#include "tcenterlinevectP.h"

//==========================================================================

//============================================

//      Sequence conversion into TStroke

//============================================

// Globals

namespace {

const double Polyg_eps_max = 1;     // Sequence simplification max error

const double Polyg_eps_mul = 0.75;  // Sequence simpl. thickness-multiplier

                                    // error

const double Quad_eps_max =

    infinity;  // As above, for sequence conversion into strokes

// const double Quad_eps_mul= 0.2;     //NOTE: Substituted by

// globals->currConfig->m_penalty

}

//--------------------------------------------------------------------------

//-------------------------------

//      Simplify Sequences

//-------------------------------

// EXPLANATION:  Before converting sequences in strokes, we simplify them

// by eliminating sequence of points which lie on the same straight line,

// leaving the extremities only.

class SequenceSimplifier {

  const Sequence *m_s;

  const SkeletonGraph *m_graph;

private:

  class Length {

  public:

    int n;

    double l;

    UINT firstNode, secondNode;

    Length() : n(0), l(0) {}

    Length(int n_, double l_) : n(n_), l(l_) {}

    inline void infty(void) {

      n = infinity;

      l = infinity;

    }

    inline bool operator<(Length sl) {

      return n < sl.n ? 1 : n > sl.n ? 0 : l < sl.l ? 1 : 0;

    }

    inline Length operator+(Length sl) { return Length(n + sl.n, l + sl.l); }

  };

  Length lengthOf(UINT a, UINT aLink, UINT b);

public:

  // Methods

  SequenceSimplifier(const Sequence *s) : m_s(s), m_graph(m_s->m_graphHolder) {}

  void simplify(std::vector<unsigned int=""> &result);</unsigned>

};

//--------------------------------------------------------------------------

// Bellman algorithm for Sequences

// NOTE: Circular Sequences are dealt.

void SequenceSimplifier::simplify(std::vector<unsigned int=""> &result) {</unsigned>

  // Initialize variables

  unsigned int n;

  unsigned int i, j, iLink, jLink;

  // NOTE: If s is circular, we have to protect

  i     = m_s->m_head;

  iLink = m_s->m_headLink;

  // NOTE: If m_head==m_tail then we have to force the first step by "|| n==1"

  for (n = 1; i != m_s->m_tail || n == 1; ++n, m_s->next(i, iLink))

    ;

  Length L_att, L_min, l_min, l_ji;

  unsigned int p_i, a, b;

  std::vector<length> M(n);</length>

  std::vector<length> K(n);</length>

  std::vector<unsigned int=""> P(n);</unsigned>

  // Search for minimal path

  i     = m_s->m_head;

  iLink = m_s->m_headLink;

  for (a = 1; i != m_s->m_tail || a == 1; m_s->next(i, iLink), ++a) {

    L_min.infty();

    l_min.infty();

    p_i = 0;

    j                  = m_s->m_head;

    jLink              = m_s->m_headLink;

    unsigned int iNext = m_graph->getNode(i).getLink(iLink).getNext();

    for (b = 0; j != iNext || b == 0; m_s->next(j, jLink), ++b) {

      if ((L_att = M[b] + (l_ji = lengthOf(j, jLink, iNext))) < L_min) {

        L_min = L_att;

        p_i   = b;

        l_min = l_ji;

      }

    }

    M[a] = L_min;

    K[a] = l_min;

    P[a] = p_i;

  }

  // Copies minimal path found to the output reducedIndices vector

  // NOTE: size() is added due to circular sequences case handling

  unsigned int redSize = result.size();

  result.resize(redSize + M[n - 1].n + 1);

  result[redSize + M[n - 1].n] = K[n - 1].secondNode;

  for (b = n - 1, a = redSize + M[n - 1].n - 1; b > 0; b = P[b], --a)

    result[a] = K[b].firstNode;

