 
    / std::sqrt( (normals[0]*normals[0])*(normals[1]*normals[1]));

  // Resolve roundoff error
  if ( cos_a>1) cos_a=1;
  if ( cos_a<-1) cos_a=-1;

  return std::acos( cos_a);
}

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void edge_average ( const COM::Attribute *  attr, Value &  val  ) const

inline

Get the avarage value of the nodes of a given halfedge.

Value must have operators + and * defined.

Definition at line 508 of file Manifold_2.h.

References Node::addr(), destination(), and origin().

Referenced by edge_center(), and face_average().

                                                                 {
    val = 0.5*(*reinterpret_cast<const Value *>(destination().addr(attr))+
               *reinterpret_cast<const Value *>(origin().addr(attr))); 
  }

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void edge_center ( Point_3< Real > &  mid ) const

inline

Get the edge center of the given halfedge.

Definition at line 495 of file Manifold_2.h.

References _pm, COM_NC, edge_average(), and Simple_manifold_2::pane().

  { edge_average( _pm->pane()->attribute( COM::COM_NC), 
                  reinterpret_cast<Vector_3<Real> &>(mid)); }

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void face_average ( const COM::Attribute *  attr, Value &  val  ) const

inline

Get the average value of the nodes of the incident face of a given halfedge.

If this is a border halfedge, then return its edge averagd. Value must have operators + and * defined.

Definition at line 517 of file Manifold_2.h.

References Node::addr(), edge_average(), is_border(), next(), and origin().

Referenced by face_center().

                                                                  {
    // If this is a border halfedge, then return its edge center.
    if ( is_border()) { edge_average( attr, val); return; }
  
    // Otherwise, compute the center
    val = Value(0);
    
    int count=0;
    Halfedge h=*this, h0=h;

    do {
      val += *reinterpret_cast<const Value*>(h.origin().addr( attr));
      ++count;
    } while ( (h=h.next()) != h0);
    
    val/=count;
  }

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void face_center ( Point_3< Real > &  cnt ) const

inline

Get the face center of the incident face of a given halfedge.

If this is a border halfedge, then return its midpoint.

Definition at line 501 of file Manifold_2.h.

References _pm, COM_NC, face_average(), and Simple_manifold_2::pane().

  { face_average( _pm->pane()->attribute( COM::COM_NC), 
                  reinterpret_cast<Vector_3<Real> &>(cnt)); }

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Edge_ID id ( ) const

inline

Obtain the ID of the edge.

Definition at line 547 of file Manifold_2.h.

References _eID.

Referenced by get_normal().

{ return _eID; }

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bool is_border ( ) const

inline

Is the edge a border edge?

Definition at line 476 of file Manifold_2.h.

References _eID, _mode, _pm, and Pane_manifold_2::is_border_edge().

Referenced by Halfedge_data_structure_decorator< _HDS >::add_facet_to_border(), Polyhedron_incremental_builder_3< HDS >::add_vertex_to_facet(), addr(), Rocsurf::compute_edge_lengths(), Window_manifold_2::determine_primaries(), Halfedge_data_structure_decorator< _HDS >::erase_facet(), face_average(), Halfedge_data_structure_decorator< _HDS >::fill_hole(), Pane_manifold_2::get_next_edge(), get_normal(), Pane_manifold_2::get_prev_edge(), Node::is_border(), Halfedge_data_structure_decorator< _HDS >::join_vertex(), Polyhedron_incremental_builder_3< HDS >::lookup_halfedge(), Polyhedron_incremental_builder_3< HDS >::lookup_hole(), and Halfedge_data_structure_decorator< _HDS >::make_hole().

  { return _pm->is_border_edge( _eID, _mode); }

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bool is_physical_border ( ) const

inline

Is the edge on the physical boundary?

Definition at line 480 of file Manifold_2.h.

References _eID, _pm, and Pane_manifold_2::is_physical_border_edge().

Referenced by dihedral_angle().

  { return _pm->is_physical_border_edge( _eID); }

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Halfedge next ( ) const

inline

Get the next halfedge of its owner element.

