set the luminosity of a color ARGB value - Android Graphics

Android examples for Graphics:Color RGB Value

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Description

set the luminosity of a color ARGB value

Demo Code

/*******************************************************************************
 * Copyright (c) 2011 MadRobot.//from w  w w  . j  a va  2s. c o m
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v2.1
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * 
 * Contributors:
 *  Elton Kent - initial API and implementation
 ******************************************************************************/
//package com.java2s;

public class Main {
    /**
     * set the luminosity of a ARGB value
     * 
     * @param color
     *            argb value
     * @param percent
     *            percent always less than or equal to 100
     * @return
     */
    public static int setLuminosity(int color, int percent) {
        int a = (color >> 24) & 0xff;
        int r = (color >> 16) & 0xff;
        int g = (color >> 8) & 0xff;
        int b = color & 0xff;

        int t = (r * percent) / 100;
        r -= t;
        t = (g * percent) / 100;
        g -= t;
        t = (b * percent) / 100;
        b -= t;
        return toRGB(a, r, g, b);
    }

    /**
     * 
     * @param alpha
     * @param red
     * @param green
     * @param blue
     * @return
     */
    public static int toRGB(int alpha, int red, int green, int blue) {
        return (alpha & 0xff) << 24 | (red & 0xff) << 16
                | (green & 0xff) << 8 | (blue & 0xff) << 0;
    }
}

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