}

//--------------------------------------------------------------------------

// Length between two sequence points

SequenceSimplifier::Length SequenceSimplifier::lengthOf(UINT a, UINT aLink,

                                                        UINT b) {

  UINT curr, old;

  T3DPointD v;

  double d, vv;

  Length res;

  res.n          = 1;

  res.firstNode  = a;

  res.secondNode = b;

  v  = *m_graph->getNode(b) - *m_graph->getNode(a);

  vv = norm(v);

  curr = m_graph->getNode(a).getLink(aLink).getNext();

  old  = a;

  // If the distance between extremities is small, check if the same holds

  // for internal points; if so, ok - otherwise set infty().

  if (vv < 0.1) {

    for (; curr != b; m_s->advance(old, curr)) {

      d = tdistance(*m_graph->getNode(curr), *m_graph->getNode(a));

      if (d > 0.1) res.infty();

    }

    return res;

  }

  // Otherwise, check distances from line passing from a and b

  v = v * (1 / vv);

  for (; curr != b; m_s->advance(old, curr)) {

    d = tdistance2(*m_graph->getNode(curr), v, *m_graph->getNode(a));

    if (d >

        std::min(m_graph->getNode(curr)->z * Polyg_eps_mul, Polyg_eps_max)) {

      res.infty();

      return res;

    } else

      res.l += d;

  }

  return res;

}

//==========================================================================

//===============================

//      Sequence conversion

//===============================

// EXPLANATION: Sequences convert into TStrokes by applying a SequenceConverter

//  class. A graph minimal-path algorithm is run by using a

//  lexicographic-ordered

//  (number of quadratics, error) length.

class SequenceConverter {

  const Sequence *m_s;

  const SkeletonGraph *m_graph;

  double m_penalty;

public:

  // Length construction globals (see 'lengthOf' method)

  unsigned int middle;

  std::vector<double> pars;</double>

  class Length {

  public:

    int n;

    double l;

    std::vector<t3dpointd> CPs;</t3dpointd>

    Length() : n(0), l(0) {}

    Length(int n_, double l_) : n(n_), l(l_) {}

    inline void infty(void) {

      n = infinity;

      l = infinity;

    }

    inline bool operator<(Length sl) {

      return n < sl.n ? 1 : n > sl.n ? 0 : l < sl.l ? 1 : 0;

    }

    inline Length operator+(Length sl) { return Length(n + sl.n, l + sl.l); }

    void set_CPs(const T3DPointD &a, const T3DPointD &b, const T3DPointD &c) {

      CPs.resize(3);

      CPs[0] = a;

      CPs[1] = b;

      CPs[2] = c;

    }

    void set_CPs(const T3DPointD &a, const T3DPointD &b, const T3DPointD &c,

                 const T3DPointD &d, const T3DPointD &e) {

      CPs.resize(5);

      CPs[0] = a;

      CPs[1] = b;

      CPs[2] = c;

      CPs[3] = d;

      CPs[4] = e;

    }

  };

  // Intermediate Sequence form

  std::vector<t3dpointd> middleAddedSequence;</t3dpointd>

  std::vector<unsigned int=""> *inputIndices;</unsigned>

  // Methods

  SequenceConverter(const Sequence *s, double penalty)

      : m_s(s), m_graph(m_s->m_graphHolder), m_penalty(penalty) {}

  Length lengthOf(unsigned int a, unsigned int b);

  void addMiddlePoints();

  TStroke *operator()(std::vector<unsigned int=""> *indices);</unsigned>

  // Length construction methods

  bool parametrize(unsigned int a, unsigned int b);

  void lengthOfTriplet(unsigned int i, Length &len);

  bool calculateCPs(unsigned int i, unsigned int j, Length &len);

  bool penalty(unsigned int a, unsigned int b, Length &len);

};

//--------------------------------------------------------------------------

// Changes in stroke thickness are considered more penalizating

inline double ellProd(const T3DPointD &a, const T3DPointD &b) {

  return a.x * b.x + a.y * b.y + 5 * a.z * b.z;

}

//--------------------------------------------------------------------------

// EXPLANATION:  After simplification, we receive a vector<uint> of indices</uint>

// corresponding to the vertices of the simplified current sequence.

