Program.cs

using System;
using System.IO;
using System.Drawing;
using System.Globalization;

namespace Rastermatic
{
    class Program
    {
        static void Main(string[] args)
        {
            const float PixelSize = 0.47f;

            string InputFilepath;
            Bitmap InputBitmap;

            string OutputFilename;
            string OutputFilepath;
            string OutputContent;

            Size BitmapSize;
            Color ColorPrevious = Color.Empty;
            Color ColorCurrent = Color.Empty;

            // Transparent pixels (alpha = 0) are rendered as space
            bool IsTransparentPrevious = false;
            bool IsTransparentCurrent = false;
            int TransparentCount = 0;

            Console.WriteLine("SP Rastermatic 1.1.2");
            Console.WriteLine("Copyright (C) 2021 hpgbproductions");
            Console.WriteLine("Released under GNU General Public License V3.0");
            Console.WriteLine();
            Console.WriteLine("Enter image file path>");
            InputFilepath = Console.ReadLine();
            InputFilepath = InputFilepath.Replace("\"", "");

            Console.WriteLine();
            Console.WriteLine("Opening image...");

            // Load image file
            try
            {
                InputBitmap = new Bitmap(Image.FromFile(InputFilepath));
            }
            catch (Exception ex)
            {
                FailExport(ex, "an error occured when importing the specified file");
                return;
            }

            // Write export contents
            try
            {
                // Write the start of the sub-assembly file
                OutputContent = @"<?xml version=""1.0"" encoding=""utf-8""?>
<DesignerParts>
  <DesignerPart name = """;
                OutputContent += Path.GetFileName(InputFilepath);
                OutputContent += @$""" category=""Sub Assemblies"" icon=""GroupIconSubAssembly"" description = """">
    <Assembly>
      <Parts>
        <Part id=""2"" partType=""Label-1"" position=""0,0,0"" rotation=""270,0,0"" drag=""0,0,0,0,0,0"" materials=""0,1,2"" scale=""1,1,1"" partCollisionResponse=""Default"" calculateDrag=""false"">
           <Label.State designText = ""&lt";
           
           OutputContent += string.Format(CultureInfo.InvariantCulture, ";mspace={0:F2}em&gt;&lt;line-height={1:F2}em&gt;", PixelSize, PixelSize);

                BitmapSize = InputBitmap.Size;
                Console.WriteLine($"Image resolution: {BitmapSize.Width}x{BitmapSize.Height}");
                Console.WriteLine();

                for (int y = 0; y < BitmapSize.Height; y++)
                {
                    Console.WriteLine($"Writing data for line {y + 1} of {BitmapSize.Height}");
                    for (int x = 0; x < BitmapSize.Width; x++)
                    {
                        // Write data for a pixel
                        ColorCurrent = InputBitmap.GetPixel(x, y);
                        // Get transparency
                        // To prevent label rendering issues, the last character in a row is treated as non-transparent
                        IsTransparentCurrent = ColorCurrent.A == 0 && x < BitmapSize.Width - 1;

                        if (IsTransparentCurrent)
                        {
                            TransparentCount++;
                        }
                        else    // Current pixel is not transparent, or is the last in its row
                        {
                            if (IsTransparentPrevious)
                            {
                                OutputContent += string.Format(CultureInfo.InvariantCulture, "&lt;space={0:F3}em&gt;", PixelSize * TransparentCount);
                                TransparentCount = 0;
                            }

                            if (ColorCurrent != ColorPrevious || IsTransparentPrevious)
                            {
                                OutputContent += string.Format("&lt;color=#{0:X2}{1:X2}{2:X2}{3:X2}&gt;",
                                    ColorCurrent.R, ColorCurrent.G, ColorCurrent.B, ColorCurrent.A);
                            }
                            OutputContent += "■";
                        }

                        ColorPrevious = ColorCurrent;
                        IsTransparentPrevious = IsTransparentCurrent;
                    }

                    if (y < BitmapSize.Height - 1)
                    {
                        OutputContent += "&lt;br&gt;";
                    }
                }

                OutputContent += @$"&lt;/mspace&gt;"" fontName=""Default"" fontSize=""1"" horizontalAlignment=""Center"" verticalAlignment=""Middle"" width=""{BitmapSize.Width / 20f}"" height=""{BitmapSize.Height / 20f}"" outlineWidth=""0"" emission=""0"" offset=""0,0.006,0"" rotation=""90,0,0"" gradient=""None"" curvature=""0"" />
        </Part>
      </Parts>
      <Connections/>
    </Assembly>
  </DesignerPart>
</DesignerParts>";
            }
            catch (Exception ex)
            {
                FailExport(ex, "an error occured when writing export contents");
                return;
            }

            // Write the export contents to a file
            try
            {
                OutputFilename = Path.GetFileName(InputFilepath) + ".xml";
                OutputFilepath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), OutputFilename);
                StreamWriter writer = File.CreateText(OutputFilepath);
                writer.Write(OutputContent);
                writer.Close();
                writer.Dispose();
            }
            catch (Exception ex)
            {
                FailExport(ex, "an error occured when exporting to file");
                return;
            }

            Console.WriteLine("\nSuccessfully exported data onto desktop: " + OutputFilename);
            Console.WriteLine("Press ENTER to quit.");
            Console.ReadLine();
        }

        static void FailExport(Exception ex, string message)
        {
            Console.WriteLine("\nExport failed - " + message);
            Console.WriteLine(ex);
            Console.WriteLine("\nPress ENTER to quit.");
            Console.ReadLine();
        }
    }
}