Class java.awt.Polygon





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Class java.awt.Polygon


java.lang.Object
|
+----java.awt.Polygon



public class Polygon
extends Object
implements Shape, Serializable

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.








bounds


npoints
The total number of points.

xpoints
The array of x coordinates.

ypoints
The array of y coordinates.






Polygon()
Creates an empty polygon.

Polygon(int[], int[], int)
Constructs and initializes a polygon from the specified
parameters.






addPoint(int, int)
Appends a point to this polygon.

contains(int, int)
Determines whether the specified point is contained by this polygon.

contains(Point)
Determines whether the specified point is inside the Polygon.

getBoundingBox()

Deprecated.

getBounds()
Gets the bounding box of this polygon.

inside(int, int)

Deprecated.

translate(int, int)
Translates the vertices by deltaX along the
x axis and by deltaY along the
y axis.






npoints

public int npoints


The total number of points.


xpoints

public int xpoints[]


The array of x coordinates.


ypoints

public int ypoints[]


The array of y coordinates.


bounds

protected Rectangle bounds







Polygon

public Polygon()


Creates an empty polygon.



Polygon

public Polygon(int xpoints[],
int ypoints[],
int npoints)


Constructs and initializes a polygon from the specified
parameters.


Parameters:
xpoints - an array of x coordinates.
ypoints - an array of y coordinates.
npoints - the total number of points in the polygon.
Throws: NegativeArraySizeException
if the value of
npoints is negative.







translate

public void translate(int deltaX,
int deltaY)


Translates the vertices by deltaX along the
x axis and by deltaY along the
y axis.


Parameters:
deltaX - the amount to translate along the x axis
deltaY - the amount to translate along the y axis



addPoint

public void addPoint(int x,
int y)


Appends a point 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.


Parameters:
x - the x coordinate of the point.
y - the y coordinate of the point.
See Also:
getBounds, contains



getBounds

public Rectangle getBounds()


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 that can completely
contain the polygon.


Returns:
a rectangle that defines the bounds of this polygon.



getBoundingBox

public Rectangle getBoundingBox()


Note: getBoundingBox() is deprecated.
As of JDK version 1.1,
replaced by getBounds().



contains

public boolean contains(Point p)


Determines whether the specified point is inside the Polygon.
Uses an even-odd insideness rule (also known as an alternating
rule).


Parameters:
p - the point to be tested



contains

public boolean contains(int x,
int y)


Determines whether the specified point is contained by this polygon.

(The contains method is based on code by
Hanpeter van Vliet [[e-mail]].)


Parameters:
x - the x coordinate of the point to be tested.
y - the y coordinate of the point to be tested.
Returns:
true if the point (x, y)
is contained by this polygon;
false otherwise.



inside

public boolean inside(int x,
int y)


Note: inside() is deprecated.
As of JDK version 1.1,
replaced by contains(int, int).




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