ShareX/Greenshot.ImageEditor/Helpers/Colors.cs

/*
 * Greenshot - a free and open source screenshot tool
 * Copyright (C) 2007-2015 Thomas Braun, Jens Klingen, Robin Krom
 *
 * For more information see: http://getgreenshot.org/
 * The Greenshot project is hosted on Sourceforge: http://sourceforge.net/projects/greenshot/
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 1 of the License, or
 * (at your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

using System.Collections.Generic;
using System.Drawing;

namespace Greenshot.Helpers
{
    public static class Colors
    {
        public static bool IsVisible(Color c)
        {
            return c != null && !c.Equals(Color.Empty) && !c.Equals(Color.Transparent) && c.A > 0;
        }

        public static Color Mix(List<Color> colors)
        {
            int a = 0;
            int r = 0;
            int g = 0;
            int b = 0;
            int count = 0;
            foreach (Color color in colors)
            {
                if (!color.Equals(Color.Empty))
                {
                    a += color.A;
                    r += color.R;
                    g += color.G;
                    b += color.B;
                    count++;
                }
            }
            if (count == 0)
            {
                return Color.Empty;
            }
            return Color.FromArgb(a / count, r / count, g / count, b / count);
        }
    }
}