Package com.luciad.format.gml31.model

Class TLcdGML31Arc

java.lang.Object
com.luciad.datamodel.TLcdDataObject
com.luciad.datamodel.TLcdFeaturedDataObject
com.luciad.format.gml31.model.TLcdGML31AbstractCurveSegment
com.luciad.format.gml31.model.TLcdGML31ArcString
com.luciad.format.gml31.model.TLcdGML31Arc
All Implemented Interfaces:
ILcdDataObject, ILcdBounded, ILcdCircularArc, ILcdCircularArcBy3Points, ILcdCompositeCurve, ILcdCurve, ILcdShape, ILcd2DEditableCircularArcBy3Points, ILcd2DEditableShape, ILcdCloneable, ILcdDeepCloneable, ILcdFeatured, ILcdSelfDescribedFeatured, Serializable, Cloneable
Direct Known Subclasses:
TLcdGML31Circle
public class TLcdGML31Arc extends TLcdGML31ArcString implements ILcd2DEditableCircularArcBy3Points
An Arc is an arc string with only one arc unit, i.e. three control points including the start and end point. As arc is an arc string consisting of a single arc, the attribute "numArc" is fixed to "1".
Since:
10.0
See Also:

  • Field Details

    • INTERPOLATION_ATTR_PROPERTY

      public static final TLcdDataProperty INTERPOLATION_ATTR_PROPERTY
      Data property that maps to the interpolation attribute. The possible values for this property are instances of ELcdGML31CurveInterpolation.

    • NUM_ARC_PROPERTY

      public static final TLcdDataProperty NUM_ARC_PROPERTY
      Data property that maps to the numArc attribute. The possible values for this property are instances of Long.

    • POS_GROUP_PROPERTY

      public static final TLcdDataProperty POS_GROUP_PROPERTY
      Data property that maps to the choice between the pos and pointProperty and pointRep and posList and coordinates elements. The possible values for this property are instances of

    • NUM_DERIVATIVE_INTERIOR_PROPERTY

      public static final TLcdDataProperty NUM_DERIVATIVE_INTERIOR_PROPERTY
      Data property that maps to the numDerivativeInterior attribute. The possible values for this property are instances of long.

    • NUM_DERIVATIVES_AT_END_PROPERTY

      public static final TLcdDataProperty NUM_DERIVATIVES_AT_END_PROPERTY
      Data property that maps to the numDerivativesAtEnd attribute. The possible values for this property are instances of long.

    • NUM_DERIVATIVES_AT_START_PROPERTY

      public static final TLcdDataProperty NUM_DERIVATIVES_AT_START_PROPERTY
      Data property that maps to the numDerivativesAtStart attribute. The possible values for this property are instances of long.

  • Constructor Details

    • TLcdGML31Arc

      public TLcdGML31Arc(TLcdDataType aType)

    • TLcdGML31Arc

      public TLcdGML31Arc()

    • TLcdGML31Arc

      public TLcdGML31Arc(ILcdModelReference aModelReference)
      Creates a new instance and initializes its posGroup with a direct position list initialized with the given model reference.
      Parameters:
      aModelReference - the model reference for this arc

    • TLcdGML31Arc

      public TLcdGML31Arc(TLcdDataType aDataType, ILcdModelReference aModelReference)
      Creates a new instance and initializes its posGroup with a direct position list initialized with the given model reference.
      Parameters:
      aDataType - the data type for the arc
      aModelReference - the model reference for this arc

    • TLcdGML31Arc

      public TLcdGML31Arc(double aStartX, double aStartY, double aIntermediateX, double aIntermediateY, double aEndX, double aEndY, ILcdModelReference aModelReference)
      Creates a new instance and initializes its with the given parameters. The position list is initialized with the given model reference.
      Parameters:
      aStartX - X-coordinate of the arc's start point
      aStartY - Y-coordinate of the arc's start point
      aIntermediateX - X-coordinate of a point on the arc that is not the start nor the end point
      aIntermediateY - Y-coordinate of a point on the arc that is not the start nor the end point
      aEndX - X-coordinate of the arc's end point
      aEndY - Y-coordinate of the arc's end point
      aModelReference - the model reference for this arc

  • Method Details

    • moveStartPoint2D

      public void moveStartPoint2D(double aX, double aY)
      Description copied from interface: ILcd2DEditableCircularArcBy3Points
      Moves the start point to the given point in the 2D space. Only the first two dimensions of the ILcdShape are considered. The third dimension is left unchanged.
      Specified by:
      moveStartPoint2D in interface ILcd2DEditableCircularArcBy3Points
      Parameters:
      aX - the x coordinate of the point.
      aY - the y coordinate of the point.

