com.sun.javafx.geom

Class Line2D

java.lang.Object

com.sun.javafx.geom.Shape

com.sun.javafx.geom.Line2D

public class Line2D
extends Shape

This Line2D represents a line segment in (x,y) coordinate space. This class, like all of the Java 2D API, uses a default coordinate system called user space in which the y-axis values increase downward and x-axis values increase to the right. For more information on the user space coordinate system, see the Coordinate Systems section of the Java 2D Programmer's Guide.

Version:

1.37, 05/05/07

Field Summary

Fields

Modifier and Type	Field and Description
float	x1 The X coordinate of the start point of the line segment.
float	x2 The X coordinate of the end point of the line segment.
float	y1 The Y coordinate of the start point of the line segment.
float	y2 The Y coordinate of the end point of the line segment.

Fields inherited from class com.sun.javafx.geom.Shape

OUT_BOTTOM, OUT_LEFT, OUT_RIGHT, OUT_TOP, RECT_INTERSECTS

Constructor Summary

Constructors

Constructor and Description
Line2D() Constructs and initializes a Line with coordinates (0, 0) -> (0, 0).
Line2D(float x1, float y1, float x2, float y2) Constructs and initializes a Line from the specified coordinates.
Line2D(Point2D p1, Point2D p2) Constructs and initializes a Line2D from the specified Point2D objects.

Method Summary

Modifier and Type	Method and Description
boolean	contains(float x, float y) Tests if the specified coordinates are inside the boundary of the Shape.
boolean	contains(float x, float y, float w, float h) Tests if the interior of the Shape entirely contains the specified rectangular area.
boolean	contains(Point2D p) Tests if a specified Point2D is inside the boundary of the Shape.
Line2D	copy() Returns a new copy of this Shape instance.
boolean	equals(java.lang.Object obj)
RectBounds	getBounds() Note that there is no guarantee that the returned RectBounds is the smallest bounding box that encloses the Shape, only that the Shape lies entirely within the indicated RectBounds.
PathIterator	getPathIterator(BaseTransform tx) Returns an iteration object that defines the boundary of this Line2D.
PathIterator	getPathIterator(BaseTransform tx, float flatness) Returns an iteration object that defines the boundary of this flattened Line2D.
int	hashCode()
boolean	intersects(float x, float y, float w, float h) Tests if the interior of the Shape intersects the interior of a specified rectangular area.
boolean	intersectsLine(float x1, float y1, float x2, float y2) Tests if the line segment from (x1,y1) to (x2,y2) intersects this line segment.
boolean	intersectsLine(Line2D l) Tests if the specified line segment intersects this line segment.
static boolean	linesIntersect(float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4) Tests if the line segment from (x1,y1) to (x2,y2) intersects the line segment from (x3,y3) to (x4,y4).
float	ptLineDist(float px, float py) Returns the distance from a point to this line.
static float	ptLineDist(float x1, float y1, float x2, float y2, float px, float py) Returns the distance from a point to a line.
float	ptLineDist(Point2D pt) Returns the distance from a Point2D to this line.
float	ptLineDistSq(float px, float py) Returns the square of the distance from a point to this line.
static float	ptLineDistSq(float x1, float y1, float x2, float y2, float px, float py) Returns the square of the distance from a point to a line.
float	ptLineDistSq(Point2D pt) Returns the square of the distance from a specified Point2D to this line.
double	ptSegDist(float px, float py) Returns the distance from a point to this line segment.
static float	ptSegDist(float x1, float y1, float x2, float y2, float px, float py) Returns the distance from a point to a line segment.
float	ptSegDist(Point2D pt) Returns the distance from a Point2D to this line segment.
float	ptSegDistSq(float px, float py) Returns the square of the distance from a point to this line segment.
static float	ptSegDistSq(float x1, float y1, float x2, float y2, float px, float py) Returns the square of the distance from a point to a line segment.
float	ptSegDistSq(Point2D pt) Returns the square of the distance from a Point2D to this line segment.
int	relativeCCW(float px, float py) Returns an indicator of where the specified point (px,py) lies with respect to this line segment.
static int	relativeCCW(float x1, float y1, float x2, float y2, float px, float py) Returns an indicator of where the specified point (px,py) lies with respect to the line segment from (x1,y1) to (x2,y2).
int	relativeCCW(Point2D p) Returns an indicator of where the specified Point2D lies with respect to this line segment.
void	setLine(float x1, float y1, float x2, float y2) Sets the location of the end points of this Line2D to the specified float coordinates.
void	setLine(Line2D l) Sets the location of the end points of this Line2D to the same as those end points of the specified Line2D.
void	setLine(Point2D p1, Point2D p2) Sets the location of the end points of this Line2D to the specified Point2D coordinates.

