Bouncing projectiles don't hurt when hitting top/bottom

[Marisa Kirisame]

Bouncing projectiles explode/die as expected, but don't deal damage to the actor they hit. Linked here is an example to show this behaviour. I'd check if the bug happens on 4.2.1 but I can no longer compile it due to glibc updates and versioned symbol nonsense.

[Marisa Kirisame]

Is anyone ever going to bother with this? A crapton of mods trigger this bug, you know.

[SanyaWaffles]

This explains the weird behavior I've been experiencing with DD2's gem bombs.

Let me see if I can reproduce it.

[Major Cooke]

There's a couple ways this could be fixed.

I could either move the P_DamageMobj call into P_ExplodeMissile that's found in PIT_CheckThing (p_map.cpp line 1565), ensuring P_ExplodeMissile accurately handles all future impact damage appropriately:

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damage = tm.thing->GetMissileDamage((tm.thing->flags4 & MF4_STRIFEDAMAGE) ? 3 : 7, 1);
if ((damage > 0) || (tm.thing->flags6 & MF6_FORCEPAIN) || (tm.thing->flags7 & MF7_CAUSEPAIN))
{
   int newdam = P_DamageMobj(thing, tm.thing, tm.thing->target, damage, tm.thing->DamageType);
   //...

Or I could go the simple route and insert P_DamageMobj here:

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if (Vel.Z != 0 && (BounceFlags & BOUNCE_Actors))
{
   bool res = P_BounceActor(this, onmo, true);
   // If the bouncer is a missile and has hit the other actor it needs to be exploded here
   // to be in line with the case when an actor's side is hit.
   if (!res && (flags & MF_MISSILE))
   {
      P_ExplodeMissile(this, nullptr, onmo);
   }
}

Which one seems better? The former, I can include a boolean that disables damage as needed.

[Marisa Kirisame]

wouldn't calling explodemissile cause the projectile to, you know, explode, even in cases where they might still keep bouncing?

[Graf Zahl]

Yes. It's also not the function inflicting the damage.

[Major Cooke]

If neither of those are fitting solutions, what is?

[Graf Zahl]

That's the problem, I don't really know how to do it without causing unintended side effects.

[SanyaWaffles]

This is becoming extremely noticeable at times in my project. You can hit an enemy square on the top and there's no damage or whatever when using bouncing bombs. It's an extremely aggravating bug and there's no way to fix.

[Major Cooke]

It might be worth going back to Cacodemon345's commits and finding out what he fixed.