arrow2d.java

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/**
 * Copyright (C) 2004 C. Schalkwijk, Response B.V.
 *
 * [e-mail]
 * Response B.V
 * Jagersbosstraat 26
 * 5241 JT Rosmalen
 * THE NETHERLANDS
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this library;
 * if not, write to the
 *
 * Free Software Foundation, Inc.,
 * 59 Temple Place,
 * Suite 330,
 * Boston,
 * MA 02111-1307 USA
 *
 * Response B.V., hereby disclaims all copyright interest in the library 'DeSL'
 * (a developer support library) written by Coen Schalkwijk.
 *
 * H. Houet, Director of Response B.V.
 * 27th April 2004
 * (hard copy of the disclaimer in possession of C. Schalkwijk)
 *
 */


package desl.graphic.geom;

import java.awt.Polygon;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.PathIterator;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.awt.geom.Line2D;

import java.io.Serializable;

/**
 * Line ending with an arrow.</P>
 *
 * <b>TODO</b> Add arrow to both sides, includes dynamic iterator (point count differs if arrow has two heads).<BR>
 * <b>TODO</b> Add settings for arrow stile<BR>
 * <b>TODO</b> Add double/float precision implementations.<BR>
 * <BR>
 * <b>Change history</b><br>
 * [ 2004-09-27 ] C. Schalkwijk	- Initial setup.<BR>
 * [ 2004-09-28 ] C. Schalkwijk	- Shape is a full polygon, removed final identifier<BR>
 * <BR>
 * @author C. Schalkwijk
 * @version 0.2
 *
 */
public class Arrow2D
    implements Shape, java.io.Serializable {

  private double x1 = 0;
  private double y1 = 0;
  private double x2 = 0;
  private double y2 = 0;
  public Shape head = null;
  public Shape tail = null;
   public Shape head2 = null;
  private Shape arrow = null;

  /**
   *
   */
  public Arrow2D(Point2D begin, Point2D end) {
    this.x1 = begin.getX();
    this.y1 = begin.getY();
    this.x2 = end.getX();
    this.y2 = end.getY();
    this.initArrow();

  }

  /**
   *
   * @param x1
   * @param y1
   * @param x2
   * @param y2
   * @return
   */
  protected double calcAngle(float x1, float y1, float x2, float y2) {
    double rad = 0.0d;
    float dx = x2 - x1;
    float dy = y2 - y1;

    if (dx == 0.0) {
      if (dy == 0.0) {
        rad = 0.0;
      }
      else if (dy > 0.0) {
        rad = Math.PI / 2.0;
      }
      else {
        rad = Math.PI * 3.0 / 2.0;
      }
    }
    else if (dy == 0.0) {
      if (dx > 0.0) {
        rad = 0.0;
      }
      else {
        rad = Math.PI;
      }
    }
    else {
      if (dx < 0.0) {
        rad = Math.atan(dy / dx) + Math.PI;
      }
      else if (dy < 0.0) {
        rad = Math.atan(dy / dx) + (2 * Math.PI);
      }
      else {
        rad = Math.atan(dy / dx);
      }
    }

    return rad;
  }

  /**
   *
   *
   */
  private void initArrow() {
    int length = (int) Math.sqrt(Math.pow(Math.abs(x1 - x2), 2) +
                                 Math.pow(Math.abs(y1 - y2), 2));

    Polygon poly = new Polygon();
    poly.addPoint( (int) x1, (int) y1);
    poly.addPoint( (int) x1 + length, (int) y1);
    Polygon poly2 = new Polygon();
    poly2.addPoint( (int) x1 + length - 10, (int) y1 - 5);
    poly2.addPoint( (int) x1 + length, (int) y1);
    poly2.addPoint( (int) x1 + length - 10, (int) y1 + 5);
    poly2.addPoint( (int) x1 + length - 10, (int) y1 - 5);
    Polygon poly3 = new Polygon();
    poly2.addPoint( (int) x1 + 10, (int) y1 - 5);
    poly2.addPoint( (int) x1 , (int) y1);
    poly2.addPoint( (int) x1 + 10, (int) y1 + 5);
    poly2.addPoint( (int) x1 + 10, (int) y1 - 5);

    double rad = this.calcAngle( (float)this.x1, (float)this.y1, (float)this.x2, (float)this.y2);
    AffineTransform tx = AffineTransform.getRotateInstance(rad, x1, y1);

    this.arrow = tx.createTransformedShape( (Shape) poly);
    this.tail = tx.createTransformedShape( (Shape) poly);
    this.head = tx.createTransformedShape( (Shape) poly2);
    this.head2 = tx.createTransformedShape( (Shape) poly3);
  }

  /**
   *
   * @return
   */
  public Shape getArrow() {
    return this.arrow;
  }

  /**
   *
   */
  public Rectangle2D getBounds2D() {
    double x, y, w, h;

    if (x1 < x2) {
      x = x1;
      w = x2 - x1;
    }
    else {
      x = x2;
      w = x1 - x2;
    }
    if (y1 < y2) {
      y = y1;
      h = y2 - y1;
    }
    else {
      y = y2;
      h = y1 - y2;
    }
    return new Rectangle2D.Double(x, y, w, h);
  }

  /**
   *
   */
  public Rectangle getBounds() {
    return this.getBounds2D().getBounds();
  }

  /**
   *
   */
  public boolean contains(double x, double y) {
    return this.tail.contains(x, y) || this.head.contains(x, y)|| this.head2.contains(x, y);
  }

  /**
   *
   */
  public boolean contains(double x, double y, double w, double h) {
    return this.tail.contains(x, y, w, h) || this.head.contains(x, y, w, h)|| this.head2.contains(x, y, w, h);
  }

  /**
   *
   */
  public boolean intersects(double x, double y, double w, double h) {
    return this.tail.intersects(x, y, w, h) || this.head.intersects(x, y, w, h)||this.head2.intersects(x, y, w, h);
  }

  /**
   *
   */
  public boolean contains(Point2D p) {
    return this.tail.contains(p) || this.head.contains(p)|| this.head2.contains(p);
  }

  /**
   *
   */
  public boolean contains(Rectangle2D r) {

    return this.tail.contains(r) || this.head.contains(r)|| this.head2.contains(r);
  }

  /**
   *
   */
  public boolean intersects(Rectangle2D r) {
    return this.tail.intersects(r) || this.head.intersects(r)|| this.head2.intersects(r);
  }

  /**
   *
   */
  public PathIterator getPathIterator(AffineTransform at) {
    return new ArrowIterator(this, at);
  }

  /**
   *
   */
  public PathIterator getPathIterator(AffineTransform at, double flatness) {
    return new ArrowIterator(this, at);
  }

  public double getX1() {
    return this.x1;
  }

  public double getY1() {
    return this.y1;
  }

  public Point2D getP1() {
    return null;
  }

  public double getX2() {
    return this.x2;
  }

  public double getY2() {
    return this.y2;
  }

  public Point2D getP2() {
    return null;
  }

}