// Before beginning conversion, we need to add middle points between the

// above vertex points.

inline void SequenceConverter::addMiddlePoints() {

  unsigned int i, j, n;

  n = inputIndices->size();

  middleAddedSequence.clear();

  if (n == 2) {

    middleAddedSequence.resize(3);

    middleAddedSequence[0] = *m_graph->getNode((*inputIndices)[0]);

    middleAddedSequence[1] = (*m_graph->getNode((*inputIndices)[0]) +

                              *m_graph->getNode((*inputIndices)[1])) *

                             0.5;

    middleAddedSequence[2] = *m_graph->getNode((*inputIndices)[1]);

  } else {

    middleAddedSequence.resize(2 * n - 3);

    middleAddedSequence[0] = *m_graph->getNode((*inputIndices)[0]);

    for (i = j = 1; i < n - 2; ++i, j += 2) {

      middleAddedSequence[j]     = *m_graph->getNode((*inputIndices)[i]);

      middleAddedSequence[j + 1] = (*m_graph->getNode((*inputIndices)[i]) +

                                    *m_graph->getNode((*inputIndices)[i + 1])) *

                                   0.5;

    }

    middleAddedSequence[j]     = *m_graph->getNode((*inputIndices)[n - 2]);

    middleAddedSequence[j + 1] = *m_graph->getNode((*inputIndices)[n - 1]);

  }

}

//--------------------------------------------------------------------------

TStroke *SequenceConverter::operator()(std::vector<unsigned int=""> *indices) {</unsigned>

  // Prepare Sequence

  inputIndices = indices;

  addMiddlePoints();

  // Initialize local variables

  unsigned int n =

      (middleAddedSequence.size() + 1) / 2;  // Number of middle points

  // unsigned int i, j;

  unsigned int i;

  int j;

  Length L_att, L_min, l_min, l_ji;

  unsigned int p_i, a, b;

  std::vector<length> M(n);</length>

  std::vector<length> K(n);</length>

  std::vector<unsigned int=""> P(n);</unsigned>

  // Bellman algorithm

  for (i = 2, a = 1; i < middleAddedSequence.size(); i += 2, ++a) {

    L_min.infty();

    l_min.infty();

    p_i = 0;

    // for(j=0, b=0; j

    for (j = i - 2, b = j / 2; j >= 0; j -= 2, --b) {

      if ((L_att = M[b] + (l_ji = lengthOf(j, i))) < L_min) {

        L_min = L_att;

        p_i   = b;

        l_min = l_ji;

      }

      // NOTE: The following else may be taken out to perform a deeper

      // search for optimal result. However, it prevents quadratic complexities

      // on large-scale images.

      else if (l_ji.n == infinity)

        break;  // Stops searching for current i

    }

    M[a] = L_min;

    K[a] = l_min;

    P[a] = p_i;

  }

  // Read off the output

  std::vector<tthickpoint> controlPoints(2 * M[n - 1].n + 1);</tthickpoint>

  for (b = n - 1, a = 2 * M[n - 1].n; b > 0; b = P[b]) {

    for (i             = K[b].CPs.size() - 1; i > 0; --i, --a)

      controlPoints[a] = K[b].CPs[i];

  }

  controlPoints[0] = middleAddedSequence[0];

  TStroke *res = new TStroke(controlPoints);

  return res;

}

//--------------------------------------------------------------------------

//--------------------------------------

//      Conversion Length build-up

//--------------------------------------

SequenceConverter::Length SequenceConverter::lengthOf(unsigned int a,

                                                      unsigned int b) {

  Length l;

  // If we have a triplet, apply a specific procedure

  if (b == a + 2) {

    lengthOfTriplet(a, l);

    return l;

