test/source/blender/freestyle/intern/view_map/ViewMap.cpp

/* SPDX-FileCopyrightText: 2008-2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

/** \file
 * \ingroup freestyle
 * \brief Classes to define a View Map (ViewVertex, ViewEdge, etc.)
 */

#include <cfloat>

#include "ViewMap.h"
#include "ViewMapAdvancedIterators.h"
#include "ViewMapIterators.h"

#include "../geometry/GeomUtils.h"

#include "BLI_sys_types.h"

namespace Freestyle {

/**********************************/
/*                                */
/*                                */
/*             ViewMap            */
/*                                */
/*                                */
/**********************************/

ViewMap *ViewMap::_pInstance = nullptr;

ViewMap::~ViewMap()
{
  // The view vertices must be deleted here as some of them are shared between two shapes:
  for (vector<ViewVertex *>::iterator vv = _VVertices.begin(), vvend = _VVertices.end();
       vv != vvend;
       vv++)
  {
    delete (*vv);
  }
  _VVertices.clear();

  for (vector<ViewShape *>::iterator vs = _VShapes.begin(), vsend = _VShapes.end(); vs != vsend;
       vs++)
  {
    delete (*vs);
  }
  _VShapes.clear();

  _FEdges.clear();
  _SVertices.clear();
  _VEdges.clear();
}

void ViewMap::Clean()
{
  vector<FEdge *> tmpEdges;

  for (vector<ViewShape *>::iterator vs = _VShapes.begin(), vsend = _VShapes.end(); vs != vsend;
       vs++)
  {
    vector<FEdge *> &edges = (*vs)->sshape()->getEdgeList();
    for (vector<FEdge *>::iterator it = edges.begin(), itend = edges.end(); it != itend; it++) {
      if ((*it)->isTemporary()) {
        (*it)->setTemporary(false);  // avoid being counted multiple times
        tmpEdges.push_back(*it);
      }
    }
  }

  for (vector<FEdge *>::iterator it = tmpEdges.begin(), itend = tmpEdges.end(); it != itend; it++)
  {
    for (vector<ViewShape *>::iterator vs = _VShapes.begin(), vsend = _VShapes.end(); vs != vsend;
         vs++)
    {
      (*vs)->sshape()->RemoveEdge(*it);
    }
    (*it)->vertexA()->RemoveFEdge(*it);
    (*it)->vertexB()->RemoveFEdge(*it);
    delete (*it);
  }
}

ViewShape *ViewMap::viewShape(uint id)
{
  int index = _shapeIdToIndex[id];
  return _VShapes[index];
}

void ViewMap::AddViewShape(ViewShape *iVShape)
{
  _shapeIdToIndex[iVShape->getId().getFirst()] = _VShapes.size();
  _VShapes.push_back(iVShape);
}

const FEdge *ViewMap::getClosestFEdge(real x, real y) const
{
  // find the closest of this candidates:
  real minDist = DBL_MAX;
  FEdge *winner = nullptr;
  for (fedges_container::const_iterator fe = _FEdges.begin(), feend = _FEdges.end(); fe != feend;
       fe++)
  {
    Vec2d A((*fe)->vertexA()->point2D()[0], (*fe)->vertexA()->point2D()[1]);
    Vec2d B((*fe)->vertexB()->point2D()[0], (*fe)->vertexB()->point2D()[1]);
    real dist = GeomUtils::distPointSegment<Vec2r>(Vec2r(x, y), A, B);
    if (dist < minDist) {
      minDist = dist;
      winner = (*fe);
    }
  }

  return winner;
}

const ViewEdge *ViewMap::getClosestViewEdge(real x, real y) const
{
  // find the closest of this candidates:
  real minDist = DBL_MAX;
  FEdge *winner = nullptr;
  for (fedges_container::const_iterator fe = _FEdges.begin(), feend = _FEdges.end(); fe != feend;
       fe++)
  {
    Vec2d A((*fe)->vertexA()->point2D()[0], (*fe)->vertexA()->point2D()[1]);
    Vec2d B((*fe)->vertexB()->point2D()[0], (*fe)->vertexB()->point2D()[1]);
    real dist = GeomUtils::distPointSegment<Vec2r>(Vec2r(x, y), A, B);
    if (dist < minDist) {
      minDist = dist;
      winner = (*fe);
    }
  }
  if (!winner) {
    return nullptr;
  }

