public class TLcdGML31Arc extends TLcdGML31ArcString implements ILcd2DEditableCircularArcBy3Points
Modifier and Type  Field and Description 

static TLcdDataProperty 
INTERPOLATION_ATTR_PROPERTY
Data property that maps to the
interpolation attribute. 
static TLcdDataProperty 
NUM_ARC_PROPERTY
Data property that maps to the
numArc attribute. 
static TLcdDataProperty 
NUM_DERIVATIVE_INTERIOR_PROPERTY
Data property that maps to the
numDerivativeInterior attribute. 
static TLcdDataProperty 
NUM_DERIVATIVES_AT_END_PROPERTY
Data property that maps to the
numDerivativesAtEnd attribute. 
static TLcdDataProperty 
NUM_DERIVATIVES_AT_START_PROPERTY
Data property that maps to the
numDerivativesAtStart attribute. 
static TLcdDataProperty 
POS_GROUP_PROPERTY
Data property that maps to the choice between the
pos and pointProperty and pointRep and posList and coordinates elements. 
INTERPOLATION_CIRCLE_BY_3POINTS, INTERPOLATION_CIRCLE_BY_CENTERPOINT, INTERPOLATION_CIRCULARARC_BY_3POINTS, INTERPOLATION_CIRCULARARC_BY_BULGE, INTERPOLATION_CIRCULARARC_BY_CENTERPOINT, INTERPOLATION_ELLIPTICAL, INTERPOLATION_GEODESIC, INTERPOLATION_LINEAR, INTERPOLATION_MIXED, INTERPOLATION_RHUMB
Constructor and Description 

TLcdGML31Arc() 
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.

TLcdGML31Arc(ILcdModelReference aModelReference)
Creates a new instance and initializes its posGroup with a direct
position list initialized with the given model reference.

TLcdGML31Arc(TLcdDataType aType) 
TLcdGML31Arc(TLcdDataType aDataType,
ILcdModelReference aModelReference)
Creates a new instance and initializes its posGroup with a direct
position list initialized with the given model reference.

Modifier and Type  Method and Description 

void 
computePointSFCT(double aParam,
ILcd3DEditablePoint aPointSFCT)
Computes a point of the curve, defined by the given parameter.

boolean 
contains2D(double aX,
double aY)
Checks whether this
ILcdShape contains the given point in
the 2D space. 
boolean 
contains2D(ILcdPoint aPoint)
Checks whether this
ILcdShape contains the given ILcdPoint in the 2D space. 
boolean 
contains3D(double aX,
double aY,
double aZ)
Checks whether this
ILcdShape contains the given point in
the 3D space. 
boolean 
contains3D(ILcdPoint aPoint)
Checks whether this
ILcdShape contains the given ILcdPoint in the 3D space. 
double 
getArcAngle()
Returns the angle over which this
ILcdCircularArc extends (in degrees). 
ILcdBounds 
getBounds()
Returns the
ILcdBounds by which the geometry of this ILcdBounded object
is bounded. 
ILcdPoint 
getCenter()
Returns the center of this
ILcdCircularArc . 
ILcdPoint 
getEndPoint()
Retrieves the end point of the curve.

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

ILcdPoint 
getFocusPoint()
Returns the focus point of this
ILcdShape . 
ILcdPoint 
getIntermediatePoint()
Returns an intermediate point of this arc.

String 
getInterpolation()
Returns the interpolation method used by this curve.

ELcdGML31CurveInterpolation 
getInterpolationAttr()
Returns the value of the property that maps to the
interpolation attribute. 
double 
getLength2D(double aParam1,
double aParam2)
Returns the length between two points of the curve,
defined by the given parameters.

int 
getLineSegmentIntersectionCount(ILcdPoint aP1,
ILcdPoint aP2)
Returns the number of intersections between this curve and a line segment
defined by the two specified points.

Long 
getNumArc()
Returns the value of the property that maps to the
numArc attribute. 
long 
getNumDerivativeInterior()
Returns the value of the property that maps to the
numDerivativeInterior attribute. 
long 
getNumDerivativesAtEnd()
Returns the value of the property that maps to the
numDerivativesAtEnd attribute. 
long 
getNumDerivativesAtStart()
Returns the value of the property that maps to the
numDerivativesAtStart attribute. 
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. 
double 
getRadius()
Returns the radius of this
ILcdCircularArc . 
double 
getStartAngle()
Returns the start angle of this
ILcdCircularArc (in degrees). 
ILcdPoint 
getStartPoint()
Retrieves the start point of the curve.