  }

  // otherwise

  if (!parametrize(a, b) || !calculateCPs(a, b, l) || !penalty(a, b, l))

    l.infty();

  return l;

}

//--------------------------------------------------------------------------

void SequenceConverter::lengthOfTriplet(unsigned int i, Length &len) {

  T3DPointD A = middleAddedSequence[i];

  T3DPointD B = middleAddedSequence[i + 1];

  T3DPointD C = middleAddedSequence[i + 2];

  // We assume that this convertion is faithful, avoiding length penalty

  len.l    = 0;

  double d = tdistance(B, C - A, A);

  if (d <= 2) {

    len.n = 1;

    len.set_CPs(A, B, C);

  } else if (d <= 6) {

    len.n       = 2;

    d           = (d - 1) / d;

    T3DPointD U = A + d * (B - A), V = C + d * (B - C);

    len.set_CPs(A, U, (U + V) * 0.5, V, C);

  } else {

    len.n = 2;

    len.set_CPs(A, (A + B) * 0.5, B, (B + C) * 0.5, C);

  }

}

//--------------------------------------------------------------------------

bool SequenceConverter::parametrize(unsigned int a, unsigned int b) {

  unsigned int curr, old;

  unsigned int i;

  double w, t;

  double den;

  pars.clear();

  pars.push_back(0);

  for (old = a, curr = a + 1, den = 0; curr < b; old = curr, curr += 2) {

    w = norm(middleAddedSequence[curr] - middleAddedSequence[old]);

    den += w;

    pars.push_back(w);

  }

  w = norm(middleAddedSequence[b] - middleAddedSequence[old]);

  den += w;

  pars.push_back(w);

  if (den < 0.1) return 0;

  for (i = 1, t = 0; i < pars.size(); ++i) {

    t += 2 * pars[i] / den;

    pars[i] = t;

  }

  // Seek the interval which holds 1 - the middle interval

  for (middle = 0; middle < pars.size() && pars[middle + 1] <= 1; ++middle)

    ;

  return 1;

}

//==========================================================================

//------------------------

//    CP construcion

//------------------------

// NOTE: Check my thesis for variable meanings (int_ stands for 'integral').

// Some integrals (int_) for the CP linear system resolution

inline T3DPointD int_H(const T3DPointD &A, const T3DPointD &B, double t1,

                       double t2) {

  return -(0.375 * (pow(t2, 4) - pow(t1, 4))) * B +

         (pow(t2, 3) - pow(t1, 3)) * (B * 0.6667 - A * 0.5) +

         (pow(t2, 2) - pow(t1, 2)) * A;

}

//--------------------------------------------------------------------------

inline T3DPointD int_K(const T3DPointD &A, const T3DPointD &B, double t1,

                       double t2) {

  return (pow(t2, 4) - pow(t1, 4)) * (B * 0.125) +

         (pow(t2, 3) - pow(t1, 3)) * (A * 0.1667);

}

//--------------------------------------------------------------------------

bool SequenceConverter::calculateCPs(unsigned int i, unsigned int j,

                                     Length &len) {

  unsigned int curr, old;

  TAffine M;

  TPointD l;

  T3DPointD a, e, x, y, A, B;

  T3DPointD IH, IK, IM, IN_;  //"IN" seems to be reserved word

  double HxL, KyL, MxO, NyO;

  unsigned int k;

  a = middleAddedSequence[i];

  e = middleAddedSequence[j];

  x = middleAddedSequence[i + 1] - a;

  y = middleAddedSequence[j - 1] - e;

  // Build TAffine M

  double par = ellProd(x, y) / 5;

  M          = TAffine(ellProd(x, x) / 3, par, 0, par, ellProd(y, y) / 3, 0);

  // Costruisco il termine noto b:

