com.partnersoft.geometry
Class Polygon

java.lang.Object
  com.partnersoft.geometry.Polygon

public class Polygon
extends java.lang.Object

A single, DoubleBuffer-based polygon.

Author:

Paul Reavis Copyright 2002 Partner Software, Inc.

Field Summary

DoubleBuffer

coords

Constructor Summary

Polygon()

Polygon(DoubleBuffer buffy)

Polygon(int size)

Method Summary

void	addVertex(double x, double y)
Polygon	clipToLine(Line clipEdge) Clips along a single infinite edge.
Polygon	clipToRectangle(double minX, double minY, double maxX, double maxY) Clips the polygon to the given rectangle.
java.lang.Object	clone()
static boolean	containsDegenerateSegments(DoubleBuffer coords)
Point	getCentroid()
Rectangle	getExtents()
double	getLength()
int	getVertexCount()
boolean	isDegenerate()
static boolean	isDegenerate(DoubleBuffer coords)
boolean	isInside(double x, double y)
void	reduceDetail(double granularity)
static void	reduceDetail(DoubleBuffer coords, double granularity) Attempts to reduce the complexity of the line by eliminating points which add nothing to the detail at a certain granularity.
TriangleArray	tessellate() Converts the polygon into a set of triangles.
void	tessellate(TriangleArray results) Converts the polygon into a set of triangles.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

coords

public DoubleBuffer coords

Constructor Detail

Polygon

public Polygon()

Polygon

public Polygon(int size)

Polygon

public Polygon(DoubleBuffer buffy)

Method Detail

clone

public java.lang.Object clone()

Overrides:

clone in class java.lang.Object

reduceDetail

public final void reduceDetail(double granularity)

reduceDetail

public static final void reduceDetail(DoubleBuffer coords,
                                      double granularity)

Attempts to reduce the complexity of the line by eliminating points which add nothing to the detail at a certain granularity. Granularity is defined as a discretizing parameter - it sets up a grid of that cell size and points which fall into the same grid cell are regarded as identical. May reduce it to a single point, so watch out.

isDegenerate

public static final boolean isDegenerate(DoubleBuffer coords)

containsDegenerateSegments

public static final boolean containsDegenerateSegments(DoubleBuffer coords)

addVertex

public void addVertex(double x,
                      double y)

getCentroid

public final Point getCentroid()

getLength

public final double getLength()

getExtents

public final Rectangle getExtents()

isInside

public boolean isInside(double x,
                        double y)

getVertexCount

public int getVertexCount()

clipToRectangle

public Polygon clipToRectangle(double minX,
                               double minY,
                               double maxX,
                               double maxY)

Clips the polygon to the given rectangle. Returns zero or more polygons. Uses the Sutherland-Hodgman algorithm (Foley, van Dam et. al pg 128).

clipToLine

public Polygon clipToLine(Line clipEdge)

Clips along a single infinite edge. The edge is described as a line segment; anything to the left as you proceed from x1,y1 to x2,y2 is considered "inside". Also part of Sutherland-Hodgman algorithm.

isDegenerate

public final boolean isDegenerate()

tessellate

public TriangleArray tessellate()

Converts the polygon into a set of triangles.

tessellate

public void tessellate(TriangleArray results)

Converts the polygon into a set of triangles.