Notices by Tom Forsyth (tomf@mastodon.gamedev.place), page 2

But HL2 did actually work pretty well. Joe spent a lot of time making the boat sequences work in a reasonable way.

There's a sequence of stacking boxes near the start that is somewhat infuriating in the original - the stack keeps falling over - but in VR it's really easy to place them well.

Also, whacking the manhacks with your crowbar goes from being a panicked flailing in flatscreen, to being an elegant one-swing home-run hit in VR.

Luckily, there was some other excuse to reissue HL2 anyway (see https://developer.valvesoftware.com/wiki/Source_2013) and the VR version worked pretty well, so we put the VR support on a command-line, labelled it "beta", rebuilt the whole of HL2 and prepared to ship it.

Of course we've played a bunch of HL2 by this point, testing all the VR stuff works. But we just skipped to the relevant chapters - we never actually played through from the start. And I hadn't played it through in a while, so I thought I'd do that in VR, start to finish. If I discovered anything that still didn't work, I could at least document it in the release notes.

So I started it up, selected new game, played the intro section. It's a fairly well-known section - you arrive at the train station with a message from Breen, a guard makes you pick up a can, and then you have to go into a room and... uh... I got stuck. I wasn't dead, I just couldn't go anywhere. I was stuck in a corridor with a guard, and nowhere to go. Bizarre.

What is meant to happen is a guard (spoiler alert - it's actually Barney in disguise) bangs on a door, the door opens, he says "get in", and then the game waits for you to enter the room before the script proceeds.

But in this case the door sort of rattled, but didn't open, and then locked shut again. So you can't get in the room, and the gate closed behind you, so you can't go do anything else. The guard waits forever, pointing at the locked door, and you're stuck.

I checked a video online, wondering if my memory was faulty - nope, the door's meant to open automatically, and you walk in. https://www.youtube.com/watch?v=y_3vMUOayyc&t=215s (at 3:40). But... now it doesn't!

Oh dear. We can't ship this. I get some other folks, including some folks who worked on HL2 originally, and yep - it's broken. And it's broken when you're not in VR either - so it's not something Joe and I broke. But nobody knows why - none of the relevant code has changed.

Someone even goes back in the source history and compiles the original game as it shipped - nope, that original version is also broken. How can this possibly be? At this point people are freaking out - this isn't a normal bug - it appears to have traveled backwards in time and infected the original!

After about a day remembering how to use the debugging and replay tools, someone smart (sorry, I don't remember who) figured out what was going wrong.

If you watch the video, when the door unlocks and then opens, there's a second guard standing inside the room to the left of the opening door. That guard is actually standing very slightly too close - the very corner of his bounding box intersects the door's path as it opens. So what's happening is the door starts to open, slightly nudges into the guard's toe, bounces back, closes, and then automatically locks. And because there's no script to deal with this and re-open the door, you're stuck.

Recent discussion about the perils of doors in gamedev reminded me of a bug caused by a door in a game you may have heard of called "Half Life 2". Are you sitting comfortably? Then I shall begin.

"Let's Learn x86-64 Assembly!" by @nicebyte

This is a really good absolute basics intro to x64 assembly, and includes a bunch of stuff I certainly didn't know.

https://gpfault.net/posts/asm-tut-0.txt.html

CMYK test finch. Useful for printer calibration.

Repeating my occasional and yet desperate plea to all my nerdy friends - DO NOT PLAY WITH COMPILERS. It is a trap. You will write it forever, and it will never do what you want, nobody will ever use it, it will not be fulfilling, and you will waste your precious life. Please, for the love of the gods, find something more satisfying to do than scream at a parser and SSA/ASTs.

Applying for a passport renewal...

Your photo must be:
unaltered by computer software
a jpg or jpeg file

Folks, I have startling news about JPEGs...

@fatlimey We already have two different float16 formats. Feels like you could add a whole bunch more pretty easily and fine-tune for your use cases. It's not quite per-app-specific compression (because you need a fast & cheap encode from f24ish to whatever 16 bit format you choose), but seems like hardware could easily support 8 different ones.

@fatlimey The paper then goes on to talk about different fp8 formats, but now we truly are just in LUT territory. Convert to the most appropriate fp16, then just look up whatever mapping you want. Whatever makes sense for your app.

@tomjennings @mcc Let us know if you find it.

@tomjennings @mcc That's the whole discussion. They do not have the *assembler syntax* which is a different thing.

@mcc IIRC a lot of the extended syntax was defined by MASM, sometimes to make life simpler for their extremely powerful macros. I don't know how much of that was also adopted by NASM. So well worth checking with both MASM and NASM. But yes - lots of oral tradition here...