  // Calculate polygonal integrals

  // Integral from 0.0 to 1.0

  for (k = 0, old = i, curr = i + 1; k < middle; ++k, old = curr, curr += 2) {

    B = (middleAddedSequence[curr] - middleAddedSequence[old]) *

        (1 / (pars[k + 1] - pars[k]));

    A = middleAddedSequence[old] - pars[k] * B;

    IH += int_H(A, B, pars[k], pars[k + 1]);

    IK += int_K(A, B, pars[k], pars[k + 1]);

  }

  if (curr == j + 1) curr = j;

  B = (middleAddedSequence[curr] - middleAddedSequence[old]) *

      (1 / (pars[k + 1] - pars[k]));

  A = middleAddedSequence[old] - pars[k] * B;

  IH += int_H(A, B, pars[k], 1.0);

  IK += int_K(A, B, pars[k], 1.0);

  // Integral from 1.0 to 2.0

  for (k = pars.size() - 1, old = j, curr = j - 1; k > middle + 1;

       --k, old = curr, curr -= 2) {

    B = (middleAddedSequence[curr] - middleAddedSequence[old]) *

        (1 / (pars[k] - pars[k - 1]));

    A = middleAddedSequence[curr] - (2 - pars[k - 1]) * B;

    IM += int_K(A, B, 2 - pars[k], 2 - pars[k - 1]);

    IN_ += int_H(A, B, 2 - pars[k], 2 - pars[k - 1]);

  }

  if (old == i + 1) curr = i;

  B = (middleAddedSequence[curr] - middleAddedSequence[old]) *

      (1 / (pars[k] - pars[k - 1]));

  A = middleAddedSequence[curr] - (2 - pars[k - 1]) * B;

  IM += int_K(A, B, 2 - pars[k], 1.0);

  IN_ += int_H(A, B, 2 - pars[k], 1.0);

  // Polygonal-free integrals

  T3DPointD f = (a + e) * 0.5;

  HxL         = (ellProd(a, x) * 0.3) + (ellProd(f, x) / 5.0);

  NyO         = (ellProd(e, y) * 0.3) + (ellProd(f, y) / 5.0);

  KyL         = (ellProd(a, y) / 15.0) + (ellProd(f, y) / 10.0);

  MxO         = ((e * x) / 15.0) + (ellProd(f, x) / 10.0);

  // Infine, ho il termine noto

  l = TPointD(ellProd(IH, x) - HxL + ellProd(IM, x) - MxO,

              ellProd(IK, y) - KyL + ellProd(IN_, y) - NyO);

  M.a13 = -l.x;

  M.a23 = -l.y;

  // Check validity conditions:

  //  a) System is not singular

  if (fabs(M.det()) < 0.01) return 0;

  M = M.inv();

  //  b) Shift (solution) is positive

  if (M.a13 < 0 || M.a23 < 0) return 0;

  T3DPointD b = a + M.a13 * x;

  T3DPointD d = e + M.a23 * y;

  //  c) The height of every CP must be >=0

  if (b.z < 0 || d.z < 0) return 0;

  len.set_CPs(a, b, (b + d) * 0.5, d, e);

  return 1;

}

//==========================================================================

//------------------------

//      Penalties

//------------------------

inline T3DPointD int_B0a(const T3DPointD &A, const T3DPointD &B, double t1,

                         double t2) {

  return (0.25 * (pow(t2, 4) - pow(t1, 4))) * B +

         ((pow(t2, 3) - pow(t1, 3)) / 3.0) * (A - 2.0 * B) +

         (0.5 * (pow(t2, 2) - pow(t1, 2))) * (B - 2.0 * A) + (t2 - t1) * A;

}

//--------------------------------------------------------------------------

inline T3DPointD int_B1a(const T3DPointD &A, const T3DPointD &B, double t1,

                         double t2) {

  return -(0.5 * (pow(t2, 4) - pow(t1, 4))) * B +

         (2.0 * ((pow(t2, 3) - pow(t1, 3)) / 3.0) * (B - A) +

          (pow(t2, 2) - pow(t1, 2)) * A);

