Brine2D.Input.SDL 0.3.2-alpha

Brine2D

The ASP.NET of game engines - A modern .NET 10 game engine built on SDL3 for creating 2D games with C#.

Brine2D brings the familiar patterns and developer experience of ASP.NET to game development. If you've built web apps with ASP.NET, you'll feel right at home building games with Brine2D.

Features

• Input System - Keyboard, mouse, gamepad with polling and events
• Sprite Rendering - Hardware-accelerated with sprite sheets and animations
• Animation System - Frame-based with multiple clips and events
• Audio System - Sound effects and music via SDL3_mixer
• Scene Management - Async loading, transitions, and lifecycle hooks
• Tilemap Support - Tiled (.tmj) integration with auto-collision
• Collision Detection - AABB and circle colliders with spatial partitioning
• Camera System - 2D camera with zoom, rotation, and bounds
• UI Framework - Immediate-mode UI with theming and tooltips
• Configuration - JSON-based settings with hot reload support
• Dependency Injection - ASP.NET Core-style DI container
• Logging - Structured logging with Microsoft.Extensions.Logging
• Multiple Backends - SDL3 GPU (alpha) and Legacy renderer

Why Brine2D?

ASP.NET Developers Will Feel at Home

// Looks familiar? That's the point!
var builder = GameApplication.CreateBuilder(args);

// Configure services just like ASP.NET
builder.Services.AddSDL3Input();
builder.Services.AddSDL3Audio();

builder.Services.AddSDL3Rendering(options =>
{
    options.WindowTitle = "My Game";
    options.WindowWidth = 1280;
    options.WindowHeight = 720;
});

// Register your scenes like controllers
builder.Services.AddScene<GameScene>();

var game = builder.Build();

await game.RunAsync<GameScene>();

Key Similarities to ASP.NET

Quick Start

Installation

Using NuGet (Recommended)

Create a new .NET 10 console project and add Brine2D:

dotnet new console -n MyGame
cd MyGame
dotnet add package Brine2D.Desktop --version 0.3.0-alpha

That's it! Brine2D.Desktop includes everything you need to start building games.

Package Options

For most users, install the meta-package:

dotnet add package Brine2D.Desktop

Advanced: Install only what you need:

# Core abstractions only
dotnet add package Brine2D.Core
dotnet add package Brine2D.Engine

# Choose your implementations
dotnet add package Brine2D.Rendering.SDL
dotnet add package Brine2D.Input.SDL
dotnet add package Brine2D.Audio.SDL

Your First Game

Create Program.cs:

using Brine2D.Core;
using Brine2D.Hosting;
using Brine2D.Input;
using Brine2D.Input.SDL;
using Brine2D.Rendering;
using Brine2D.Rendering.SDL;
using Microsoft.Extensions.Logging;

// Create the game application builder
var builder = GameApplication.CreateBuilder(args);

// Configure SDL3 rendering
builder.Services.AddSDL3Rendering(options =>
{
    options.WindowTitle = "My First Brine2D Game";
    options.WindowWidth = 1280;
    options.WindowHeight = 720;
    options.VSync = true;
});

// Add SDL3 input
builder.Services.AddSDL3Input();

// Register your scene
builder.Services.AddScene<GameScene>();

// Build and run
var game = builder.Build();
await game.RunAsync<GameScene>();

// Define your game scene
public class GameScene : Scene
{
    private readonly IRenderer _renderer;
    private readonly IInputService _input;
    private readonly IGameContext _gameContext;

    public GameScene(
        IRenderer renderer,
        IInputService input,
        IGameContext gameContext,
        ILogger<GameScene> logger) : base(logger)
    {
        _renderer = renderer;
        _input = input;
        _gameContext = gameContext;
    }

    protected override void OnRender(GameTime gameTime)
    {
        _renderer.Clear(Color.CornflowerBlue);
        _renderer.BeginFrame();
        
        _renderer.DrawText("Hello, Brine2D!", 100, 100, Color.White);
        
        _renderer.EndFrame();
    }

    protected override void OnUpdate(GameTime gameTime)
    {
        if (_input.IsKeyPressed(Keys.Escape))
        {
            _gameContext.RequestExit();
        }
    }
}

Run your game:

dotnet run

Alpha Release Notice

⚠️ This is an alpha release (0.3.0-alpha)

What works:

• ✅ Legacy rendering (sprites, primitives, text)
• ✅ Input system (keyboard, mouse, gamepad)
• ✅ Audio system
• ✅ Animation system
• ✅ Collision detection
• ✅ Tilemap support
• ✅ UI framework
• ✅ Camera system

What doesn't work yet:

• ❌ GPU renderer (use Backend = "LegacyRenderer" in config)
• ❌ Entity Component System (planned for 0.4.0)
• ❌ Scene graph (planned for 0.5.0)

Expect breaking changes before 1.0!

