/*******************************************************************************
* Copyright (c) 2007, 2009 Wind River Systems and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Wind River Systems - initial API and implementation
*******************************************************************************/
package org.eclipse.cdt.dsf.debug.internal.ui.disassembly.util;
import org.eclipse.swt.graphics.RGB;
/**
* HSL (Hue, Saturation, Luminance) color model.
*/
public class HSL {
public double hue;
public double saturation;
public double luminance;
/**
* Create HSL from RGB.
*/
public HSL(RGB rgb) {
super();
double red = rgb.red / 255.0;
double green = rgb.green / 255.0;
double blue = rgb.blue / 255.0;
double cmax= Math.max(Math.max(red, green), blue);
double cmin= Math.min(Math.min(red, green), blue);
luminance = (cmax+cmin)/2;
if (cmax == cmin) {
hue = 0;
saturation = 0;
} else {
double delta = cmax-cmin;
if (luminance < 0.5) {
saturation = delta / (cmax + cmin);
} else {
saturation = delta / (2 - cmax - cmin);
}
if (red == cmax) {
hue = (green - blue) / delta;
} else if (green == cmax) {
hue = 2 + (blue - red) / delta;
} else {
hue = 4 + (red - green) / delta;
}
hue /= 6;
if (hue < 0) {
hue += 1;
} else if (hue > 1) {
hue -= 1;
}
}
}
public RGB toRGB() {
int red,green,blue;
if (saturation == 0) {
red = (int)Math.round(255*luminance);
green = red;
blue = red;
} else {
double m1, m2;
if (luminance <= 0.5) {
m2 = luminance * (1 + saturation);
} else {
m2 = luminance + saturation - luminance * saturation;
}
m1 = 2 * luminance - m2;
red = hueToColorValue(hue + 1./3., m1, m2);
green = hueToColorValue(hue, m1, m2);
blue = hueToColorValue(hue - 1./3., m1, m2);
}
return new RGB(red, green, blue);
}
private static int hueToColorValue(double hue, double m1, double m2) {
double v;
if (hue < 0) {
hue += 1;
} else if (hue > 1) {
hue -= 1;
}
if (6*hue < 1) {
v = m1 + (m2-m1) * hue * 6;
} else if (2*hue < 1) {
v = m2;
} else if (3*hue < 2) {
v = m1 + (m2-m1) * (2./3. - hue) * 6;
} else {
v = m1;
}
return (int)Math.round(255 * v);
}
/**
* Returns a string containing a concise, human-readable
* description of the receiver.
*
* @return a string representation of the <code>HSL</code>
*/
@Override
public String toString () {
return "HSL {" + hue + ", " + saturation + ", " + luminance + "}"; //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
}
}