/* -*- mode: C++ ; c-file-style: "stroustrup" -*- *****************************
 * QwtPolar Widget Library
 * Copyright (C) 2008   Uwe Rathmann
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the Qwt License, Version 1.0
 *****************************************************************************/

#include "qwt_math.h"
#include "qwt_polar_fitter.h"

class QwtPolarFitter::PrivateData
{
  public:
    PrivateData():
        stepCount( 5 )
    {
    }

    int stepCount;
};

/*!
   Constructor

   \param stepCount Number of points, that will be inserted between 2 points
   \sa setStepCount()
*/
QwtPolarFitter::QwtPolarFitter( int stepCount )
{
  d_data = new PrivateData;
  d_data->stepCount = stepCount;
}

//! Destructor
QwtPolarFitter::~QwtPolarFitter()
{
  delete d_data;
}

/*!
   Assign the number of points, that will be inserted between 2 points
   The default value is 5.

   \param stepCount Number of steps

   \sa stepCount()
*/
void QwtPolarFitter::setStepCount( int stepCount )
{
  d_data->stepCount = qwtMax( stepCount, 0 );
}

/*!
   \return Number of points, that will be inserted between 2 points
   \sa setStepCount()
*/
int QwtPolarFitter::stepCount() const
{
  return d_data->stepCount;
}

/*!
   Insert stepCount() number of additional points between 2 elements
   of points.

   \param points Array of points
   \return Array of points including the additional points
*/
#if QT_VERSION < 0x040000
QwtArray<QwtDoublePoint> QwtPolarFitter::fitCurve(
  const QwtArray<QwtDoublePoint> &points ) const
#else
QPolygonF QwtPolarFitter::fitCurve(
  const QPolygonF &points ) const
#endif
{
  if ( d_data->stepCount <= 0 || points.size() <= 1 )
    return points;

#if QT_VERSION < 0x040000
  QwtArray<QwtDoublePoint> fittedPoints;
#else
  QPolygonF fittedPoints;
#endif

  int numPoints = points.size() + ( points.size() - 1 ) * d_data->stepCount;

  fittedPoints.resize( numPoints );

  int index = 0;
  fittedPoints[index++] = points[0];
  for ( int i = 1; i < ( int )points.size(); i++ )
  {
    const QwtDoublePoint &p1 = points[i-1];
    const QwtDoublePoint &p2 = points[i];

    const double dx = ( p2.x() - p1.x() ) / d_data->stepCount;
    const double dy = ( p2.y() - p1.y() ) / d_data->stepCount;
    for ( int j = 1; j <= d_data->stepCount; j++ )
    {
      const double x = p1.x() + j * dx;
      const double y = p1.y() + j * dy;

      fittedPoints[index++] = QwtDoublePoint( x, y );
    }
  }
  fittedPoints.resize( index );

  return fittedPoints;
}