}

//--------------------------------------------------------------------------

inline T3DPointD int_B2a(const T3DPointD &A, const T3DPointD &B, double t1,

                         double t2) {

  return (0.25 * (pow(t2, 4) - pow(t1, 4))) * B +

         ((pow(t2, 3) - pow(t1, 3)) / 3.0) * A;

}

//--------------------------------------------------------------------------

inline double int_a2(const T3DPointD &A, const T3DPointD &B, double t1,

                     double t2) {

  return ellProd(A, A) * (t2 - t1) + ellProd(A, B) * (pow(t2, 2) - pow(t1, 2)) +

         (ellProd(B, B) * (pow(t2, 3) - pow(t1, 3)) / 3.0);

}

//--------------------------------------------------------------------------

// Penalty is the integral of the square norm of differences between polygonal

// and quadratics.

bool SequenceConverter::penalty(unsigned int a, unsigned int b, Length &len) {

  unsigned int curr, old;

  const std::vector<t3dpointd> &CPs = len.CPs;</t3dpointd>

  T3DPointD A, B, P0, P1, P2;

  double p, p_max;

  unsigned int k;

  len.n = 2;  // A couple of arcs

  // Prepare max penalty p_max

  p_max = 0;

  for (curr = a + 1, old = a, k = 0; curr < b; ++k, old = curr, curr += 2) {

    p_max += (middleAddedSequence[curr].z + middleAddedSequence[old].z) *

             (pars[k + 1] - pars[k]) / 2;

  }

  p_max += (middleAddedSequence[b].z + middleAddedSequence[old].z) *

           (pars[k + 1] - pars[k]) / 2;

  // Confronting 4th power of error with mean polygonal thickness

  // - can be changed

  p_max = std::min(sqrt(p_max) * m_penalty, Quad_eps_max);

  // CP only integral

  p = (ellProd(CPs[0], CPs[0]) + 2 * ellProd(CPs[2], CPs[2]) +

       ellProd(CPs[4], CPs[4]) + ellProd(CPs[0], CPs[1]) +

       ellProd(CPs[1], CPs[2]) + ellProd(CPs[2], CPs[3]) +

       ellProd(CPs[3], CPs[4])) /

          5.0 +

      (2 * (ellProd(CPs[1], CPs[1]) + ellProd(CPs[3], CPs[3])) +

       ellProd(CPs[0], CPs[2]) + ellProd(CPs[2], CPs[4])) /

          15.0;

  // Penalty from 0.0 to 1.0

  P0 = P1 = P2 = T3DPointD();

  for (k = 0, old = a, curr = a + 1; k < middle; ++k, old = curr, curr += 2) {

    B = (middleAddedSequence[curr] - middleAddedSequence[old]) *

        (1 / (pars[k + 1] - pars[k]));

    A = middleAddedSequence[old] - pars[k] * B;

    // Mixed integral

    P0 += int_B0a(A, B, pars[k], pars[k + 1]);

    P1 += int_B1a(A, B, pars[k], pars[k + 1]);

    P2 += int_B2a(A, B, pars[k], pars[k + 1]);

    // Sequence integral

    p += int_a2(A, B, pars[k], pars[k + 1]);

  }

  if (curr == b + 1) curr = b;

  B = (middleAddedSequence[curr] - middleAddedSequence[old]) *

      (1 / (pars[k + 1] - pars[k]));

  A = middleAddedSequence[old] - pars[k] * B;

  // Mixed integral

  P0 += int_B0a(A, B, pars[k], 1.0);

  P1 += int_B1a(A, B, pars[k], 1.0);

  P2 += int_B2a(A, B, pars[k], 1.0);

  // Sequence integral

  p += int_a2(A, B, pars[k], 1.0);

  p -= 2 * (ellProd(P0, CPs[0]) + ellProd(P1, CPs[1]) + ellProd(P2, CPs[2]));

