Common features for ZDoom and Eternity

[kb1]

Da Werecat said:

I think the importance of compatibility is a valid question. Do you really need another PrBoom+ embedded in Eternity? Is it worth the effort of maintaining a codebase full of compatibility branching? Maintaining demo compatibility with Eternity itself must be inconvenient enough.

Unification with ZDoom also seems to be a double-edged sword. On one hand, Eternity will have more wads to run - more reasons to try it. On the other hand, it will have less exclusives - more reasons to stick with ZDoom.

Maintaining demo compatibility is the #1 way to know that:
1. Your port will feel like vanilla.
2. You haven't broken something fundamental.
3. Your port will play vanilla demos :)

It's not that bad, except for a half-dozen or so ugly areas where largish chunks of code must be used to get the old behavior. And most of that is for Boom/MBF compatibility - the code for vanilla compatibility is rather small. I missed the startup demos, that's why I went back and added demo compatibility to my port, and I'll never go back. It just has too many advantages to remove it now. I bet the same goes for Eternity, and the other ports that strive for compatibility.

[Graf Zahl]

AlexMax said:

Come on man, the kind of thing I was talking about was just mentioned a few posts ago. I probably should have added "back in the day", as it's not terribly common these days, but I know that Zandronum still has to deal with upstream physics changes from time to time (like here and here).

EDIT: I pasted a link to this post in a doom development channel, and literally the first thing out of somebody's mouth.

Yes, the jumping stuff was one of the occurences I didn't catch in time. Strange, though, that the outcome was a minor result for ZDoom but apparently a huge problem for Zandronum... But in general it happened more than once that I had to re-fix some of these, you can find a good example here:

http://forum.zdoom.org/viewtopic.php?f=7&t=25534&hilit=seeker+missile+evasion

<Somebody> "...bug fix had unintended consequences but saying that they constantly happen is outright wrong."
<Somebody> HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA
* Somebody falls off chair
<Somebody> that's fucking golden

This is not to gang up on you, but to illustrate that the impression that ZDoom "constantly" changes physics is not uncommon. I didn't make it up from wholecloth. When you have demo support, you don't need to convince people that things don't break because they can see for themselves, but when you don't, you get misinformation and hunches exactly like these.

You know, I tend to ignore people who are complaining in the background without ever making a report about the issues they have. They are hard to take seriuously and most likely those who never use ZDoom and form their opinion from hearsay. And if the issues they have won't get reported, well, what I do not know I cannot fix. I tend to take compatibility issues very seriously, but first someone has to tell me about them!

Me personally? I don't really care - Zandronum has been my primary port for years, I have no personal complaints with the physics, and I'm willing to bet that more people play classic duels with ZDoom physics and a few compatflags these days than vanilla.

I'd say most people play vanilla maps in general with some sort of altered physics. As long as the game *feels* right they are ok with it, and realistically the only people who can detect these differences while playing are those whose gameplay style constists out of constant use of speedrunning tricks etc.

[Hell Theatre]

Quasar said:

In short, don't try to dictate to me what my priorities should be. I started renewed investigation and work on Aeon precisely because I now have printz working on the other stuff that was standing in my way and making me feel obligated to slave on something that doesn't interest me. I may have created UDMF, but its implementation is, frankly, a pretty banal task. And I just don't have time for it.

Duly noted. Now the things I never understood about Eternity suddenly make sense.
Of course this probably means that Eternity will forever remain that odd port out there that may have been great but never was to be. Let's hope that Printz can make some progress then.

[Gez]

Quasar said:

I may have created UDMF, but its implementation is, frankly, a pretty banal task. And I just don't have time for it.

No need for you to do the implementation, but maybe just offering some feedback to what Printz is doing, even if it's just a simple "proceed" or "stop"... There is a need to define at least one Eternity namespace for UDMF, and you're the only one in position to do so officially, or alternatively grant permission to someone else to do so.

[printz]

I've been busy implementing parameterized specials equivalent to the Doom ones, and I still am (while I'm not busy fixing demo desyncs). It's possible the UDMF proposition will suffer changes after I have things finished. Personally I kinda got the message from historical threads and IRC comments: it will seek to be familiar to the ZDoom implementation, and it will prefer parameterized specials, while still supporting (but not recommending) Boom specials in a remote-numbered namespace, if really really needed. Personally I'll also value feedback from active Eternity mappers.

Quasar told me on IRC that it's fine.

[Graf Zahl]

printz said:

it will seek to be familiar to the ZDoom implementation, and it will prefer parameterized specials, while still supporting (but not recommending) Boom specials in a remote-numbered namespace, if really really needed. Personally I'll also value feedback from active Eternity mappers.

Quasar told me on IRC that it's fine.

Wouldn't it be better to implement everything cleanly in Hexen format and then use the same numbering, instead of the current hodgepodge where the numbers do not match Hexen's and this wild mixing is possible?

I think that should be left behind with Extradata.

[Hell Theatre]

Graf Zahl said:

I think that should be left behind with Extradata.

I have to agree with this sentiment.

Make a clean break and do this properly! There is no need to have access to the old linedef types at all, if everything gets properly implemented. ZDoom already did this, so you have a complete roadmap of what's needed to make any access to the old stuff completely unnecessary, meaning that even as an emergency fallback option there's no point keeping them accessible.

[printz]

Graf Zahl said:

Wouldn't it be better to implement everything cleanly in Hexen format and then use the same numbering, instead of the current hodgepodge where the numbers do not match Hexen's and this wild mixing is possible?

I think that should be left behind with Extradata.

I actually said that the Boom specials may be left in a remote, high-numbered set, while I keep the UDMF namespace ZDoom/Hexen-like. Not the current ExtraData-compatible set. But maybe I'll expose none of the Boom ones, after all, if they all are contained (Quasar suggested this, if needed).

But I really want to nitpick things here to map exactly to classic Doom and Boom specials, and also fit Hexen.

[Graf Zahl]

Ok, I misunderstood that part. You should still try to make it unnecessary. If you use ZDoom's xlat/eternity.txt for checking and implement everything on it there should only be a handful of Eternity-specific features left that currently cannot be handled. The only one that immediately comes to mind are the two-way portals, for which there is no corresponding type at the moment.

What you then do with ZDoom exclusive specials which are not derived from Boom or Hexen is up to you.

[vadrig4r]

Hell Theatre said:

Duly noted. Now the things I never understood about Eternity suddenly make sense.
Of course this probably means that Eternity will forever remain that odd port out there that may have been great but never was to be. Let's hope that Printz can make some progress then.

Who the fuck are you and why should anyone care about your opinion?

[BrainMuncher]

vadrig4r said:

Who the fuck are you and why should anyone care about your opinion?

[printz]

vadrig4r said:

Who the fuck are you and why should anyone care about your opinion?

No need to shoo him away; he may sound a bit demanding but I agree with him that I should focus on some stuff.