Methods inherited from class com.sun.javafx.geom.Shape

accumulate, accumulateCubic, accumulateCubic, accumulateQuad, contains, intersects, intersectsLine, outcode, pointCrossingsForCubic, pointCrossingsForLine, pointCrossingsForPath, pointCrossingsForQuad, rectCrossingsForCubic, rectCrossingsForLine, rectCrossingsForPath, rectCrossingsForQuad

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Field Detail

x1

public float x1

The X coordinate of the start point of the line segment.

y1

public float y1

The Y coordinate of the start point of the line segment.

x2

public float x2

The X coordinate of the end point of the line segment.

y2

public float y2

The Y coordinate of the end point of the line segment.

Constructor Detail

Line2D

public Line2D()

Constructs and initializes a Line with coordinates (0, 0) -> (0, 0).

Line2D

public Line2D(float x1,
              float y1,
              float x2,
              float y2)

Constructs and initializes a Line from the specified coordinates.

Parameters:

x1 - the X coordinate of the start point

y1 - the Y coordinate of the start point

x2 - the X coordinate of the end point

y2 - the Y coordinate of the end point

Line2D

public Line2D(Point2D p1,
              Point2D p2)

Constructs and initializes a Line2D from the specified Point2D objects.

Parameters:

p1 - the start Point2D of this line segment

p2 - the end Point2D of this line segment

Method Detail

setLine

public void setLine(float x1,
                    float y1,
                    float x2,
                    float y2)

Sets the location of the end points of this Line2D to the specified float coordinates.

Parameters:

x1 - the X coordinate of the start point

y1 - the Y coordinate of the start point

x2 - the X coordinate of the end point

y2 - the Y coordinate of the end point

setLine

public void setLine(Point2D p1,
                    Point2D p2)

Sets the location of the end points of this Line2D to the specified Point2D coordinates.

Parameters:

p1 - the start Point2D of the line segment

p2 - the end Point2D of the line segment

setLine

public void setLine(Line2D l)

Sets the location of the end points of this Line2D to the same as those end points of the specified Line2D.

Parameters:

l - the specified Line2D

getBounds

public RectBounds getBounds()

Note that there is no guarantee that the returned RectBounds is the smallest bounding box that encloses the Shape, only that the Shape lies entirely within the indicated RectBounds.

Specified by:

getBounds in class Shape

Returns:

an instance of RectBounds

contains

public boolean contains(float x,
                        float y)

Description copied from class: Shape

Tests if the specified coordinates are inside the boundary of the Shape.

Specified by:

contains in class Shape

Parameters:

x - the specified X coordinate to be tested

y - the specified Y coordinate to be tested

Returns:

true if the specified coordinates are inside the Shape boundary; false otherwise.

contains

public boolean contains(float x,
                        float y,
                        float w,
                        float h)

Description copied from class: Shape

Tests if the interior of the Shape entirely contains the specified rectangular area. All coordinates that lie inside the rectangular area must lie within the Shape for the entire rectanglar area to be considered contained within the Shape.

The Shape.contains() method allows a Shape implementation to conservatively return false when:

• the intersect method returns true and
• the calculations to determine whether or not the Shape entirely contains the rectangular area are prohibitively expensive.

This means that for some Shapes this method might return false even though the Shape contains the rectangular area. The Area class performs more accurate geometric computations than most Shape objects and therefore can be used if a more precise answer is required.

Specified by:

contains in class Shape

Parameters:

x - the X coordinate of the upper-left corner of the specified rectangular area

y - the Y coordinate of the upper-left corner of the specified rectangular area

w - the width of the specified rectangular area

h - the height of the specified rectangular area

Returns:

true if the interior of the Shape entirely contains the specified rectangular area; false otherwise or, if the Shape contains the rectangular area and the intersects method returns true and the containment calculations would be too expensive to perform.

See Also:

Shape.intersects(float, float, float, float)

contains

public boolean contains(Point2D p)

Description copied from class: Shape

Tests if a specified Point2D is inside the boundary of the Shape.

