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.
LevelLocals on the left side of.a function call will now always be remapped to 'Level', which will either remap to the same-named instance variable or the global deprecated one.
In a few degenerate cases where there is a conflicting local variable named 'level' it may error out but that is unavoidable here but this is very unlikely.
- moved parts of the render setup out of the separate render functions.
Things like particle and polyobject linking were duplicated several times for rendering different things in different renderers.
These things only need to be set up once before the renderer is started so it makes a lot more sense to consolidate them into one place outside the actual rendering code.
There is no need to do this deep inside the renderer where it required code duplication and made it problematic to execute on multiple levels.
This is now being done before and after the top level call into the renderer in d_main.cpp.
This also serializes the interpolator itself to avoid problems with the Serialize functions adding the interpolations into the list which can only work with a single global instance.
Since currently there is only one level, this will obvciously only run once on that level for the time being.
This is mainly used for CCMDs and CVARs which either print some diagnostics or change some user-settable configuration.
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 doesn't really write out any info for the pointer, if the level does not match it just errors out.
This is both for quick detection of badly used level data and for automatic restoring of the pointer from the serializer's working level.
This also removed the temporary workarounds in DAutomap and DLevelScript to restore these pointers when a savegame is loaded.
UI always runs on the primary level, so this does not need the ability to operate on multiple levels. Additionally, this can later be set to null when running play code so that scope violations result in an abort.
This also changes the action special interface to pass a Level parameter to the separate functions and makes a few other minor adjustments to the polyobject code.
This caused bad calculations with CMF_OFFSETPITCH. Note that to compensate for the fix, the SphericalCoords function had to have its own inversion of the value removed so that it calculates the same result as before.
There are several places where a temporary change of light mode is needed, all these made this change in the global level struct. Now the change is only local to the active draw info.
I have to wonder why it had to use such a complicated implementation that provided no advantages whatsoever.
The new code is just 1/5th of the old one's size and much closer to Hexen's original implementation which also was a simple array but with no means to resize the queue.
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.
