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	/*
	* 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
	* questions.
	*/

	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;
	}
	}

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