Overrides:

contains in class Shape

Parameters:

p - the specified Point2D to be tested

Returns:

true if the specified Point2D is inside the boundary of the Shape; false otherwise.

intersects

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

Description copied from class: Shape

Tests if the interior of the Shape intersects the interior of a specified rectangular area. The rectangular area is considered to intersect the Shape if any point is contained in both the interior of the Shape and the specified rectangular area.

The Shape.intersects() method allows a Shape implementation to conservatively return true when:

• there is a high probability that the rectangular area and the Shape intersect, but
• the calculations to accurately determine this intersection are prohibitively expensive.

This means that for some Shapes this method might return true even though the rectangular area does not intersect the Shape. The Area class performs more accurate computations of geometric intersection than most Shape objects and therefore can be used if a more precise answer is required.

Specified by:

intersects in class Shape

Parameters:

x - the X coordinate of the upper-left corner of the specified rectangular area

y - the Y coordinate of the upper-left corner of the specified rectangular area

w - the width of the specified rectangular area

h - the height of the specified rectangular area

Returns:

true if the interior of the Shape and the interior of the rectangular area intersect, or are both highly likely to intersect and intersection calculations would be too expensive to perform; false otherwise.

relativeCCW

public static int relativeCCW(float x1,
                              float y1,
                              float x2,
                              float y2,
                              float px,
                              float py)

Returns an indicator of where the specified point (px,py) lies with respect to the line segment from (x1,y1) to (x2,y2). The return value can be either 1, -1, or 0 and indicates in which direction the specified line must pivot around its first end point, (x1,y1), in order to point at the specified point (px,py).

A return value of 1 indicates that the line segment must turn in the direction that takes the positive X axis towards the negative Y axis. In the default coordinate system used by Java 2D, this direction is counterclockwise.

A return value of -1 indicates that the line segment must turn in the direction that takes the positive X axis towards the positive Y axis. In the default coordinate system, this direction is clockwise.

A return value of 0 indicates that the point lies exactly on the line segment. Note that an indicator value of 0 is rare and not useful for determining colinearity because of floating point rounding issues.

If the point is colinear with the line segment, but not between the end points, then the value will be -1 if the point lies "beyond (x1,y1)" or 1 if the point lies "beyond (x2,y2)".

Parameters:

x1 - the X coordinate of the start point of the specified line segment

y1 - the Y coordinate of the start point of the specified line segment

x2 - the X coordinate of the end point of the specified line segment

y2 - the Y coordinate of the end point of the specified line segment

px - the X coordinate of the specified point to be compared with the specified line segment

py - the Y coordinate of the specified point to be compared with the specified line segment

Returns:

an integer that indicates the position of the third specified coordinates with respect to the line segment formed by the first two specified coordinates.

relativeCCW

public int relativeCCW(float px,
                       float py)

Returns an indicator of where the specified point (px,py) lies with respect to this line segment. See the method comments of #relativeCCW(double, double, double, double, double, double) to interpret the return value.

Parameters:

px - the X coordinate of the specified point to be compared with this Line2D

py - the Y coordinate of the specified point to be compared with this Line2D

Returns:

an integer that indicates the position of the specified coordinates with respect to this Line2D

See Also:

#relativeCCW(double, double, double, double, double, double)

relativeCCW

public int relativeCCW(Point2D p)

Returns an indicator of where the specified Point2D lies with respect to this line segment. See the method comments of #relativeCCW(double, double, double, double, double, double) to interpret the return value.

Parameters:

p - the specified Point2D to be compared with this Line2D

Returns:

an integer that indicates the position of the specified Point2D with respect to this Line2D

See Also:

#relativeCCW(double, double, double, double, double, double)

linesIntersect

public static boolean linesIntersect(float x1,
                                     float y1,
                                     float x2,
                                     float y2,
                                     float x3,
                                     float y3,
                                     float x4,
                                     float y4)

Tests if the line segment from (x1,y1) to (x2,y2) intersects the line segment from (x3,y3) to (x4,y4).

Parameters:

x1 - the X coordinate of the start point of the first specified line segment

y1 - the Y coordinate of the start point of the first specified line segment

x2 - the X coordinate of the end point of the first specified line segment

y2 - the Y coordinate of the end point of the first specified line segment

x3 - the X coordinate of the start point of the second specified line segment

y3 - the Y coordinate of the start point of the second specified line segment

x4 - the X coordinate of the end point of the second specified line segment

y4 - the Y coordinate of the end point of the second specified line segment

Returns:

true if the first specified line segment and the second specified line segment intersect each other; false otherwise.

intersectsLine

public boolean intersectsLine(float x1,
                              float y1,
                              float x2,
                              float y2)

Tests if the line segment from (x1,y1) to (x2,y2) intersects this line segment.

