A RAM Edition of Dirty Coding Tricks

A pretty common trick that was part of game programmer lore back in the PS2 / Xbox era was to have a large static array hidden away in some code file somewhere. When days before shipping you couldn't quite fit the release build in to memory this allowed a heroic programmer to miraculously 'find' a few hundred extra kilobytes of memory by reducing the size of the array by just enough to fit.

There was a less common variant of this for finding some extra performance by reducing the iterations of a loop doing no-ops somewhere in the main game loop.

Sadly this usually works only once, especially if it's one person doing it.

I used to work on the performance team at a Bay Area company. One of the things we did to keep our JavaScript bundle sizes under control was introduce a "ratchet". There was a threshold, enforced by CI, that you couldn't let the bundle size exceed without getting in touch with us first and figuring something out. [0]

This worked wonders for a while, until a few different teams were starting new feature development. At that point, the ratchet was forcing teams to pause their feature development to do cleanup work, which made the PMs very unhappy. Engineers got salty because they would remove dead code, only to find that another engineer had gobbled up the space they'd freed before they could land their own commit.

Engineers started working around the ratchet by hoarding dead code and disguising it to look "not dead" so that it could be easily removed later when a few dozen kilobytes were needed.

There were many thing that weren't good at this company, and the culture around ownership of the shared codebase was definitely one of them. I'd like to think that there are plenty of teams that don't have this problem, but I'm inclined to think that it's human nature to subvert these sorts of things by default.

[0] This was necessary because of the volume of tech debt. Teams/engineers had a bad habit of building new things, then not cleaning up the stuff the new things replaced. At one point, we estimated that over a third of the JavaScript was dead code. Some teams had gotten to the point where the codebase contained >2 versions of their product, while only one of them was physically accessible to users.

Back in the era where this was somewhat common on games it only had to work once. In those days you burned a master for a console game and once it shipped that game was done. There were no zero day patches (or any other kind of patches) and no updates to the game once it shipped.

Often it would be the lead programmer on the game who put this array in and it wouldn't necessarily be known about by everyone. It wouldn't have worked well if people were constantly grabbing bits of memory from it during development. It worked because it was a 'secret' and its use was reserved for shipping.

Rust is definitely being looked at. The reason there are no big projects is that it’s still so new. For example the ability to write custom allocator is still going through the RFC process last I looked. Further it takes many man years of effort to write a AAA level game engine so there is quite a lot of inertia preventing moving to something new. We’re at the phase where people are experimenting within a relatively immature ecosystem. We’re probably a year or two away from a big project using Rust for part of their development process and at least four or five from a large project written from scratch. There are quite a few hobbiest and open source game projects though.

I have seen it mentioned here on page 4: https://www.gamasutra.com/view/feature/132500/dirty_coding_t...

There's yet another article on dirty game hacks that I recall due to EULA self-hack: https://www.gamasutra.com/view/feature/194772/dirty_game_dev...

I have no idea why this article doesn't link to these two and just to the 2017 one because it's not like these are current generation tricks, it's just that Brandon Sheffield took to write about them again (one of the articles above is actually his and the other one is by GDM that he is editor in chief of).

Also, the Crash Bandicoot text is the most impressive one and the first in this article but it was very widely circulated for a while now on several sites (including on HN once), despite the "nobody was the wiser until now" at the start of the article.