  return winner->viewedge();
}

TVertex *ViewMap::CreateTVertex(const Vec3r &iA3D,
                                const Vec3r &iA2D,
                                FEdge *iFEdgeA,
                                const Vec3r &iB3D,
                                const Vec3r &iB2D,
                                FEdge *iFEdgeB,
                                const Id &id)
{
  ViewShape *vshapeA = iFEdgeA->viewedge()->viewShape();
  SShape *shapeA = iFEdgeA->shape();
  ViewShape *vshapeB = iFEdgeB->viewedge()->viewShape();
  SShape *shapeB = iFEdgeB->shape();

  SVertex *Ia = shapeA->CreateSVertex(iA3D, iA2D, iFEdgeA->vertexA()->getId());
  SVertex *Ib = shapeB->CreateSVertex(iB3D, iB2D, iFEdgeB->vertexA()->getId());

  // depending on which of these 2 svertices is the nearest from the viewpoint, we're going to
  // build the TVertex by giving them in an order or another (the first one must be the nearest)
  real dista = Ia->point2D()[2];
  real distb = Ib->point2D()[2];

  TVertex *tvertex;
  if (dista < distb) {
    tvertex = new TVertex(Ia, Ib);
  }
  else {
    tvertex = new TVertex(Ib, Ia);
  }

  tvertex->setId(id);

  // add these vertices to the view map
  AddViewVertex(tvertex);
  AddSVertex(Ia);
  AddSVertex(Ib);

  // and this T Vertex to the view shapes:
  vshapeA->AddVertex(tvertex);
  vshapeB->AddVertex(tvertex);

  return tvertex;
}

ViewVertex *ViewMap::InsertViewVertex(SVertex *iVertex, vector<ViewEdge *> &newViewEdges)
{
  NonTVertex *vva = dynamic_cast<NonTVertex *>(iVertex->viewvertex());
  if (vva) {
    return vva;
  }
  // because it is not already a ViewVertex, this SVertex must have only 2 FEdges. The incoming one
  // still belongs to ioEdge, the outgoing one now belongs to newVEdge
  const vector<FEdge *> &fedges = iVertex->fedges();
  if (fedges.size() != 2) {
    cerr << "ViewMap warning: Can't split the ViewEdge" << endl;
    return nullptr;
  }
  FEdge *fend(nullptr), *fbegin(nullptr);
  for (vector<FEdge *>::const_iterator fe = fedges.begin(), feend = fedges.end(); fe != feend;
       ++fe) {
    if ((*fe)->vertexB() == iVertex) {
      fend = (*fe);
    }
    if ((*fe)->vertexA() == iVertex) {
      fbegin = (*fe);
    }
    if ((fbegin != nullptr) && (fend != nullptr)) {
      break;
    }
  }
  ViewEdge *ioEdge = fbegin->viewedge();
  ViewShape *vshape = ioEdge->viewShape();
  vva = new NonTVertex(iVertex);
  // if the ViewEdge is a closed loop, we don't create a new VEdge
  if (ioEdge->A() == nullptr) {
    // closed loop
    ioEdge->setA(vva);
    ioEdge->setB(vva);
    // update sshape
    vshape->sshape()->RemoveEdgeFromChain(ioEdge->fedgeA());
    vshape->sshape()->RemoveEdgeFromChain(ioEdge->fedgeB());

    ioEdge->setFEdgeA(fbegin);
    ioEdge->setFEdgeB(fend);

    // Update FEdges
    fend->setNextEdge(nullptr);
    fbegin->setPreviousEdge(nullptr);

    // update new View Vertex:
    vva->AddOutgoingViewEdge(ioEdge);
    vva->AddIncomingViewEdge(ioEdge);

    vshape->sshape()->AddChain(ioEdge->fedgeA());
    vshape->sshape()->AddChain(ioEdge->fedgeB());
  }
  else {
    // Create new ViewEdge
    ViewEdge *newVEdge = new ViewEdge(vva, ioEdge->B(), fbegin, ioEdge->fedgeB(), vshape);
    newVEdge->setId(Id(ioEdge->getId().getFirst(), ioEdge->getId().getSecond() + 1));
    newVEdge->setNature(ioEdge->getNature());
    // newVEdge->UpdateFEdges(); // done in the ViewEdge constructor
    // Update old ViewEdge
    ioEdge->setB(vva);
    ioEdge->setFEdgeB(fend);

