ExportOrdinalsStraight Class Reference

Utility class to interpolate points spaced evenly along a piecewise defined curve with line segments between points. More...

#include <ExportOrdinalsStraight.h>

Collaboration diagram for ExportOrdinalsStraight:

Public Member Functions
	ExportOrdinalsStraight ()
	Single constructor. More...
ExportValuesOrdinal	ordinalsAtIntervalsGraphWithoutTransformation (const Points &points, double pointsInterval) const
	Compute ordinals, without any conversion to graph coordinates. More...
ExportValuesOrdinal	ordinalsAtIntervalsGraphWithTransformation (const Points &points, const Transformation &transformation, double pointsInterval) const
	Compute ordinals, converting screen coordinates to graph coordinates. More...

Detailed Description

Utility class to interpolate points spaced evenly along a piecewise defined curve with line segments between points.

Definition at line 19 of file ExportOrdinalsStraight.h.

Constructor & Destructor Documentation

ExportOrdinalsStraight()

ExportOrdinalsStraight::ExportOrdinalsStraight

(

)

Single constructor.

Definition at line 16 of file ExportOrdinalsStraight.cpp.

{
}

Member Function Documentation

ordinalsAtIntervalsGraphWithoutTransformation()

ExportValuesOrdinal ExportOrdinalsStraight::ordinalsAtIntervalsGraphWithoutTransformation	(	const Points &	points,
		double	pointsInterval
	)		const

Compute ordinals, without any conversion to graph coordinates.

Definition at line 20 of file ExportOrdinalsStraight.cpp.

{
  LOG4CPP_INFO_S ((*mainCat)) << "ExportOrdinalsStraight::ordinalsAtIntervalsGraph";

  // Results
  ExportValuesOrdinal ordinals;

  // Integrate the distances for the subintervals
  double distanceAlongSegment = 0;
  QPointF posLast (points [0].posScreen().x(),
                   points [0].posScreen().y());
  double ordinalLast = 0;

  // Simplest method to find the intervals is to break up the curve into many smaller intervals, and then aggregate them
  // into intervals that, as much as possible, have the desired length. Simplicity wins out over accuracy in this
  // approach - accuracy is sacrificed to achieve simplicity
  for (int iP = 0; iP < points.count(); iP++) {

    const Point &pointNew = points.at (iP);
    QPointF posNew = pointNew.posScreen();
    
    QPointF posDelta = posNew - posLast;
    double segmentLength = qSqrt (posDelta.x() * posDelta.x() + posDelta.y() * posDelta.y());

    while (distanceAlongSegment < segmentLength) {

      double sLocal = distanceAlongSegment / segmentLength;

      ordinals.push_back (ordinalLast + sLocal);

      distanceAlongSegment += pointsInterval;
    }

    distanceAlongSegment -= segmentLength;
    ordinalLast = pointNew.ordinal();
    posLast = posNew;
  }

  return ordinals;
}

ordinalsAtIntervalsGraphWithTransformation()

ExportValuesOrdinal ExportOrdinalsStraight::ordinalsAtIntervalsGraphWithTransformation	(	const Points &	points,
		const Transformation &	transformation,
		double	pointsInterval
	)		const

Compute ordinals, converting screen coordinates to graph coordinates.

Definition at line 62 of file ExportOrdinalsStraight.cpp.

{
  LOG4CPP_INFO_S ((*mainCat)) << "ExportOrdinalsStraight::ordinalsAtIntervalsGraph";

  // Results
  ExportValuesOrdinal ordinals;

  // Integrate the distances for the subintervals
  double distanceAlongSegment = 0;
  QPointF posLast;
  transformation.transformScreenToRawGraph (points [0].posScreen(),
                                            posLast);
  double ordinalLast = 0;

  // Simplest method to find the intervals is to break up the curve into many smaller intervals, and then aggregate them
  // into intervals that, as much as possible, have the desired length. Simplicity wins out over accuracy in this
  // approach - accuracy is sacrificed to achieve simplicity
  for (int iP = 0; iP < points.count(); iP++) {

    const Point &pointNew = points.at (iP);
    QPointF posNew;
    transformation.transformScreenToRawGraph (pointNew.posScreen(),
                                              posNew);

    QPointF posDelta = posNew - posLast;
    double segmentLength = qSqrt (posDelta.x() * posDelta.x() + posDelta.y() * posDelta.y());

    while (distanceAlongSegment < segmentLength) {

      double sLocal = distanceAlongSegment / segmentLength;

      ordinals.push_back (ordinalLast + sLocal);

      distanceAlongSegment += pointsInterval;
    }

    ordinalLast = pointNew.ordinal();
    posLast = posNew;
  }

  return ordinals;
}

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The documentation for this class was generated from the following files:

• Export/ExportOrdinalsStraight.h
• Export/ExportOrdinalsStraight.cpp