public abstract class Path2D extends Object implements Shape, Cloneable
The Path2D
class provides a simple, yet flexible shape which represents an arbitrary geometric path. It can fully represent any path which can be iterated by the PathIterator
interface including all of its segment types and winding rules and it implements all of the basic hit testing methods of the Shape
interface.
Use Path2D.Float
when dealing with data that can be represented and used with floating point precision. Use Path2D.Double
for data that requires the accuracy or range of double precision.
Path2D
provides exactly those facilities required for basic construction and management of a geometric path and implementation of the above interfaces with little added interpretation. If it is useful to manipulate the interiors of closed geometric shapes beyond simple hit testing then the Area
class provides additional capabilities specifically targeted at closed figures. While both classes nominally implement the Shape
interface, they differ in purpose and together they provide two useful views of a geometric shape where Path2D
deals primarily with a trajectory formed by path segments and Area
deals more with interpretation and manipulation of enclosed regions of 2D geometric space.
The PathIterator
interface has more detailed descriptions of the types of segments that make up a path and the winding rules that control how to determine which regions are inside or outside the path.
Modifier and Type | Class and Description |
---|---|
static class |
Path2D.Double The |
static class |
Path2D.Float The |
public static final int WIND_EVEN_ODD
An even-odd winding rule for determining the interior of a path.
PathIterator.WIND_EVEN_ODD
, Constant Field Valuespublic static final int WIND_NON_ZERO
A non-zero winding rule for determining the interior of a path.
PathIterator.WIND_NON_ZERO
, Constant Field Valuespublic abstract void moveTo(double x, double y)
Adds a point to the path by moving to the specified coordinates specified in double precision.
x
- the specified X coordinatey
- the specified Y coordinatepublic abstract void lineTo(double x, double y)
Adds a point to the path by drawing a straight line from the current coordinates to the new specified coordinates specified in double precision.
x
- the specified X coordinatey
- the specified Y coordinatepublic abstract void quadTo(double x1, double y1, double x2, double y2)
Adds a curved segment, defined by two new points, to the path by drawing a Quadratic curve that intersects both the current coordinates and the specified coordinates (x2,y2)
, using the specified point (x1,y1)
as a quadratic parametric control point. All coordinates are specified in double precision.
x1
- the X coordinate of the quadratic control pointy1
- the Y coordinate of the quadratic control pointx2
- the X coordinate of the final end pointy2
- the Y coordinate of the final end pointpublic abstract void curveTo(double x1, double y1, double x2, double y2, double x3, double y3)
Adds a curved segment, defined by three new points, to the path by drawing a Bézier curve that intersects both the current coordinates and the specified coordinates (x3,y3)
, using the specified points (x1,y1)
and (x2,y2)
as Bézier control points. All coordinates are specified in double precision.
x1
- the X coordinate of the first Bézier control pointy1
- the Y coordinate of the first Bézier control pointx2
- the X coordinate of the second Bézier control pointy2
- the Y coordinate of the second Bézier control pointx3
- the X coordinate of the final end pointy3
- the Y coordinate of the final end pointpublic final void closePath()
Closes the current subpath by drawing a straight line back to the coordinates of the last moveTo
. If the path is already closed then this method has no effect.
public final void append(Shape s, boolean connect)
Appends the geometry of the specified Shape
object to the path, possibly connecting the new geometry to the existing path segments with a line segment. If the connect
parameter is true
and the path is not empty then any initial moveTo
in the geometry of the appended Shape
is turned into a lineTo
segment. If the destination coordinates of such a connecting lineTo
segment match the ending coordinates of a currently open subpath then the segment is omitted as superfluous. The winding rule of the specified Shape
is ignored and the appended geometry is governed by the winding rule specified for this path.
s
- the Shape
whose geometry is appended to this pathconnect
- a boolean to control whether or not to turn an initial moveTo
segment into a lineTo
segment to connect the new geometry to the existing pathpublic abstract void append(PathIterator pi, boolean connect)
Appends the geometry of the specified PathIterator
object to the path, possibly connecting the new geometry to the existing path segments with a line segment. If the connect
parameter is true
and the path is not empty then any initial moveTo
in the geometry of the appended Shape
is turned into a lineTo
segment. If the destination coordinates of such a connecting lineTo
segment match the ending coordinates of a currently open subpath then the segment is omitted as superfluous. The winding rule of the specified Shape
is ignored and the appended geometry is governed by the winding rule specified for this path.
pi
- the PathIterator
whose geometry is appended to this pathconnect
- a boolean to control whether or not to turn an initial moveTo
segment into a lineTo
segment to connect the new geometry to the existing pathpublic final int getWindingRule()
Returns the fill style winding rule.
WIND_EVEN_ODD
, WIND_NON_ZERO
, setWindingRule(int)
public final void setWindingRule(int rule)
Sets the winding rule for this path to the specified value.
rule
- an integer representing the specified winding ruleIllegalArgumentException
- if rule
is not either WIND_EVEN_ODD
or WIND_NON_ZERO
getWindingRule()
public final Point2D getCurrentPoint()
Returns the coordinates most recently added to the end of the path as a Point2D
object.