    // Update FEdges
    fend->setNextEdge(nullptr);
    fbegin->setPreviousEdge(nullptr);

    // update new View Vertex:
    vva->AddOutgoingViewEdge(newVEdge);
    vva->AddIncomingViewEdge(ioEdge);

    NonTVertex *vvb = dynamic_cast<NonTVertex *>(newVEdge->B());
    if (vvb) {
      vvb->Replace(ioEdge, newVEdge);
    }

    // update ViewShape
    // vshape->AddEdge(newVEdge);
    // update SShape
    vshape->sshape()->AddChain(fbegin);
    // update ViewMap
    //_VEdges.push_back(newVEdge);
    newViewEdges.push_back(newVEdge);
  }

  // update ViewShape
  vshape->AddVertex(vva);

  // update ViewMap
  _VVertices.push_back(vva);

  return vva;
}

#if 0
FEdge *ViewMap::Connect(FEdge *ioEdge, SVertex *ioVertex, vector<ViewEdge *> &oNewVEdges)
{
  SShape *sshape = ioEdge->shape();
  FEdge *newFEdge = sshape->SplitEdgeIn2(ioEdge, ioVertex);
  AddFEdge(newFEdge);
  InsertViewVertex(ioVertex, oNewVEdges);
  return newFEdge;
}
#endif

/**********************************/
/*                                */
/*                                */
/*             TVertex            */
/*                                */
/*                                */
/**********************************/

// is dve1 before dve2 ? (does it have a smaller angle ?)
static bool ViewEdgeComp(ViewVertex::directedViewEdge &dve1, ViewVertex::directedViewEdge &dve2)
{
  FEdge *fe1;
  if (dve1.second) {
    fe1 = dve1.first->fedgeB();
  }
  else {
    fe1 = dve1.first->fedgeA();
  }
  FEdge *fe2;
  if (dve2.second) {
    fe2 = dve2.first->fedgeB();
  }
  else {
    fe2 = dve2.first->fedgeA();
  }

  Vec3r V1 = fe1->orientation2d();
  Vec2r v1(V1.x(), V1.y());
  v1.normalize();
  Vec3r V2 = fe2->orientation2d();
  Vec2r v2(V2.x(), V2.y());
  v2.normalize();
  if (v1.y() > 0) {
    if (v2.y() < 0) {
      return true;
    }

    return (v1.x() > v2.x());
  }

  if (v2.y() > 0) {
    return false;
  }

  return (v1.x() < v2.x());
}

void TVertex::setFrontEdgeA(ViewEdge *iFrontEdgeA, bool incoming)
{
  if (!iFrontEdgeA) {
    cerr << "Warning: null pointer passed as argument of TVertex::setFrontEdgeA()" << endl;
    return;
  }
  _FrontEdgeA = directedViewEdge(iFrontEdgeA, incoming);
  if (!_sortedEdges.empty()) {
    edge_pointers_container::iterator dve = _sortedEdges.begin(), dveend = _sortedEdges.end();
    for (; (dve != dveend) && ViewEdgeComp(**dve, _FrontEdgeA); ++dve) {
      /* pass */
    }
    _sortedEdges.insert(dve, &_FrontEdgeA);
  }
  else {
    _sortedEdges.push_back(&_FrontEdgeA);
  }
}

void TVertex::setFrontEdgeB(ViewEdge *iFrontEdgeB, bool incoming)
{
  if (!iFrontEdgeB) {
    cerr << "Warning: null pointer passed as argument of TVertex::setFrontEdgeB()" << endl;
    return;
  }
  _FrontEdgeB = directedViewEdge(iFrontEdgeB, incoming);
  if (!_sortedEdges.empty()) {
    edge_pointers_container::iterator dve = _sortedEdges.begin(), dveend = _sortedEdges.end();
    for (; (dve != dveend) && ViewEdgeComp(**dve, _FrontEdgeB); ++dve) {
      /* pass */
    }
    _sortedEdges.insert(dve, &_FrontEdgeB);
  }
  else {
    _sortedEdges.push_back(&_FrontEdgeB);
  }
}

