//
//  Copyright (C) : Please refer to the COPYRIGHT file distributed 
//   with this source distribution. 
//
//  This program is free software; you can redistribute it and/or
//  modify it under the terms of the GNU General Public License
//  as published by the Free Software Foundation; either version 2
//  of the License, or (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
///////////////////////////////////////////////////////////////////////////////

#include "Bezier.h"
#include "FitCurve.h"

using namespace std;

BezierCurveSegment::BezierCurveSegment()
{
}

BezierCurveSegment::~BezierCurveSegment()
{
}

void BezierCurveSegment::AddControlPoint(const Vec2d& iPoint)
{
  _ControlPolygon.push_back(iPoint);
  if(_ControlPolygon.size() == 4)
    Build();
}

void BezierCurveSegment::Build()
{
  if(_ControlPolygon.size() != 4)
    return;

  // Compute the rightmost part of the matrix:
  vector<Vec2d>::const_iterator p0,p1,p2,p3;
  p0 = _ControlPolygon.begin();
  p1 = p0;++p1;
  p2 = p1;++p2;
  p3 = p2;++p3;
  float x[4], y[4];
  
  x[0] = -p0->x()+3*p1->x()-3*p2->x()+p3->x();
  x[1] = 3*p0->x()-6*p1->x()+3*p2->x();
  x[2] = -3*p0->x()+3*p1->x();
  x[3] = p0->x();

  y[0] = -p0->y()+3*p1->y()-3*p2->y()+p3->y();
  y[1] = 3*p0->y()-6*p1->y()+3*p2->y();
  y[2] = -3*p0->y()+3*p1->y();
  y[3] = p0->y();

  int nvertices = 12;
  float increment = 1.0/(float)nvertices;
  float t = 0.f;
  for(int i=0; i<=nvertices; ++i)
  {
    _Vertices.push_back(Vec2d((x[3] + t*(x[2] + t*(x[1] + t*x[0]))), 
                              (y[3] + t*(y[2] + t*(y[1] + t*y[0])))));
    t+=increment;
  }
}

BezierCurve::BezierCurve()
{
  _currentSegment = new BezierCurveSegment;
}

BezierCurve::BezierCurve(vector<Vec2d>& iPoints, double error)
{
  FitCurveWrapper fitcurve;
  _currentSegment = new BezierCurveSegment;
  vector<Vec2d> curve;

  fitcurve.FitCurve(iPoints, curve, error);
  int i=0;
  vector<Vec2d>::iterator v,vend;
  for(v=curve.begin(),vend=curve.end();
  v!=vend;
  ++v)
  {
    if((i == 0) || (i%4 != 0))
      AddControlPoint(*v);
    ++i;
  }
}

BezierCurve::~BezierCurve()
{
  if(_currentSegment)
    delete _currentSegment;
}

void BezierCurve::AddControlPoint(const Vec2d& iPoint)
{
  _ControlPolygon.push_back(iPoint);
  _currentSegment->AddControlPoint(iPoint);
  if(_currentSegment->size() == 4)
  {
    _Segments.push_back(_currentSegment);
    _currentSegment = new BezierCurveSegment;
    _currentSegment->AddControlPoint(iPoint);
  }
}