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`java.lang.Object`

`java.awt.Polygon`

**Implemented Interfaces:**- Serializable, Shape

This class represents a polygon, a closed, two-dimensional region in a
coordinate space. The region is bounded by an arbitrary number of line
segments, between (x,y) coordinate vertices. The polygon has even-odd
winding, meaning that a point is inside the shape if it crosses the
boundary an odd number of times on the way to infinity.

There are some public fields; if you mess with them in an inconsistent manner, it is your own fault when you get NullPointerException, ArrayIndexOutOfBoundsException, or invalid results. Also, this class is not threadsafe.

**Since:**- 1.0

**See Also:**- Serialized Form

## Field Summary

`protected Rectangle`

`bounds`

- The bounding box of this polygon.

`int`

`npoints`

- This total number of endpoints.

`int[]`

`xpoints`

- The array of X coordinates of endpoints.

`int[]`

`ypoints`

- The array of Y coordinates of endpoints.

## Constructor Summary

`Polygon()`

- Initializes an empty polygon.

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

- Create a new polygon with the specified endpoints.

## Method Summary

`void`

`addPoint(int x, int y)`

- Adds the specified endpoint to the polygon.

`boolean`

`contains(double x, double y)`

- Tests whether or not the specified point is inside this polygon.

`boolean`

`contains(double x, double y, double w, double h)`

- Test if a high-precision rectangle lies completely in the shape.

`boolean`

`contains(int x, int y)`

- Tests whether or not the specified point is inside this polygon.

`boolean`

`boolean`

`boolean`

`contains(Rectangle2D r)`

- Test if a high-precision rectangle lies completely in the shape.

`Rectangle`

`getBoundingBox()`

**Deprecated.***use*`getBounds()`

instead

`Rectangle`

`getBounds()`

- Returns the bounding box of this polygon.

`Rectangle2D`

`getBounds2D()`

- Returns a high-precision bounding box of this polygon.

`PathIterator`

`getPathIterator(AffineTransform transform)`

- Return an iterator along the shape boundary.

`PathIterator`

`getPathIterator(AffineTransform transform, double flatness)`

- Return an iterator along the flattened version of the shape boundary.

`boolean`

`inside(int x, int y)`

**Deprecated.***use*`contains(int,int)`

instead

`boolean`

`intersects(double x, double y, double w, double h)`

- Test if a high-precision rectangle intersects the shape.

`boolean`

`intersects(Rectangle2D r)`

- Test if a high-precision rectangle intersects the shape.

`void`

`invalidate()`

- Invalidate or flush all cached data.

`void`

`reset()`

- Reset the polygon to be empty.

`void`

`translate(int dx, int dy)`

- Translates the polygon by adding the specified values to all X and Y coordinates.

### Methods inherited from class java.lang.Object

`clone`

,`equals`

,`extends Object> getClass`

,`finalize`

,`hashCode`

,`notify`

,`notifyAll`

,`toString`

,`wait`

,`wait`

,`wait`

protected Rectangle bounds

The bounding box of this polygon. This is lazily created and cached, so it must be invalidated after changing points.

See Also:`getBounds()`

public int[] xpoints

The array of X coordinates of endpoints. This should not be null.

See Also:`addPoint(int,int)`

public int[] ypoints

The array of Y coordinates of endpoints. This should not be null.

See Also:`addPoint(int,int)`

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

Create a new polygon with the specified endpoints. The arrays are copied, so that future modifications to the parameters do not affect the polygon.

Parameters:`xpoints`

- the array of X coordinates for this polygon`ypoints`

- the array of Y coordinates for this polygon`npoints`

- the total number of endpoints in this polygon

Throws:`NegativeArraySizeException`

- if npoints is negative`IndexOutOfBoundsException`

- if npoints exceeds either array`NullPointerException`

- if xpoints or ypoints is null

public void addPoint(int x, int y)

Adds the specified endpoint to the polygon. This updates the bounding box, if it has been created.

Parameters:`x`

- the X coordinate of the point to add`y`

- the Y coordiante of the point to add

public boolean contains(double x, double y)

Tests whether or not the specified point is inside this polygon.

Parameters:`x`

- the X coordinate of the point to test`y`

- the Y coordinate of the point to test

Returns:- true if the point is inside this polygon

Since:- 1.2

public boolean contains(double x, double y, double w, double h)

Test if a high-precision rectangle lies completely in the shape. This is true if all points in the rectangle are in the shape. This implementation is precise.

Parameters:`x`

- the x coordinate of the rectangle`y`

- the y coordinate of the rectangle`w`

- the width of the rectangle, treated as point if negative`h`

- the height of the rectangle, treated as point if negative

Returns:- true if the rectangle is contained in this shape

Since:- 1.2

public boolean contains(int x, int y)

Tests whether or not the specified point is inside this polygon.

