The Far clipping plane did not need to be nearly as high as it was, the new value is 32768, which I suspect is about how far software can render before it completely falls apart.
It is desirable to increase the near clipping plane to between 6-10, but it can introduce more issues with close geometry not being drawn when the player or camera is scaled or viewheight is set to MIN in first person view. It would also stop sprites from being drawn ever so slightly too early, but this isn't too much of an issue and isn't too noticeable with those values. Might look into scaling near clipping plane in accordance to camera scale in the future.
The reason for wanting to increase the near clipping plane is because the small value can cause very noticeable Z-fighting where there shouldn't be on older GPU's, usually Intel ones, that don't support 24-bits for the depth buffer.
Additionally, place some optimisations in both software and OpenGL; in particular one has been added for when all of back and front sector (floor and ceiling) is sky: since everything is "open" anyway, we can simply the usual checks involved.
Thankfully it was really just a copy+paste of the code I already tinkered with for the normal ceiling sky based thok barriers, but tweaked for floors instead
Draw Textures and Flats that have holes in them like a solid polygon so they use the depth buffer and don't need to be sorted
Disable all linear filtering on textures and flats that have holes in them, the linear filtering introduces translucency into the textures where the edges are. Leaving them with either a black border, or causing pixels behind the slightly translucent areas to not be drawn. Doesn't apply to sprites and the HUD as they are always already sorted properly.
Make the Alpha Testing more strict on non-translucent blend modes. This makes it so any transparency below 0.5 is discarded instead. Would make anything that is blended and has holes in it look slightly better, only the HUD and MD2s where the texture has holes are effected currently.
Set TF_TRANSPARENT on flat texture flags when there are holes in the texture.
Minor fix to make sure MD2s always set the right blend mode
Consistent flat alignment
Does what it says on the tin. Consistent between the three different plane drawers:
* Software flat (previously the only one working as intended)
* Software sloped (took a lot of work)
* OpenGL flat and sloped (worked reasonably well but used different signs for some reason)
Check out root/!LatestSRB2Files/srb2win_branch_flat2.exe, root/toaster/flatalignment.wad and any in-dev DSZ1 to test it all out.
See merge request !78
OpenGL papersprites
I don't know if anyone actually tested Sryder's original OpenGL papersprites support before it was merged in, but there was some issues with the papersprites themselves "wobbling" about in a sort of weird way depending on the angle you view it from or where you are. It's easiest to see what I mean if you just load up sawb.wad, and strafe about when viewing one of the sawblades.
Thankfully all I really needed to do was tweak the way angles work for papersprites. I also cleaned up Sryder's original code a little, not that I really needed to do so though.
See merge request !96
OpenGL slope FOF lighting fix
This fixes some issues with sloped FOFs that affect lighting in OpenGL (as in, those that cast a shadow or have a colormap). Particularly, they can do strange things to any wall textures adjacent to them, as we've noticed ourselves in levels for 2.2. =P
See merge request !194
Polyobject segs should ONLY be drawn if the polyobject itself is in the polylist of a subsector being rendered. That way you won't sometimes see polyobject walls through level boundaries, if you happen to be close enough to their pre-spawn locations outside the level (or in them, if you decided to go on a noclip journey).
Other notes:
* on second thought I'll keep the hw_clip functions' gld prefixes rather than HWR, not like it matters either way
* despite the extra lag it does fix the issues with translucent walls and such when displayed at different vertical angles, such as with the GFZ1 waterfall
Some texture-related fixes
Bugs fixed in this branch:
* upper/lower/middle textures with non-existent texture ids being capable of crashing the game. For instance, RVZ1 has colormap codes on non-colormap linedefs, which causes them to wind up with invalid texture ids because of how the game tries to interpret lower/upper textures with "#" followed by characters on normal linedefs. Fortunately these "textures" are normally not visible anyway (since they're all in control sectors) unless they are swapped with in-level textures by some crazy Lua script of some sort...
* animated single-patch textures with holes displaying garbage on first viewing (see this thread: https://mb.srb2.org/showthread.php?t=42195)
* the heights of the lighting (shadows or colormapping) from water/translucent/shadowcasting/etc FOFs become messed up when displayed on repeated midtextures.
See merge request !144
