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§1.35 Class Polygon
public class java.awt.Polygon
extends java.lang.Object (I-§1.12)
{
// Fields
public int npoints; §1.35.1
public int xpoints[]; §1.35.2
public int ypoints[]; §1.35.3
// Constructors
public Polygon(); §1.35.4
public Polygon(int xpoints[], int ypoints[], §1.35.5
int npoints);
// Methods
public void addPoint(int x, int y); §1.35.6
public Rectangle getBoundingBox(); §1.35.7
public boolean inside(int x, int y); §1.35.8
}
A polygon consists of a list of
, where each successive pair of coordinates defines a
side of the polygon
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.
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
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 (getBoundingBox (II-§1.35.7) or inside (II-§1.35.8)) has already been performed, this
method updates the bounding box.
- Parameters:
x
- the x coordinate of the point
y
- the y coordinate of the point
getBoundingBox
public Rectangle getBoundingBox()
- Returns:
- the smallest rectangle than contains this polygon
inside
public boolean inside(int x, int y)
- Determines if the specified point is inside this polygon. This method uses
an even-odd insideness rule (also known as an "alternating rule") to determine whether the pont
is inside this polygon.
- It is based on code by Hanpeter van Vliet (hvvliet@inter.nl.net).
- Parameters:
x
- the xcoordinate of the point to be tested
y
- the y coordinate of the point to be tested
- Returns:
- true if the point
is inside this polygon; false otherwise.
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Java API Document (HTML generated by dkramer on April 22, 1996)
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