Class Line2D
- java.lang.Object
-
- java.awt.geom.Line2D
- Direct Known Subclasses:
-
Line2D.Double
,Line2D.Float
public abstract class Line2D extends Object implements Shape, Cloneable
This Line2D
represents a line segment in (x,y)
coordinate space.
This class is only the abstract superclass for all objects that store a 2D line segment. The actual storage representation of the coordinates is left to the subclass.
- Since:
- 1.2
Nested Class Summary
Modifier and Type | Class | Description |
---|---|---|
static class | Line2D.Double | A line segment specified with double coordinates. |
static class | Line2D.Float | A line segment specified with float coordinates. |
Constructor Summary
Modifier | Constructor | Description |
---|---|---|
protected | Line2D() | This is an abstract class that cannot be instantiated directly. |
Method Summary
Modifier and Type | Method | Description |
---|---|---|
Object | clone() | Creates a new object of the same class as this object. |
boolean | contains(double x,
double y) | Tests if a specified coordinate is inside the boundary of this |
boolean | contains(double x,
double y,
double w,
double h) | Tests if the interior of this |
boolean | contains(Point2D p) | Tests if a given |
boolean | contains(Rectangle2D r) | Tests if the interior of this |
Rectangle | getBounds() | Returns an integer |
abstract Point2D | getP1() | Returns the start |
abstract Point2D | getP2() | Returns the end |
PathIterator | getPathIterator(AffineTransform at) | Returns an iteration object that defines the boundary of this |
PathIterator | getPathIterator(AffineTransform at,
double flatness) | Returns an iteration object that defines the boundary of this flattened |
abstract double | getX1() | Returns the X coordinate of the start point in double precision. |
abstract double | getX2() | Returns the X coordinate of the end point in double precision. |
abstract double | getY1() | Returns the Y coordinate of the start point in double precision. |
abstract double | getY2() | Returns the Y coordinate of the end point in double precision. |
boolean | intersects(double x,
double y,
double w,
double h) | Tests if the interior of the |
boolean | intersects(Rectangle2D r) | Tests if the interior of the |
boolean | intersectsLine(double x1,
double y1,
double x2,
double y2) | Tests if the line segment from |
boolean | intersectsLine(Line2D l) | Tests if the specified line segment intersects this line segment. |
static boolean | linesIntersect(double x1,
double y1,
double x2,
double y2,
double x3,
double y3,
double x4,
double y4) | Tests if the line segment from |
double | ptLineDist(double px,
double py) | Returns the distance from a point to this line. |
static double | ptLineDist(double x1,
double y1,
double x2,
double y2,
double px,
double py) | Returns the distance from a point to a line. |
double | ptLineDist(Point2D pt) | Returns the distance from a |
double | ptLineDistSq(double px,
double py) | Returns the square of the distance from a point to this line. |
static double | ptLineDistSq(double x1,
double y1,
double x2,
double y2,
double px,
double py) | Returns the square of the distance from a point to a line. |
double | ptLineDistSq(Point2D pt) | Returns the square of the distance from a specified |
double | ptSegDist(double px,
double py) | Returns the distance from a point to this line segment. |
static double | ptSegDist(double x1,
double y1,
double x2,
double y2,
double px,
double py) | Returns the distance from a point to a line segment. |
double | ptSegDist(Point2D pt) | Returns the distance from a |
double | ptSegDistSq(double px,
double py) | Returns the square of the distance from a point to this line segment. |
static double | ptSegDistSq(double x1,
double y1,
double x2,
double y2,
double px,
double py) | Returns the square of the distance from a point to a line segment. |
double | ptSegDistSq(Point2D pt) | Returns the square of the distance from a |
int | relativeCCW(double px,
double py) | Returns an indicator of where the specified point |
static int | relativeCCW(double x1,
double y1,
double x2,
double y2,
double px,
double py) | Returns an indicator of where the specified point |
int | relativeCCW(Point2D p) | Returns an indicator of where the specified |
abstract void | setLine(double x1,
double y1,
double x2,
double y2) | Sets the location of the end points of this |
void | setLine(Line2D l) | Sets the location of the end points of this |
void | setLine(Point2D p1,
Point2D p2) | Sets the location of the end points of this |
Methods declared in class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods declared in interface java.awt.Shape
getBounds2D
Constructor Detail
Line2D
protected Line2D()
This is an abstract class that cannot be instantiated directly. Type-specific implementation subclasses are available for instantiation and provide a number of formats for storing the information necessary to satisfy the various accessory methods below.
- Since:
- 1.2
- See Also:
-
Line2D.Float
,Line2D.Double
Method Detail
getX1
public abstract double getX1()
Returns the X coordinate of the start point in double precision.
