#include "ext/SquarePotential.h"

#include <tmathutil.h></tmathutil.h>

#include <algorithm></algorithm>

using namespace std;

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

void ToonzExt::SquarePotential::setParameters_(const TStroke *ref, double par,

                                               double al) {

  ref_          = ref;

  par_          = par;

  actionLength_ = al;

  assert(ref_);

  strokeLength_  = ref->getLength();

  lengthAtParam_ = ref->getLength(par);

  // lunghezza dal pto di click all'inizio della curva

  leftFactor_ = min(lengthAtParam_,

                    actionLength_ * 0.5);  // lengthAtParam_ / strokeLength_;

  // lunghezza dal pto di click alla fine

  rightFactor_ = min(strokeLength_ - lengthAtParam_, actionLength_ * 0.5);

  // considero come intervallo di mapping [-range,range].

  //  4 ha come valore c.a. 10exp-6

  //  cioé sposterei un pixel su un movimento di un milione di pixel

  range_ = 2.8;

}

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

ToonzExt::SquarePotential::~SquarePotential() {}

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

double ToonzExt::SquarePotential::value_(double value2test) const {

  return this->compute_value(value2test);

}

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

// normalization of parameter in range interval

double ToonzExt::SquarePotential::compute_shape(double value2test) const {

  double x                       = ref_->getLength(value2test);

  double shape                   = this->actionLength_ * 0.5;

  if (isAlmostZero(shape)) shape = 1.0;

  x                              = ((x - lengthAtParam_) * range_) / shape;

  return x;

}

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

double ToonzExt::SquarePotential::compute_value(double value2test) const {

  // use

  //     2

  //  1-x

  //

  double x   = 0.0;

  double res = 0.0;

  // length  at parameter

  x = ref_->getLength(value2test);

  double tmp_al = actionLength_ * 0.5;

  // compute correct parameter considering offset

  // try to have a square curve like shape

  //

  //       2

  //  m = x

  //

  if (leftFactor_ == 0.0)

    x = 1.0 - x / tmp_al;

  else if (rightFactor_ == 0.0)

    x = (x - (strokeLength_ - tmp_al)) / tmp_al;

  else {

    if (x <= lengthAtParam_ && ((lengthAtParam_ - x) <= leftFactor_))

      x = (x - (lengthAtParam_ - leftFactor_)) / leftFactor_;

    else if (x > lengthAtParam_ && ((x - lengthAtParam_) < rightFactor_))

      x = (rightFactor_ - (x - lengthAtParam_)) / rightFactor_;

    else

      x = -1;

  }

  if (x < 0.0) return 0.0;

  // assert( 0.0 <= x &&

  //  x <= 1.0 + TConsts::epsilon );

  res = sq(x);

  return res;

}

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

ToonzExt::Potential *ToonzExt::SquarePotential::clone() {

  return new SquarePotential;

}

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

//  End Of File

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