math.geom2d.line
Class LineArc2D

java.lang.Object
  math.geom2d.line.StraightObject2D
      math.geom2d.line.LineArc2D

All Implemented Interfaces:

java.awt.Shape, ContinuousCurve2D, ContinuousOrientedCurve2D, Curve2D, OrientedCurve2D, SmoothCurve2D, SmoothOrientedCurve2D, Shape2D

Direct Known Subclasses:

LineSegment2D, Ray2D, StraightLine2D

public class LineArc2D
extends StraightObject2D
implements SmoothCurve2D, ContinuousOrientedCurve2D

LineArc2D is a generic class to represent edges, straight lines, and rays. It is defeined as a StraightObject2D : origin point, and direction vector. Moreover, two internal variables t0 and t1 define the limit of the object (with t0

Author:

dlegland

Field Summary

protected double	t0
protected double	t1

Fields inherited from class math.geom2d.line.StraightObject2D

dx, dy, x0, y0

Fields inherited from interface math.geom2d.curve.ContinuousCurve2D

CIRCLE, CLOSED_EDGE, LOOP, OPEN_EDGE

Fields inherited from interface math.geom2d.Shape2D

ACCURACY, defaultClipWindow, EMPTY_SET

Constructor Summary

LineArc2D(double x1, double y1, double dx, double dy, double t0, double t1)
Construct a line arc by the coordinate of two points and two positions on the line.

LineArc2D(LineArc2D line)
Construcion by copy of another line arc

LineArc2D(Point2D point1, Point2D point2, double t0, double t1)

LineArc2D(StraightObject2D line, double t0, double t1)
Construct a line arc contained in the same straight line as first argument, with bounds of arc given by t0 and t1

Method Summary

java.awt.geom.GeneralPath	appendPath(java.awt.geom.GeneralPath path) append a line to the current path.
CurveSet2D<? extends LineArc2D>	clip(Box2D box) Clip the circle arc by a box.
boolean	contains(double xp, double yp) Returns true if the point (x, y) lies on the line covering the object, with precision given by Shape2D.ACCURACY.
boolean	contains(java.awt.geom.Point2D pt)
boolean	equals(LineArc2D arc) Compare two edges, and returns true if they have the two same vertices.
boolean	equals(java.lang.Object obj)
Polyline2D	getAsPolyline(int n) Returns an approximation of the curve as a polyline with n line segments.
Box2D	getBoundingBox() Returns the bounding box of the shape.
java.awt.Rectangle	getBounds() Return bounding box of the shape.
java.awt.geom.Rectangle2D	getBounds2D() Return more precise bounds for the shape.
java.util.Collection<ContinuousCurve2D>	getContinuousCurves() Returns the collection of continuous curves which constitute this curve.
double	getCurvature(double t) returns 0 as every straight object.
double	getDistance(double x, double y) Get the distance of the point (x, y) to this object.
double	getDistance(java.awt.geom.Point2D p) Get the distance of the point (x, y) to this object.
Point2D	getFirstPoint() Return the first point of the edge.
java.awt.geom.GeneralPath	getInnerPath()
Point2D	getLastPoint() Return the last point of the edge.
double	getLength() Returns the length of the edge.
java.awt.geom.PathIterator	getPathIterator(java.awt.geom.AffineTransform t) Return pathiterator for this line arc.
java.awt.geom.PathIterator	getPathIterator(java.awt.geom.AffineTransform t, double flatness) Return pathiterator for this line arc.
Point2D	getPoint(double t) Gets the point from a parametric representation of the curve.
Point2D	getPoint(double t, Point2D point) Same as getPoint(t), but gives the point as a parameter.
Point2D	getPoint1() Return the first point of the edge.
Point2D	getPoint2() Return the last point of the edge.
double	getPosition(Point2D point) Gets the position of the point on the line arc.
LineArc2D	getReverseCurve() Returns the line arc which have the same trace, but has the inverse parametrization.
java.util.Collection<? extends SmoothCurve2D>	getSmoothPieces() Returns an array containing the curve itself.
LineArc2D	getSubCurve(double t0, double t1) Return a new LineArc2D, which is the portion of the linearc delimited by parameters t0 and t1.
double	getT0() Returns the parameter of the first point of the edge, arbitrarly set to 0.
double	getT1() Returns the parameter of the last point of the edge, arbitraly set to 1.
Vector2D	getTangent(double t)
double	getWindingAngle(java.awt.geom.Point2D point) Return the angle portion that the curve turn around the given point.
double	getX1()
double	getX2()
double	getY1()
double	getY2()
boolean	intersects(double x, double y, double w, double h) Tests if the Line intersects the interior of a specified rectangular area.
boolean	intersects(java.awt.geom.Rectangle2D r) Tests if the Line intersects the interior of a specified rectangle2D.
boolean	isBounded() return true if both t0 and t1 are different from infinity.
boolean	isInside(java.awt.geom.Point2D p) return true if the given point lies to the left of the line when travaling along the line in the direcion given by its direction vector.
double	project(Point2D point) Gets the position of the closest point on the line arc.
java.lang.String	toString()
LineArc2D	transform(AffineTransform2D trans) Transforms the curve by an affine transform.

