using PaintDotNet.SystemLayer;
using System;
using System.Drawing;

namespace PaintDotNet
{
    /// <summary>
    /// Provides a set of standard UnaryPixelOps.
    /// </summary>
    public sealed class UnaryPixelOps
    {
        private UnaryPixelOps()
        {
        }

        /// <summary>
        /// Always returns a constant color.
        /// </summary>
        [Serializable]
        public class Constant : UnaryPixelOp
        {
            private ColorBgra setColor;

            public override ColorBgra Apply(ColorBgra color)
            {
                return setColor;
            }

            public unsafe override void Apply(ColorBgra* dst, ColorBgra* src, int length)
            {
                while (length > 0)
                {
                    *dst = setColor;
                    ++dst;
                    --length;
                }
            }

            public unsafe override void Apply(ColorBgra* ptr, int length)
            {
                while (length > 0)
                {
                    *ptr = setColor;
                    ++ptr;
                    --length;
                }
            }

            public Constant(ColorBgra setColor)
            {
                this.setColor = setColor;
            }
        }
    }
}