BetterLyrics/ColorThief.WinUI3/CMap.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace ColorThiefDotNet
{
    /// <summary>
    ///     Color map
    /// </summary>
    internal class CMap
    {
        private readonly List<VBox> vboxes = new List<VBox>();
        private List<QuantizedColor> palette;

        public void Push(VBox box)
        {
            palette = null;
            vboxes.Add(box);
        }

        public List<QuantizedColor> GeneratePalette()
        {
            if(palette == null)
            {
                palette = (from vBox in vboxes
                    let rgb = vBox.Avg(false)
                    let color = FromRgb(rgb[0], rgb[1], rgb[2])
                    select new QuantizedColor(color, vBox.Count(false))).ToList();
            }

            return palette;
        }

        public int Size()
        {
            return vboxes.Count;
        }

        public int[] Map(int[] color)
        {
            foreach(var vbox in vboxes.Where(vbox => vbox.Contains(color)))
            {
                return vbox.Avg(false);
            }
            return Nearest(color);
        }

        public int[] Nearest(int[] color)
        {
            var d1 = double.MaxValue;
            int[] pColor = null;

            foreach(var t in vboxes)
            {
                var vbColor = t.Avg(false);
                var d2 = Math.Sqrt(Math.Pow(color[0] - vbColor[0], 2)
                                   + Math.Pow(color[1] - vbColor[1], 2)
                                   + Math.Pow(color[2] - vbColor[2], 2));
                if(d2 < d1)
                {
                    d1 = d2;
                    pColor = vbColor;
                }
            }
            return pColor;
        }

        public VBox FindColor(double targetLuma, double minLuma, double maxLuma, double targetSaturation, double minSaturation, double maxSaturation)
        {
            VBox max = null;
            double maxValue = 0;
            var highestPopulation = vboxes.Select(p => p.Count(false)).Max();

            foreach(var swatch in vboxes)
            {
                var avg = swatch.Avg(false);
                var hsl = FromRgb(avg[0], avg[1], avg[2]).ToHsl();
                var sat = hsl.S;
                var luma = hsl.L;

                if(sat >= minSaturation && sat <= maxSaturation &&
                   luma >= minLuma && luma <= maxLuma)
                {
                    var thisValue = Mmcq.CreateComparisonValue(sat, targetSaturation, luma, targetLuma,
                        swatch.Count(false), highestPopulation);

                    if(max == null || thisValue > maxValue)
                    {
                        max = swatch;
                        maxValue = thisValue;
                    }
                }
            }

            return max;
        }

        public Color FromRgb(int red, int green, int blue)
        {
            var color = new Color
            {
                A = 255,
                R = (byte)red,
                G = (byte)green,
                B = (byte)blue
            };

            return color;
        }
    }
}