java.lang.Object | |
↳ | java.awt.Polygon |
The Polygon
class encapsulates a description of a
closed, two-dimensional region within a coordinate space. This
region is bounded by an arbitrary number of line segments, each of
which is one side of the polygon. Internally, a polygon
comprises of a list of (x,y)
coordinate pairs, where each pair defines a vertex of the
polygon, and two successive pairs are the endpoints of a
line that is a side of the polygon. The first and final
pairs of (x,y)
points are joined by a line segment
that closes the polygon. This Polygon
is defined with
an even-odd winding rule. See
WIND_EVEN_ODD
for a definition of the even-odd winding rule.
This class's hit-testing methods, which include the
contains
, intersects
and inside
methods, use the insideness definition described in the
Shape
class comments.
Fields | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
bounds | The bounds of this Polygon . |
||||||||||
npoints | The total number of points. | ||||||||||
xpoints | The array of X coordinates. | ||||||||||
ypoints | The array of Y coordinates. |
Public Constructors | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Creates an empty polygon.
| |||||||||||
Constructs and initializes a
Polygon from the specified
parameters. |
Public Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Appends the specified coordinates to this
Polygon . | |||||||||||
Determines whether the specified
Point is inside this
Polygon . | |||||||||||
Determines whether the specified coordinates are inside this
Polygon . | |||||||||||
Tests if a specified
Point2D is inside the boundary
of the Shape . | |||||||||||
Tests if the specified coordinates are inside the boundary of the
Shape . | |||||||||||
Tests if the interior of the
Shape entirely contains
the specified rectangular area. | |||||||||||
Tests if the interior of the
Shape entirely contains the
specified Rectangle2D . | |||||||||||
This method is deprecated.
As of JDK version 1.1,
replaced by
getBounds() . | |||||||||||
Gets the bounding box of this
Polygon . | |||||||||||
Returns a high precision and more accurate bounding box of
the
Shape than the getBounds method. | |||||||||||
Returns an iterator object that iterates along the boundary of this
Polygon and provides access to the geometry
of the outline of this Polygon . | |||||||||||
Returns an iterator object that iterates along the boundary of
the
Shape and provides access to the geometry of the
outline of the Shape . | |||||||||||
This method is deprecated.
As of JDK version 1.1,
replaced by
contains(int, int) . | |||||||||||
Tests if the interior of the
Shape intersects the
interior of a specified rectangular area. | |||||||||||
Tests if the interior of the
Shape intersects the
interior of a specified Rectangle2D . | |||||||||||
Invalidates or flushes any internally-cached data that depends
on the vertex coordinates of this
Polygon . | |||||||||||
Resets this
Polygon object to an empty polygon. | |||||||||||
Translates the vertices of the
Polygon by
deltaX along the x axis and by
deltaY along the y axis. |
[Expand]
Inherited Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
From class
java.lang.Object
| |||||||||||
From interface
java.awt.Shape
|
The array of X coordinates. The number of elements in
this array might be more than the number of X coordinates
in this Polygon
. The extra elements allow new points
to be added to this Polygon
without re-creating this
array. The value of npoints
is equal to the
number of valid points in this Polygon
.@serial
The array of Y coordinates. The number of elements in
this array might be more than the number of Y coordinates
in this Polygon
. The extra elements allow new points
to be added to this Polygon
without re-creating this
array. The value of npoints
is equal to the
number of valid points in this Polygon
.@serial
Creates an empty polygon.
Constructs and initializes a Polygon
from the specified
parameters.
xpoints | an array of X coordinates |
---|---|
ypoints | an array of Y coordinates |
npoints | the total number of points in the
Polygon |
NegativeArraySizeException | if the value of
npoints is negative. |
---|---|
IndexOutOfBoundsException | if npoints is
greater than the length of xpoints
or the length of ypoints . |
NullPointerException | if xpoints or
ypoints is null . |
Appends the specified coordinates to this Polygon
.