void TVertex::setBackEdgeA(ViewEdge *iBackEdgeA, bool incoming)
{
  if (!iBackEdgeA) {
    cerr << "Warning: null pointer passed as argument of TVertex::setBackEdgeA()" << endl;
    return;
  }
  _BackEdgeA = directedViewEdge(iBackEdgeA, incoming);
  if (!_sortedEdges.empty()) {
    edge_pointers_container::iterator dve = _sortedEdges.begin(), dveend = _sortedEdges.end();
    for (; (dve != dveend) && ViewEdgeComp(**dve, _BackEdgeA); ++dve) {
      /* pass */
    }
    _sortedEdges.insert(dve, &_BackEdgeA);
  }
  else {
    _sortedEdges.push_back(&_BackEdgeA);
  }
}

void TVertex::setBackEdgeB(ViewEdge *iBackEdgeB, bool incoming)
{
  if (!iBackEdgeB) {
    cerr << "Warning: null pointer passed as argument of TVertex::setBackEdgeB()" << endl;
    return;
  }
  _BackEdgeB = directedViewEdge(iBackEdgeB, incoming);
  if (!_sortedEdges.empty()) {
    edge_pointers_container::iterator dve = _sortedEdges.begin(), dveend = _sortedEdges.end();
    for (; (dve != dveend) && ViewEdgeComp(**dve, _BackEdgeB); ++dve) {
      /* pass */
    }
    _sortedEdges.insert(dve, &_BackEdgeB);
  }
  else {
    _sortedEdges.push_back(&_BackEdgeB);
  }
}

void TVertex::Replace(ViewEdge *iOld, ViewEdge *iNew)
{
  // theoretically, we only replace edges for which this
  // view vertex is the B vertex
  if ((iOld == _FrontEdgeA.first) && (_FrontEdgeA.first->B() == this)) {
    _FrontEdgeA.first = iNew;
    return;
  }
  if ((iOld == _FrontEdgeB.first) && (_FrontEdgeB.first->B() == this)) {
    _FrontEdgeB.first = iNew;
    return;
  }
  if ((iOld == _BackEdgeA.first) && (_BackEdgeA.first->B() == this)) {
    _BackEdgeA.first = iNew;
    return;
  }
  if ((iOld == _BackEdgeB.first) && (_BackEdgeB.first->B() == this)) {
    _BackEdgeB.first = iNew;
    return;
  }
}

/** iterators access */
ViewVertex::edge_iterator TVertex::edges_begin()
{
  // return edge_iterator(_FrontEdgeA, _FrontEdgeB, _BackEdgeA, _BackEdgeB, _FrontEdgeA);
  return edge_iterator(_sortedEdges.begin(), _sortedEdges.end(), _sortedEdges.begin());
}

ViewVertex::const_edge_iterator TVertex::edges_begin() const
{
  // return const_edge_iterator(_FrontEdgeA, _FrontEdgeB, _BackEdgeA, _BackEdgeB, _FrontEdgeA);
  return const_edge_iterator(_sortedEdges.begin(), _sortedEdges.end(), _sortedEdges.begin());
}

ViewVertex::edge_iterator TVertex::edges_end()
{
  // return edge_iterator(_FrontEdgeA, _FrontEdgeB, _BackEdgeA, _BackEdgeB,
  // directedViewEdge(0,true));
  return edge_iterator(_sortedEdges.begin(), _sortedEdges.end(), _sortedEdges.end());
}

ViewVertex::const_edge_iterator TVertex::edges_end() const
{
  // return const_edge_iterator(_FrontEdgeA, _FrontEdgeB, _BackEdgeA, _BackEdgeB,
  // directedViewEdge(0, true));
  return const_edge_iterator(_sortedEdges.begin(), _sortedEdges.end(), _sortedEdges.end());
}

ViewVertex::edge_iterator TVertex::edges_iterator(ViewEdge *iEdge)
{
  for (edge_pointers_container::iterator it = _sortedEdges.begin(), itend = _sortedEdges.end();
       it != itend;
       it++)
  {
    if ((*it)->first == iEdge) {
      return edge_iterator(_sortedEdges.begin(), _sortedEdges.end(), it);
    }
  }
  return edge_iterator(_sortedEdges.begin(), _sortedEdges.end(), _sortedEdges.begin());

