Core
Entity Component System
Scenes are trees of entities built on Flecs. Components are plain data, registered once and serialized through reflection.
EntityTransformSprite2D
Architecture Skip to content
Luau API Addons
latest · main @ 69c4a50
ATMO EngineBuild 2D games, entity by entity.
A lightweight C++23 engine with an Entity Component System, Luau scripting and a built-in editor.
Why ATMO
Everything a 2D game needs, nothing in the way
Scripting
Gameplay in Luau
Attach a script to an entity and implement Create, Update and PhysicsUpdate. Bindings expose transforms, input and physics.
this:getTransform()Editor
A built-in editor
Compose scenes in the hierarchy, tune components in the inspector and play the game without leaving the editor.
HierarchyInspectorPlay mode
Get started Addons
Extensible by design
Addons bring assets, Luau code or native libraries that receive the engine's core systems through AtmoAPI.
ATMO_REGISTER_ADDON()Code
Script in Luau. Extend in C++.
Gameplay lives in small Luau scripts attached to entities. When you need more, an addon compiles to a native library loaded by the editor.
move_sprite.luau
luau
function Update(deltaTime)
local transform = this:getTransform()
if transform == nil then return end
if Input.isPressed("D") then
transform.position.x = transform.position.x + 100 * deltaTime
end
if Input.isPressed("Q") then
transform.position.x = transform.position.x - 100 * deltaTime
end
endFrom assets/script/move_sprite.luau in the engine repository.
my_addon.cpp
cpp
#include "addon/addon.hpp"
#include <spdlog/spdlog.h>
using namespace atmo::addon;
ATMO_REGISTER_ADDON()
{
spdlog::info("Hello world from My Addon addon!");
}The entry point the editor generates for a new library addon.
Roadmap
Where ATMO is heading
Foundations Shipped
Engine core
- ECS world on Flecs
- SDL3 windowing, rendering and input
- Resource manager and packed assets
Alpha Shipped
Editor
- Scene hierarchy and inspector
- Project file explorer
- Play and stop from the editor
Beta In progress
Scripting and addons
- Luau scripts on entities
- Script error reporting
- Addon templates and loading
- 2D physics with Box2D
Next Planned
Export and art tools
- Project export
- Sprite drawing tools
- Asset import and export
1.0 Planned
Stable release
- Stability and performance
- Complete manual
- Luau API reference