Having everything lumped together made this a maintenance hassle because it affected how the level has to be stored.
This hasn't been tested yet, so it may not work as intended!
I think these were the last two still missing it, all remaining uses of the global level variable are in code that doesn't get run through a level tick and are supposed to access the primary level.
The playsim really has no idea what the renderer is supposed to do here and the current system has some serious issues that eventually need addressing. So it is better to just set a flag that an actor needs to have its view interpolation reset if being used as a camera and let the render code deal with it.
This will keep the playsim clean of future changes to this feature.
This was always used with 'consoleplayer' which really is the only thing making sense here. But this is a part of the global state which should be avoided in play code.
In particular, this makes no real sense in case of secondary maps where it should always return false.
The Map loader may not access any global state at all - everything it can touch must be exchangable.
Furthermore, if we want to sandbox each level, there may be no direct access to any kind of global state whatsoever from the play code.
Depending on serialization order is not a good idea here, so now it's no longer stored as a parent in the main level script but explicitly checked for when looking for a variable.
This was done to ensure that this code only runs when the thinker itself is fully set up.
With a constructor there is no control about such things, if some common initialization needs to be done it has to be in the base constructor, but that makes the entire approach chosen here to ensure proper linking into the thinker chains impossible.
ZDoom originally did it that way, which resulted in a very inflexible system and required some awful hacks to let the serializer work with it - the corresponding bSerialOverride flag is now gone.
The only thinker class still having a constructor is DFraggleThinker, because it contains non-serializable data that needs to be initialized in a piece of code that always runs, regardless of whether the object is created explicitly or from a savegame.
This involves passing the level explicitly to many functions. What was done here may seem a bit excessive but at least it covers everything.
Most importantly, the global ActiveThinker pointer has been moved into FLevelLocals and is now getting tracked properly by the level without using dangerous assumptions about how the game organizes its data.
Unlike the other classes, the places where variables from this class were accessed were quite scattered so there isn't much scriptified code. Instead, most of these places are now using the script variable access methods.
This was the last remaining subclass of AActor, meaning that class Actor can now be opened for user-side extensions.
This thing made sense when GZDoom and ZDoom were separate projects to avoid having to change some core files for the added options.
Now, with only 3 ones remaining, one for FraggleScript and two for Extradata the overhead here is just too high. The 3 variables can just be moved to level_info_t without carrying along this much baggage.
Now a child type can decide for itself how to treat 'amount'.
The scripting interfaces to this function in ACS and FraggleScript have been consolidated and also scriptified.