#if 0
  directedViewEdge dEdge;
  if (_FrontEdgeA.first == iEdge) {
    dEdge = _FrontEdgeA;
  }
  else if (_FrontEdgeB.first == iEdge) {
    dEdge = _FrontEdgeB;
  }
  else if (_BackEdgeA.first == iEdge) {
    dEdge = _BackEdgeA;
  }
  else if (_BackEdgeB.first == iEdge) {
    dEdge = _BackEdgeB;
  }
  return edge_iterator(_FrontEdgeA, _FrontEdgeB, _BackEdgeA, _BackEdgeB, dEdge);
#endif
}

ViewVertex::const_edge_iterator TVertex::edges_iterator(ViewEdge *iEdge) const
{
  for (edge_pointers_container::const_iterator it = _sortedEdges.begin(),
                                               itend = _sortedEdges.end();
       it != itend;
       it++)
  {
    if ((*it)->first == iEdge) {
      return const_edge_iterator(_sortedEdges.begin(), _sortedEdges.end(), it);
    }
  }
  return const_edge_iterator(_sortedEdges.begin(), _sortedEdges.end(), _sortedEdges.begin());

#if 0
  directedViewEdge dEdge;
  if (_FrontEdgeA.first == iEdge) {
    dEdge = _FrontEdgeA;
  }
  else if (_FrontEdgeB.first == iEdge) {
    dEdge = _FrontEdgeB;
  }
  else if (_BackEdgeA.first == iEdge) {
    dEdge = _BackEdgeA;
  }
  else if (_BackEdgeB.first == iEdge) {
    dEdge = _BackEdgeB;
  }
  return const_edge_iterator(_FrontEdgeA, _FrontEdgeB, _BackEdgeA, _BackEdgeB, dEdge);
#endif
}

ViewVertexInternal::orientedViewEdgeIterator TVertex::edgesBegin()
{
  return ViewVertexInternal::orientedViewEdgeIterator(
      _sortedEdges.begin(), _sortedEdges.end(), _sortedEdges.begin());
}

ViewVertexInternal::orientedViewEdgeIterator TVertex::edgesEnd()
{
  return ViewVertexInternal::orientedViewEdgeIterator(
      _sortedEdges.begin(), _sortedEdges.end(), _sortedEdges.end());
}

ViewVertexInternal::orientedViewEdgeIterator TVertex::edgesIterator(ViewEdge *iEdge)
{
  for (edge_pointers_container::iterator it = _sortedEdges.begin(), itend = _sortedEdges.end();
       it != itend;
       it++)
  {
    if ((*it)->first == iEdge) {
      return ViewVertexInternal::orientedViewEdgeIterator(
          _sortedEdges.begin(), _sortedEdges.end(), it);
    }
  }
  return ViewVertexInternal::orientedViewEdgeIterator(
      _sortedEdges.begin(), _sortedEdges.end(), _sortedEdges.begin());
}

/**********************************/
/*                                */
/*                                */
/*             NonTVertex         */
/*                                */
/*                                */
/**********************************/

void NonTVertex::AddOutgoingViewEdge(ViewEdge *iVEdge)
{
  // let's keep the viewedges ordered in CCW order in the 2D image plan
  directedViewEdge idve(iVEdge, false);
  if (!_ViewEdges.empty()) {
    edges_container::iterator dve = _ViewEdges.begin(), dveend = _ViewEdges.end();
    for (; (dve != dveend) && ViewEdgeComp(*dve, idve); ++dve) {
      /* pass */
    }
    _ViewEdges.insert(dve, idve);
  }
  else {
    _ViewEdges.push_back(idve);
  }
}

void NonTVertex::AddIncomingViewEdge(ViewEdge *iVEdge)
{
  // let's keep the viewedges ordered in CCW order in the 2D image plan
  directedViewEdge idve(iVEdge, true);
  if (!_ViewEdges.empty()) {
    edges_container::iterator dve = _ViewEdges.begin(), dveend = _ViewEdges.end();
    for (; (dve != dveend) && ViewEdgeComp(*dve, idve); ++dve) {
      /* pass */
    }
    _ViewEdges.insert(dve, idve);
  }
  else {
    _ViewEdges.push_back(idve);
  }
}