Methods inherited from class math.geom2d.line.StraightObject2D

contains, contains, getCartesianEquation, getDistance, getHorizontalAngle, getIntersection, getIntersection, getIntersections, getOrigin, getParallel, getParametric, getPerpendicular, getPolarCoefficients, getPositionOnLine, getPositionOnLine, getProjectedPoint, getProjectedPoint, getSignedDistance, getSignedDistance, getSignedPolarCoefficients, getSupportLine, getSymmetric, getSymmetric, getVector, isClosed, isColinear, isColinear, isInside, isParallel, isParallel

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface math.geom2d.curve.ContinuousCurve2D

isClosed

Methods inherited from interface math.geom2d.curve.OrientedCurve2D

getSignedDistance, getSignedDistance

Methods inherited from interface math.geom2d.curve.Curve2D

getIntersections

Methods inherited from interface java.awt.Shape

contains, contains

Field Detail

t0

protected double t0

t1

protected double t1

Constructor Detail

LineArc2D

public LineArc2D(Point2D point1,
                 Point2D point2,
                 double t0,
                 double t1)

Parameters:

point1 - the point located at t=0

point2 - the point located at t=1

t0 - the lower bound of line arc parameterization

t1 - the upper bound of line arc parameterization

LineArc2D

public LineArc2D(StraightObject2D line,
                 double t0,
                 double t1)

Construct a line arc contained in the same straight line as first argument, with bounds of arc given by t0 and t1

Parameters:

line - an object defining the supporting line

t0 - the lower bound of line arc parameterization

t1 - the upper bound of line arc parameterization

LineArc2D

public LineArc2D(LineArc2D line)

Construcion by copy of another line arc

Parameters:

line - the line to copy

LineArc2D

public LineArc2D(double x1,
                 double y1,
                 double dx,
                 double dy,
                 double t0,
                 double t1)

Construct a line arc by the coordinate of two points and two positions on the line.

Parameters:

x1 - the x-coordinate of the first point

y1 - the y-coordinate of the first point

x2 - the x-coordinate of the second point

y2 - the y-coordinate of the second point

t0 - the starting position of the arc

t1 - the ending position of the arc

Method Detail

getLength

public double getLength()

Returns the length of the edge.

getPoint1

public Point2D getPoint1()

Return the first point of the edge. In the case of a line, or a ray starting from -infinity, returns Point2D.INFINITY_POINT.

Returns:

the first point of the arc

getPoint2

public Point2D getPoint2()

Return the last point of the edge. In the case of a line, or a ray ending at infinity, returns Point2D.INFINITY_POINT.

Returns:

the last point of the arc.

getX1

public double getX1()

getY1

public double getY1()

getX2

public double getX2()

getY2

public double getY2()

getTangent

public Vector2D getTangent(double t)

Specified by:

getTangent in interface SmoothCurve2D

getCurvature

public double getCurvature(double t)

returns 0 as every straight object.

Specified by:

getCurvature in interface SmoothCurve2D

getAsPolyline

public Polyline2D getAsPolyline(int n)

Description copied from interface: ContinuousCurve2D

Returns an approximation of the curve as a polyline with n line segments. If the curve is closed, the method should return an instance of ClosedPolyline2D.

Specified by:

getAsPolyline in interface ContinuousCurve2D

Parameters:

n - the number of line segments

Returns:

a closed polyline with n line segments.

getSmoothPieces

public java.util.Collection<? extends SmoothCurve2D> getSmoothPieces()

Returns an array containing the curve itself.

