Utils.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Net.Http;
using System.Threading.Tasks;
using Avalonia;
using Avalonia.Media.Imaging;
using Avalonia.Platform;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using SkiaSharp;
using Formatting = Newtonsoft.Json.Formatting;

namespace ColorSplitter;

public static class ImageExtensions
{
    public static class ImageHelper
    {
        public static Bitmap LoadFromResource(Uri resourceUri)
        {
            return new Bitmap(AssetLoader.Open(resourceUri));
        }
    }
    
    public static Bitmap ConvertToAvaloniaBitmap(this SKBitmap bitmap)
    {
        using var bm = bitmap.PeekPixels();
        using var img = SKImage.FromPixels(bm);
        using var enc = img.Encode();
        using var stream = enc.AsStream();
        return new Bitmap(stream);
    }
    
    public static SKBitmap ConvertToSKBitmap(this Bitmap bitmap)
    {
        using (var memoryStream = new MemoryStream())
        {
            // Save Avalonia Bitmap to MemoryStream
            bitmap.Save(memoryStream);
            memoryStream.Seek(0, SeekOrigin.Begin);

            // Load MemoryStream into SKBitmap
            return SKBitmap.Decode(memoryStream);
        }
    }

    public static unsafe SKBitmap NormalizeColor(this SKBitmap SourceBitmap)
    {
        var srcColor = SourceBitmap.ColorType;;

        if (srcColor == SKColorType.Bgra8888) return SourceBitmap;
        // Ensure we don't need to normalize it.

        SKBitmap OutputBitmap = new(SourceBitmap.Width, SourceBitmap.Height);

        var srcPtr = (byte*)SourceBitmap.GetPixels().ToPointer();
        var dstPtr = (byte*)OutputBitmap.GetPixels().ToPointer();

        var width = OutputBitmap.Width;
        var height = OutputBitmap.Height;
        
        Console.WriteLine(srcColor);

        for (var row = 0; row < height; row++)
        for (var col = 0; col < width; col++)
            if (srcColor == SKColorType.Gray8 || srcColor == SKColorType.Alpha8)
            {
                var b = *srcPtr++;
                *dstPtr++ = b;
                *dstPtr++ = b;
                *dstPtr++ = b;
                *dstPtr++ = 255;
            }
            else if (srcColor == SKColorType.Rgba8888)
            {
                var r = *srcPtr++;
                var g = *srcPtr++;
                var b = *srcPtr++;
                var a = *srcPtr++;
                *dstPtr++ = b;
                *dstPtr++ = g;
                *dstPtr++ = r;
                *dstPtr++ = a;
            }
            else if (srcColor == SKColorType.Argb4444)
            {
                var r = *srcPtr++;
                var g = *srcPtr++;
                var b = *srcPtr++;
                var a = *srcPtr++;
                *dstPtr++ = (byte)(b * 2);
                *dstPtr++ = (byte)(g * 2);
                *dstPtr++ = (byte)(r * 2);
                *dstPtr++ = a;
            }

        SourceBitmap.Dispose();
        SourceBitmap = OutputBitmap;

        return SourceBitmap;
    }
}

public class Config
{
    public static string FolderPath =
        Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "AutoDraw");

    public static string ConfigPath = Path.Combine(FolderPath, "config.json");

    public static string? GetEntry(string entry)
    {
        if (!File.Exists(ConfigPath)) return null;
        var json = File.ReadAllText(ConfigPath);
        var parse = JObject.Parse(json);
        return (string?)parse[entry];
    }
}