Point2D
object containing the ending coordinates of the path or null
if there are no points in the path.public final void reset()
Resets the path to empty. The append position is set back to the beginning of the path and all coordinates and point types are forgotten.
public abstract void transform(AffineTransform at)
Transforms the geometry of this path using the specified AffineTransform
. The geometry is transformed in place, which permanently changes the boundary defined by this object.
at
- the AffineTransform
used to transform the areapublic final Shape createTransformedShape(AffineTransform at)
Returns a new Shape
representing a transformed version of this Path2D
. Note that the exact type and coordinate precision of the return value is not specified for this method. The method will return a Shape that contains no less precision for the transformed geometry than this Path2D
currently maintains, but it may contain no more precision either. If the tradeoff of precision vs. storage size in the result is important then the convenience constructors in the Path2D.Float
and Path2D.Double
subclasses should be used to make the choice explicit.
at
- the AffineTransform
used to transform a new Shape
.Shape
, transformed with the specified AffineTransform
.public final 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)
getBounds
in interface Shape
Rectangle
that completely encloses the Shape
.Shape.getBounds2D()
public static boolean contains(PathIterator pi, double x, double y)
Tests if the specified coordinates are inside the closed boundary of the specified PathIterator
.
This method provides a basic facility for implementors of the Shape
interface to implement support for the Shape.contains(double, double)
method.
pi
- the specified PathIterator
x
- the specified X coordinatey
- the specified Y coordinatetrue
if the specified coordinates are inside the specified PathIterator
; false
otherwisepublic static boolean contains(PathIterator pi, Point2D p)
Tests if the specified Point2D
is inside the closed boundary of the specified PathIterator
.
This method provides a basic facility for implementors of the Shape
interface to implement support for the Shape.contains(Point2D)
method.
pi
- the specified PathIterator
p
- the specified Point2D
true
if the specified coordinates are inside the specified PathIterator
; false
otherwisepublic final boolean contains(double x, double y)
Tests if the specified coordinates are inside the boundary of the Shape
, as described by the definition of insideness.
contains
in interface Shape
x
- the specified X coordinate to be testedy
- the specified Y coordinate to be testedtrue
if the specified coordinates are inside the Shape
boundary; false
otherwise.public final boolean contains(Point2D p)
Tests if a specified Point2D
is inside the boundary of the Shape
, as described by the definition of insideness.
contains
in interface Shape
p
- the specified Point2D
to be testedtrue
if the specified Point2D
is inside the boundary of the Shape
; false
otherwise.public static boolean contains(PathIterator pi, double x, double y, double w, double h)
Tests if the specified rectangular area is entirely inside the closed boundary of the specified PathIterator
.
This method provides a basic facility for implementors of the Shape
interface to implement support for the Shape.contains(double, double, double, double)
method.
This method object may conservatively return false in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such segments could lie entirely within the interior of the path if they are part of a path with a WIND_NON_ZERO
winding rule or if the segments are retraced in the reverse direction such that the two sets of segments cancel each other out without any exterior area falling between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.
pi
- the specified PathIterator
x
- the specified X coordinatey
- the specified Y coordinatew
- the width of the specified rectangular areah
- the height of the specified rectangular areatrue
if the specified PathIterator
contains the specified rectangular area; false
otherwise.public static boolean contains(PathIterator pi, Rectangle2D r)
Tests if the specified Rectangle2D
is entirely inside the closed boundary of the specified PathIterator
.
This method provides a basic facility for implementors of the Shape
interface to implement support for the Shape.contains(Rectangle2D)
method.
This method object may conservatively return false in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such segments could lie entirely within the interior of the path if they are part of a path with a WIND_NON_ZERO
winding rule or if the segments are retraced in the reverse direction such that the two sets of segments cancel each other out without any exterior area falling between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.
pi
- the specified PathIterator
r
- a specified Rectangle2D
true
if the specified PathIterator
contains the specified Rectangle2D
; false
otherwise.public final boolean contains(double x, double y, double w, double h)
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 rectangular area to be considered contained within the Shape
.
The Shape.contains()
method allows a Shape
implementation to conservatively return false
when:
intersect
method returns true
and Shape
entirely contains the rectangular area are prohibitively expensive. 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. This method object may conservatively return false in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such segments could lie entirely within the interior of the path if they are part of a path with a WIND_NON_ZERO
winding rule or if the segments are retraced in the reverse direction such that the two sets of segments cancel each other out without any exterior area falling between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.
contains
in interface Shape
x
- the X coordinate of the upper-left corner of the specified rectangular areay
- the Y coordinate of the upper-left corner of the specified rectangular areaw
- the width of the specified rectangular areah
- the height of the specified rectangular areatrue
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.Area
, Shape.intersects(double, double, double, double)
public final boolean contains(Rectangle2D r)
Tests if the interior of the Shape
entirely contains the specified Rectangle2D
. The Shape.contains()
method allows a Shape
implementation to conservatively return false
when:
intersect
method returns true
and Shape
entirely contains the Rectangle2D
are prohibitively expensive. Shapes
this method might return false
even though the Shape
contains the Rectangle2D
. The Area
class performs more accurate geometric computations than most Shape
objects and therefore can be used if a more precise answer is required.
