Returns the RGB equivalent of a given HSL (Hue/Saturation/Luminance) color. - Java 2D Graphics

Java examples for 2D Graphics:Color RGB

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Description

Returns the RGB equivalent of a given HSL (Hue/Saturation/Luminance) color.

Demo Code

/*/*from  ww  w .ja v  a 2 s. c o m*/
 * This is a fork of GHEAT_JAVA https://github.com/varunpant/GHEAT-JAVA
 * <p>
 * The MIT License
 * <p>
 * Copyright (c) 2014 Varun Pant
 * <p>
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 * <p>
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 * <p>
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * <p>
 */
//package com.java2s;
import java.awt.*;

public class Main {
    public static void main(String[] argv) throws Exception {
        float h = 2.45678f;
        float s = 2.45678f;
        float l = 2.45678f;
        System.out.println(HSLtoRGB(h, s, l));
    }

    /**
     * <p>Returns the RGB equivalent of a given HSL (Hue/Saturation/Luminance)
     * color.</p>
     *
     * @param h the hue component, between 0.0 and 1.0
     * @param s the saturation component, between 0.0 and 1.0
     * @param l the luminance component, between 0.0 and 1.0
     * @return a new <code>Color</code> object equivalent to the HSL components
     */
    public static Color HSLtoRGB(float h, float s, float l) {
        int[] rgb = HSLtoRGB(h, s, l, null);
        return new Color(rgb[0], rgb[1], rgb[2]);
    }

    /**
     * <p>Returns the RGB equivalent of a given HSL (Hue/Saturation/Luminance)
     * color. All three RGB components are integers between 0 and 255.</p>
     *
     * @param h   the hue component, between 0.0 and 1.0
     * @param s   the saturation component, between 0.0 and 1.0
     * @param l   the luminance component, between 0.0 and 1.0
     * @param rgb a pre-allocated array of ints; can be null
     * @return <code>rgb</code> if non-null, a new array of 3 ints otherwise
     * @throws IllegalArgumentException if <code>rgb</code> has a length lower
     *                                  than 3
     */
    public static int[] HSLtoRGB(float h, float s, float l, int[] rgb) {
        if (rgb == null) {
            rgb = new int[3];
        } else if (rgb.length < 3) {
            throw new IllegalArgumentException(
                    "rgb array must have a length of" + " at least 3");
        }

        if (h < 0)
            h = 0.0f;
        else if (h > 1.0f)
            h = 1.0f;
        if (s < 0)
            s = 0.0f;
        else if (s > 1.0f)
            s = 1.0f;
        if (l < 0)
            l = 0.0f;
        else if (l > 1.0f)
            l = 1.0f;

        int R, G, B;

        if (s - 0.01f <= 0.0f) {
            R = (int) (l * 255.0f);
            G = (int) (l * 255.0f);
            B = (int) (l * 255.0f);
        } else {
            float var_1, var_2;
            if (l < 0.5f) {
                var_2 = l * (1 + s);
            } else {
                var_2 = (l + s) - (s * l);
            }
            var_1 = 2 * l - var_2;

            R = (int) (255.0f * hue2RGB(var_1, var_2, h + (1.0f / 3.0f)));
            G = (int) (255.0f * hue2RGB(var_1, var_2, h));
            B = (int) (255.0f * hue2RGB(var_1, var_2, h - (1.0f / 3.0f)));
        }

        rgb[0] = R;
        rgb[1] = G;
        rgb[2] = B;

        return rgb;
    }

    private static float hue2RGB(float v1, float v2, float vH) {
        if (vH < 0.0f) {
            vH += 1.0f;
        }
        if (vH > 1.0f) {
            vH -= 1.0f;
        }
        if ((6.0f * vH) < 1.0f) {
            return (v1 + (v2 - v1) * 6.0f * vH);
        }
        if ((2.0f * vH) < 1.0f) {
            return (v2);
        }
        if ((3.0f * vH) < 2.0f) {
            return (v1 + (v2 - v1) * ((2.0f / 3.0f) - vH) * 6.0f);
        }
        return (v1);
    }
}

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