Name: tb29552 Date: 01/17/2000


java version "1.2.2"
HotSpot VM (1.0.1, mixed mode, build c)

java.awt.Polygon.xpoints (or .ypoints) has more elements than the npoints. The extra
points have all (0,0) coordinate. If this is intentional (to provide extra
reserve space ), it should have been stated in the API-documentation for
java.awt.Polygon

Example:

import java.awt.*;

public class PolygonTest {
    // MAIN
    public static void main(String[] args) {
        // possible corners of the polygon
        int n = 0;

        if(args.length>0){
            try{
                n = (new Integer(args[0])).intValue();
            } catch(Exception e){
                prt("can't convert it to int...");
                prt("integer expected. ");
            }
        }

        // minimum 3 sides
        n = (n<2) ? 3:n;

        // an empty polygon
        Polygon pol = new Polygon();
        // populated with n corners
        for(int i=0;i<n;i++){
            pol.addPoint(i+1,i+1);
        }

        // npoints is correct
        prt("There are "+n+" sides. (npoints)" );
        // x- and y-coordinates
        int [] x = pol.xpoints;
        int [] y = pol.ypoints;
        // should this not be equal to n?
        int m = x.length;
        prt("xpoints.length = "+m+" !");

        // printing the coordinates of the polygon
        // where do the extra corners with (0,0) come from?
        for(int i=0;i<m;i++){
            prt("Node "+i+": X="+x[i]+" Y="+y[i]);
        }
    }

    // println
    public static void prt(String s){
        System.out.println(s);
    }
}
(Review ID: 99960)
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