Parameters:

x1 - the X coordinate of the start point of the specified line segment

y1 - the Y coordinate of the start point of the specified line segment

x2 - the X coordinate of the end point of the specified line segment

y2 - the Y coordinate of the end point of the specified line segment

Returns:

if this line segment and the specified line segment intersect each other; false otherwise.

intersectsLine

public boolean intersectsLine(Line2D l)

Tests if the specified line segment intersects this line segment.

Parameters:

l - the specified Line2D

Returns:

true if this line segment and the specified line segment intersect each other; false otherwise.

ptSegDistSq

public static float ptSegDistSq(float x1,
                                float y1,
                                float x2,
                                float y2,
                                float px,
                                float py)

Returns the square of the distance from a point to a line segment. The distance measured is the distance between the specified point and the closest point between the specified end points. If the specified point intersects the line segment in between the end points, this method returns 0.0.

Parameters:

x1 - the X coordinate of the start point of the specified line segment

y1 - the Y coordinate of the start point of the specified line segment

x2 - the X coordinate of the end point of the specified line segment

y2 - the Y coordinate of the end point of the specified line segment

px - the X coordinate of the specified point being measured against the specified line segment

py - the Y coordinate of the specified point being measured against the specified line segment

Returns:

a double value that is the square of the distance from the specified point to the specified line segment.

See Also:

#ptLineDistSq(double, double, double, double, double, double)

ptSegDist

public static float ptSegDist(float x1,
                              float y1,
                              float x2,
                              float y2,
                              float px,
                              float py)

Returns the distance from a point to a line segment. The distance measured is the distance between the specified point and the closest point between the specified end points. If the specified point intersects the line segment in between the end points, this method returns 0.0.

Parameters:

x1 - the X coordinate of the start point of the specified line segment

y1 - the Y coordinate of the start point of the specified line segment

x2 - the X coordinate of the end point of the specified line segment

y2 - the Y coordinate of the end point of the specified line segment

px - the X coordinate of the specified point being measured against the specified line segment

py - the Y coordinate of the specified point being measured against the specified line segment

Returns:

a double value that is the distance from the specified point to the specified line segment.

See Also:

#ptLineDist(double, double, double, double, double, double)

ptSegDistSq

public float ptSegDistSq(float px,
                         float py)

Returns the square of the distance from a point to this line segment. The distance measured is the distance between the specified point and the closest point between the current line's end points. If the specified point intersects the line segment in between the end points, this method returns 0.0.

Parameters:

px - the X coordinate of the specified point being measured against this line segment

py - the Y coordinate of the specified point being measured against this line segment

Returns:

a double value that is the square of the distance from the specified point to the current line segment.

See Also:

#ptLineDistSq(double, double)

ptSegDistSq

public float ptSegDistSq(Point2D pt)

Returns the square of the distance from a Point2D to this line segment. The distance measured is the distance between the specified point and the closest point between the current line's end points. If the specified point intersects the line segment in between the end points, this method returns 0.0.

Parameters:

pt - the specified Point2D being measured against this line segment.

Returns:

a double value that is the square of the distance from the specified Point2D to the current line segment.

See Also:

ptLineDistSq(Point2D)

ptSegDist

public double ptSegDist(float px,
                        float py)

Returns the distance from a point to this line segment. The distance measured is the distance between the specified point and the closest point between the current line's end points. If the specified point intersects the line segment in between the end points, this method returns 0.0.

Parameters:

px - the X coordinate of the specified point being measured against this line segment

py - the Y coordinate of the specified point being measured against this line segment

Returns:

a double value that is the distance from the specified point to the current line segment.

See Also:

#ptLineDist(double, double)

ptSegDist

public float ptSegDist(Point2D pt)

Returns the distance from a Point2D to this line segment. The distance measured is the distance between the specified point and the closest point between the current line's end points. If the specified point intersects the line segment in between the end points, this method returns 0.0.

Parameters:

pt - the specified Point2D being measured against this line segment

Returns:

a double value that is the distance from the specified Point2D to the current line segment.

