- removed the mCameraPos variable in FGLRenderer because it was only used in one place where it is just as easy to use the global viewx/y/z variables directly.
Since rendering is asynchronous, the camera texture scene may not be finished once the main scene's lights get filled in. Unfortunately forcing a synchronization with glFinisg has bad side effects on performance the only remaining option is to use separate parts of the buffer for both scenes, which in extreme cases may increase the light buffer's size - but on modern hardware that shouldn't be a problem.
- avoid rebinding the same texture multiple times, as there's considerable overhead in the texture manager.
- check gl_sort_textures only once per scene, not per draw list.
- use sampler objects to avoid creating up to 4 different system textures for one game texture just because of different clamping settings.
- avoids flushing all textures for change of texture filter mode.
- separate sprite and regular dimensions on the material level to have better control over which one gets used. It's now an explicit parameter of ValidateTexture. The main reason for this change is better handling of wall sprites which may not be subjected to such handling.
- create mipmaps based on use case, not texture type.
- allows removal of FCloneTexture hack for proper sharing of the same sprite for decals and other purposes.
- better precaching of skyboxes.
- added a light preprocessing pass to the renderer so that a non-persistent buffer can be used with minimal mapping/unmapping. This only gets used if necessary because it adds some overhead to the renderer.
After thinking about it for a day or so I believe it's the best option to remove all compatibility code because it's a major obstacle for a transition to a core profile.
On GL 3.x+ this isn't needed at all and on older hardware it causes performance issues, in particular with hires textures due to impossibility of precaching.
In addition it forces some really awkward handling of lighting for things that have their own color, like stenciled sprites or particles.
With this special case gone it will be possible to handle this case in a saner manner than it is right now.
As compensation for older hardware a fullscreen blend will be drawn over the entire screen. This won't be 100% accurate but it's preferable to keeping the current method.
This means it won't work anymore on anything that doesn't support OpenGL 4.0, but I don't think this is a problem. On older NVidia cards performance gains could not be seen and on older AMDs using the vertex buffer was even worse as long as it got mixed with immediate mode rendering.
- removed gl_vid_compatibility. With the bump to 1.4 no hardware requiring this flag is supported anymore.
- disabled 16 bit framebuffers for the same reason. As a conseqence all code for rendering without stencil could also be removed.
