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];
}