    • moveEndPoint2D

      public void moveEndPoint2D(double aX, double aY)
      Description copied from interface: ILcd2DEditableCircularArcBy3Points
      Moves the end point to the given point in the 2D space. Only the first two dimensions of the ILcdShape are considered. The third dimension is left unchanged.
      Specified by:
      moveEndPoint2D in interface ILcd2DEditableCircularArcBy3Points
      Parameters:
      aX - the x coordinate of the point.
      aY - the y coordinate of the point.

    • moveIntermediatePoint2D

      public void moveIntermediatePoint2D(double aX, double aY)
      Description copied from interface: ILcd2DEditableCircularArcBy3Points
      Moves the intermediate point to the given point in the 2D space. Only the first two dimensions of the ILcdShape are considered. The third dimension is left unchanged.
      Specified by:
      moveIntermediatePoint2D in interface ILcd2DEditableCircularArcBy3Points
      Parameters:
      aX - the x coordinate of the point.
      aY - the y coordinate of the point.

    • translateStartPoint2D

      public void translateStartPoint2D(double aDeltaX, double aDeltaY)
      Description copied from interface: ILcd2DEditableCircularArcBy3Points
      Translates the start point from its current position over the given translation vector in the 2D space. Only the first two dimensions of the points are considered. The third dimension is left unchanged.
      Specified by:
      translateStartPoint2D in interface ILcd2DEditableCircularArcBy3Points
      Parameters:
      aDeltaX - the x coordinate of the translation vector.
      aDeltaY - the y coordinate of the translation vector.

    • translateEndPoint2D

      public void translateEndPoint2D(double aDeltaX, double aDeltaY)
      Description copied from interface: ILcd2DEditableCircularArcBy3Points
      Translates the end point from its current position over the given translation vector in the 2D space. Only the first two dimensions of the points are considered. The third dimension is left unchanged.
      Specified by:
      translateEndPoint2D in interface ILcd2DEditableCircularArcBy3Points
      Parameters:
      aDeltaX - the x coordinate of the translation vector.
      aDeltaY - the y coordinate of the translation vector.

    • translateIntermediatePoint2D

      public void translateIntermediatePoint2D(double aDeltaX, double aDeltaY)
      Description copied from interface: ILcd2DEditableCircularArcBy3Points
      Translates the intermediate point from its current position over the given translation vector in the 2D space. Only the first two dimensions of the points are considered. The third dimension is left unchanged.
      Specified by:
      translateIntermediatePoint2D in interface ILcd2DEditableCircularArcBy3Points
      Parameters:
      aDeltaX - the x coordinate of the translation vector.
      aDeltaY - the y coordinate of the translation vector.

    • getIntermediatePoint

      public ILcdPoint getIntermediatePoint()
      Description copied from interface: ILcdCircularArcBy3Points
      Returns an intermediate point of this arc.
      Specified by:
      getIntermediatePoint in interface ILcdCircularArcBy3Points
      Returns:
      an intermediate point of this arc.

    • getRadius

      public double getRadius()
      Description copied from interface: ILcdCircularArc
      Returns the radius of this ILcdCircularArc.
      Specified by:
      getRadius in interface ILcdCircularArc
      Returns:
      the radius of this ILcdCircularArc.

    • getCenter

      public ILcdPoint getCenter()
      Description copied from interface: ILcdCircularArc
      Returns the center of this ILcdCircularArc.
      Specified by:
      getCenter in interface ILcdCircularArc
      Returns:
      the center of this ILcdCircularArc.

    • getStartAngle

      public double getStartAngle()
      Description copied from interface: ILcdCircularArc
      Returns the start angle of this ILcdCircularArc (in degrees). The angle is measured from 3 o'clock position, positive counter-clockwise.
      Specified by:
      getStartAngle in interface ILcdCircularArc
      Returns:
      the start angle of the arc (in degrees). The angle is measured from 3 o'clock position, positive counter-clockwise.

    • getArcAngle

      public double getArcAngle()
      Description copied from interface: ILcdCircularArc
      Returns the angle over which this ILcdCircularArc extends (in degrees). The angle is positive counter-clockwise.
      Specified by:
      getArcAngle in interface ILcdCircularArc
      Returns:
      the angle over which the arc extends (in degrees). The angle is positive counter-clockwise.

    • getStartPoint

      public ILcdPoint getStartPoint()
      Description copied from interface: ILcdCurve
      Retrieves the start point of the curve.

