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.
- move a few variables from SceneDrawer to FRenderViewpoint.
The global r_viewpoint variable is left alone now to always represent the current viewpoint to the play code.
The main reason behind this change is to reduce the amount of global variables being used by the hardware renderer's scene processing code.
This removes 3 uniforms, consisting of 9 floats. Those were merged into other values that never get used at the same time.
It also moves the costly setup of the fixed colormap out of the render state into the 2D processing code.
Since 3D forces use of render buffers now, it is no longer necessary to draw the entire scene with the colormap active, meaning it can be handled more efficiently.
This is now allowed to overestimate the number of vertices to reduce computation time for a rarely occuring special case that was eating most of the time and was causing errors with some walls.
Decals will now be processed into a list in the processing pass, allowing to use the vertex buffer even on GL3 hardware and to offload this part of the work to a multithreaded worker task.
