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.
Most importantly, the separate command line options for switching on the legacy buffer handling have been removed.
There's really no need for them anymore, because unlike in earlier versions many of the implementation differences no longer exist - with the exception of where the light and vertex buffer contents are generated.
For testing this, -glversion 3 is sufficient.
Like Linux and macOS this will only support borderless fullscreen in the active desktop resolution now, which is what modern systems need.
The list of discrete resolutions has been removed as it makes no sense anymore with a fixed video mode - all the other scaling options remain active, though.
Lots of this was still laid out for DirectDraw. This removes most of Begin2D so that it can be done more cleanlz.
Note that this commit renders weapon sprites and screen blends incorrectly. Those will be fixed in an upcoming commit.
- with renderers freely switchable, some shortcuts in the 3D floor code had to be removed, because now the hardware renderer can get FF_THISINSIDE-flagged 3D floors.
- changed handling of attenuated lights in the legacy renderer to be adjusted when being rendered instead of when being spawned. For the software renderer the light needs to retain its original values.
This does not work with a setup where the same backend is driving both renderers.
Most of this is now routed through 'screen', and the decision between renderers has to be made inside the actual render functions.
The software renderer is still driven by a thin opaque interface to keep it mostly an isolated module.
In its current form this is quite useless. What's really needed is to require a lock on the RenderBuffer for the 3D scene, but since this is not needed for the 2D stuff anymore it can be done far simpler.
This was a bad idea from the start and really only made sense with DirectDraw.
These days a FrameBuffer represents an abstract hardware canvas that shares nothing with a software canvas so having these classes linked together makes things needlessly complicated.
The software render buffer is now a canvas object owned by the FrameBuffer.
Note that this commit deactivates a few things in the software renderer, but from the looks of it none of those will be needed anymore if we set OpenGL 2 as minimum target.