      This is equivalent to computePointSFCT(0).

      Specified by:
      getStartPoint in interface ILcdCompositeCurve
      Specified by:
      getStartPoint in interface ILcdCurve
      Overrides:
      getStartPoint in class TLcdGML31ArcString
      Returns:
      the start point of the curve

    • getEndPoint

      public ILcdPoint getEndPoint()
      Description copied from interface: ILcdCurve
      Retrieves the end point of the curve.

      This is equivalent to computePointSFCT(1).

      Specified by:
      getEndPoint in interface ILcdCompositeCurve
      Specified by:
      getEndPoint in interface ILcdCurve
      Overrides:
      getEndPoint in class TLcdGML31ArcString
      Returns:
      the end point of the curve

    • getStartTangent2D

      public double getStartTangent2D()
      Description copied from interface: ILcdCurve
      Returns the angle of the curve's tangent at the start point, in degrees counterclockwise from the direction at 3 o'clock.

      The tangent orientation is from the start point towards the rest of the shape.

      This is the same as getTangent2D(0).

      Specified by:
      getStartTangent2D in interface ILcdCurve
      Overrides:
      getStartTangent2D in class TLcdGML31ArcString
      Returns:
      the curve's angle in the start point

    • getEndTangent2D

      public double getEndTangent2D()
      Description copied from interface: ILcdCurve
      Returns the angle of the curve's tangent at the end point, in degrees counterclockwise from the direction at 3 o'clock.

      The tangent orientation is from the end point, away from the curve before it.

      This is the same as getTangent2D(1).

      Specified by:
      getEndTangent2D in interface ILcdCurve
      Overrides:
      getEndTangent2D in class TLcdGML31ArcString
      Returns:
      the curve's angle in the end point

    • getTangent2D

      public double getTangent2D(double aParam)
      Description copied from interface: ILcdCurve
      Returns the angle of the curve's tangent in the point defined by the given parameter, in degrees counterclockwise from the direction at 3 o'clock.

      The tangent orientation is from the point at parameter aParam towards the rest of the shape.

      Specified by:
      getTangent2D in interface ILcdCurve
      Overrides:
      getTangent2D in class TLcdGML31ArcString
      Parameters:
      aParam - a value of the closed interval [0,1]
      Returns:
      the curve's angle in the point defined by the given parameter

    • getLength2D

      public double getLength2D(double aParam1, double aParam2)
      Description copied from interface: ILcdCurve
      Returns the length between two points of the curve, defined by the given parameters.
      • When aParam1 == aParam2, the length is 0.
      • When aParam1 == 0 and aParam2 == 1, the length is the whole length of the curve.
      • When aParam1 > aParam2, the length is (aParam1 to 1) + (0 to aParam2).
      Specified by:
      getLength2D in interface ILcdCurve
      Overrides:
      getLength2D in class TLcdGML31ArcString
      Parameters:
      aParam1 - a value of the closed interval [0,1]
      aParam2 - a value of the closed interval [0,1]
      Returns:
      the length of the curve.

    • computePointSFCT

      public void computePointSFCT(double aParam, ILcd3DEditablePoint aPointSFCT)
      Description copied from interface: ILcdCurve
      Computes a point of the curve, defined by the given parameter.
      Specified by:
      computePointSFCT in interface ILcdCurve
      Overrides:
      computePointSFCT in class TLcdGML31ArcString
      Parameters:
      aParam - a value of the closed interval [0,1]
      aPointSFCT - the point to store the computed curve point in

    • getInterpolation

      public String getInterpolation()
      Description copied from interface: ILcdCurve
      Returns the interpolation method used by this curve.

      A set of predefined constants are defined in this interface, which are used by the default ILcdCurve implementations provided by LuciadLightspeed.

      Custom implementations can define their own constants, and use them to interpret the interpolation of the curve.

      Specified by:
      getInterpolation in interface ILcdCircularArc
      Specified by:
      getInterpolation in interface ILcdCircularArcBy3Points
      Specified by:
      getInterpolation in interface ILcdCompositeCurve
      Specified by:
      getInterpolation in interface ILcdCurve
      Overrides:
      getInterpolation in class TLcdGML31ArcString
      Returns:
      the interpolation method used by this curve.

    • getLineSegmentIntersectionCount

      public int getLineSegmentIntersectionCount(ILcdPoint aP1, ILcdPoint aP2)
      Description copied from interface: ILcdCurve
      Returns the number of intersections between this curve and a line segment defined by the two specified points.

