public abstract class Path2D extends Object implements Shape, Cloneable
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
Double class defines a geometric path with
coordinates stored in double precision floating point. |
static class |
Path2D.Float
The
Float class defines a geometric path with
coordinates stored in single precision floating point. |
Modifier and Type | Field and Description |
---|---|
static int |
WIND_EVEN_ODD
An even-odd winding rule for determining the interior of
a path.
|
static int |
WIND_NON_ZERO
A non-zero winding rule for determining the interior of a
path.
|
Modifier and Type | Method and Description |
---|---|
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. |
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. |
abstract Object |
clone()
Creates a new object of the same class as this object.
|
void |
closePath()
Closes the current subpath by drawing a straight line back to
the coordinates of the last
moveTo . |
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. |
boolean |
contains(double x,
double y,
double w,
double h)
Tests if the interior of the
Shape entirely contains
the specified rectangular area. |
static boolean |
contains(PathIterator pi,
double x,
double y)
Tests if the specified coordinates are inside the closed
boundary of the specified
PathIterator . |
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 . |
static boolean |
contains(PathIterator pi,
Point2D p)
Tests if the specified
Point2D is inside the closed
boundary of the specified PathIterator . |
static boolean |
contains(PathIterator pi,
Rectangle2D r)
Tests if the specified
Rectangle2D is entirely inside the
closed boundary of the specified PathIterator . |
boolean |
contains(Point2D p)
Tests if a specified
Point2D is inside the boundary
of the Shape , as described by the
definition of insideness. |
boolean |
contains(Rectangle2D r)
Tests if the interior of the
Shape entirely contains the
specified Rectangle2D . |
Shape |
createTransformedShape(AffineTransform at)
Returns a new
Shape representing a transformed version
of this Path2D . |
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. |
Rectangle |
getBounds()
Returns an integer
Rectangle that completely encloses the
Shape . |
Point2D |
getCurrentPoint()
Returns the coordinates most recently added to the end of the path
as a
Point2D object. |
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. |
int |
getWindingRule()
Returns the fill style winding rule.
|
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. |
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. |
static boolean |
intersects(PathIterator pi,
Rectangle2D r)
Tests if the interior of the specified
PathIterator
intersects the interior of a specified Rectangle2D . |
boolean |
intersects(Rectangle2D r)
Tests if the interior of the
Shape intersects the
interior of a specified Rectangle2D . |
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.
|
abstract void |
moveTo(double x,
double y)
Adds a point to the path by moving to the specified
coordinates specified in double precision.
|
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. |
void |
reset()
Resets the path to empty.
|
void |
setWindingRule(int rule)
Sets the winding rule for this path to the specified value.
|
abstract void |
transform(AffineTransform at)
Transforms the geometry of this path using the specified
AffineTransform . |
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
getBounds2D, getPathIterator
public static final int WIND_EVEN_ODD
PathIterator.WIND_EVEN_ODD
,
Constant Field Valuespublic static final int WIND_NON_ZERO
PathIterator.WIND_NON_ZERO
,
Constant Field Valuespublic abstract void moveTo(double x, double y)
x
- the specified X coordinatey
- the specified Y coordinatepublic abstract void lineTo(double x, double y)
x
- the specified X coordinatey
- the specified Y coordinatepublic abstract void quadTo(double x1, double y1, double x2, double y2)
(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)
(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()
moveTo
. If the path is already
closed then this method has no effect.public final void append(Shape s, boolean connect)
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)
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()
WIND_EVEN_ODD
,
WIND_NON_ZERO
,
setWindingRule(int)
public final void setWindingRule(int rule)
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()
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()
public abstract void transform(AffineTransform at)
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)
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()
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)
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)
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)
Shape
, as described by the
definition of insideness.public final boolean contains(Point2D p)
Point2D
is inside the boundary
of the Shape
, as described by the
definition of insideness.public static boolean contains(PathIterator pi, double x, double y, double w, double h)
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)
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)
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)
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)
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)
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)
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)
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)
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()
clone
in class Object
OutOfMemoryError
- if there is not enough memory.Cloneable
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