If an operation that calculates the bounding box of this
Polygon
has already been performed, such as
getBounds
or contains
, then this
method updates the bounding box.
x | the specified X coordinate |
---|---|
y | the specified Y coordinate |
Determines whether the specified Point
is inside this
Polygon
.
p | the specified Point to be tested |
---|
true
if the Polygon
contains the
Point
; false
otherwise.Determines whether the specified coordinates are inside this
Polygon
.
x | the specified X coordinate to be tested |
---|---|
y | the specified Y coordinate to be tested |
true
if this Polygon
contains
the specified coordinates (x,y)
;
false
otherwise.Tests if a specified Point2D
is inside the boundary
of the Shape
.
p | the specified Point2D to be tested |
---|
true
if the specified Point2D
is
inside the boundary of the Shape
;
false
otherwise.Tests if the specified coordinates are inside the boundary of the
Shape
.
x | the specified X coordinate to be tested |
---|---|
y | the specified Y coordinate to be tested |
true
if the specified coordinates are inside
the Shape
boundary; false
otherwise.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:
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.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 |
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.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.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.
This method is deprecated.
As of JDK version 1.1,
replaced by getBounds()
.
Returns the bounds of this Polygon
.
Polygon
.Gets the bounding box of this Polygon
.
The bounding box is the smallest Rectangle
whose
sides are parallel to the x and y axes of the
coordinate space, and can completely contain the Polygon
.
Rectangle
that defines the bounds of this
Polygon
.Returns a high precision and more accurate bounding box of
the Shape
than the getBounds
method.
Note that there is no guarantee that the returned
Rectangle2D
is the smallest bounding box that encloses
the Shape
, only that the Shape
lies
entirely within the indicated Rectangle2D
. The
bounding box returned by this method is usually tighter than that
returned by the getBounds
method and never fails due
to overflow problems since the return value can be an instance of
the Rectangle2D
that uses double precision values to
store the dimensions.
Rectangle2D
that is a
high-precision bounding box of the Shape
.Returns an iterator object that iterates along the boundary of this
Polygon
and provides access to the geometry
of the outline of this Polygon
. An optional
AffineTransform
can be specified so that the coordinates
returned in the iteration are transformed accordingly.
at | an optional AffineTransform to be applied to the
coordinates as they are returned in the iteration, or
null if untransformed coordinates are desired |
---|
PathIterator
object that provides access to the
geometry of this Polygon
.Returns an iterator object that iterates along the boundary of
the Shape
and provides access to the geometry of the
outline of the Shape
. Only SEG_MOVETO, SEG_LINETO, and
SEG_CLOSE point types are returned by the iterator.
Since polygons are already flat, the flatness
parameter
is ignored. An optional AffineTransform
can be specified
in which case the coordinates returned in the iteration are transformed
accordingly.
at | an optional AffineTransform to be applied to the
coordinates as they are returned in the iteration, or
null if untransformed coordinates are desired |
---|---|
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
endpoints. Since polygons are already flat the
flatness parameter is ignored. |
PathIterator
object that provides access to the
Shape
object's geometry.
This method is deprecated.
As of JDK version 1.1,
replaced by contains(int, int)
.
Determines whether the specified coordinates are contained in this
Polygon
.
x | the specified X coordinate to be tested |
---|---|
y | the specified Y coordinate to be tested |
true
if this Polygon
contains
the specified coordinates (x,y)
;
false
otherwise.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.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 |
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.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.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.Invalidates or flushes any internally-cached data that depends
on the vertex coordinates of this Polygon
.
This method should be called after any direct manipulation
of the coordinates in the xpoints
or
ypoints
arrays to avoid inconsistent results
from methods such as getBounds
or contains
that might cache data from earlier computations relating to
the vertex coordinates.
Resets this Polygon
object to an empty polygon.
The coordinate arrays and the data in them are left untouched
but the number of points is reset to zero to mark the old
vertex data as invalid and to start accumulating new vertex
data at the beginning.
All internally-cached data relating to the old vertices
are discarded.
Note that since the coordinate arrays from before the reset
are reused, creating a new empty Polygon
might
be more memory efficient than resetting the current one if
the number of vertices in the new polygon data is significantly
smaller than the number of vertices in the data from before the
reset.
Translates the vertices of the Polygon
by
deltaX
along the x axis and by
deltaY
along the y axis.
deltaX | the amount to translate along the X axis |
---|---|
deltaY | the amount to translate along the Y axis |