* make all legacy light modes except 'Doom' MAPINFO only. A CVAR still exists for testing but its value won't be saved to the config.
* user can only select between "performance', 'software' and 'vanilla'. 'performance' is the old 'Doom' mode which is still needed to speed things up on low end hardware.
* MAPINFO can not enforce any of the two software light modes, as low end users require the option to change this to the 'performance' setting. Selecting one will always revert to the user's light mode selection.
This implements a bruteforce approach for 2D line antialiasing.
It's not perfect by any means, but it seems to do its job well enough.
Since it draws 9 lines instead of 1 line per segment, it's significantly
more expensive but should still be usable on modern hardware (except
on very complex maps).
Automap line antialiasing is disabled by default and can be enabled
with the `am_lineantialiasing 1` cvar.
This solves two problems:
* The linked list is too slow, a map is better. A map cannot be used with statically allocated CVARs because order of initialization is undefined.
* The current CVAR system is an unordered mishmash of static variables and dynamically allocated ones and the means of identification are unsafe. With this everything is allocated on the heap so it can all be handled the same by the cleanup code.
This can be used to improve automap readability on high-resolution
displays.
Some automap options in the menu were reordered to follow a more
logical order.
* Implement renderstyle and transparent actor sprite rendering in automap
* Add "am_advspriterender" CVAR and add invisible actor checks.
* Rename cvar to `am_thingrenderstyles`
currentUILevel is now primaryLevel.
For ZScript, currentVMLevel was added. This is also exported as 'level' and will change as needed.
This also means that no breaking deprecations will be needed in the future, because in order to sandbox a level only 4 variables need to be handled: level, players, playeringame and consoleplayer.
The remaining global variables are not relevant for the level state.
The static 'level' has been mostly removed from the code except some places that still need work.
This made reviewing the code for accessing the global state hard, because the doomdef.h contains mainly constants, this particular item was the only thing in there that represents actual engine state.
