This Week in Game Engines #40

Welcome to This week in Game Engines! This is a digest on gamedev tech news and articles from the week before.

This week we have a scripting language for puzzle games, a scripting language for many games, EVE Online still using Python 2 as a scripting language, motorcycle physics, and much more!

Scripting Languages and where to find them

I had a nice interaction on Mastodon of a user requesting me to add "Luau" as a programming language tag, a thing that would help other users to find their Game Engine Volta. That makes a lot of sense, so of-course I promptly added on the website.

This got me thinking on the original reason I didn't added Luau, though. I considered it a Lua variation (which is true) that only ran on Roblox Studio as a scripting language, but Luau does add its own set of semantics on top of Lua, plus it doesn't transpile to Lua like Typescript does to Javascript - it runs on its own Engines with extra features, such as better sandboxing and performance considerations. More importantly, Luau is not exclusive to Roblox Studio like GDScript is to Godot, so it makes sense for game developers to look specifically for Game Engines compatible with Luau instead of Lua.

But what makes a Scripting Language in the first place? There is no hard definition because it is a broad set of categories, but the general vibe requisites are:

1. Runs in an interpreter instead of a compiler.
2. Is typically used for smaller tools or as an API for an application.

Number (1) is easy to check, (2) is the tricky fuzzy definition. This creates a spectrum of interesting scripting languages, and I'd like to talk about some of them today.

The DSLs

Domain Specific Languages is a fancy name for languages that were made for one thing in particular, or as the main API to one specific platform.

Godot and GDScript

GDScript is the most popular example, being similar to Python and the main gateway to Godot. GDScript usefulness is in the fact that it is 100% integrated in Godot, and like it is described in this 2016 Godot article, it is the perfect example of the usefulness of a DSL language in a Game Engine:

"Binding code was always large, complex and prone to bugs. True multi-threading (with a stack per thread, but sharing memory) was not supported, and vector types had to be created with custom userpointers, which provided much slower performance than built-in types. Added to that, we could never completely eliminate the stalls related to the garbage collector.

GDScript was born as a way to make all these problems go away. When users write code in GDScript within the IDE, everything simply “just works” and you have the added value of live code completion. None of this could have been made with a third party language. We tried, we became experts at it, but it just didn’t work out."

Puzzlescript and Puzzlescript

A reverse Sokoban game I made myself using Puzzlescript

Puzzlescript is the scripting language of my favorite puzzle Game Engine called, well, Puzzlescript. It is an interesting case of a DSL because the language writes like a puzzle of sorts. Instead of the usual imperative style of programming with variables, you write the rules of the game. The canonical example is Sokoban:

• If a player is trying to walk into a crate, try to push that crate.

In PuzzleScript, you will write this as:

• [ > Player | Crate ] -> [ > Player | > Crate ]

It is very weird, very fun, and once you get the hang of the language, you can create a lot of stuff with it. It has a niche in Itch.io too, and even I made some puzzles myself.

The Embeddables

Those are the full-fledged languages that you can embed their engine on top of another application.

Lua(u)

Lua lived among Game Engines since times of old, back when programmers had to apecode their games with their bare hands. It is built on top of C with the intention to be easily extendable and embeddable, and many successful Game Engines support it. Also, it was made in 🎉🇧🇷Brazil🇧🇷🎉.

But Lua wasn't made specifically for games, unlike Luau - out of Roblox Studio, and allowing to easily sandbox code so users can generate content while reducing the surface of dangerous access to players computers, among many other features targeting the game development ecosystem.

Python

Now usually this category would be a little bit harder to find an example (most Python-related Game Engines are written in python themselves, not embedding Python in them), but this week we had this amazing article from the EVE Online folks about them migrating from Python 2 (!) to Python 3 in the year of our lord 2026. The fact that an existing application with hundreds of thousands of users had Python 2 embedded is very surprising but I guess I just underestimated EVE Online legacy.