      This information can be used to perform containment calculations, if this curve is closed or if this curve is part of a composite closed curve. By determining the number of intersections between this curve and a line segment starting from a given point in a fixed direction, one can determine whether a point is located within the closed curve by using the even-odd rule.

      Specified by:
      getLineSegmentIntersectionCount in interface ILcdCurve
      Overrides:
      getLineSegmentIntersectionCount in class TLcdGML31ArcString
      Parameters:
      aP1 - the first point of the line segment
      aP2 - the second point of the line segment
      Returns:
      the number of intersections between the curve and the line segment

    • move2D

      public void move2D(ILcdPoint aPoint)
      Description copied from interface: ILcd2DEditableShape
      Moves this ILcd2DEditableShape to the given point in the 2D space. The focus point is used as the handle by which the shape is moved. Only the first two dimensions of the ILcdShape and the ILcdPoint are considered. The third dimension is left unchanged.
      Specified by:
      move2D in interface ILcd2DEditableShape
      Parameters:
      aPoint - the ILcdPoint to move to.
      See Also:

    • move2D

      public void move2D(double aX, double aY)
      Description copied from interface: ILcd2DEditableShape
      Moves this ILcd2DEditableShape to the given point in the 2D space. The focus point is used as the handle by which the shape is moved. Only the first two dimensions of the ILcdShape are considered. The third dimension is left unchanged.
      Specified by:
      move2D in interface ILcd2DEditableShape
      Parameters:
      aX - the x coordinate of the point.
      aY - the y coordinate of the point.

    • translate2D

      public void translate2D(double aDeltaX, double aDeltaY)
      Description copied from interface: ILcd2DEditableShape
      Translates this ILcd2DEditableShape from its current position over the given translation vector in the 2D space. Only the first two dimensions of the ILcdShape are considered. The third dimension is left unchanged.
      Specified by:
      translate2D in interface ILcd2DEditableShape
      Parameters:
      aDeltaX - the x coordinate of the translation vector.
      aDeltaY - the y coordinate of the translation vector.

    • getFocusPoint

      public ILcdPoint getFocusPoint()
      Description copied from interface: ILcdShape
      Returns the focus point of this ILcdShape.
      Specified by:
      getFocusPoint in interface ILcdShape
      Overrides:
      getFocusPoint in class TLcdGML31ArcString
      Returns:
      the focus point of this ILcdShape.

    • contains2D

      public boolean contains2D(ILcdPoint aPoint)
      Description copied from interface: ILcdShape
      Checks whether this ILcdShape contains the given ILcdPoint in the 2D space. Only the first two dimensions of the ILcdShape and the ILcdPoint are considered.
      Specified by:
      contains2D in interface ILcdShape
      Overrides:
      contains2D in class TLcdGML31ArcString
      Parameters:
      aPoint - the ILcdPoint to test.
      Returns:
      the boolean result of the containment test.
      See Also:

    • contains2D

      public boolean contains2D(double aX, double aY)
      Description copied from interface: ILcdShape
      Checks whether this ILcdShape contains the given point in the 2D space. Only the first two dimensions of the ILcdShape are considered.
      Specified by:
      contains2D in interface ILcdShape
      Overrides:
      contains2D in class TLcdGML31ArcString
      Parameters:
      aX - the x coordinate of the point.
      aY - the y coordinate of the point.
      Returns:
      the boolean result of the containment test.

    • contains3D

      public boolean contains3D(ILcdPoint aPoint)
      Description copied from interface: ILcdShape
      Checks whether this ILcdShape contains the given ILcdPoint in the 3D space.
      Specified by:
      contains3D in interface ILcdShape
      Overrides:
      contains3D in class TLcdGML31ArcString
      Parameters:
      aPoint - the ILcdPoint to test.
      Returns:
      the boolean result of the containment test.
      See Also:

    • contains3D

      public boolean contains3D(double aX, double aY, double aZ)
      Description copied from interface: ILcdShape
      Checks whether this ILcdShape contains the given point in the 3D space.
      Specified by:
      contains3D in interface ILcdShape
      Overrides:
      contains3D in class TLcdGML31ArcString
      Parameters:
      aX - the x coordinate of the point.
      aY - the y coordinate of the point.
      aZ - the z coordinate of the point.
      Returns:
      the boolean result of the containment test.

    • getBounds

      public ILcdBounds getBounds()
      Description copied from interface: ILcdBounded
      Returns the ILcdBounds by which the geometry of this ILcdBounded object is bounded.

