Module ij
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. Use the public 'xpoints' and 'ypoints' fields to access the coordinates and the 'npoints' field to determine the number of points.

  • Field Details

    • npoints

      public int npoints
      The number of points in the 'xpoints' and 'ypoints' arrays.

    • xpoints

      public float[] xpoints

    • ypoints

      public float[] ypoints

  • Constructor Details

    • 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 Details

    • 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.

    • contains

      public boolean contains(float x, float y)
      A version of contains() that accepts float arguments.

    • 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.

    • translate

      public void translate(double x, double y)

    • toString

      public String toString()
      Overrides:
      toString in class Object