Troubleshooting

"GPU renderer not supported"

• Set "Backend": "LegacyRenderer" in gamesettings.json
• GPU renderer is incomplete in 0.3.0-alpha

"SDL3 native libraries not found"

• SDL3 is included via SDL3-CS NuGet package
• Native libraries are automatically copied to output directory
• If issues persist, manually download SDL3 from libsdl.org

Performance issues

• Use TextureScaleMode.Nearest for pixel art
• Enable VSync: options.VSync = true
• Use collision spatial partitioning for many objects

Need help?

• GitHub Issues
• Discussions

Creating a Scene (Like an ASP.NET Controller)

using Brine2D.Core;
using Brine2D.Input;
using Brine2D.Rendering;
using Microsoft.Extensions.Logging;

// Scenes are like Controllers, they get dependencies injected.
public class GameScene : Scene
{
    private readonly IGameContext _gameContext;
    private readonly IInputService _input;
    private readonly IRenderer _renderer;

    // Constructor injection just like ASP.NET
    public GameScene
    (
        IRenderer renderer,
        IInputService input,
        IGameContext gameContext,
        ILogger<GameScene> logger
    )
        : base(logger)
    {
        _renderer = renderer;
        _input = input;
        _gameContext = gameContext;
    }

    protected override void OnRender(GameTime gameTime)
    {
        _renderer.Clear(Color.CornflowerBlue);
        _renderer.BeginFrame();

        // Your rendering code here

        _renderer.EndFrame();
    }

    protected override void OnUpdate(GameTime gameTime)
    {
        if (_input.IsKeyPressed(Keys.Escape))
        {
            _gameContext.RequestExit();
        }
    }
}

Examples

Loading and Drawing Sprites

using Brine2D.Core;
using Brine2D.Rendering;

public class SpriteScene : Scene
{
    private readonly IRenderer _renderer;
    private readonly ITextureLoader _textureLoader;

    private ITexture? _playerTexture;

    protected override async Task OnLoadAsync(CancellationToken cancellationToken)
    {
        // Load with nearest neighbor filtering for pixel art
        _playerTexture = await _textureLoader.LoadTextureAsync
        (
            "assets/player.png",
            TextureScaleMode.Nearest,
            cancellationToken
        );
    }

    protected override void OnRender(GameTime gameTime)
    {
        _renderer.Clear(Color.Black);
        _renderer.BeginFrame();

        if (_playerTexture != null)
        {
            _renderer.DrawTexture(_playerTexture, 100, 100);
        }

        _renderer.EndFrame();
    }
}

Sprite Animation

using Brine2D.Core;
using Brine2D.Core.Animation;
using Brine2D.Rendering;

public class AnimatedScene : Scene
{
    private SpriteAnimator? _animator;
    private ITexture? _spriteSheet;

    protected override async Task OnLoadAsync(CancellationToken cancellationToken)
    {
        _spriteSheet = await _textureLoader.LoadTextureAsync
        (
            "assets/character.png",
            TextureScaleMode.Nearest,
            cancellationToken
        );

        _animator = new SpriteAnimator();

        // Create walk animation from sprite sheet
        var walkAnim = AnimationClip.FromSpriteSheet
        (
            "walk",
            32,
            32,
            8,
            8
        );

        _animator.AddAnimation(walkAnim);
        _animator.Play("walk");
    }

    protected override void OnRender(GameTime gameTime)
    {
        _renderer.Clear(Color.Black);
        _renderer.BeginFrame();

        if (_spriteSheet != null && _animator?.CurrentFrame != null)
        {
            var frame = _animator.CurrentFrame;
            var rect = frame.SourceRect;

            _renderer.DrawTexture
            (
                _spriteSheet,
                rect.X, rect.Y, rect.Width, rect.Height,
                100, 100, 64, 64
            );
        }

        _renderer.EndFrame();
    }

    protected override void OnUpdate(GameTime gameTime)
    {
        _animator?.Update((float)gameTime.DeltaTime);
    }
}