      If the geometry does not allow retrieving valid bounds (for example a polyline with 0 points) the return value is unspecified. It is highly recommended to return an undefined bounds. You can create undefined bounds using the default constructors of TLcdLonLatBounds or TLcdXYBounds.

      Specified by:
      getBounds in interface ILcdBounded
      Overrides:
      getBounds in class TLcdGML31ArcString
      Returns:
      the ILcdBounds by which the geometry of this ILcdBounded object is bounded.

    • getInterpolationAttr

      public ELcdGML31CurveInterpolation getInterpolationAttr()
      Returns the value of the property that maps to the interpolation attribute.

      The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism uses the control points and control parameters to determine the position of this curve segment. For an ArcString the interpolation is fixed as "circularArc3Points".

      Returns:
      the value of the INTERPOLATION_ATTR_PROPERTY property.

    • setInterpolationAttr

      public void setInterpolationAttr(ELcdGML31CurveInterpolation aValue)
      Sets the value of the property that maps to the interpolation attribute.

      The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism uses the control points and control parameters to determine the position of this curve segment. For an ArcString the interpolation is fixed as "circularArc3Points".

      Parameters:
      aValue - the value to set for the INTERPOLATION_ATTR_PROPERTY property.

    • getNumArc

      public Long getNumArc()
      Returns the value of the property that maps to the numArc attribute.

      The number of arcs in the arc string can be explicitly stated in this attribute. The number of control points in the arc string must be 2 * numArc + 1.

      Returns:
      the value of the NUM_ARC_PROPERTY property.

    • setNumArc

      public void setNumArc(Long aValue)
      Sets the value of the property that maps to the numArc attribute.

      The number of arcs in the arc string can be explicitly stated in this attribute. The number of control points in the arc string must be 2 * numArc + 1.

      Parameters:
      aValue - the value to set for the NUM_ARC_PROPERTY property.

    • getPosGroup

      public Object getPosGroup()
      Returns the value of the property that maps to the choice between the pos and pointProperty and pointRep and posList and coordinates elements.

      The possible values for this property are instances of

      Returns:
      the value of the POS_GROUP_PROPERTY property.

    • setPosGroup

      public void setPosGroup(Object aValue)
      Sets the value of the property that maps to the choice between the pos and pointProperty and pointRep and posList and coordinates elements.

      The possible values for this property are instances of

      Parameters:
      aValue - the value to set for the POS_GROUP_PROPERTY property.

    • getNumDerivativeInterior

      public long getNumDerivativeInterior()
      Returns the value of the property that maps to the numDerivativeInterior attribute.

      The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity. NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that allow them to adjust the values of the derivatives to support C 1 or higher continuity.

      Returns:
      the value of the NUM_DERIVATIVE_INTERIOR_PROPERTY property.

    • setNumDerivativeInterior

      public void setNumDerivativeInterior(long aValue)
      Sets the value of the property that maps to the numDerivativeInterior attribute.

      The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity. NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that allow them to adjust the values of the derivatives to support C 1 or higher continuity.

      Parameters:
      aValue - the value to set for the NUM_DERIVATIVE_INTERIOR_PROPERTY property.

    • getNumDerivativesAtEnd

      public long getNumDerivativesAtEnd()
      Returns the value of the property that maps to the numDerivativesAtEnd attribute.

      The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity. NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that allow them to adjust the values of the derivatives to support C 1 or higher continuity.

      Returns:
      the value of the NUM_DERIVATIVES_AT_END_PROPERTY property.

    • setNumDerivativesAtEnd

      public void setNumDerivativesAtEnd(long aValue)
      Sets the value of the property that maps to the numDerivativesAtEnd attribute.

      The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity. NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that allow them to adjust the values of the derivatives to support C 1 or higher continuity.

      Parameters:
      aValue - the value to set for the NUM_DERIVATIVES_AT_END_PROPERTY property.

    • getNumDerivativesAtStart

      public long getNumDerivativesAtStart()
      Returns the value of the property that maps to the numDerivativesAtStart attribute.

      The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity. NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that allow them to adjust the values of the derivatives to support C 1 or higher continuity.

      Returns:
      the value of the NUM_DERIVATIVES_AT_START_PROPERTY property.

    • setNumDerivativesAtStart

      public void setNumDerivativesAtStart(long aValue)
      Sets the value of the property that maps to the numDerivativesAtStart attribute.

      The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity. NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that allow them to adjust the values of the derivatives to support C 1 or higher continuity.

      Parameters:
      aValue - the value to set for the NUM_DERIVATIVES_AT_START_PROPERTY property.