content: /**
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.lucene.spatial.geometry.shape;
  
  
  /**
   * 2D vector
   *
   * <p><font color="red"><b>NOTE:</b> This API is still in
   * flux and might change in incompatible ways in the next
   * release.</font>
   */
  public class Vector2D {
    private double x;
    private double y;
  
    /**
     * Create a vector from the origin of the coordinate system to the given
     * point
     * 
     * @param x
     * @param y
     */
    public Vector2D(double x, double y) {
      this.x = x;
      this.y = y;
    }
  
    /**
     * Create a vector from the origin of the coordinate system to the given
     * point
     */
    public Vector2D(Point2D p) {
      this(p.getX(), p.getY());
    }
  
    /**
     * Create a vector from one point to another
     * 
     * @param from
     * @param to
     */
    public Vector2D(Point2D from, Point2D to) {
      this(to.getX() - from.getX(), to.getY() - from.getY());
    }
  
    public Vector2D() {
      this.x = 0;
      this.y = 0;
    }
  
    public Vector2D(Vector2D other) {
      this.x = other.x;
      this.y = other.y;
    }
  
    public double getX() {
      return x;
    }
  
    public double getY() {
      return y;
    }
  
    public void setX(double x) {
      this.x = x;
    }
  
    public void setY(double y) {
      this.y = y;
    }
  
    public void set(double x, double y) {
      this.x = x;
      this.y = y;
    }
  
    public boolean equals(Vector2D other) {
      return other != null && x == other.x && y == other.y;
    }
  
    public double dot(Vector2D in) {
      return ((x) * in.x) + (y * in.y);
    }
  
    /**
     * Vector length (magnitude) squared
     */
    public double normSqr() {
      // Cast to F to prevent overflows
      return (x * x) + (y * y);
    }
  
    public double norm() {
      return Math.sqrt(normSqr());
    }
  
    public Vector2D mult(double d) {
      return new Vector2D(x*d, y*d);
    }
  
    @Override
    public int hashCode() {
      final int prime = 31;
      int result = 1;
      long temp;
      temp = Double.doubleToLongBits(x);
      result = prime * result + (int) (temp ^ (temp >>> 32));
      temp = Double.doubleToLongBits(y);
      result = prime * result + (int) (temp ^ (temp >>> 32));
      return result;
    }
  
    @Override
    public boolean equals(Object obj) {
      if (this == obj)
        return true;
      if (obj == null)
        return false;
      if (getClass() != obj.getClass())
        return false;
      Vector2D other = (Vector2D) obj;
      if (Double.doubleToLongBits(x) != Double.doubleToLongBits(other.x))
        return false;
      if (Double.doubleToLongBits(y) != Double.doubleToLongBits(other.y))
        return false;
      return true;
    }
    
  }
  