If the current edge is a border edges, it returns the next border edge along the boundary.

Definition at line 465 of file Manifold_2.h.

References _eID, _mode, _pm, and Pane_manifold_2::get_next_edge().

Referenced by Polyhedron_incremental_builder_3< HDS >::add_vertex_to_facet(), Rocsurf::compute_edge_lengths(), Halfedge_data_structure_decorator< _HDS >::erase_connected_component(), Halfedge_data_structure_decorator< _HDS >::erase_connected_component_face_cycle(), Halfedge_data_structure_decorator< _HDS >::erase_facet(), face_average(), Halfedge_data_structure_decorator< _HDS >::find_prev(), Halfedge_data_structure_decorator< _HDS >::find_prev_around_vertex(), Halfedge_data_structure_decorator< _HDS >::flip_edge(), get_deformed_normal(), Pane_manifold_2::get_prev_edge(), Halfedge_data_structure_decorator< _HDS >::insert_halfedge(), Halfedge_data_structure_decorator< _HDS >::insert_tip(), Halfedge_data_structure_decorator< _HDS >::inside_out(), Halfedge_data_structure_decorator< _HDS >::is_valid(), Halfedge_data_structure_decorator< _HDS >::join_facet(), Halfedge_data_structure_decorator< _HDS >::join_loop(), Halfedge_data_structure_decorator< _HDS >::join_vertex(), Polyhedron_incremental_builder_3< HDS >::lookup_halfedge(), Polyhedron_incremental_builder_3< HDS >::lookup_hole(), Halfedge_data_structure_decorator< _HDS >::remove_halfedge(), Halfedge_data_structure_decorator< _HDS >::remove_tip(), Halfedge_data_structure_decorator< _HDS >::reorient_facet(), Halfedge_data_structure_decorator< _HDS >::set_facet_in_facet_loop(), Halfedge_data_structure_decorator< _HDS >::set_vertex_in_vertex_loop(), and Halfedge_data_structure_decorator< _HDS >::split_loop().

{ return _pm->get_next_edge( _eID, _mode); }

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Vector_3< Real > normal

(

)

const

Get the normal of the incident facet.

Definition at line 1259 of file Manifold_2.C.

References get_normal().

Referenced by c3d6nm(), and dihedral_angle().

                                      {
  return get_normal( *this, Vector_2<Real>( 0.5, 0.5));
}

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bool operator!= ( const Halfedge &  h ) const

inline

Are two halfedges different?

Definition at line 566 of file Manifold_2.h.

References _eID, and _pm.

  { return _pm!=h._pm || _eID!=h._eID; }

bool operator< ( const Halfedge &  h ) const

inline

Does the current halfedge has a smaller ID then the given one?

Definition at line 570 of file Manifold_2.h.

References _eID, _pm, and Simple_manifold_2::pane().

                                           {
    int pid1=_pm->pane()->id(), pid2=h._pm->pane()->id();
    return pid1<pid2 || pid1==pid2 && _eID<h._eID; 
  }

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bool operator== ( const Halfedge &  h ) const

inline

Are two halfedges the same?

Definition at line 562 of file Manifold_2.h.

References _eID, and _pm.

  { return _pm==h._pm && _eID==h._eID; }

Halfedge opposite ( ) const

inline

Get the ID of the opposite edge of a given edge.

Definition at line 454 of file Manifold_2.h.

References _eID, _mode, _pm, and Pane_manifold_2::get_opposite_edge().