  // Penalty from 1.0 to 2.0

  P0 = P1 = P2 = T3DPointD();

  for (k = pars.size() - 1, old = b, curr = b - 1; k > middle + 1;

       --k, old = curr, curr -= 2) {

    B = (middleAddedSequence[curr] - middleAddedSequence[old]) *

        (1 / (pars[k] - pars[k - 1]));

    A = middleAddedSequence[curr] - (2 - pars[k - 1]) * B;

    // Mixed integral

    P0 += int_B0a(A, B, 2 - pars[k], 2 - pars[k - 1]);

    P1 += int_B1a(A, B, 2 - pars[k], 2 - pars[k - 1]);

    P2 += int_B2a(A, B, 2 - pars[k], 2 - pars[k - 1]);

    // Sequence integral

    p += int_a2(A, B, 2 - pars[k], 2 - pars[k - 1]);

  }

  if (old == a + 1) curr = a;

  B = (middleAddedSequence[curr] - middleAddedSequence[old]) *

      (1 / (pars[k] - pars[k - 1]));

  A = middleAddedSequence[curr] - (2 - pars[k - 1]) * B;

  // Mixed integral

  P0 += int_B0a(A, B, 2 - pars[k], 1.0);

  P1 += int_B1a(A, B, 2 - pars[k], 1.0);

  P2 += int_B2a(A, B, 2 - pars[k], 1.0);

  // Sequence integral

  p += int_a2(A, B, 2 - pars[k], 1.0);

  p -= 2 * (ellProd(P0, CPs[4]) + ellProd(P1, CPs[3]) + ellProd(P2, CPs[2]));

  // OCCHIO! Ho visto ancora qualche p<0! Da rivedere - non dovrebbe...

  if (p > p_max || p < 0)

    return 0;

  else

    len.l = p;

  return 1;

}

//--------------------------------------------------------------------------

//-----------------------------

//      Convertion Mains

//-----------------------------

inline TStroke *convert(const Sequence &s, double penalty) {

  SkeletonGraph *graph = s.m_graphHolder;

  TStroke *result;

  // First, we simplify the skeleton sequences found

  std::vector<unsigned int=""> reducedIndices;</unsigned>

  // NOTE: If s is circular, we have to protect head==tail 's adjacent nodes.

  // We then move away s tail and head, and insert them in the reducedIndices

  // apart from simplification.

  if (s.m_head == s.m_tail && graph->getNode(s.m_head).degree() == 2) {

    Sequence t = s;

    SequenceSimplifier simplifier(&t);

    reducedIndices.push_back(s.m_head);

    t.m_head     = graph->getNode(s.m_head).getLink(0).getNext();

    t.m_headLink = !graph->getNode(t.m_head).linkOfNode(s.m_head);

    t.m_tail     = graph->getNode(s.m_tail).getLink(1).getNext();

    t.m_tailLink = !graph->getNode(t.m_tail).linkOfNode(s.m_tail);

    simplifier.simplify(reducedIndices);

    reducedIndices.push_back(s.m_tail);

  } else {

    SequenceSimplifier simplifier(&s);

    simplifier.simplify(reducedIndices);

  }

  // For segments, apply this immediate conversion

  if (reducedIndices.size() == 2) {

    std::vector<tthickpoint> segment(3);</tthickpoint>

    segment[0] = *graph->getNode(s.m_head);

    segment[1] = (*graph->getNode(s.m_head) + *graph->getNode(s.m_tail)) * 0.5;

    segment[2] = *graph->getNode(s.m_tail);

    return new TStroke(segment);

  }

  // Then, we convert the sequence in a quadratic stroke

  SequenceConverter converter(&s, penalty);

  result = converter(&reducedIndices);

  // If it is a circular stroke, setSelfLoop

  // NOTA: Sembra che pero' in questo modo non venga assegnato colore al confine

  // con la cornice!!!

  //        => Solo nel caso outline...?