/** iterators access */
ViewVertex::edge_iterator NonTVertex::edges_begin()
{
  return edge_iterator(_ViewEdges.begin(), _ViewEdges.end(), _ViewEdges.begin());
}

ViewVertex::const_edge_iterator NonTVertex::edges_begin() const
{
  return const_edge_iterator(_ViewEdges.begin(), _ViewEdges.end(), _ViewEdges.begin());
}

ViewVertex::edge_iterator NonTVertex::edges_end()
{
  return edge_iterator(_ViewEdges.begin(), _ViewEdges.end(), _ViewEdges.end());
}

ViewVertex::const_edge_iterator NonTVertex::edges_end() const
{
  return const_edge_iterator(_ViewEdges.begin(), _ViewEdges.end(), _ViewEdges.end());
}

ViewVertex::edge_iterator NonTVertex::edges_iterator(ViewEdge *iEdge)
{
  for (edges_container::iterator it = _ViewEdges.begin(), itend = _ViewEdges.end(); it != itend;
       it++)
  {
    if ((it)->first == iEdge) {
      return edge_iterator(_ViewEdges.begin(), _ViewEdges.end(), it);
    }
  }
  return edge_iterator(_ViewEdges.begin(), _ViewEdges.end(), _ViewEdges.begin());
}

ViewVertex::const_edge_iterator NonTVertex::edges_iterator(ViewEdge *iEdge) const
{
  for (edges_container::const_iterator it = _ViewEdges.begin(), itend = _ViewEdges.end();
       it != itend;
       it++)
  {
    if ((it)->first == iEdge) {
      return const_edge_iterator(_ViewEdges.begin(), _ViewEdges.end(), it);
    }
  }
  return const_edge_iterator(_ViewEdges.begin(), _ViewEdges.end(), _ViewEdges.begin());
}

ViewVertexInternal::orientedViewEdgeIterator NonTVertex::edgesBegin()
{
  return ViewVertexInternal::orientedViewEdgeIterator(
      _ViewEdges.begin(), _ViewEdges.end(), _ViewEdges.begin());
}

ViewVertexInternal::orientedViewEdgeIterator NonTVertex::edgesEnd()
{
  return ViewVertexInternal::orientedViewEdgeIterator(
      _ViewEdges.begin(), _ViewEdges.end(), _ViewEdges.end());
}

ViewVertexInternal::orientedViewEdgeIterator NonTVertex::edgesIterator(ViewEdge *iEdge)
{
  for (edges_container::iterator it = _ViewEdges.begin(), itend = _ViewEdges.end(); it != itend;
       it++)
  {
    if ((it)->first == iEdge) {
      return ViewVertexInternal::orientedViewEdgeIterator(
          _ViewEdges.begin(), _ViewEdges.end(), it);
    }
  }
  return ViewVertexInternal::orientedViewEdgeIterator(
      _ViewEdges.begin(), _ViewEdges.end(), _ViewEdges.begin());
}

/**********************************/
/*                                */
/*                                */
/*             ViewEdge           */
/*                                */
/*                                */
/**********************************/

real ViewEdge::getLength2D() const
{
  float length = 0.0f;
  ViewEdge::const_fedge_iterator itlast = fedge_iterator_last();
  ViewEdge::const_fedge_iterator it = fedge_iterator_begin(), itend = fedge_iterator_end();
  Vec2r seg;
  do {
    seg = Vec2r((*it)->orientation2d()[0], (*it)->orientation2d()[1]);
    length += seg.norm();
    ++it;
  } while ((it != itend) && (it != itlast));
  return length;
}

//! view edge iterator
ViewEdge::edge_iterator ViewEdge::ViewEdge_iterator()
{
  return edge_iterator(this);
}

ViewEdge::const_edge_iterator ViewEdge::ViewEdge_iterator() const
{
  return const_edge_iterator((ViewEdge *)this);
}

//! feature edge iterator
ViewEdge::fedge_iterator ViewEdge::fedge_iterator_begin()
{
  return fedge_iterator(this->_FEdgeA, this->_FEdgeB);
}

ViewEdge::const_fedge_iterator ViewEdge::fedge_iterator_begin() const
{
  return const_fedge_iterator(this->_FEdgeA, this->_FEdgeB);
}