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

double 
getTangent2D(double aParam)
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.

void 
move2D(double aX,
double aY)
Moves this
ILcd2DEditableShape to the given point in the 2D space. 
void 
move2D(ILcdPoint aPoint)
Moves this
ILcd2DEditableShape to the given point in the 2D space. 
void 
moveEndPoint2D(double aX,
double aY)
Moves the end point to the given point in the 2D space.

void 
moveIntermediatePoint2D(double aX,
double aY)
Moves the intermediate point to the given point in the 2D space.

void 
moveStartPoint2D(double aX,
double aY)
Moves the start point to the given point in the 2D space.

void 
setInterpolationAttr(ELcdGML31CurveInterpolation aValue)
Sets the value of the property that maps to the
interpolation attribute. 
void 
setNumArc(Long aValue)
Sets the value of the property that maps to the
numArc attribute. 
void 
setNumDerivativeInterior(long aValue)
Sets the value of the property that maps to the
numDerivativeInterior attribute. 
void 
setNumDerivativesAtEnd(long aValue)
Sets the value of the property that maps to the
numDerivativesAtEnd attribute. 
void 
setNumDerivativesAtStart(long aValue)
Sets the value of the property that maps to the
numDerivativesAtStart attribute. 
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. 
void 
translate2D(double aDeltaX,
double aDeltaY)
Translates this
ILcd2DEditableShape from its current position over the given translation
vector in the 2D space. 
void 
translateEndPoint2D(double aDeltaX,
double aDeltaY)
Translates the end point from its current position
over the given translation vector in the 2D space.

void 
translateIntermediatePoint2D(double aDeltaX,
double aDeltaY)
Translates the intermediate point from its current position
over the given translation vector in the 2D space.

void 
translateStartPoint2D(double aDeltaX,
double aDeltaY)
Translates the start point from its current position
over the given translation vector in the 2D space.