Playing Audio

using Brine2D.Audio;
using Brine2D.Core;
using Brine2D.Input;

public class AudioScene : Scene
{
    private readonly IAudioService _audio;

    private IMusic? _bgMusic;
    private ISoundEffect? _jumpSound;

    protected override async Task OnLoadAsync(CancellationToken cancellationToken)
    {
        _jumpSound = await _audio.LoadSoundAsync("assets/jump.wav", cancellationToken);
        _bgMusic = await _audio.LoadMusicAsync("assets/music.mp3", cancellationToken);

        _audio.PlayMusic(_bgMusic);
    }

    protected override void OnUpdate(GameTime gameTime)
    {
        if (_input.IsKeyPressed(Keys.Space) && _jumpSound != null)
        {
            _audio.PlaySound(_jumpSound);
        }
    }
}

Input Handling

using Brine2D.Core;
using Brine2D.Input;

protected override void OnUpdate(GameTime gameTime)
{
    // Keyboard
    if (_input.IsKeyDown(Keys.W))
    {
        /* Move up */
    }

    if (_input.IsKeyPressed(Keys.Space))
    {
        /* Jump */
    }

    // Mouse
    var mousePos = _input.MousePosition;

    if (_input.IsMouseButtonPressed(MouseButton.Left))
    {
        /* Click */
    }

    // Gamepad
    if (_input.IsGamepadConnected())
    {
        var leftStick = _input.GetGamepadLeftStick();

        if (_input.IsGamepadButtonPressed(GamepadButton.A))
        {
            /* Jump */
        }
    }
}

Configuration

Create a gamesettings.json file in your project:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Brine2D": "Debug"
    }
  },
  "Rendering": {
    "WindowTitle": "My Game",
    "WindowWidth": 1280,
    "WindowHeight": 720,
    "VSync": true,
    "Fullscreen": false,
    "Backend": "LegacyRenderer"
  }
}

Architecture

Brine2D follows a modular architecture with clear separation of concerns:

Core Packages

• Brine2D.Core - Core abstractions, animation, collision, tilemap
• Brine2D.Engine - Game loop and scene management
• Brine2D.Hosting - ASP.NET-style application hosting

Abstraction Layers

• Brine2D.Rendering - Rendering abstractions (IRenderer, ITexture, ICamera)
• Brine2D.Input - Input abstractions (IInputService, keyboard, mouse, gamepad)
• Brine2D.Audio - Audio abstractions (IAudioService, music, sound effects)

SDL3 Implementations

• Brine2D.Rendering.SDL - SDL3 GPU + Legacy renderer implementation
• Brine2D.Input.SDL - SDL3 input implementation
• Brine2D.Audio.SDL - SDL3_mixer audio implementation

Extensions

• Brine2D.UI - UI framework (buttons, inputs, dialogs, tabs)

Meta-Package

• Brine2D.Desktop - All-in-one package (recommended for most users)

Requirements

• .NET 10 SDK
• SDL3 (included via SDL3-CS NuGet package)
• SDL3_image (for texture loading)
• SDL3_mixer (for audio playback)

Platform Support

SDL3 provides cross-platform support, but we've only tested on Windows so far. Community testing on other platforms is welcome!

Building from Source

If you want to build from source or contribute:

git clone https://github.com/CrazyPickleStudios/Brine2D.git
cd Brine2D
dotnet build

Then reference the projects directly in your game:

<ItemGroup>
  <ProjectReference Include="..\Brine2D\src\Brine2D.Desktop\Brine2D.Desktop.csproj" />
</ItemGroup>

Samples

Check out the samples/ directory for complete working examples:

• BasicGame - Animation and input demo
• PlatformerGame - Coming soon
• AdvancedGame - Coming soon

Community & Support

• GitHub Discussions - Ask questions, share projects
• Issue Tracker - Report bugs, request features
• Documentation - Full guides and API reference
• Sample Projects - Learn by example

Roadmap

0.4.0-alpha

• Entity Component System (ECS)
• More working samples

0.5.0-beta

• Scene graph with hierarchical transforms
• Complete GPU renderer

1.0.0

• Stable API
• Complete documentation
• Production-ready

See the full roadmap.

Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

License

MIT License - see LICENSE file for details

Credits

Built with:

• SDL3 - Simple DirectMedia Layer
• SDL3-CS - C# bindings for SDL3

Made with ❤️ by CrazyPickle Studios