Referenced by Polyhedron_incremental_builder_3< HDS >::add_vertex_to_facet(), Halfedge_data_structure_decorator< _HDS >::close_tip(), Rocsurf::compute_edge_lengths(), Halfedge_data_structure_decorator< _HDS >::create_loop(), Halfedge_data_structure_decorator< _HDS >::create_segment(), dihedral_angle(), Halfedge_data_structure_decorator< _HDS >::erase_connected_component(), Halfedge_data_structure_decorator< _HDS >::erase_connected_component_face_cycle(), Halfedge_data_structure_decorator< _HDS >::erase_facet(), Halfedge_data_structure_decorator< _HDS >::find_prev_around_vertex(), Halfedge_data_structure_decorator< _HDS >::flip_edge(), Pane_manifold_2::get_next_edge(), Pane_manifold_2::get_prev_edge(), Halfedge_data_structure_decorator< _HDS >::insert_tip(), Halfedge_data_structure_decorator< _HDS >::is_valid(), Halfedge_data_structure_decorator< _HDS >::join_facet(), Halfedge_data_structure_decorator< _HDS >::join_loop(), Halfedge_data_structure_decorator< _HDS >::join_vertex(), Polyhedron_incremental_builder_3< HDS >::lookup_halfedge(), Polyhedron_incremental_builder_3< HDS >::lookup_hole(), Halfedge_data_structure_decorator< _HDS >::remove_tip(), Halfedge_data_structure_decorator< _HDS >::set_vertex_in_vertex_loop(), Halfedge_data_structure_decorator< _HDS >::split_facet(), Halfedge_data_structure_decorator< _HDS >::split_loop(), and Halfedge_data_structure_decorator< _HDS >::split_vertex().

  { return _pm->get_opposite_edge( _eID, _mode); }

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Node origin ( ) const

inline

Obtain the (primary copy of the) origin of the edge.

Definition at line 468 of file Manifold_2.h.

References _eID, _mode, _pm, Simple_manifold_2::get_origin(), and Pane_manifold_2::get_primary().

Referenced by edge_average(), face_average(), get_deformed_normal(), and tangent().

  { return _pm->get_primary( _pm->get_origin( _eID), _mode); }

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const COM::Pane* pane ( ) const

inline

Obtain the owner Pane_manifold_2 of the node.

Definition at line 543 of file Manifold_2.h.

References _pm, and Simple_manifold_2::pane().

Referenced by get_normal(), and Pane_manifold_2::size_of_edges().

  { if ( _pm) return _pm->pane(); else return NULL; }

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const Pane_manifold_2* pane_manifold ( ) const

inline

Obtain the pane manifold that owns the edge.

Definition at line 540 of file Manifold_2.h.

References _pm.

Referenced by get_normal(), Pane_manifold_2::get_opposite_edge(), Node::halfedge(), Pane_manifold_2::is_border_edge(), and Pane_manifold_2::size_of_edges().

{ return _pm; }

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Halfedge prev ( ) const

inline

Get the previous halfedge of its owner element.

If the current edge is a border edges, it returns the previous border edge along the boundary.

Definition at line 460 of file Manifold_2.h.

References _eID, _mode, _pm, and Pane_manifold_2::get_prev_edge().

Referenced by Halfedge_data_structure_decorator< _HDS >::find_prev(), Halfedge_data_structure_decorator< _HDS >::find_prev_around_vertex(), Pane_manifold_2::get_next_edge(), and Halfedge_data_structure_decorator< _HDS >::get_prev().

{ return _pm->get_prev_edge( _eID, _mode); }

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Vector_3<Real> tangent ( ) const

inline

Get the tangent of the given halfedge.

Definition at line 484 of file Manifold_2.h.

References destination(), origin(), and Node::point().

Referenced by Rocsurf::compute_edge_lengths(), and get_tangent().

  { return destination().point()-origin().point(); }

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Member Data Documentation

Edge_ID _eID

protected

Definition at line 577 of file Manifold_2.h.

Referenced by addr(), destination(), id(), is_border(), is_physical_border(), next(), operator!=(), operator<(), operator==(), opposite(), origin(), and prev().

Access_Mode _mode

protected

Definition at line 578 of file Manifold_2.h.

Referenced by destination(), is_border(), next(), opposite(), origin(), and prev().

const Pane_manifold_2* _pm

protected

Definition at line 576 of file Manifold_2.h.

Referenced by addr(), attr(), destination(), edge_center(), face_center(), is_border(), is_physical_border(), next(), operator!=(), operator<(), operator==(), opposite(), origin(), pane(), pane_manifold(), and prev().

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The documentation for this class was generated from the following files:

• Manifold_2.h
• Manifold_2.C