- Returns:
- the X coordinate of the start point of this
Line2D
object. - Since:
- 1.2
getY1
public abstract double getY1()
Returns the Y coordinate of the start point in double precision.
- Returns:
- the Y coordinate of the start point of this
Line2D
object. - Since:
- 1.2
getP1
public abstract Point2D getP1()
Returns the start Point2D
of this Line2D
.
- Returns:
- the start
Point2D
of thisLine2D
. - Since:
- 1.2
getX2
public abstract double getX2()
Returns the X coordinate of the end point in double precision.
- Returns:
- the X coordinate of the end point of this
Line2D
object. - Since:
- 1.2
getY2
public abstract double getY2()
Returns the Y coordinate of the end point in double precision.
- Returns:
- the Y coordinate of the end point of this
Line2D
object. - Since:
- 1.2
getP2
public abstract Point2D getP2()
Returns the end Point2D
of this Line2D
.
- Returns:
- the end
Point2D
of thisLine2D
. - Since:
- 1.2
setLine
public abstract void setLine(double x1, double y1, double x2, double y2)
Sets the location of the end points of this Line2D
to the specified double 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 - Since:
- 1.2
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 startPoint2D
of the line segment -
p2
- the endPoint2D
of the line segment - Since:
- 1.2
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 specifiedLine2D
- Since:
- 1.2
relativeCCW
public static int relativeCCW(double x1, double y1, double x2, double y2, double px, double 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 collinearity 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.
- Since:
- 1.2
relativeCCW
public int relativeCCW(double px, double 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 thisLine2D
-
py
- the Y coordinate of the specified point to be compared with thisLine2D
- Returns:
- an integer that indicates the position of the specified coordinates with respect to this
Line2D
- Since:
- 1.2
- 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 specifiedPoint2D
to be compared with thisLine2D
- Returns:
- an integer that indicates the position of the specified
Point2D
with respect to thisLine2D
- Since:
- 1.2
- See Also:
relativeCCW(double, double, double, double, double, double)
linesIntersect
public static boolean linesIntersect(double x1, double y1, double x2, double y2, double x3, double y3, double x4, double 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. - Since:
- 1.2
intersectsLine
public boolean intersectsLine(double x1, double y1, double x2, double 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:
-
true
if this line segment and the specified line segment intersect each other;false
otherwise. - Since:
- 1.2
intersectsLine
public boolean intersectsLine(Line2D l)
Tests if the specified line segment intersects this line segment.
- Parameters:
-
l
- the specifiedLine2D
- Returns:
-
true
if this line segment and the specified line segment intersect each other;false
otherwise. - Since:
- 1.2
ptSegDistSq
public static double ptSegDistSq(double x1, double y1, double x2, double y2, double px, double 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.
- Since:
- 1.2
- See Also:
ptLineDistSq(double, double, double, double, double, double)
ptSegDist
public static double ptSegDist(double x1, double y1, double x2, double y2, double px, double 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.
- Since:
- 1.2
- See Also:
ptLineDist(double, double, double, double, double, double)
ptSegDistSq
public double ptSegDistSq(double px, double 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.
- Since:
- 1.2
- See Also:
ptLineDistSq(double, double)
ptSegDistSq
public double 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 specifiedPoint2D
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. - Since:
- 1.2
- See Also:
ptLineDistSq(Point2D)
ptSegDist
public double ptSegDist(double px, double 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.
- Since:
- 1.2
- See Also:
ptLineDist(double, double)
ptSegDist
public double 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 specifiedPoint2D
being measured against this line segment - Returns:
- a double value that is the distance from the specified
Point2D
to the current line segment. - Since:
- 1.2
- See Also:
ptLineDist(Point2D)
ptLineDistSq
public static double ptLineDistSq(double x1, double y1, double x2, double y2, double px, double 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.
- Since:
- 1.2
- See Also:
ptSegDistSq(double, double, double, double, double, double)
ptLineDist
public static double ptLineDist(double x1, double y1, double x2, double y2, double px, double 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.
- Since:
- 1.2
- See Also:
ptSegDist(double, double, double, double, double, double)
ptLineDistSq
public double ptLineDistSq(double px, double 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.
- Since:
- 1.2
- See Also:
ptSegDistSq(double, double)
ptLineDistSq
public double 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 specifiedPoint2D
being measured against this line - Returns:
- a double value that is the square of the distance from a specified
Point2D
to the current line. - Since:
- 1.2
- See Also:
ptSegDistSq(Point2D)
ptLineDist
public double ptLineDist(double px, double 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.
- Since:
- 1.2
- See Also:
ptSegDist(double, double)
ptLineDist
public double 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 specifiedPoint2D
being measured - Returns:
- a double value that is the distance from a specified
Point2D
to the current line. - Since:
- 1.2
- See Also:
ptSegDist(Point2D)
contains
public boolean contains(double x, double y)
Tests if a specified coordinate is inside the boundary of this Line2D
. This method is required to implement the Shape
interface, but in the case of Line2D
objects it always returns false
since a line contains no area.