  // NOTA: Considera anche che pure le outline possono essere splittate per la

  // colorazione!!

  // if(globals->currConfig->m_maxThickness == 0.0 && s.m_head == s.m_tail &&

  // s.m_graphHolder->getNode(s.m_head).degree() == 2)

  // //globals->currConfig->m_outline

  //  result->setSelfLoop(true);

  // Pass the SkeletonArc::SS_OUTLINE attribute to the output stroke

  if (graph->getNode(s.m_head)

          .getLink(s.m_headLink)

          ->hasAttribute(SkeletonArc::SS_OUTLINE))

    result->setFlag(SkeletonArc::SS_OUTLINE, true);

  else if (graph->getNode(s.m_head)

               .getLink(s.m_headLink)

               ->hasAttribute(SkeletonArc::SS_OUTLINE_REVERSED))

    result->setFlag(SkeletonArc::SS_OUTLINE_REVERSED, true);

  return result;

}

//--------------------------------------------------------------------------

// Converts each forward or single Sequence of the image in its corresponding

// TStroke. Output is a vector<tstroke*>* whose ownership belongs to the user.</tstroke*>

// This allow sorts on the TStroke vector *before* adding any stroke to the

// output TVectorImage.

// std::vector<tstroke*>* conversionToStrokes(void)</tstroke*>

void conversionToStrokes(std::vector<tstroke *=""> &strokes,</tstroke>

                         VectorizerCoreGlobals &g) {

  SequenceList &singleSequences           = g.singleSequences;

  JointSequenceGraphList &organizedGraphs = g.organizedGraphs;

  double penalty                          = g.currConfig->m_penalty;

  unsigned int i, j, k;

  // Convert single sequences

  for (i = 0; i < singleSequences.size(); ++i) {

    if (singleSequences[i].m_head == singleSequences[i].m_tail) {

      // If the sequence is circular, move your endpoints to an edge middle, in

      // order

      // to allow a soft junction

      SkeletonGraph *currGraph = singleSequences[i].m_graphHolder;

      unsigned int head     = singleSequences[i].m_head;

      unsigned int headLink = singleSequences[i].m_headLink;

      unsigned int next = currGraph->getNode(head).getLink(headLink).getNext();

      unsigned int nextLink = currGraph->getNode(next).linkOfNode(head);

      unsigned int addedNode = singleSequences[i].m_graphHolder->newNode(

          (*currGraph->getNode(head) + *currGraph->getNode(next)) * 0.5);

      singleSequences[i].m_graphHolder->insert(addedNode, head, headLink);

      *singleSequences[i].m_graphHolder->node(addedNode).link(0) =

          *singleSequences[i].m_graphHolder->node(head).link(headLink);

      singleSequences[i].m_graphHolder->insert(addedNode, next, nextLink);

      *singleSequences[i].m_graphHolder->node(addedNode).link(1) =

          *singleSequences[i].m_graphHolder->node(next).link(nextLink);

      singleSequences[i].m_head     = addedNode;

      singleSequences[i].m_headLink = 0;

      singleSequences[i].m_tail     = addedNode;

      singleSequences[i].m_tailLink = 1;

    }

    strokes.push_back(convert(singleSequences[i], penalty));

  }

  // Convert graph sequences

  for (i = 0; i < organizedGraphs.size(); ++i)

    for (j = 0; j < organizedGraphs[i].getNodesCount(); ++j)

      if (!organizedGraphs[i].getNode(j).hasAttribute(

              JointSequenceGraph::ELIMINATED))

        // Otherwise eliminated by junction recovery

        for (k = 0; k < organizedGraphs[i].getNode(j).getLinksCount(); ++k) {

          // A sequence is taken at both extremities in our organized graphs

          if (organizedGraphs[i].getNode(j).getLink(k)->isForward())

            strokes.push_back(

                convert(*organizedGraphs[i].getNode(j).getLink(k), penalty));

        }

}