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Gusta said:
For me this is a typical doom engine bug when exactly north-south or east-west trigger linedefs simply doesn't work while player is strafing over them.

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jongo said:
By the way, i would really like to listen to some explanations about what happens in the end of map18 - why does this linedef stops working. I noticed it accidentaly, used it, but dont have any technical explanation about it.

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1. P_CrossSpecialLine (p_spec.c) accidentally allows certain types of projectile to activate walk-triggered linedefs that allow monsters.
   (Instead of just testing the MF_MISSILE mobj flag like you'd expect, the code explicitly disallows a particular list of mobj types -- all the projectile types in Doom. Obviously it was never updated for Doom 2. I think this shows P_CrossSpecialLine was written long before they thought of adding the MF_MISSILE flag.)
2. So P_CrossSpecialLine calls EV_Teleport (p_telept.c) in which all projectiles are immediately rejected. (by testing MF_MISSILE)
3. Nevertheless, P_CrossSpecialLine will still consume any single-use linedef, even when the linedef action fails. This is only the case for doom2.exe - this particular behaviour is fixed in Boom.

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RjY said:
... the code explicitly disallows a particular list of mobj types -- all the projectile types in Doom. Obviously it was never updated for Doom 2.

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Grazza said:
So you're saying that revenant and mancubus fireballs will always cancel single-use teleporter lines in Doom2.exe?

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Or, more generally, cancel all single-use special linedefs, without triggering them? That sounds like quite an exploitable new insight.

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Grazza said:
Or, more generally, cancel all single-use special linedefs, without triggering them?

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jongo said:
Probably my last tools-assisted demo for HR. I have built map30 Nightmare speedrun in 0:09 using a quadruple AV jump.
I seem to have problems with webspace again, so i just attached it.

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