RoundImageDrawing

repro.cs

// See https://aka.ms/new-console-template for more information
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices;

string imageBase64 = "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";

if (args.Length != 1)
{
    Console.WriteLine("Specify 1 to generate image, specify 2 to compare inputs as an argument.");
    return;
}

bool result = int.TryParse(args[0], out int value);

if (!result)
{
    return;
}

if (value == 1)
{
    string filePath = RuntimeInformation.FrameworkDescription.StartsWith(".NET Core", StringComparison.OrdinalIgnoreCase) ?
        @"C:\repos\tmp\netcoreapp31.txt" : @"C:\repos\tmp\netfx.txt";
    RoundImageAndWriteBytes(imageBase64, filePath);
}
else if(value == 2)
{
    CompareInputs();
}

void RoundImageAndWriteBytes(string base64Image, string filePath)
{
    var bytes = Convert.FromBase64String(imageBase64);

    using MemoryStream ms = new MemoryStream(bytes);
    using var graphicsPath = new GraphicsPath();
    var image = Image.FromStream(ms);

    var dim = Math.Min(image.Width, image.Height);
    var bmp = new Bitmap(dim, dim);

    graphicsPath.AddEllipse(0, 0, dim, dim);

    using (var graphics = Graphics.FromImage(bmp))
    {
        graphics.SmoothingMode = SmoothingMode.AntiAlias;
        graphics.FillRectangle(Brushes.Magenta, 0, 0, dim, dim);
        graphics.SetClip(graphicsPath);
        graphics.DrawImage(image, Point.Empty);
    }

    bmp.MakeTransparent(Color.Magenta);
    using MemoryStream dest = new MemoryStream();
    bmp.Save(dest, ImageFormat.Png);
    bmp.Save(@"C:\repos\tmp\out.png");

    ms.Seek(0, SeekOrigin.Begin);
    var finalArray = ms.ToArray();
    var finalStr = string.Join(",", finalArray);

    File.WriteAllText(filePath, finalStr);
}

void CompareInputs()
{
    string netfxText = File.ReadAllText(@"C:\repos\tmp\netfx.txt");
    string netcoreappText = File.ReadAllText(@"C:\repos\tmp\netcoreapp31.txt");

    byte[] netfxBytes = netfxText.Split(',').Select(s => Byte.Parse(s)).ToArray();
    byte[] netcoreappBytes = netcoreappText.Split(',').Select(s => Byte.Parse(s)).ToArray();

    Console.WriteLine($"Length -- netfx {netfxBytes.Length}, netcoreapp {netcoreappBytes.Length}");

    if (netfxBytes.Length != netcoreappBytes.Length)
    {
        return;
    }

    bool different = false;

    for (int i = 0; i < netfxBytes.Length; i++)
    {
        byte netfxByte = netfxBytes[i];
        byte netcoreappByte = netcoreappBytes[i];

        if (netfxByte != netcoreappByte)
        {
            different = true;
            Console.WriteLine($"Byte changed at index: {i} -- netfx {netfxByte}, netcoreapp {netcoreappByte}");
        }
    }

    if (!different)
    {
        Console.WriteLine("No differences were found");
    }
}