helios - Exploratory Development of an ECS-based Game Engine​

All set and done, project goal reached!

Well, almost...

The project quickly shifted away from its initially intended focus on gameplay and graphics implementation toward a deeper engagement with engine architectures, and the result breaks with classical OOP paradigms: In the report I published today (the engine document), I document this transition from deep inheritance hierarchies to a data-oriented (DOD) system.

In my previous post, I outlined the high-level separation between Commands and Events in helios, along with the basic double-buffered EventBus and CommandBuffer concepts. Since then, I've iterated significantly on the architecture, and I'm excited to share what has emerged: A Phase/Pass structure that provides much finer control over when events become visible and when commands execute.

Over the past few weeks, I’ve been busy refining the helios GameLoop to enable player interactions with various GameObjects. This included, in particular, controlling the player ship, spawning enemies, and - the holy grail of every game - the collision system.

Wrapping up the year with GameObject pooling and a SpawnSystem based on conditions and strategies. On to collision detection! 🕹️ 👾

Merry Christmas - Milestone 3 is out. This one is smaller on flashy visuals but much bigger where it matters: the framework now helps to build gameplay faster. Over the last week I focused on three practical gaps that showed up while iterating on the spaceship demo: clearer system boundaries, easier composition of behavior, and stable, cheap shooting.

Milestone 2 is out. I originally planned to add some camera controls, but ended up rewriting how cameras integrate with the scene graph entirely. Along the way I also built the foundations for the game object system, a bunch of ImGui debug widgets, and a small spaceship demo where you fly around with a gamepad.

Since wrapping up milestone_1 in October, I've been working on tooling and performance infrastructure. The focus has been on frame timing control and debugging capabilities - things you need before scaling up to more complex scenes.

I use GitHub Copilot mainly for Code Reviews. I think it's tremendously helpful when working on a solo project with a large codebase as it hints at typos and logic issues that easily slip under the radar when writing only coarse-grained tests for the sake of it. I also tried Claude and Gemini. All those tools are sometimes helpful, sometimes annoying.

What's been on my mind: when I accept code I haven't thought through myself - do I still understand what I'm actually building?

Finishing milestone_1​

I've published an accompanying technical report on my game framework helios that outlines the key architectural decisions behind the prototype and discuss its further development.

Prototyping the Rendering Pipeline​

As announced in a previous post, I've made progress on the rendering pipeline. The SceneGraph and RenderPass system are in place now, separating scene graph traversal from the actual rendering commands.