Eclipse Draw2d
3.3

org.eclipse.draw2d.geometry
Class Geometry

java.lang.Object
  extended by org.eclipse.draw2d.geometry.Geometry

public class Geometry
extends Object

A Utilities class for geometry operations.

Since:
3.1

Constructor Summary
Geometry()
           
 
Method Summary
static boolean linesIntersect(int ux, int uy, int vx, int vy, int sx, int sy, int tx, int ty)
          Determines whether the two line segments formed by the given coordinates intersect.
static boolean polygonContainsPoint(PointList points, int x, int y)
          One simple way of finding whether the point is inside or outside a simple polygon is to test how many times a ray starting from the point intersects the edges of the polygon.
static boolean polylineContainsPoint(PointList points, int x, int y, int tolerance)
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Geometry

public Geometry()
Method Detail

linesIntersect

public static boolean linesIntersect(int ux,
                                     int uy,
                                     int vx,
                                     int vy,
                                     int sx,
                                     int sy,
                                     int tx,
                                     int ty)
Determines whether the two line segments formed by the given coordinates intersect. If one of the two line segments starts or ends on the other line, then they are considered to be intersecting.

Parameters:
ux - x coordinate of starting point of line 1
uy - y coordinate of starting point of line 1
vx - x coordinate of ending point of line 1
vy - y coordinate of endpoing point of line 1
sx - x coordinate of the starting point of line 2
sy - y coordinate of the starting point of line 2
tx - x coordinate of the ending point of line 2
ty - y coordinate of the ending point of line 2
Returns:
true if the two line segments formed by the given coordinates cross
Since:
3.1

polylineContainsPoint

public static boolean polylineContainsPoint(PointList points,
                                            int x,
                                            int y,
                                            int tolerance)
Since:
3.5
See Also:
PointList.polylineContainsPoint(int, int, int)

polygonContainsPoint

public static boolean polygonContainsPoint(PointList points,
                                           int x,
                                           int y)
One simple way of finding whether the point is inside or outside a simple polygon is to test how many times a ray starting from the point intersects the edges of the polygon. If the point in question is not on the boundary of the polygon, the number of intersections is an even number if the point is outside, and it is odd if inside.

Since:
3.5
See Also:
PointList.polygonContainsPoint(int, int)

Eclipse Draw2d
3.3

Copyright (c) IBM Corp. and others 2000, 2007. All Rights Reserved.