content: // ===============================================================================
  // Authors: AFRL/RQQD
  // Organization: Air Force Research Laboratory, Aerospace Systems Directorate, Power and Control Division
  // 
  // Copyright (c) 2017 Government of the United State of America, as represented by
  // the Secretary of the Air Force.  No copyright is claimed in the United States under
  // Title 17, U.S. Code.  All Other Rights Reserved.
  // ===============================================================================
  
  /*
   * GRAL: GRAphing Library for Java(R)
   *
   * (C) Copyright 2009-2013 Erich Seifert <dev[at]erichseifert.de>,
   * Michael Seifert <mseifert[at]error-reports.org>
   *
   * This file is part of GRAL.
   *
   * GRAL 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 3 of the License, or
   * (at your option) any later version.
   *
   * GRAL 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 GRAL.  If not, see <http://www.gnu.org/licenses/>.
   */
  package de.erichseifert.gral.plots.colors;
  
  
  /**
   * An abstract base class for implementations of {@code ContinuousColorMapper}
   * that allow to apply a a scaling factor to the values passed to
   * {@link #get(double)}.
   */
  public abstract class ScaledContinuousColorMapper
  		extends ContinuousColorMapper {
  	/** Version id for serialization. */
  	private static final long serialVersionUID = 323911118647457851L;
  
  	/** Offset. **/
  	private double offset;
  	/** Scaling factor. **/
  	private double scale;
  
  	/**
  	 * Default constructor that initializes a new instance with a default
  	 * offset of 0.0 and a scale of 1.0.
  	 */
  	public ScaledContinuousColorMapper() {
  		this(0.0, 1.0);
  	}
  
  	/**
  	 * Constructor that initializes a new instance with a specified offset and
  	 * scaling factor.
  	 * @param offset Offset.
  	 * @param scale Scaling factor.
  	 */
  	public ScaledContinuousColorMapper(double offset, double scale) {
  		this.offset = offset;
  		this.scale = scale;
  	}
  
  	/**
  	 * Returns the current offset value.
  	 * @return Offset value.
  	 */
  	public double getOffset() {
  		return offset;
  	}
  
  	/**
  	 * Sets a new offset value.
  	 * @param offset Offset value.
  	 */
  	public void setOffset(double offset) {
  		this.offset = offset;
  	}
  
  	/**
  	 * Returns the current scaling factor.
  	 * @return Scaling factor.
  	 */
  	public double getScale() {
  		return scale;
  	}
  
  	/**
  	 * Sets a new scaling factor for passed values.
  	 * @param scale Scaling factor.
  	 */
  	public void setScale(double scale) {
  		this.scale = scale;
  	}
  
  	/**
  	 * Sets offset and scale based on start and end values.
  	 * @param start Start value.
  	 * @param end End value.
  	 */
  	public void setRange(double start, double end) {
  		setOffset(start);
  		setScale(end - start);
  	}
  
  	/**
  	 * Linearly transforms a value using offset and scale.
  	 * @param value Original value.
  	 * @return Transformed value.
  	 */
  	protected Double scale(double value) {
  		return (value - getOffset())/getScale();
  	}
  
  	@Override
  	public boolean equals(Object obj) {
  		if (!(obj instanceof ScaledContinuousColorMapper)) {
  			return false;
  		}
  		ScaledContinuousColorMapper cm = (ScaledContinuousColorMapper) obj;
  		return getOffset() == cm.getOffset() && getScale() == cm.getScale()
  			&& getMode() == cm.getMode();
  	}
  
  	@Override
  	public int hashCode() {
  		long bits = Double.doubleToLongBits(getOffset());
  		bits ^= Double.doubleToLongBits(getScale()) * 31;
  		return ((int) bits) ^ ((int) (bits >> 32));
  	}
  }
  