- Specified by:
-
contains
in interfaceShape
- Parameters:
-
x
- the X coordinate of the specified point to be tested -
y
- the Y coordinate of the specified point to be tested - Returns:
-
false
because aLine2D
contains no area. - Since:
- 1.2
contains
public boolean contains(Point2D p)
Tests if a given Point2D
is inside the boundary of this Line2D
. This method is required to implement the Shape
interface, but in the case of Line2D
objects it always returns false
since a line contains no area.
- Specified by:
-
contains
in interfaceShape
- Parameters:
-
p
- the specifiedPoint2D
to be tested - Returns:
-
false
because aLine2D
contains no area. - Since:
- 1.2
intersects
public boolean intersects(double x, double y, double w, double h)
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.
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 interfaceShape
- 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 theShape
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. - Since:
- 1.2
- See Also:
Area
intersects
public boolean intersects(Rectangle2D r)
Tests if the interior of the Shape
intersects the interior of a specified Rectangle2D
. The Shape.intersects()
method allows a Shape
implementation to conservatively return true
when:
- there is a high probability that the
Rectangle2D
and theShape
intersect, but - the calculations to accurately determine this intersection are prohibitively expensive.
Shapes
this method might return true
even though the Rectangle2D
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 interfaceShape
- Parameters:
-
r
- the specifiedRectangle2D
- Returns:
-
true
if the interior of theShape
and the interior of the specifiedRectangle2D
intersect, or are both highly likely to intersect and intersection calculations would be too expensive to perform;false
otherwise. - Since:
- 1.2
- See Also:
Shape.intersects(double, double, double, double)
contains
public boolean contains(double x, double y, double w, double h)
Tests if the interior of this Line2D
entirely contains the specified set of rectangular coordinates. This method is required to implement the Shape
interface, but in the case of Line2D
objects it always returns false since a line contains no area.
- Specified by:
-
contains
in interfaceShape
- 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:
-
false
because aLine2D
contains no area. - Since:
- 1.2
- See Also:
-
Area
,Shape.intersects(double, double, double, double)
contains
public boolean contains(Rectangle2D r)
Tests if the interior of this Line2D
entirely contains the specified Rectangle2D
. This method is required to implement the Shape
interface, but in the case of Line2D
objects it always returns false
since a line contains no area.
- Specified by:
-
contains
in interfaceShape
- Parameters:
-
r
- the specifiedRectangle2D
to be tested - Returns:
-
false
because aLine2D
contains no area. - Since:
- 1.2
- See Also:
Shape.contains(double, double, double, double)
getBounds
public Rectangle getBounds()
Returns an integer Rectangle
that completely encloses the Shape
. Note that there is no guarantee that the returned Rectangle
is the smallest bounding box that encloses the Shape
, only that the Shape
lies entirely within the indicated Rectangle
. The returned Rectangle
might also fail to completely enclose the Shape
if the Shape
overflows the limited range of the integer data type. The getBounds2D
method generally returns a tighter bounding box due to its greater flexibility in representation.
Note that the definition of insideness can lead to situations where points on the defining outline of the shape
may not be considered contained in the returned bounds
object, but only in cases where those points are also not considered contained in the original shape
.
If a point
is inside the shape
according to the contains(point)
method, then it must be inside the returned Rectangle
bounds object according to the contains(point)
method of the bounds
. Specifically:
shape.contains(x,y)
requires bounds.contains(x,y)
If a point
is not inside the shape
, then it might still be contained in the bounds
object:
bounds.contains(x,y)
does not imply shape.contains(x,y)
- Specified by:
-
getBounds
in interfaceShape
- Returns:
- an integer
Rectangle
that completely encloses theShape
. - Since:
- 1.2
- See Also:
Shape.getBounds2D()
getPathIterator
public PathIterator getPathIterator(AffineTransform at)
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 interfaceShape
- Parameters:
-
at
- the specifiedAffineTransform
- Returns:
- a
PathIterator
that defines the boundary of thisLine2D
. - Since:
- 1.2
getPathIterator
public PathIterator getPathIterator(AffineTransform at, double 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 interfaceShape
- Parameters:
-
at
- the specifiedAffineTransform
-
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 aLine2D
object is always flat, this parameter is ignored. - Returns:
- a
PathIterator
that defines the boundary of the flattenedLine2D
- Since:
- 1.2
clone
public Object clone()
Creates a new object of the same class as this object.
- Overrides:
-
clone
in classObject
- Returns:
- a clone of this instance.
- Throws:
-
OutOfMemoryError
- if there is not enough memory. - Since:
- 1.2
- See Also:
Cloneable