More interestingly, they embedded a specific version of Python 2 called Stackless Python, a version of Python that allows you to run hundreds of thousands of tiny tasks, called "tasklets", in a single main thread. It was their best solution for concurrent code while still using an easy-to-use language back in 2003 (!).

If you want to take a deeper look, EVE Online Game Engine Carbon was recently open source and you can check where the Python code lives with C++ here.

Engine Updates

MelonJS is reaching v20.0.0 version, with a changelog you can check here. The most important thing is the introduction of a complete WebGPU integration, everyone's favorite graphical backend for the web which allows fine-grained control for rendering in the browser (WebGL 2.0 and Canvas rendering options are still available, though). There are also many improvements in rendering, performance, and even 3D collisions.

Everyone's favorite Javascript rendering framework and the backbone of some of the JS engines listed on the website. Pixi.js version 8.20.0 introduces several new features, including WGSL shader overrides, depth-stencil formats, and partial buffer updates. It also includes bug fixes for various issues, such as incorrect hit testing for polygons and incorrect edge containment for rectangles. Additionally, there are some minor improvements and chores, such as tidying up cube/mip handling and removing dead links.

Refactor was so big that they changed the name of the engine from Supernova to Doriax. The v0.7 update introduces a new backend architecture, project-level scene and bundle management, custom build hooks, and high DPI support. The editor and engine now share the same native backends, and bundles are converted to C++ code for runtime instantiation. The changelog is worth checking out here.

Another C++ and Lua Game Engine, Overload added interesting features on its v1.9, including Skeletal animation, Lua LSP support, exposed Lua script properties in the Editor inspector, and many other fixes you can check here.

Also from Engines Database Aggregator

• Creating a Custom Motorcycle System for Unreal Engine 5. Another nice interview from 80.lv, this time a game developer making their own Motorcycle vehicle in Unreal Engine with custom physics. I also learned a thing or two of actual motorcycle mechanics reading the article.
• Easy to use Entity Component System (ECS) crafted with Odin. An ECS library made in Odin that made some rounds on my feed. Not exactly novel but the README writeup is really good, including how the different entities lives in memory.
• Architectural Hell: How GTA IV Forced the PS3's Cell Processor to Sweat. I knew PS3 was the odd one in that generation hardware architecture, but this is an amazing article about how GTA IV got ported to PS3 and how Rockstar had to re-architect their RAGE engine.
• Decoding Magic School Lunar's Save Game Format. A bit (heh) of retro scavenging on the save file of Magic School Lunar to discover how to bypass the file checksum and edit the player character levels.

Human in the Loop

Hey! Henrique here.

I'm still trying to figure out the best format for the newsletter, including talking a bit more about smaller engines, the weird gamedev tech out there, but I didn't had time to sit with my thoughts yet. One critical thing is that the newsletter has to at least touch the most important updates of the week (it is This Week in Engines after all), but I'd like to talk more about the weird ways someone can make games (there are many wonderful weird little engines listed on EnginesDatabase!). I'm open to suggestions though, so ping me below or at my email (henriquelalves@enginesdatabase.com).

Also, I'm a little bit ashamed to admit that the combo of trying to reach some critical mass of followers on LinkedIn + the many AI posts I have to read is taking a toll on my mind, so there is still some balance I have to achieve between "becoming a LinkedIn thinkfluencer" and "be a normal fucking human being".

And I'm learning to curse a little bit more on my posts to make it sound more legit and less GPTish. I guess that's a good outcome? There are not many legit reasons to say whoever contributed to the modern Social Media landscape is an assfuckface without sounding childish, but you can't blame me if I don't want to look like a bot.

Anyway, a bit of venting from this hell of a week. If you want to help out with the website maintenance, you can always become a supporter (and also post your gamedev stuff on the Aggregator, so I have more material to talk on the newsletter!)

Thanks for keeping up with me, and see you next week!

Missed something?

If you have any suggestions, send me feedback on Mastodon, drop an email at henriquelalves@enginesdatabase.com, or just comment below! And if you want to add a new game engine to the website, consider suggesting a new Game Engine.