Iciclecreek.Avalonia.SixelBuffer

Iciclecreek.Avalonia.SixelBuffer

Render Avalonia applications directly in your terminal using Sixel graphics. This library provides a custom windowing and rendering subsystem that converts Avalonia's Skia output into Sixel image sequences, enabling full GUI applications to run inside a terminal emulator that supports Sixel graphics.

Overview

Iciclecreek.Avalonia.SixelBuffer replaces Avalonia's native windowing platform with a terminal-based implementation:

• Sixel rendering -- Avalonia controls are rendered via Skia, quantized to a 256-color palette, and output as Sixel escape sequences.
• Input handling -- Keyboard and mouse input are read from stdin using VT/ANSI escape sequence parsing (including SGR extended mouse tracking).
• Frame diffing -- Only changed regions are re-rendered, with dirty-rect tracking and SIMD-optimized sixel band construction for performance.
• Software cursor -- A composited software cursor is drawn into the frame since hardware cursors aren't available in terminal mode.

Requires a Sixel-capable terminal emulator such as Windows Terminal, WezTerm, iTerm2, etc. See https://www.arewesixelyet.com/ for a list of compatible terminals.

Install

dotnet add package Iciclecreek.Avalonia.SixelBuffer 

Configuring Program.cs

Create a new target console application and replace the contents of Program.cs with the following code to initialize Avalonia with the SixelBuffer platform:

using Avalonia;
using Avalonia.Terminal;

internal static class Program
{
    [STAThread]
    private static void Main(string[] args)
    {
        BuildAvaloniaApp()
            .StartWithConsoleLifetime(args);
    }

    public static AppBuilder BuildAvaloniaApp()
    {
        return AppBuilder.Configure<App>()
            .UseStandardRuntimePlatformSubsystem()
            .WithInterFont()
            .UseSixelBuffer();
    }
}

Notes

• Terminal compatibility -- Your terminal must support Sixel graphics. Tested with Windows Terminal, WezTerm,
• Render rate -- The default render timer runs at 10 FPS to balance responsiveness with terminal throughput. NOTE: If you set too high input will be starved.
• No native Menus -- Don't use NativeMenu/NativeMenuItem as they won't work in terminal mode. Use Avalonia's Menu control instead.
• No native popups -- Popups and dropdown overlays are managed within the single terminal frame rather than as separate OS windows.
• Avalonia version pinning -- The library uses Avalonia private APIs and must be pinned to the exact Avalonia version (currently 12.0.2).
• Mouse resolution -- Mouse input is limited to the terminal's reporting resolution, which is the same as the character cell grid. This
• means you won't get pixel-level mouse coordinates, only the cell coordinates of the terminal.