See Also:

ptLineDist(Point2D)

ptLineDistSq

public static float ptLineDistSq(float x1,
                                 float y1,
                                 float x2,
                                 float y2,
                                 float px,
                                 float py)

Returns the square of the distance from a point to a line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by the specified coordinates. If the specified point intersects the line, this method returns 0.0.

Parameters:

x1 - the X coordinate of the start point of the specified line

y1 - the Y coordinate of the start point of the specified line

x2 - the X coordinate of the end point of the specified line

y2 - the Y coordinate of the end point of the specified line

px - the X coordinate of the specified point being measured against the specified line

py - the Y coordinate of the specified point being measured against the specified line

Returns:

a double value that is the square of the distance from the specified point to the specified line.

See Also:

#ptSegDistSq(double, double, double, double, double, double)

ptLineDist

public static float ptLineDist(float x1,
                               float y1,
                               float x2,
                               float y2,
                               float px,
                               float py)

Returns the distance from a point to a line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by the specified coordinates. If the specified point intersects the line, this method returns 0.0.

Parameters:

x1 - the X coordinate of the start point of the specified line

y1 - the Y coordinate of the start point of the specified line

x2 - the X coordinate of the end point of the specified line

y2 - the Y coordinate of the end point of the specified line

px - the X coordinate of the specified point being measured against the specified line

py - the Y coordinate of the specified point being measured against the specified line

Returns:

a double value that is the distance from the specified point to the specified line.

See Also:

#ptSegDist(double, double, double, double, double, double)

ptLineDistSq

public float ptLineDistSq(float px,
                          float py)

Returns the square of the distance from a point to this line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by this Line2D. If the specified point intersects the line, this method returns 0.0.

Parameters:

px - the X coordinate of the specified point being measured against this line

py - the Y coordinate of the specified point being measured against this line

Returns:

a double value that is the square of the distance from a specified point to the current line.

See Also:

#ptSegDistSq(double, double)

ptLineDistSq

public float ptLineDistSq(Point2D pt)

Returns the square of the distance from a specified Point2D to this line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by this Line2D. If the specified point intersects the line, this method returns 0.0.

Parameters:

pt - the specified Point2D being measured against this line

Returns:

a double value that is the square of the distance from a specified Point2D to the current line.

See Also:

ptSegDistSq(Point2D)

ptLineDist

public float ptLineDist(float px,
                        float py)

Returns the distance from a point to this line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by this Line2D. If the specified point intersects the line, this method returns 0.0.

Parameters:

px - the X coordinate of the specified point being measured against this line

py - the Y coordinate of the specified point being measured against this line

Returns:

a double value that is the distance from a specified point to the current line.

See Also:

#ptSegDist(double, double)

ptLineDist

public float ptLineDist(Point2D pt)

Returns the distance from a Point2D to this line. The distance measured is the distance between the specified point and the closest point on the infinitely-extended line defined by this Line2D. If the specified point intersects the line, this method returns 0.0.

Parameters:

pt - the specified Point2D being measured

Returns:

a double value that is the distance from a specified Point2D to the current line.

See Also:

ptSegDist(Point2D)

getPathIterator

public PathIterator getPathIterator(BaseTransform tx)

Returns an iteration object that defines the boundary of this Line2D. The iterator for this class is not multi-threaded safe, which means that this Line2D class does not guarantee that modifications to the geometry of this Line2D object do not affect any iterations of that geometry that are already in process.

Specified by:

getPathIterator in class Shape

Parameters:

tx - the specified BaseTransform

Returns:

a PathIterator that defines the boundary of this Line2D.

getPathIterator

public PathIterator getPathIterator(BaseTransform tx,
                                    float flatness)

Returns an iteration object that defines the boundary of this flattened Line2D. The iterator for this class is not multi-threaded safe, which means that this Line2D class does not guarantee that modifications to the geometry of this Line2D object do not affect any iterations of that geometry that are already in process.

Specified by:

getPathIterator in class Shape

Parameters:

tx - the specified BaseTransform

flatness - the maximum amount that the control points for a given curve can vary from colinear before a subdivided curve is replaced by a straight line connecting the end points. Since a Line2D object is always flat, this parameter is ignored.

Returns:

a PathIterator that defines the boundary of the flattened Line2D

copy

public Line2D copy()

Description copied from class: Shape

Returns a new copy of this Shape instance.

Specified by:

copy in class Shape

Returns:

a copy of this shape

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object