[wyldfire]

As others have said in this thread, they did.

But to answer your question as if they had not yet: it's never "just" recompiling. It's:

* recompile (and fix any warnings/errors indicated by the compiler)

* re-test ... the entire game

* fix the bugs that are encountered in test

* release/publish the game for Windows ARM64

Whatever this effort is, it's much much more than "just" recompiling. You could imagine motivated individuals on the engineering team chipping away at this list of their own accord. But following through with a product requires significant effort and coordination that often is weighed against the potential revenue that this new market could provide.

[mort96]

A really fun thing is that arm and x86 have different char signedness: char is signed on x86, unsigned on arm. This has tripped me up more than a few times when I try to compile software that's only been tested on x86 for an arm machine.

Now WoW already supports Apple Silicon on macOS so most of that was already taken care of, but I'm betting there's a lot of Windows-specific code in there too.

[pdpi]

They've supported macOS through all of PowerPC, Intel, and now ARM. I'm sure Windows on ARM should be trivial for them.

[mort96]

They did the work your parent comment describes for macOS on PowerPC, macOS on Intel, and macOS on arm. They can do the work, but it's still work.

[jajuuka]

I think it also depends on urgency. When Apple unveiled Intel and Apple Silicon they were very clearly the future of the platforms with large buy in from day 1. Blizzard seems to have a good relationship with Apple since they released the Apple Silicon version of WoW almost the day the first laptops started shipping to customers.

Windows on ARM isn't really the same ballpark. They were still there early, but the platform is still changing quite a bit.

[MangoToupe]

> * re-test ... the entire game

That seems a bit absurd. Surely many parts of the game won't likely have bits of code that interact with architecture in unique ways. Especially if you wrote the game in relatively portable code to begin with (as WoW almost certainly was).

I mean idk, maybe windows arm64 is a uniquely nasty target. But i'm skeptical.

[kergonath]

> Surely many parts of the game won't likely have bits of code that interact with architecture in unique ways.

I came across a performance-killing bug that made the game unplayable (less than 1fps on a Mac Studio). It happened in a couple of dungeons (I spotted 2). From my tests it was caused by a specific texture in the field of view at a certain distance. There was no problem on Intel Macs, AFAICT. My old MBP was terrible but did not get any performance hit.

This is what can happen any time you don’t test even a tiny corner of the game. Also, bear in mind that this depends on graphics settings and you get a nightmare of a test matrix.

[MangoToupe]

> From my tests it was caused by a specific texture in the field of view at a certain distance.

Surely that's a GPU thing and not an CPU thing, yea? Or was something about the texture processing architecture-dependent?

[kergonath]

On a Mac Studio it’s kind of the same thing. It’s the GPU core that was in all M1 chips. I could not reproduce it with AMD GPUs, but I also did not try very hard. I remember being annoyed because I always needed to remember to look away when we were doing these instances otherwise we’d fail it because of the time it took to get out of it.

The core issue is that something slipped through the cracks. I don’t blame them, it’s a huge game and testing takes quite a lot of time. But testing does matter.

[jama211]

I mean you can release it with loads of parts untested and just _hope_ there aren’t bugs there, it’s definitely an option. It’s risk vs reward there.

[mobilio]

few days ago there was thread here about Valve and 20 years FPU bug...

https://news.ycombinator.com/item?id=46009962

WoW was released 21 years ago AFAIK

[Wowfunhappy]

…the thing is, this is the type of bug I could also imagine happening under emulation. Or just following an OS update.

[jama211]

That was a fantastic read, thank you for this

[dgellow]

now I feel old...