Polygon (ocap 1.2 API)

java.lang.Object
- java.awt.Polygon

All Implemented Interfaces:

Shape, Serializable
```
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. This Polygon is defined with an even-odd winding rule. (The even-odd rule specifies that a point lies inside the path if a ray drawn in any direction from that point to infinity is crossed by path segments an odd number of times.) This class's hit-testing methods, which include the contains, intersects and inside methods, use the insideness definition described in the Shape class comments.

Since:

JDK1.0

Version:

1.26, 07/24/98

Author:

Sami Shaio, Herb Jellinek

See Also:
Shape, Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`protected Rectangle`	`bounds` Bounds of the polygon.
`int`	`npoints` The total number of points.
`int[]`	`xpoints` The array of x coordinates.
`int[]`	`ypoints` The array of y coordinates.

Constructor Summary

Constructors
Constructor and Description
`Polygon()` Creates an empty polygon.
`Polygon(int[] xpoints, int[] ypoints, int npoints)` Constructs and initializes a `Polygon` from the specified parameters.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addPoint(int x, int y)` Appends the specified coordinates to this `Polygon`.
`boolean`	`contains(int x, int y)` Determines whether the specified coordinates are inside this `Polygon`.
`boolean`	`contains(Point p)` Determines whether the specified `Point` is inside this `Polygon`.
`Rectangle`	`getBounds()` Gets the bounding box of this `Polygon`.
`void`	`invalidate()` Invalidates or flushes any internally-cached data that depends on the vertex coordinates of this `Polygon`.
`void`	`reset()` Resets this `Polygon` object to an empty polygon.
`void`	`translate(int deltaX, int deltaY)` Translates the vertices of the `Polygon` by `deltaX` along the x axis and by `deltaY` along the y axis.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - npoints
```
public int npoints
```
    The total number of points. The value of npoints represents the number of valid points in this Polygon and might be less than the number of elements in xpoints or ypoints. This value can be NULL.
    
    See Also:
    addPoint(int, int)
  - xpoints
```
public int[] xpoints
```
    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.
    
    See Also:
    addPoint(int, int)
  - ypoints
```
public int[] ypoints
```
    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.
    
    See Also:
    addPoint(int, int)
  - bounds
```
protected Rectangle bounds
```
    Bounds of the polygon. This value can be NULL. Please see the javadoc comments getBounds().
    
    See Also:
    getBounds()
- Constructor Detail
  - 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.
    
    IndexOutOfBoundsException - if npoints is greater than the length of xpoints or the length of ypoints.
    
    NullPointerException - if xpoints or ypoints is null.
- Method Detail
  - reset
```
public void reset()
```
    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.
    
    Since:
    
    1.4
    
    See Also:
    invalidate()
  - invalidate
```
public void invalidate()
```
    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.
    
    Since:
    
    1.4
    
    See Also:
    getBounds()
  - translate
```
public void translate(int deltaX,
             int deltaY)
```
    Translates the vertices of the Polygon 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
    Since:
    
    JDK1.1
  - addPoint
```
public void addPoint(int x,
            int y)
```
    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.
    
    Parameters:
    x - the specified x coordinate
    y - the specified y coordinate
    See Also:
    getBounds(), contains(java.awt.Point)
  - 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 can completely contain the Polygon.
    
    Specified by:
    
    getBounds in interface Shape
    
    Returns:
    a Rectangle that defines the bounds of this Polygon.
    Since:
    
    JDK1.1
  - contains
```
public boolean contains(Point p)
```
    Determines whether the specified Point is inside this Polygon.
    
    Parameters:
    p - the specified Point to be tested
    
    Returns:
    true if the Polygon contains the Point; false otherwise.
  - contains
```
public boolean contains(int x,
               int y)
```
    Determines whether the specified coordinates are inside this Polygon.
    
    Parameters:
    x - the specified x coordinate to be tested
    y - the specified y coordinate to be tested
    
    Returns:
    true if this Polygon contains the specified coordinates, (x, y); false otherwise.
    Since:
    
    JDK1.1

Class Polygon

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

npoints

xpoints

ypoints

bounds

Constructor Detail

Polygon

Polygon

Method Detail

reset

invalidate

translate

addPoint

getBounds

contains

contains