This method object may conservatively return false in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such segments could lie entirely within the interior of the path if they are part of a path with a WIND_NON_ZERO
winding rule or if the segments are retraced in the reverse direction such that the two sets of segments cancel each other out without any exterior area falling between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.
contains
in interface Shape
r
- The specified Rectangle2D
true
if the interior of the Shape
entirely contains the Rectangle2D
; false
otherwise or, if the Shape
contains the Rectangle2D
and the intersects
method returns true
and the containment calculations would be too expensive to perform.Shape.contains(double, double, double, double)
public static boolean intersects(PathIterator pi, double x, double y, double w, double h)
Tests if the interior of the specified PathIterator
intersects the interior of a specified set of rectangular coordinates.
This method provides a basic facility for implementors of the Shape
interface to implement support for the Shape.intersects(double, double, double, double)
method.
This method object may conservatively return true in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such a case may occur if some set of segments of the path are retraced in the reverse direction such that the two sets of segments cancel each other out without any interior area between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.
pi
- the specified PathIterator
x
- the specified X coordinatey
- the specified Y coordinatew
- the width of the specified rectangular coordinatesh
- the height of the specified rectangular coordinatestrue
if the specified PathIterator
and the interior of the specified set of rectangular coordinates intersect each other; false
otherwise.public static boolean intersects(PathIterator pi, Rectangle2D r)
Tests if the interior of the specified PathIterator
intersects the interior of a specified Rectangle2D
.
This method provides a basic facility for implementors of the Shape
interface to implement support for the Shape.intersects(Rectangle2D)
method.
This method object may conservatively return true in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such a case may occur if some set of segments of the path are retraced in the reverse direction such that the two sets of segments cancel each other out without any interior area between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.
pi
- the specified PathIterator
r
- the specified Rectangle2D
true
if the specified PathIterator
and the interior of the specified Rectangle2D
intersect each other; false
otherwise.public final 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:
Shape
intersect, but 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. This method object may conservatively return true in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such a case may occur if some set of segments of the path are retraced in the reverse direction such that the two sets of segments cancel each other out without any interior area between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.
intersects
in interface Shape
x
- the X coordinate of the upper-left corner of the specified rectangular areay
- the Y coordinate of the upper-left corner of the specified rectangular areaw
- the width of the specified rectangular areah
- the height of the specified rectangular areatrue
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.Area
public final 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:
Rectangle2D
and the Shape
intersect, but 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.
This method object may conservatively return true in cases where the specified rectangular area intersects a segment of the path, but that segment does not represent a boundary between the interior and exterior of the path. Such a case may occur if some set of segments of the path are retraced in the reverse direction such that the two sets of segments cancel each other out without any interior area between them. To determine whether segments represent true boundaries of the interior of the path would require extensive calculations involving all of the segments of the path and the winding rule and are thus beyond the scope of this implementation.
intersects
in interface Shape
r
- the specified Rectangle2D
true
if the interior of the Shape
and the interior of the specified Rectangle2D
intersect, or are both highly likely to intersect and intersection calculations would be too expensive to perform; false
otherwise.Shape.intersects(double, double, double, double)
public final PathIterator getPathIterator(AffineTransform at, double flatness)
Returns an iterator object that iterates along the Shape
boundary and provides access to a flattened view of the Shape
outline geometry.
Only SEG_MOVETO, SEG_LINETO, and SEG_CLOSE point types are returned by the iterator.
If an optional AffineTransform
is specified, the coordinates returned in the iteration are transformed accordingly.
The amount of subdivision of the curved segments is controlled by the flatness
parameter, which specifies the maximum distance that any point on the unflattened transformed curve can deviate from the returned flattened path segments. Note that a limit on the accuracy of the flattened path might be silently imposed, causing very small flattening parameters to be treated as larger values. This limit, if there is one, is defined by the particular implementation that is used.
Each call to this method returns a fresh PathIterator
object that traverses the Shape
object geometry independently from any other PathIterator
objects in use at the same time.
It is recommended, but not guaranteed, that objects implementing the Shape
interface isolate iterations that are in process from any changes that might occur to the original object's geometry during such iterations.
The iterator for this class is not multi-threaded safe, which means that this Path2D
class does not guarantee that modifications to the geometry of this Path2D
object do not affect any iterations of that geometry that are already in process.
getPathIterator
in interface Shape
at
- an optional AffineTransform
to be applied to the coordinates as they are returned in the iteration, or null
if untransformed coordinates are desiredflatness
- the maximum distance that the line segments used to approximate the curved segments are allowed to deviate from any point on the original curvePathIterator
that independently traverses a flattened view of the geometry of the Shape
.public abstract Object clone()
Creates a new object of the same class as this object.
clone
in class Object
OutOfMemoryError
- if there is not enough memory.Cloneable
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