Package ij.process

Class FloatPolygon

java.lang.Object

ij.process.FloatPolygon

public class FloatPolygon
extends Object

Used by the Roi classes to return float coordinate arrays and to determine if a point is inside or outside of spline fitted selections.

Field Summary

Fields

Modifier and Type	Field	Description
int	npoints	The number of points.
float[]	xpoints
float[]	ypoints

Constructor Summary

Constructors

Constructor	Description
FloatPolygon()	Constructs an empty FloatPolygon.
FloatPolygon(float[] xpoints, float[] ypoints)	Constructs a FloatPolygon from x and y arrays.
FloatPolygon(float[] xpoints, float[] ypoints, int npoints)	Constructs a FloatPolygon from x and y arrays.

Method Summary

Modifier and Type	Method	Description
void	addPoint(double x, double y)
void	addPoint(float x, float y)
boolean	contains(double x, double y)	Returns 'true' if the point (x,y) is inside this polygon.
FloatPolygon	duplicate()
Rectangle	getBounds()
FloatPolygon	getConvexHull()	Uses the gift wrap algorithm to find the convex hull of all points in this FloatPolygon and returns it as a new FloatPolygon.
Rectangle2D.Double	getFloatBounds()
double	getLength(boolean isLine)
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

npoints

public int npoints

The number of points.

xpoints

public float[] xpoints

ypoints

public float[] ypoints

Constructor Detail

FloatPolygon

public FloatPolygon()

Constructs an empty FloatPolygon.

FloatPolygon

public FloatPolygon(float[] xpoints,
                    float[] ypoints)

Constructs a FloatPolygon from x and y arrays.

FloatPolygon

public FloatPolygon(float[] xpoints,
                    float[] ypoints,
                    int npoints)

Constructs a FloatPolygon from x and y arrays.

Method Detail

contains

public boolean contains(double x,
                        double y)

Returns 'true' if the point (x,y) is inside this polygon. This is a Java version of the remarkably small C program by W. Randolph Franklin at http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html#The%20C%20Code In the absence of numerical errors, x coordinates exactly at a boundary are taken as if in the area immediately at the left of the boundary. For horizontal boundaries, y coordinates exactly at the border are taken as if in the area immediately above it (i.e., in decreasing y direction). The ImageJ convention of an offset of 0.5 pixels between pixel centers and outline coordinates is not taken into consideration; this method returns the purely geometrical relationship.

getBounds

public Rectangle getBounds()

getFloatBounds

public Rectangle2D.Double getFloatBounds()

addPoint

public void addPoint(float x,
                     float y)

addPoint

public void addPoint(double x,
                     double y)

duplicate

public FloatPolygon duplicate()

getLength

public double getLength(boolean isLine)

getConvexHull

public FloatPolygon getConvexHull()

Uses the gift wrap algorithm to find the convex hull of all points in this FloatPolygon and returns it as a new FloatPolygon. The sequence of the points on the convex hull is counterclockwise.

toString

public String toString()

Overrides:

toString in class Object