This was done to clean up the license and to ensure that any commercial fork of the engine has to obey the far stricter requirements concerning source distribution. The old license was compatible with GPLv2 whereas combining GPLv2 and LGPLv3 force a license upgrade to GPLv3. The license of code that originates from ZDoomGL has not been changed.
- added colormap shader to postprocessing.
This replaces the in-place application of fullscreen colormaps if renderbuffers are active. This way the fully composed scene gets inverted, not each element on its own which is highly problematic for additively blended things.
- only disable clip planes on Windows, but not on Linux or macOS.
- If a driver reports full OpenGL 4.5 support, assume that all features are working properly.
Unfortunately the math behind the old clip planes is utterly impenetrable and so poorly documented that I have no idea how to set that up, so it is deactivated for now. It wasn't working anyway.
Regular skies need it off but SkyViewpoints need it on - and all others need to use the parent's setting.
So without engine side tracking we can end up rendering the sky with this setting off, resulting in omission of the fog layer.
- we need to check all GL versions when trying to get a context because some drivers only give us the version we request, leaving out newer features that are not exposed via extension.
- added some status info about uniform blocks.
- reactivate alpha testing per fixed function pipeline
- use the 'modern' way to define clip planes (GL_CLIP_DISTANCE). This is far more portable than the old glClipPlane method and a lot more robust than checking this in the fragment shader.
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.
- Also fixed some very strange thing in the shader's desaturate function. For unknown reasons using the 'mix' function there did not work.
- fixed: The fog boundary special shader could not be used.
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.