clone, clone, getCurves
canSetFeature, getFeature, getFeature, getFeatureCount, getFeaturedDescriptor, setFeature, setFeature
getDataType, getValue, getValue, hasValue, hasValue, setValue, setValue, toString
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
clone
public static final TLcdDataProperty INTERPOLATION_ATTR_PROPERTY
interpolation
attribute.
The possible values for this property are instances of ELcdGML31CurveInterpolation
.public static final TLcdDataProperty NUM_ARC_PROPERTY
numArc
attribute.
The possible values for this property are instances of Long
.public static final TLcdDataProperty POS_GROUP_PROPERTY
pos
and pointProperty
and pointRep
and posList
and coordinates
elements.
The possible values for this property are instances of
List<TLcdGML31DirectPosition>
List<TLcdGML31PointProperty>
List<TLcdGML31PointProperty>
TLcdGML31DirectPositionList
TLcdGML31Coordinates
public static final TLcdDataProperty NUM_DERIVATIVE_INTERIOR_PROPERTY
numDerivativeInterior
attribute.
The possible values for this property are instances of long
.public static final TLcdDataProperty NUM_DERIVATIVES_AT_END_PROPERTY
numDerivativesAtEnd
attribute.
The possible values for this property are instances of long
.public static final TLcdDataProperty NUM_DERIVATIVES_AT_START_PROPERTY
numDerivativesAtStart
attribute.
The possible values for this property are instances of long
.public TLcdGML31Arc(TLcdDataType aType)
public TLcdGML31Arc()
public TLcdGML31Arc(ILcdModelReference aModelReference)
aModelReference
 the model reference for this arcpublic TLcdGML31Arc(TLcdDataType aDataType, ILcdModelReference aModelReference)
aDataType
 the data type for the arcaModelReference
 the model reference for this arcpublic TLcdGML31Arc(double aStartX, double aStartY, double aIntermediateX, double aIntermediateY, double aEndX, double aEndY, ILcdModelReference aModelReference)
aStartX
 Xcoordinate of the arc's start pointaStartY
 Ycoordinate of the arc's start pointaIntermediateX
 Xcoordinate of a point on the arc that is not the start nor the end
pointaIntermediateY
 Ycoordinate of a point on the arc that is not the start nor the end
pointaEndX
 Xcoordinate of the arc's end pointaEndY
 Ycoordinate of the arc's end pointaModelReference
 the model reference for this arcpublic void moveStartPoint2D(double aX, double aY)
ILcd2DEditableCircularArcBy3Points
ILcdShape
are considered.
The third dimension is left unchanged.moveStartPoint2D
in interface ILcd2DEditableCircularArcBy3Points
aX
 the x coordinate of the point.aY
 the y coordinate of the point.public void moveEndPoint2D(double aX, double aY)
ILcd2DEditableCircularArcBy3Points
ILcdShape
are considered.
The third dimension is left unchanged.moveEndPoint2D
in interface ILcd2DEditableCircularArcBy3Points
aX
 the x coordinate of the point.aY
 the y coordinate of the point.public void moveIntermediatePoint2D(double aX, double aY)
ILcd2DEditableCircularArcBy3Points
ILcdShape
are considered.
The third dimension is left unchanged.moveIntermediatePoint2D
in interface ILcd2DEditableCircularArcBy3Points
aX
 the x coordinate of the point.aY
 the y coordinate of the point.public void translateStartPoint2D(double aDeltaX, double aDeltaY)
ILcd2DEditableCircularArcBy3Points
translateStartPoint2D
in interface ILcd2DEditableCircularArcBy3Points
aDeltaX
 the x coordinate of the translation vector.aDeltaY
 the y coordinate of the translation vector.public void translateEndPoint2D(double aDeltaX, double aDeltaY)
ILcd2DEditableCircularArcBy3Points
translateEndPoint2D
in interface ILcd2DEditableCircularArcBy3Points
aDeltaX
 the x coordinate of the translation vector.aDeltaY
 the y coordinate of the translation vector.public void translateIntermediatePoint2D(double aDeltaX, double aDeltaY)
ILcd2DEditableCircularArcBy3Points
translateIntermediatePoint2D
in interface ILcd2DEditableCircularArcBy3Points
aDeltaX
 the x coordinate of the translation vector.aDeltaY
 the y coordinate of the translation vector.public ILcdPoint getIntermediatePoint()
ILcdCircularArcBy3Points
getIntermediatePoint
in interface ILcdCircularArcBy3Points
public double getRadius()
ILcdCircularArc
ILcdCircularArc
.getRadius
in interface ILcdCircularArc
ILcdCircularArc
.public ILcdPoint getCenter()
ILcdCircularArc
ILcdCircularArc
.getCenter
in interface ILcdCircularArc
ILcdCircularArc
.public double getStartAngle()
ILcdCircularArc
ILcdCircularArc
(in degrees). The angle is
measured from 3 o'clock position, positive counterclockwise.getStartAngle
in interface ILcdCircularArc
public double getArcAngle()
ILcdCircularArc
ILcdCircularArc
extends (in degrees). The angle
is positive counterclockwise.getArcAngle
in interface ILcdCircularArc
public ILcdPoint getStartPoint()
ILcdCurve
This is equivalent to computePointSFCT(0)
.
getStartPoint
in interface ILcdCompositeCurve
getStartPoint
in interface ILcdCurve
getStartPoint
in class TLcdGML31ArcString
public ILcdPoint getEndPoint()
ILcdCurve
This is equivalent to computePointSFCT(1)
.
getEndPoint
in interface ILcdCompositeCurve
getEndPoint
in interface ILcdCurve
getEndPoint
in class TLcdGML31ArcString
public double getStartTangent2D()
ILcdCurve
The tangent orientation is from the start point towards the rest of the shape.
This is the same as getTangent2D(0)
.
getStartTangent2D
in interface ILcdCurve
getStartTangent2D
in class TLcdGML31ArcString
public double getEndTangent2D()
ILcdCurve
The tangent orientation is from the end point, away from the curve before it.
This is the same as getTangent2D(1)
.
getEndTangent2D
in interface ILcdCurve
getEndTangent2D
in class TLcdGML31ArcString
public double getTangent2D(double aParam)
ILcdCurve
The tangent orientation is from the point at parameter aParam
towards the rest of the shape.
ILcdCurve.getStartTangent2D()
.ILcdCurve.getEndTangent2D()
.getTangent2D
in interface ILcdCurve
getTangent2D
in class TLcdGML31ArcString
aParam
 a value of the closed interval [0,1]public double getLength2D(double aParam1, double aParam2)
