/*
 * ome.util.math.geom2D.EllipseAreaAdapter
 *
 *   Copyright 2006 University of Dundee. All rights reserved.
 *   Use is subject to license terms supplied in LICENSE.txt
 */

package ome.util.math.geom2D;

import java.awt.Rectangle;
import java.awt.geom.Ellipse2D;
import java.util.ArrayList;

/**
 * This following class is the <code>body</code> of the
 * {@link EllipseArea handle}.
 * 
 * @author Jean-Marie Burel      <a
 *         href="mailto:j.burel@dundee.ac.uk">j.burel@dundee.ac.uk</a>
 * @author <br>
 *         Andrea Falconi      <a
 *         href="mailto:a.falconi@dundee.ac.uk"> a.falconi@dundee.ac.uk</a>
 * @version 2.2 <small> (<b>Internal version:</b> $Revision$ $Date:
 *          2005/06/09 15:01:32 $) </small>
 * @since OME2.2
 */
class EllipseAreaAdapter extends Ellipse2D.Float implements PlaneArea {

    /** Space used to determine if a point is on the boundaries. */
    private static double epsilon = 1.0;

    /**
     * Creates a new instance.
     * 
     * @param x
     *            The x-coordinate of the top-left corner.
     * @param y
     *            The y-coordinate of the top-left corner.
     * @param width
     *            The width of the ellipse.
     * @param height
     *            The height of the ellipse.
     */
    EllipseAreaAdapter(float x, float y, float width, float height) {
        super(x, y, width, height);
    }

    /**
     * Implemented as specified in the {@link PlaneArea} I/F.
     * 
     * @see PlaneArea#scale(double)
     */
    public void scale(double factor) {
        Rectangle r = getBounds();
        setFrame((int) (r.x * factor), (int) (r.y * factor),
                (int) (r.width * factor), (int) (r.height * factor));
    }

    /**
     * Implemented as specified in the {@link PlaneArea} I/F.
     * 
     * @see PlaneArea#getPoints()
     */
    public PlanePoint[] getPoints() {
        Rectangle r = getBounds();
        ArrayList vector = new ArrayList(r.height * r.width);
        int xEnd = r.x + r.width, yEnd = r.y + r.height;
        int x, y;
        for (y = r.y; y < yEnd; ++y) {
            for (x = r.x; x < xEnd; ++x) {
                if (contains(x, y)) {
                    vector.add(new PlanePoint(x, y));
                }
            }
        }
        return (PlanePoint[]) vector.toArray(new PlanePoint[vector.size()]);
    }

    /**
     * Implemented as specified in the {@link PlaneArea} I/F.
     * 
     * @see PlaneArea#setBounds(int, int, int, int)
     */
    public void setBounds(int x, int y, int width, int height) {
        setFrame(x, y, width, height);
    }

    /**
     * Implemented as specified in the {@link PlaneArea} I/F. The equation of an
     * ellipse is of the form
     * <p>
     * ((x-x0)/a)^2+((y-y0)/b)^2 = 1
     * </p>
     * where a = getWidth()/2, b = getHeight()/2, x0 = getX()+a, y0 = getY()+b.
     * 
     * @see PlaneArea#onBoundaries(double, double)
     */
    public boolean onBoundaries(double x, double y) {
        double wEps = getWidth() + 2 * epsilon, hEps = getHeight() + 2
                * epsilon;
        if (wEps <= 0.0 || hEps <= 0) {
            return false;
        }
        double normx = (x - getX()) / wEps - getWidth() / (2 * wEps);
        double normy = (y - getY()) / hEps - getHeight() / (2 * hEps);
        return normx * normx + normy * normy <= 0.25 && !contains(x, y);
    }

    /**
     * Implemented as specified in the {@link ome.util.mem.Copiable Copiable}
     * I/F.
     * 
     * @see ome.util.mem.Copiable#copy()
     */
    public Object copy() {
        return super.clone();
    }

}