Specified by:

getSmoothPieces in interface ContinuousCurve2D

Overrides:

getSmoothPieces in class StraightObject2D

getWindingAngle

public double getWindingAngle(java.awt.geom.Point2D point)

Description copied from interface: OrientedCurve2D

Return the angle portion that the curve turn around the given point. Result is a signed angle.

Specified by:

getWindingAngle in interface OrientedCurve2D

Parameters:

point - a point of the plane

Returns:

a signed angle

isInside

public boolean isInside(java.awt.geom.Point2D p)

return true if the given point lies to the left of the line when travaling along the line in the direcion given by its direction vector.

Specified by:

isInside in interface OrientedCurve2D

Parameters:

p - the point to test

Returns:

true if point p lies on the 'left' of the line.

getT0

public double getT0()

Returns the parameter of the first point of the edge, arbitrarly set to 0.

Specified by:

getT0 in interface Curve2D

getT1

public double getT1()

Returns the parameter of the last point of the edge, arbitraly set to 1.

Specified by:

getT1 in interface Curve2D

getPoint

public Point2D getPoint(double t)

Description copied from interface: Curve2D

Gets the point from a parametric representation of the curve. If the parameter lies outside the definition range, the parameter corresponding to the closest bound is used instead. This method can be used to draw an approximated outline of a curve, by selecting multiple values for t and drawing lines between them.

Specified by:

getPoint in interface Curve2D

getPoint

public Point2D getPoint(double t,
                        Point2D point)

Description copied from interface: Curve2D

Same as getPoint(t), but gives the point as a parameter. This avoids repetitive memory allocations.

Specified by:

getPoint in interface Curve2D

getFirstPoint

public Point2D getFirstPoint()

Return the first point of the edge. In the case of a line, or a ray starting from -infinity, returns Point2D.INFINITY_POINT.

Specified by:

getFirstPoint in interface Curve2D

Returns:

the last point of the arc

getLastPoint

public Point2D getLastPoint()

Return the last point of the edge. In the case of a line, or a ray ending at infinity, returns Point2D.INFINITY_POINT.

Specified by:

getLastPoint in interface Curve2D

Returns:

the last point of the arc

getPosition

public double getPosition(Point2D point)

Gets the position of the point on the line arc. If point belongs to the line, this position is defined by the ratio:

t = (xp - x0)/dx <\code>, or equivalently:

t = (yp - y0)/dy <\code>.

If point does not belong to edge, returns Double.NaN.

Specified by:

getPosition in interface Curve2D

Parameters:

point - a point belonging to the curve

Returns:

the position of the point on the curve

project

public double project(Point2D point)

Gets the position of the closest point on the line arc. If point belongs to the line, this position is defined by the ratio:

t = (xp - x0)/dx <\code>, or equivalently:

t = (yp - y0)/dy <\code>.

If point does not belong to edge, returns t0, or t1, depending on which one is the closest.

Specified by:

project in interface Curve2D

Parameters:

point - a point to project

Returns:

the position of the closest orthogonal projection

getReverseCurve

public LineArc2D getReverseCurve()

Returns the line arc which have the same trace, but has the inverse parametrization.

Specified by:

getReverseCurve in interface ContinuousCurve2D

Specified by:

getReverseCurve in interface ContinuousOrientedCurve2D

Specified by:

getReverseCurve in interface Curve2D

Specified by:

getReverseCurve in interface OrientedCurve2D

Specified by:

getReverseCurve in interface SmoothCurve2D

Specified by:

getReverseCurve in interface SmoothOrientedCurve2D

getContinuousCurves

public java.util.Collection<ContinuousCurve2D> getContinuousCurves()

Description copied from interface: Curve2D

Returns the collection of continuous curves which constitute this curve.

Specified by:

getContinuousCurves in interface Curve2D

Returns:

a collection of continuous curves.

getSubCurve

public LineArc2D getSubCurve(double t0,
                             double t1)

Return a new LineArc2D, which is the portion of the linearc delimited by parameters t0 and t1.

Specified by:

getSubCurve in interface ContinuousCurve2D

Specified by:

getSubCurve in interface ContinuousOrientedCurve2D

Specified by:

getSubCurve in interface Curve2D

Specified by:

getSubCurve in interface SmoothCurve2D

Specified by:

getSubCurve in interface SmoothOrientedCurve2D

Parameters:

t0 - position of the start of the sub-curve

t1 - position of the end of the sub-curve

Returns:

the portion of original curve comprised between t0 and t1.

isBounded

public boolean isBounded()

return true if both t0 and t1 are different from infinity.

