Lupinho is a web-based simulator for Lupi, a Brazilian game console. It runs directly in your browser using WebAssembly, allowing you to write and play games using a simple Lua scripting API.

The demo game is "balão-gatinho". Use the arrow keys to move and Z as the action button. You can use a joystick too.

• 🌐 Browser-based — Runs on WebAssembly, no installation required
• 📜 Lua scripting — Write your games in simple, easy-to-learn Lua
• 🎨 2D Graphics — Draw text, lines, rectangles, circles, and triangles
• 🖼️ Sprites & Tiles — Load and draw sprite sheets with flip support
• 🗺️ Tilemap System — Draw large maps with camera scrolling
• 🎮 Gamepad & Keyboard — Input support for both gamepads and keyboard
• ⚡ 60 FPS — Smooth gameplay at 60 frames per second
• 🔧 Raylib powered — Built on the lightweight Raylib graphics library

lupinho/
├── dist/               # Compiled WebAssembly output
│   ├── game.html
│   ├── game.js
│   ├── game.wasm
│   └── game.data
├── src/
│   ├── main.c          # Main entry point
│   ├── lua_api.c       # Lua bindings for ui.* API
│   ├── ui.c/h          # Rendering system & frame buffer
│   ├── types.h         # Draw item type definitions
│   ├── font.h          # Embedded bitmap font
│   ├── Makefile
│   └── libs/
│       ├── lua-web/    # Lua compiled for WebAssembly
│       └── raylib-web/ # Raylib compiled for WebAssembly
├── game-example/       # Example game directory
│   ├── game.lua        # Game entry point
│   ├── palette.lua     # Color palette definition
│   ├── lupi_manifest.txt
│   ├── img/            # Bitmap sprites
│   └── map/            # Tilemap data
└── README.md

• Emscripten SDK installed and activated

cd src

# Development build (with FPS counter)
make web

# Production build (optimized, no debug)
make production

After building, serve the dist/ folder with any HTTP server:

# Using Node.js
npx serve ../dist

Then open http://localhost:8080 in your browser.

Games are written in Lua. Your script should define the update() function, which is called every frame (60 times per second).

Called every frame. Update your game logic and draw here.

Lupinho uses a palette-based color system with 256 colors in BGR555 format (5 bits per channel, Big Endian).

All drawing functions use palette indices (0-255) for colors:

Button constants: UP, DOWN, LEFT, RIGHT, BTN_Z, BTN_Q, BTN_E, BTN_F, BTN_G

-- Define your palette
Palette = {
    0x0000, 0x1516, 0x25B4, 0x20A6, 0x1DFD, 0x46FE, 0x7FFF, 0x2532
}

-- Set palette colors
for i = 1, #Palette do
    ui.palset(i - 1, Palette[i])
end

-- Game variables
x = 200
t = 0

function update()
    t = t + 0.05
    y = math.sin(t) * 25

    ui.print("Bem-vindo ao Lupi!", 280, 180 + math.floor(y))
    ui.rect(50, 50, 130, 130, 1)
    ui.circfill(200, 100, 20, 3)
    ui.trisfill(20, 250, 100, 250, 55, 350, 4)
    
    -- Input example
    if ui.btnp(BTN_Z) then
        ui.log("Button Z pressed!")
    end
end

make clean

We encourage contributions! However, please open an issue before submitting a PR so we can discuss the changes. Issues can be written in Portuguese, Spanish, or English.

We don't have an official communication channel yet, but this README will be updated once we create one.

This project is open source.

Made with ❤️ in Brazil 🇧🇷