ILcdCurve
aParam1 == aParam2
, the length is 0.aParam1 == 0 and aParam2 == 1
, the length is the whole length of the curve.aParam1 > aParam2
, the length is (aParam1 to 1
) + (0 to aParam2
).getLength2D
in interface ILcdCurve
getLength2D
in class TLcdGML31ArcString
aParam1
 a value of the closed interval [0,1]aParam2
 a value of the closed interval [0,1]public void computePointSFCT(double aParam, ILcd3DEditablePoint aPointSFCT)
ILcdCurve
ILcdCurve.getStartPoint()
.ILcdCurve.getEndPoint()
.computePointSFCT
in interface ILcdCurve
computePointSFCT
in class TLcdGML31ArcString
aParam
 a value of the closed interval [0,1]aPointSFCT
 the point to store the computed curve point inpublic String getInterpolation()
ILcdCurve
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.
getInterpolation
in interface ILcdCircularArc
getInterpolation
in interface ILcdCircularArcBy3Points
getInterpolation
in interface ILcdCompositeCurve
getInterpolation
in interface ILcdCurve
getInterpolation
in class TLcdGML31ArcString
public int getLineSegmentIntersectionCount(ILcdPoint aP1, ILcdPoint aP2)
ILcdCurve
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 evenodd rule.
getLineSegmentIntersectionCount
in interface ILcdCurve
getLineSegmentIntersectionCount
in class TLcdGML31ArcString
aP1
 the first point of the line segmentaP2
 the second point of the line segmentpublic void move2D(ILcdPoint aPoint)
ILcd2DEditableShape
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.move2D
in interface ILcd2DEditableShape
aPoint
 the ILcdPoint
to move to.ILcd2DEditableShape.move2D(double, double)
public void move2D(double aX, double aY)
ILcd2DEditableShape
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.move2D
in interface ILcd2DEditableShape
aX
 the x coordinate of the point.aY
 the y coordinate of the point.public void translate2D(double aDeltaX, double aDeltaY)
ILcd2DEditableShape
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.translate2D
in interface ILcd2DEditableShape
aDeltaX
 the x coordinate of the translation vector.aDeltaY
 the y coordinate of the translation vector.public ILcdPoint getFocusPoint()
ILcdShape
ILcdShape
.getFocusPoint
in interface ILcdShape
getFocusPoint
in class TLcdGML31ArcString
ILcdShape
.public boolean contains2D(ILcdPoint aPoint)
ILcdShape
ILcdShape
contains the given ILcdPoint
in the 2D space.
Only the first two dimensions of the ILcdShape
and the ILcdPoint
are considered.contains2D
in interface ILcdShape
contains2D
in class TLcdGML31ArcString
aPoint
 the ILcdPoint
to test.ILcdShape.contains2D(double, double)
public boolean contains2D(double aX, double aY)
ILcdShape
ILcdShape
contains the given point in
the 2D space. Only the first two dimensions of the ILcdShape
are considered.contains2D
in interface ILcdShape
contains2D
in class TLcdGML31ArcString
aX
 the x coordinate of the point.aY
 the y coordinate of the point.public boolean contains3D(ILcdPoint aPoint)
ILcdShape
ILcdShape
contains the given ILcdPoint
in the 3D space.contains3D
in interface ILcdShape
contains3D
in class TLcdGML31ArcString
aPoint
 the ILcdPoint
to test.ILcdShape.contains3D(double, double, double)
public boolean contains3D(double aX, double aY, double aZ)
ILcdShape
ILcdShape
contains the given point in
the 3D space.contains3D
in interface ILcdShape
contains3D
in class TLcdGML31ArcString
aX
 the x coordinate of the point.aY
 the y coordinate of the point.aZ
 the z coordinate of the point.public ILcdBounds getBounds()
ILcdBounded
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
.
getBounds
in interface ILcdBounded
getBounds
in class TLcdGML31ArcString
ILcdBounds
by which the geometry of this ILcdBounded
object
is bounded.public ELcdGML31CurveInterpolation getInterpolationAttr()
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".
INTERPOLATION_ATTR_PROPERTY
property.public void setInterpolationAttr(ELcdGML31CurveInterpolation aValue)
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".
aValue
 the value to set for the INTERPOLATION_ATTR_PROPERTY
property.public Long getNumArc()
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.
NUM_ARC_PROPERTY
property.public void setNumArc(Long aValue)
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.
aValue
 the value to set for the NUM_ARC_PROPERTY
property.public Object getPosGroup()
pos
and pointProperty
and pointRep
and posList
and coordinates
elements.
The possible values for this property are instances of
List<TLcdGML31DirectPosition>
List<TLcdGML31PointProperty>
List<TLcdGML31PointProperty>
TLcdGML31DirectPositionList
TLcdGML31Coordinates
POS_GROUP_PROPERTY
property.public void setPosGroup(Object aValue)
pos
and pointProperty
and pointRep
and posList
and coordinates
elements.
The possible values for this property are instances of
List<TLcdGML31DirectPosition>
List<TLcdGML31PointProperty>
List<TLcdGML31PointProperty>
TLcdGML31DirectPositionList
TLcdGML31Coordinates
aValue
 the value to set for the POS_GROUP_PROPERTY
property.public long getNumDerivativeInterior()
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.
NUM_DERIVATIVE_INTERIOR_PROPERTY
property.public void setNumDerivativeInterior(long aValue)
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.
aValue
 the value to set for the NUM_DERIVATIVE_INTERIOR_PROPERTY
property.public long getNumDerivativesAtEnd()
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.
NUM_DERIVATIVES_AT_END_PROPERTY
property.public void setNumDerivativesAtEnd(long aValue)
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.
aValue
 the value to set for the NUM_DERIVATIVES_AT_END_PROPERTY
property.public long getNumDerivativesAtStart()
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.
NUM_DERIVATIVES_AT_START_PROPERTY
property.public void setNumDerivativesAtStart(long aValue)
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.
aValue
 the value to set for the NUM_DERIVATIVES_AT_START_PROPERTY
property.