ViewEdge::fedge_iterator ViewEdge::fedge_iterator_last()
{
  return fedge_iterator(this->_FEdgeB, this->_FEdgeB);
}

ViewEdge::const_fedge_iterator ViewEdge::fedge_iterator_last() const
{
  return const_fedge_iterator(this->_FEdgeB, this->_FEdgeB);
}

ViewEdge::fedge_iterator ViewEdge::fedge_iterator_end()
{
  return fedge_iterator(nullptr, this->_FEdgeB);
}

ViewEdge::const_fedge_iterator ViewEdge::fedge_iterator_end() const
{
  return const_fedge_iterator(nullptr, this->_FEdgeB);
}

//! embedding vertex iterator
ViewEdge::const_vertex_iterator ViewEdge::vertices_begin() const
{
  return const_vertex_iterator(this->_FEdgeA->vertexA(), nullptr, _FEdgeA);
}

ViewEdge::vertex_iterator ViewEdge::vertices_begin()
{
  return vertex_iterator(this->_FEdgeA->vertexA(), nullptr, _FEdgeA);
}

ViewEdge::const_vertex_iterator ViewEdge::vertices_last() const
{
  return const_vertex_iterator(this->_FEdgeB->vertexB(), _FEdgeB, nullptr);
}

ViewEdge::vertex_iterator ViewEdge::vertices_last()
{
  return vertex_iterator(this->_FEdgeB->vertexB(), _FEdgeB, nullptr);
}

ViewEdge::const_vertex_iterator ViewEdge::vertices_end() const
{
  return const_vertex_iterator(nullptr, _FEdgeB, nullptr);
}

ViewEdge::vertex_iterator ViewEdge::vertices_end()
{
  return vertex_iterator(nullptr, _FEdgeB, nullptr);
}

Interface0DIterator ViewEdge::verticesBegin()
{
  Interface0DIterator ret(new ViewEdgeInternal::SVertexIterator(
      this->_FEdgeA->vertexA(), this->_FEdgeA->vertexA(), nullptr, _FEdgeA, 0.0f));
  return ret;
}

Interface0DIterator ViewEdge::verticesEnd()
{
  Interface0DIterator ret(new ViewEdgeInternal::SVertexIterator(
      nullptr, this->_FEdgeA->vertexA(), _FEdgeB, nullptr, getLength2D()));
  return ret;
}

Interface0DIterator ViewEdge::pointsBegin(float /*t*/)
{
  return verticesBegin();
}

Interface0DIterator ViewEdge::pointsEnd(float /*t*/)
{
  return verticesEnd();
}

/**********************************/
/*                                */
/*                                */
/*             ViewShape          */
/*                                */
/*                                */
/**********************************/

ViewShape::~ViewShape()
{
  _Vertices.clear();

  if (!_Edges.empty()) {
    for (vector<ViewEdge *>::iterator e = _Edges.begin(), eend = _Edges.end(); e != eend; e++) {
      delete (*e);
    }
    _Edges.clear();
  }

  if (_SShape) {
    delete _SShape;
    _SShape = nullptr;
  }
}

void ViewShape::RemoveEdge(ViewEdge *iViewEdge)
{
  FEdge *fedge = iViewEdge->fedgeA();
  for (vector<ViewEdge *>::iterator ve = _Edges.begin(), veend = _Edges.end(); ve != veend; ve++) {
    if (iViewEdge == (*ve)) {
      _Edges.erase(ve);
      _SShape->RemoveEdge(fedge);
      break;
    }
  }
}

void ViewShape::RemoveVertex(ViewVertex *iViewVertex)
{
  for (vector<ViewVertex *>::iterator vv = _Vertices.begin(), vvend = _Vertices.end(); vv != vvend;
       vv++)
  {
    if (iViewVertex == (*vv)) {
      _Vertices.erase(vv);
      break;
    }
  }
}

/**********************************/
/*                                */
/*                                */
/*             ViewEdge           */
/*                                */
/*                                */
/**********************************/

void ViewEdge::UpdateFEdges()
{
  FEdge *currentEdge = _FEdgeA;
  do {
    currentEdge->setViewEdge(this);
    currentEdge = currentEdge->nextEdge();
  } while (!ELEM(currentEdge, nullptr, _FEdgeB));
  // last one
  _FEdgeB->setViewEdge(this);
}

} /* namespace Freestyle */