Parameters:`x`

- the X coordinate of the point to test`y`

- the Y coordinate of the point to test

Returns:- true if the point is inside this polygon

Since:- 1.1

See Also:`contains(double,double)`

public boolean contains(Point p)

Tests whether or not the specified point is inside this polygon.

Parameters:`p`

- the point to test

Returns:- true if the point is inside this polygon

Throws:`NullPointerException`

- if p is null

See Also:`contains(double,double)`

public boolean contains(Point2D p)

Tests whether or not the specified point is inside this polygon.

Parameters:`p`

- the point to test

Returns:- true if the point is inside this polygon

Throws:`NullPointerException`

- if p is null

Since:- 1.2

See Also:`contains(double,double)`

public boolean contains(Rectangle2D r)

Test if a high-precision rectangle lies completely in the shape. This is true if all points in the rectangle are in the shape. This implementation is precise.

Parameters:`r`

- the rectangle

Returns:- true if the rectangle is contained in this shape

Throws:`NullPointerException`

- if r is null

Since:- 1.2

public Rectangle getBoundingBox()

Deprecated.use`getBounds()`

insteadReturns the bounding box of this polygon. This is the smallest rectangle with sides parallel to the X axis that will contain this polygon.

Returns:- the bounding box for this polygon

See Also:`getBounds2D()`

public Rectangle getBounds()

Returns the bounding box of this polygon. This is the smallest rectangle with sides parallel to the X axis that will contain this polygon.

Returns:- the bounding box for this polygon

Since:- 1.1

See Also:`getBounds2D()`

public Rectangle2D getBounds2D()

Returns a high-precision bounding box of this polygon. This is the smallest rectangle with sides parallel to the X axis that will contain this polygon.

Specified by:- getBounds2D in interface Shape

Returns:- the bounding box for this polygon

Since:- 1.2

See Also:`getBounds()`

public PathIterator getPathIterator(AffineTransform transform)

Return an iterator along the shape boundary. If the optional transform is provided, the iterator is transformed accordingly. Each call returns a new object, independent from others in use. This class is not threadsafe to begin with, so the path iterator is not either.

Specified by:- getPathIterator in interface Shape

Parameters:`transform`

- an optional transform to apply to the iterator

Returns:- a new iterator over the boundary

Since:- 1.2

public PathIterator getPathIterator(AffineTransform transform, double flatness)

Return an iterator along the flattened version of the shape boundary. Since polygons are already flat, the flatness parameter is ignored, and the resulting iterator only has SEG_MOVETO, SEG_LINETO and SEG_CLOSE points. If the optional transform is provided, the iterator is transformed accordingly. Each call returns a new object, independent from others in use. This class is not threadsafe to begin with, so the path iterator is not either.

Specified by:- getPathIterator in interface Shape

Parameters:`transform`

- an optional transform to apply to the iterator`flatness`

- the maximum distance for deviation from the real boundary

Returns:- a new iterator over the boundary

Since:- 1.2

public boolean inside(int x, int y)

Deprecated.use`contains(int,int)`

insteadTests whether or not the specified point is inside this polygon.

Parameters:`x`

- the X coordinate of the point to test`y`

- the Y coordinate of the point to test

Returns:- true if the point is inside this polygon

See Also:`contains(double,double)`

public boolean intersects(double x, double y, double w, double h)

Test if a high-precision rectangle intersects the shape. This is true if any point in the rectangle is in the shape. This implementation is precise.

Specified by:- intersects in interface Shape

Parameters:`x`

- the x coordinate of the rectangle`y`

- the y coordinate of the rectangle`w`

- the width of the rectangle, treated as point if negative`h`

- the height of the rectangle, treated as point if negative

Returns:- true if the rectangle intersects this shape

Since:- 1.2

public boolean intersects(Rectangle2D r)

Test if a high-precision rectangle intersects the shape. This is true if any point in the rectangle is in the shape. This implementation is precise.

Specified by:- intersects in interface Shape

Parameters:`r`

- the rectangle

Returns:- true if the rectangle intersects this shape

Throws:`NullPointerException`

- if r is null

Since:- 1.2

public void invalidate()

Invalidate or flush all cached data. After direct manipulation of the public member fields, this is necessary to avoid inconsistent results in methods like`contains`

.

Since:- 1.4

See Also:`getBounds()`

public void reset()

Reset the polygon to be empty. The arrays are left alone, to avoid object allocation, but the number of points is set to 0, and all cached data is discarded. If you are discarding a huge number of points, it may be more efficient to just create a new Polygon.

Since:- 1.4

See Also:`invalidate()`

public void translate(int dx, int dy)

Translates the polygon by adding the specified values to all X and Y coordinates. This updates the bounding box, if it has been calculated.

Parameters:`dx`

- the amount to add to all X coordinates`dy`

- the amount to add to all Y coordinates

Since:- 1.1

Polygon.java -- class representing a polygon
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