ZScript Discussion

[Graf Zahl]

The Loremaster uses DoSpecialDamage.

The difference is, DoSpecialDamage is called when it is decided that the projectile actually should damage the target, after it has already collided. SpecialMissileHit is for performing special actions BEFORE the projectile is exploded. This is used by a few Hexen projectiles that perform special actions on collision and do not explode, like the lightining attack. Do not confuse this with collision exclusion. It may sound similar on the surface but really is not.

[Major Cooke]

Does it take the HIT* pointer flags into account before SpecialMissileHit function is checked?

[Blue Shadow]

Can ZScript class be inherited from DECORATE actor?

No. Since DECORATE is parsed last the info is not available.

This is important and should emphasized, because this means that if you have mod A, which uses ZSCRIPT, and mod B, which uses DECORATE, and you want mod A to inherit classes from mod B, well, you won't be able to do that.

[Graf Zahl]

Does it take the HIT* pointer flags into account before SpecialMissileHit function is checked?

Can't say. SpecialMissileHit gets called right before deciding if ExplodeMissile needs to be callsed.

[Major Cooke]

Oh wait, I don't need those. It takes an actor called victim instead which is all I needed.

To clarify about this recent new addition of 'let p = Classtype(objectvar)'... If 'p' is not, say, MinotaurFriend like the change you made, would it return null even though it exists as something else? That is, if it's a different class instead of minotaurfriend. Would p be null?

[Graf Zahl]

Yes. That's the entire point of a dynamic cast - it prevents that you access an incompatible object through a pointer.

[Major Cooke]

Okay, so what other 'special' words are there besides 'is' and 'let'? It's time to start adding these all to the wiki again.

[Graf Zahl]

Take a look at sc_man_scanner.re That contains all the reserved words, although many of them are just reserved but not used. Or do you only want to know the ones that do something? That list is in zcc_parser.cpp.

[Major Cooke]

The latter. And okay. Now I need clarification on what the following are:

• until
• in
• out

[Graf Zahl]

'until' is sometimes used as a negative 'while'. Although being parsed it's currently not being processed by the compiler.
In and Out are qualifiers for function parameters, 'out' causes a parameter being passed by reference. 'In' can be added as well, but has no function, it merely serves as means of documentation.

[Major Cooke]

Alright.

Next question, how does GetSpriteIndex work? Does it convert the frame's A-Z (or whatever limit it is, I forgot) from 0 to that limit? Is the 'sprite' property what we use to compare/find what sprite an actor currently has?

[Graf Zahl]

No, it takes the four character name and returns the internal index for it.

[Xaser]

Oh, that's interesting. Could that function be used to set an actor's sprite property directly via something like:

Code: Select all

self.sprite = GetSpriteIndex("SHTG");

?

(Can't test that code presently but that seems to be way thingdef_states.cpp is using said function internally. This would be extremely useful for a thing I'm planning on making).

[Graf Zahl]

Yes, that should work.

[D2JK]

Suggestion: could someone please make a wiki page or section about iterators, documenting any of the following:

- brief introduction, their purpose, and how they work
- iterator types (ActorIterator, ThinkerIterator, anything else?)
- what sort of task does each type excel at
- perhaps a brief explanation of the performance cost
- usage instructions, the options available, example code