/* ===========================================================
* Orson Charts : a 3D chart library for the Java(tm) platform
* ===========================================================
*
* (C)opyright 2013-2016, by Object Refinery Limited. All rights reserved.
*
* http://www.object-refinery.com/orsoncharts/index.html
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* If you do not wish to be bound by the terms of the GPL, an alternative
* commercial license can be purchased. For details, please see visit the
* Orson Charts home page:
*
* http://www.object-refinery.com/orsoncharts/index.html
*
*/
package com.orsoncharts.renderer;
import java.awt.Color;
import com.orsoncharts.Range;
import com.orsoncharts.util.ArgChecks;
/**
* A color scale that returns all the colors of the rainbow. Instances of
* this class are immutable and serializable.
* <br><br>
* NOTE: This class is serializable, but the serialization format is subject
* to change in future releases and should not be relied upon for persisting
* instances of this class.
*
* @since 1.1
*/
@SuppressWarnings("serial")
public class RainbowScale extends AbstractColorScale implements ColorScale {
/**
* A range to include all hues. This can be used for the
* {@code hueSubrange} argument in the constructor.
*/
public static final Range ALL_HUES = new Range(0.0, 1.0);
/**
* A hue subrange that restricts colors to the blue to red range. This can
* be used for the {@code hueSubrange} argument in the constructor.
*/
public static final Range BLUE_TO_RED_RANGE = new Range(0.0, 0.6666);
/** Storage for the color samples. */
private Color[] colors;
/**
* The subrange of hues (useful to restrict the scale to the range from
* blue to red, which is common in charts).
*/
private Range hueSubrange;
/**
* Creates a new rainbow scale for the specified value range, with 256
* color samples in the blue to red range.
*
* @param range the range ({@code null} not permitted).
*/
public RainbowScale(Range range) {
this(range, 256, BLUE_TO_RED_RANGE);
}
/**
* Creates a new rainbow scale for the specified value range, with the
* given number of samples and hues restricted to the specified range.
*
* @param range the range ({@code null} not permitted).
* @param samples the number of samples.
* @param hueSubrange the hue sub-range.
*/
public RainbowScale(Range range, int samples, Range hueSubrange) {
super(range);
ArgChecks.nullNotPermitted(hueSubrange, "hueSubrange");
this.colors = new Color[samples];
this.hueSubrange = hueSubrange;
}
/**
* Returns the number of samples used by this color scale.
*
* @return The number of samples.
*/
public int getSampleCount() {
return this.colors.length;
}
/**
* Returns the sub-range of hues used in this scale.
*
* @return The sub-range of hues.
*/
public Range getHueSubrange() {
return this.hueSubrange;
}
/**
* Converts a value to a color on the scale.
*
* @param value the value.
*
* @return A color (never {@code null}).
*/
@Override
public Color valueToColor(double value) {
Range r = getRange();
if (value < r.getMin()) {
return valueToColor(r.getMin());
}
if (value > r.getMax()) {
return valueToColor(r.getMax());
}
double fraction = getRange().percent(value);
int i = (int) (fraction * (this.colors.length - 1));
if (this.colors[i] == null) {
this.colors[i] = createRainbowColor(fraction);
}
return this.colors[i];
}
/**
* Creates the rainbow color corresponding to the specified fraction along
* the scale range.
*
* @param fraction the fraction (0.0 to 1.0).
*
* @return The color.
*/
private Color createRainbowColor(double fraction) {
double inv = 1.0 - fraction;
double hue = this.hueSubrange.value(inv);
return Color.getHSBColor((float) hue, 1.0f, 1.0f);
}
/**
* Tests this color scale for equality with an arbitrary object.
*
* @param obj the object ({@code null} permitted).
*
* @return A boolean.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof RainbowScale)) {
return false;
}
RainbowScale that = (RainbowScale) obj;
if (this.colors.length != that.colors.length) {
return false;
}
if (!this.hueSubrange.equals(that.hueSubrange)) {
return false;
}
return super.equals(obj);
}
}