Specified by:

isBounded in interface Shape2D

getDistance

public double getDistance(java.awt.geom.Point2D p)

Get the distance of the point (x, y) to this object.

Specified by:

getDistance in interface Shape2D

getDistance

public double getDistance(double x,
                          double y)

Get the distance of the point (x, y) to this object.

Specified by:

getDistance in interface Shape2D

Overrides:

getDistance in class StraightObject2D

Parameters:

x - , y : position of point

Returns:

distance between this object and the point (x,y)

clip

public CurveSet2D<? extends LineArc2D> clip(Box2D box)

Clip the circle arc by a box. The result is an instance of CurveSet2D, which contains only instances of LineArc2D. If the ellipse arc is not clipped, the result is an instance of CurveSet2D which contains 0 curves.

Specified by:

clip in interface ContinuousCurve2D

Specified by:

clip in interface ContinuousOrientedCurve2D

Specified by:

clip in interface Curve2D

Specified by:

clip in interface OrientedCurve2D

Specified by:

clip in interface SmoothCurve2D

Specified by:

clip in interface SmoothOrientedCurve2D

Specified by:

clip in interface Shape2D

Parameters:

box - the clipping box

Returns:

the clipped shape

getBoundingBox

public Box2D getBoundingBox()

Description copied from interface: Shape2D

Returns the bounding box of the shape.

Specified by:

getBoundingBox in interface Shape2D

Returns:

the bounding box of the shape.

contains

public boolean contains(java.awt.geom.Point2D pt)

Specified by:

contains in interface java.awt.Shape

contains

public boolean contains(double xp,
                        double yp)

Description copied from class: StraightObject2D

Returns true if the point (x, y) lies on the line covering the object, with precision given by Shape2D.ACCURACY.

Specified by:

contains in interface java.awt.Shape

Overrides:

contains in class StraightObject2D

getBounds

public java.awt.Rectangle getBounds()

Return bounding box of the shape.

Specified by:

getBounds in interface java.awt.Shape

getBounds2D

public java.awt.geom.Rectangle2D getBounds2D()

Return more precise bounds for the shape.

Specified by:

getBounds2D in interface java.awt.Shape

getInnerPath

public java.awt.geom.GeneralPath getInnerPath()

appendPath

public java.awt.geom.GeneralPath appendPath(java.awt.geom.GeneralPath path)

append a line to the current path. If t0 or t1 is infinite, does not append anything.

Specified by:

appendPath in interface ContinuousCurve2D

Parameters:

path - the path to modify

Returns:

the modified path

getPathIterator

public java.awt.geom.PathIterator getPathIterator(java.awt.geom.AffineTransform t)

Return pathiterator for this line arc.

Specified by:

getPathIterator in interface java.awt.Shape

getPathIterator

public java.awt.geom.PathIterator getPathIterator(java.awt.geom.AffineTransform t,
                                                  double flatness)

Return pathiterator for this line arc.

Specified by:

getPathIterator in interface java.awt.Shape

intersects

public boolean intersects(double x,
                          double y,
                          double w,
                          double h)

Tests if the Line intersects the interior of a specified rectangular area.

Specified by:

intersects in interface java.awt.Shape

intersects

public boolean intersects(java.awt.geom.Rectangle2D r)

Tests if the Line intersects the interior of a specified rectangle2D.

Specified by:

intersects in interface java.awt.Shape

transform

public LineArc2D transform(AffineTransform2D trans)

Description copied from interface: Curve2D

Transforms the curve by an affine transform. The result is an instance of Curve2D.

Specified by:

transform in interface ContinuousCurve2D

Specified by:

transform in interface ContinuousOrientedCurve2D

Specified by:

transform in interface Curve2D

Specified by:

transform in interface OrientedCurve2D

Specified by:

transform in interface SmoothCurve2D

Specified by:

transform in interface SmoothOrientedCurve2D

Specified by:

transform in interface Shape2D

Specified by:

transform in class StraightObject2D

Parameters:

trans - an affine transform

Returns:

the transformed shape

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

equals

public boolean equals(LineArc2D arc)

Compare two edges, and returns true if they have the two same vertices.

Parameters:

arc - : the line arcs to compare to.

Returns:

true if extremities of both edges are the same.