Entities

[Cobalt]

Was wondering is there a difference between :

entity THIS;


and


THIS = spawn ();


?


From what I have seen, you can assign THIS paramaters with just it being a global float, such as THIS = THAT; etc
....so I was believing merely floating it globally was like spawning it, but I guess spawn () means its now a dynamic entity and therefore can be removed?
Lets say we walked the ent list via prvm_edicts ....would we see the the global float listed or no? Is the flobal float considered a static ent? Id think no, because we can assign it paramaters via qc....

[Spike]

you're confusing yourself now.
if 'entity this' was equivelent to 'this = spawn()' then all those statements that change self=foo all the time would require spawning new entities! expensive as heck, especially when you consider self.enemy.enemy.enemy.enemy.enemy...

all entity _variables_ are merely references to an entity object. uninitialised ones refer to the world (aka: worldspawn) entity.
thus 'entity this;' is generally equivelent to 'entity this = world;'


internally the vanilla engine has a pre-allocated array of entities.
your qc entity variables are actually an integer indexing into that array.
world is entity index 0, and thus uninitialised ents are equivelent to world.

[Cobalt]

[Spike]

spawn allocates a new entity and returns a reference to that entity. one that isn't world.

[mankrip]

[mankrip]

[Cobalt]

Hmm interesting. Did some real tests with the Darkplaces engine.

entity THIS;

if (THIS == world)
eprint (THIS);


[ prints nothing , eprint ignored ]

Remove the ' if ' statement and you get:

server: FREE


Replace the ' if ' statement with :

THIS = spawn ();

and eprint returns.....

server EDICT 229:


So spawn () is giving it an edict number and no other paramaters. If its got an edict num != 0 its not world I believe.

So neither of these are technicly ' world ' , though I guess calling any .entity definitions for them would return world by default.

I was curious about this to solve an issue where the local spawn () entity would be removed, the next frame, but it was being carried to another function before that frame, yet the other function was still seeing it as a freed entity....and returning a world origin. Im guessing the only way to fix it is also put it in the global after the local is spawned, and use the global in the other function , rather than returning it as an entity (). Thanks people.