PolyLineBezierSplineData.cc

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//=============================================================================
//
//  CLASS PolyLineCircleData - IMPLEMENTATION
//
//=============================================================================


//== INCLUDES =================================================================

#include "PolyLineBezierSplineData.hh"

PolyLineBezierSplineData::PolyLineBezierSplineData(unsigned int _meshIndex)
: meshIndex_(_meshIndex)
{
}

void PolyLineBezierSplineData::addInterpolatePoint(ACG::Vec3d _position, ACG::Vec3d _normal)
{
        InterpolatePoint p;
        p.position = _position;
        p.normal   = _normal;

        points_.push_back(p);
}

bool PolyLineBezierSplineData::finishSpline()
{
  if(points_.size() < 2)
      return false;

  handles_.clear();

  for(unsigned int i = 0; i + 1 < points_.size(); i++) {

    const ACG::Vec3d firstPoint = points_[i].position, sndPoint = points_[i + 1].position;
    double r = (firstPoint - sndPoint).norm() / 4.0;
    const ACG::Vec3d dir = sndPoint - firstPoint;
    const ACG::Vec3d ort0 = dir % points_[i].normal, ort1 = dir % points_[i + 1].normal;
    ACG::Vec3d f0 = ort0 % points_[i].normal, f1 = ort1 % points_[i + 1].normal;

    ACG::Vec3d near = firstPoint - f0.normalize() * r,
               far  = sndPoint   + f1.normalize() * r;

    handles_.push_back(near);
    handles_.push_back(far);

  }

  //handles will be degenerate up to now
  for(unsigned int i = 1; i + 1 < handles_.size(); i += 2) {

    const ACG::Vec3d dir = (handles_[i + 1] - handles_[i]) / 2.0;

    InterpolatePoint& p = getInterpolatePoint(i);
    handles_[i + 1]     = p.position + dir;
    handles_[i]         = p.position - dir;
  }

  return true;
}

PolyLineBezierSplineData::InterpolatePoint& PolyLineBezierSplineData::getInterpolatePoint(unsigned int _handleIndex)
{
        if(!_handleIndex)
                return points_[0];
        else if(_handleIndex == handles_.size())
                return points_.back();
        else return points_[(_handleIndex - 1) / 2 + 1];
}