Most useless ZDoom feature?

Post by **Gez** » Thu Oct 18, 2007 4:14 am

randy wrote:When something is teleported, this flag is set, it gets moved to its new position, it's checked for collision, then the flag is cleared. It's not a "feature" at all. Ideally, it wouldn't be necessary, but it is, since Doom physics are such a mess.

Oooohhh... Would something with that flag constantly on be able to telefrag actors just by bumping into them?

MartinHowe · Post by **MartinHowe** » Thu Oct 18, 2007 4:40 am

Graf Zahl wrote:Here you go. This needs a custom MAPINFO though to assign both the intermission script and the real map names to the levels. Mine will be mostly useless because I made some further changes for my personal use to it.

Ta very much

HotWax · Post by **HotWax** » Thu Oct 18, 2007 2:35 pm

randy wrote:It has nothing to do with backwards-compatibility. As the name suggests, it's vital for teleportation. When something is teleported, this flag is set, it gets moved to its new position, it's checked for collision, then the flag is cleared. It's not a "feature" at all. Ideally, it wouldn't be necessary, but it is, since Doom physics are such a mess.

Then it seems to me that the description on the wiki needs to be updated.

Also, my point was that it certainly is not a "ZDoom feature".

Post by **randi** » Thu Oct 18, 2007 3:46 pm

Gez wrote:Would something with that flag constantly on be able to telefrag actors just by bumping into them?

No.

Post by **Graf Zahl** » Thu Oct 18, 2007 3:51 pm

randy wrote:
It has nothing to do with backwards-compatibility. As the name suggests, it's vital for teleportation. When something is teleported, this flag is set, it gets moved to its new position, it's checked for collision, then the flag is cleared. It's not a "feature" at all. Ideally, it wouldn't be necessary, but it is, since Doom physics are such a mess.

That's complete news to me. Please point me to the code where the flag is set because a search function doesn't show it to me.

Actually, that was probably the intent behind this flag before P_TeleportMove was separated from P_TryMove. Right now it's just development garbage that has never been used for anything.

Post by **randi** » Thu Oct 18, 2007 3:57 pm

Seriously? Wow. You're right. Are there any Dehacked patches that have actually used it? If not, it seems like a good candidate for deletion for just what little bit of cleanup doing so could provide.

For those wondering what specifically this flag does, it lets you walk into ceilings if the gap between the ceiling and floor is big enough to accomodate you if you weren't in the ceiling, and it prevents any lines that are activated by crossing from firing. I can't see any practical use for it.

Post by **Graf Zahl** » Thu Oct 18, 2007 4:08 pm

I don't think it's worth removing. All you might achieve is to shorten a few 'if' conditions but I don't see any real code being removed as a result - and there's still the odd Dehacked patch to consider. Who knows if it had been used somewhere in the past?

Post by **Gez** » Fri Oct 19, 2007 12:00 am

randy wrote:For those wondering what specifically this flag does, it lets you walk into ceilings if the gap between the ceiling and floor is big enough to accomodate you if you weren't in the ceiling, and it prevents any lines that are activated by crossing from firing. I can't see any practical use for it.

So, would the ceiling effect allow this cacodemon to attack the marine?

As for the linedef thing, I can see a possible use for it. Many "teleport monster" linedefs, a host of +TELEPORT monsters that won't be teleported, and a few special monsters (though technically normal) that will be teleported. It could be a way to achieve what Torm wanted here.