using System.Drawing.Imaging;

namespace Developpez.Dotnet.Drawing
{
    /// <summary>
    /// Fournit des matrices de transformation de couleurs courantes
    /// </summary>
    public static class ColorTransforms
    {
        private static readonly ColorMatrix _grayScale;
        private static readonly ColorMatrix _negative;
        private static readonly ColorMatrix _sepia;

        static ColorTransforms()
        {
            _grayScale = new ColorMatrix(
                new float[][]
                    {
                        new float[] { .3f, .3f, .3f, 0, 0 },
                        new float[] { .59f, .59f, .59f, 0, 0 },
                        new float[] { .11f, .11f, .11f, 0, 0 },
                        new float[] { 0, 0, 0, 1, 0 },
                        new float[] { 0, 0, 0, 0, 1 }
                    });

            _negative = new ColorMatrix(
                new float[][]
                    {
                        new float[] { -1, 0, 0, 0, 0 },
                        new float[] { 0, -1, 0, 0, 0 },
                        new float[] { 0, 0, -1, 0, 0 },
                        new float[] { 0, 0, 0, 1, 0 },
                        new float[] { 1, 1, 1, 0, 1 },
                    });

            _sepia = new ColorMatrix(
                new float[][]
                    {
                        new float[] { 0.393f, 0.349f, 0.272f, 0, 0 },
                        new float[] { 0.769f, 0.686f, 0.534f, 0, 0 },
                        new float[] { 0.189f, 0.168f, 0.131f, 0, 0 },
                        new float[] { 0, 0, 0, 1, 0 },
                        new float[] { 0, 0, 0, 0, 1 }
                    });
        }

        /// <summary>
        /// Transformation en niveau de gris
        /// </summary>
        public static ColorMatrix GrayScale
        {
            get { return _grayScale; }
        }

        /// <summary>
        /// Transformation en négatif
        /// </summary>
        public static ColorMatrix Negative
        {
            get { return _negative; }
        }

        /// <summary>
        /// Transformation sépia
        /// </summary>
        public static ColorMatrix Sepia
        {
            get { return _sepia; }
        }
    }
}