/*
* Copyright (c) 2008, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
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*/
package javax.swing.colorchooser;
final class ColorModelHSL extends ColorModel {
ColorModelHSL() {
super("hsl", "Hue", "Saturation", "Lightness", "Transparency"); // NON-NLS: components
}
@Override
void setColor(int color, float[] space) {
super.setColor(color, space);
RGBtoHSL(space, space);
space[3] = 1.0f - space[3];
}
@Override
int getColor(float[] space) {
space[3] = 1.0f - space[3];
HSLtoRGB(space, space);
return super.getColor(space);
}
@Override
int getMaximum(int index) {
return (index == 0) ? 360 : 100;
}
@Override
float getDefault(int index) {
return (index == 0) ? -1.0f : (index == 2) ? 0.5f : 1.0f;
}
/**
* Converts HSL components of a color to a set of RGB components.
*
* @param hsl a float array with length equal to
* the number of HSL components
* @param rgb a float array with length of at least 3
* that contains RGB components of a color
* @return a float array that contains RGB components
*/
private static float[] HSLtoRGB(float[] hsl, float[] rgb) {
if (rgb == null) {
rgb = new float[3];
}
float hue = hsl[0];
float saturation = hsl[1];
float lightness = hsl[2];
if (saturation > 0.0f) {
hue = (hue < 1.0f) ? hue * 6.0f : 0.0f;
float q = lightness + saturation * ((lightness > 0.5f) ? 1.0f - lightness : lightness);
float p = 2.0f * lightness - q;
rgb[0]= normalize(q, p, (hue < 4.0f) ? (hue + 2.0f) : (hue - 4.0f));
rgb[1]= normalize(q, p, hue);
rgb[2]= normalize(q, p, (hue < 2.0f) ? (hue + 4.0f) : (hue - 2.0f));
}
else {
rgb[0] = lightness;
rgb[1] = lightness;
rgb[2] = lightness;
}
return rgb;
}
/**
* Converts RGB components of a color to a set of HSL components.
*
* @param rgb a float array with length of at least 3
* that contains RGB components of a color
* @param hsl a float array with length equal to
* the number of HSL components
* @return a float array that contains HSL components
*/
private static float[] RGBtoHSL(float[] rgb, float[] hsl) {
if (hsl == null) {
hsl = new float[3];
}
float max = max(rgb[0], rgb[1], rgb[2]);
float min = min(rgb[0], rgb[1], rgb[2]);
float summa = max + min;
float saturation = max - min;
if (saturation > 0.0f) {
saturation /= (summa > 1.0f)
? 2.0f - summa
: summa;
}
hsl[0] = getHue(rgb[0], rgb[1], rgb[2], max, min);
hsl[1] = saturation;
hsl[2] = summa / 2.0f;
return hsl;
}
/**
* Returns the smaller of three color components.
*
* @param red the red component of the color
* @param green the green component of the color
* @param blue the blue component of the color
* @return the smaller of {@code red}, {@code green} and {@code blue}
*/
static float min(float red, float green, float blue) {
float min = (red < green) ? red : green;
return (min < blue) ? min : blue;
}
/**
* Returns the larger of three color components.
*
* @param red the red component of the color
* @param green the green component of the color
* @param blue the blue component of the color
* @return the larger of {@code red}, {@code green} and {@code blue}
*/
static float max(float red, float green, float blue) {
float max = (red > green) ? red : green;
return (max > blue) ? max : blue;
}
/**
* Calculates the hue component for HSL and HSV color spaces.
*
* @param red the red component of the color
* @param green the green component of the color
* @param blue the blue component of the color
* @param max the larger of {@code red}, {@code green} and {@code blue}
* @param min the smaller of {@code red}, {@code green} and {@code blue}
* @return the hue component
*/
static float getHue(float red, float green, float blue, float max, float min) {
float hue = max - min;
if (hue > 0.0f) {
if (max == red) {
hue = (green - blue) / hue;
if (hue < 0.0f) {
hue += 6.0f;
}
}
else if (max == green) {
hue = 2.0f + (blue - red) / hue;
}
else /*max == blue*/ {
hue = 4.0f + (red - green) / hue;
}
hue /= 6.0f;
}
return hue;
}
private static float normalize(float q, float p, float color) {
if (color < 1.0f) {
return p + (q - p) * color;
}
if (color < 3.0f) {
return q;
}
if (color < 4.0f) {
return p + (q - p) * (4.0f - color);
}
return p;
}
}