YAFC - Yet Another Fantasy Console

A retro-inspired fantasy console emulator built with C# and .NET 8, featuring Lua scripting, sprite graphics, and chiptune audio synthesis.

🎮 Overview

YAFC is a virtual console platform that allows you to create and play retro-style games. It provides a pixel-art graphics API, input handling, and audio synthesis capabilities, all powered by Lua scripts packaged in .yafc cartridge files.

✨ Features

• Lua Scripting Engine – Games are written in Lua using the MoonSharp interpreter
• Graphics System – Sprite drawing, text rendering, and a classic 16-color palette
• Audio Synthesis – 4-channel chiptune audio generation (Pulse, Triangle, Noise waveforms)
• Input Management – Keyboard controls mapped to 6 buttons (arrow keys + Z/X)
• Cartridge Format – ZIP-based .yafc files containing Lua code and sprite sheets
• VRAM Management – Efficient sprite and resource management with tile-based rendering
• Retro Aesthetic – resizable window, classic gaming feel

🏗️ Architecture

Core Components

• ConsoleRuntime – Main runtime manager; handles window, audio, input, and Lua lifecycle
• CartridgeManager – Loads and extracts game cartridge files (ZIP archives)
• VirtualConsoleApi – Lua API bindings for graphics, input, and audio
• VramResourceManager – Sprite sheet management and tile rendering
• AudioSynthesizer – Waveform generation and audio playback
• InputManager – Keyboard input polling and button state tracking

Game Lifecycle

1. Launch with a .yafc cartridge file or use menu mode
2. Load Lua code and sprite sheet from cartridge
3. Call Lua functions: init(), update(), draw() each frame
4. Render graphics and play audio through Raylib

🚀 Getting Started

Requirements

• .NET 8 SDK or later
• Windows, macOS, or Linux

Building

dotnet build YAFC.slnx
dotnet run --project YAFC

Running a Game

dotnet run --project YAFC -- path/to/game.yafc

Or launch menu mode:

dotnet run --project YAFC

🎮 Lua API Reference

Graphics

spr(id, x, y, scale, flipX, flipY)  -- Draw sprite
cls(r, g, b)                         -- Clear screen
print(text, x, y, size, r, g, b)     -- Draw text

Input

btn(id)   -- Check if button held (0-5: left/right/up/down/Z/X)
btnp(id)  -- Check if button pressed this frame

Audio

sound(channel, frequency, volume, duty)  -- Play tone on channel 1-4

Game Structure

function init()
  -- Called once at startup
end

function update()
  -- Called every frame
end

function draw()
  -- Called every frame after update
end

📦 Cartridge Format

.yafc files are ZIP archives containing:

• game.lua – Main game code
• sprites.png – Sprite sheet (indexed PNG with 16-color palette)

Roadmap

• Start screen
• Implement DPCM (NES-style compressed audio) support
• Add support for multiple BIOS regions (2-3 regional variants)

🛠️ Dependencies

• Raylib-cs – Graphics and audio rendering
• MoonSharp – Lua scripting
• NativeFileDialogSharp – File dialogs

📄 License

See LICENSE.txt for details.