fast monsters cause crashes in chocolate doom

[EsmerInHell]

When I play certain maps in Doom II through chocolate doom with fast monsters enabled, it sometimes crashes with the error message "P_SetMobjState: infinite state cycle".

 

This always seems to happen in certain moments under specific conditions, for example, when I play Tricks & Traps with fast monsters enabled and I walk into the teleporter room with the pain elementals, it doesn't crash, but when I go through nearly the entire level first, killing most of the monsters and picking up weapons, it crashes almost instantly when I walk into that room at the end. 

 

Every single time I reload my save file in the level, it crashes in that room with no exceptions with the same error message. I looked it up online with no relevant results, so I think it's safe to say the problem is exclusive to my computer. The crash also happens in other maps, mostly MAP11, but I haven't played many maps with fast monsters yet so there are likely far more.

 

I don't know any level of programming and even if I did there's no information to go off of that would help me fix this, so I'm completely lost. It makes the game almost unplayable in certain levels. Is there anyhing I can do to resolve these errors or at least make them appear less frequently? 

[Foxpup]

This is the demon speed bug, which causes pinkies to become infinitely fast (and crash the game the moment they're encountered, such as in the exit room of MAP08) when the effects of fast monsters are erroneously applied twice when loading a saved game. This has various triggers, one of which is loading a saved game while using -fast paramter while already in a level with fast monsters.

 

The workaround for your case is to start a new game from the menu (which disables fast monsters) every time before loading your saved game (which re-enables fast monsters). Note that you must still run the game with the -fast parameter for this to work, even though you're going to immediately disable its effect, as the -fast parameter is not stored in saved games (which is one of the reasons the bug occurs in the first place).

 

Note also that Chocolate Doom aims to be literally bug-for-bug compatible with the original DOS executables, so this will not be fixed (to be precise, the fact that the game now exits with an error message instead of completely locking up is the fix).

[EsmerInHell]

12 hours ago, Foxpup said:

This is the demon speed bug, which causes pinkies to become infinitely fast (and crash the game the moment they're encountered, such as in the exit room of MAP08) when the effects of fast monsters are erroneously applied twice when loading a saved game. This has various triggers, one of which is loading a saved game while using -fast paramter while already in a level with fast monsters.

 

The workaround for your case is to start a new game from the menu (which disables fast monsters) every time before loading your saved game (which re-enables fast monsters). Note that you must still run the game with the -fast parameter for this to work, even though you're going to immediately disable its effect, as the -fast parameter is not stored in saved games (which is one of the reasons the bug occurs in the first place).

 

Note also that Chocolate Doom aims to be literally bug-for-bug compatible with the original DOS executables, so this will not be fixed (to be precise, the fact that the game now exits with an error message instead of completely locking up is the fix).

 

I really didn't expect to get any replies, so thanks so much for helping me. I just tested this out and it fixes it. You rock dude.

[drfrag]

Both RUDE and Crispy fix the infinite loop.

[idbeholdME]

I remember having this issue in Doom 95 a loooong time ago. One of the reasons I started looking for a solution and found ZDoom.

 

And even then, i was able to figure out it happened with demons when loading a saved game. I even remember testing it with the one in the underground alcove in Map 05 of Doom 2 before the Hell Knight. When not loading at all, everything was fine. On first load, it made them infinitely fast, yet did not crash the game. If you alerted a demon after a load and he could reach you, he would instantly teleport next to you and you would instantly die. In the very same tic the Demon became aware of you. It was quite scary actually. After the next load, the game crashed when the demon noticed you

Edited November 16, 2020 by idbeholdME