Enabled usage of embedded thirdparty libraries to make sure that they are in buildable state
Added GTK+ version 2 or 3 as dependency to each Linux target
This is better be made part of the 2D interface.
That would have been done long ago if it hadn't been for the totally incompatible way this was handled by the purely paletted software renderer.
Now with that out of the way there is no point keeping this code this deeply embedded in the renderer.
Although this is currently safe there is no guarantee that future refactorings will keep the current draw lists, so it's better if GLDecal used its own copy of the data.
- precalculate if a sector's floor and ceiling plane overlap. This avoids rechecking this for each single call of hw_FakeFlat.
- vertices must be marked dirty every time they change after map setup. That means that ChangePlaneTexZ must do this as well, because it cannot rely on interpolation taking care of it.
- Having a 'dirty' argument for SetPlaneTexZ's ZScript version makes no sense. If the value changes from the script side the vertices must always be marked to be recalculated.
This was all over the place, with half of it using the function and half doing incomplete checks on the underlying variables.
Also did some optimization on the IGNOREHEIGHTSEC flag: Putting it on the destination sector instead of the model sector makes the check even simpler and allows to precalculate the effect of 3D floors on the heightsec, which previously had to be run on every call and made the function too complex for inlining.
* only call hw_CheckViewArea if the result is not known yet.
* check the map up front if it even contains heightsecs. This allows to shortcut the above check entirely for maps without sector transfers and will allow further optimizations.
This should fix bug reported in https://forum.zdoom.org/viewtopic.php?
f=104&t=56682.
There were two problems:
1. Algorithm to select a free voice was not appropriate. Changed to a
simple "least-recently-freed voice" algorithm.
2. Sustained voices were treated as used voices and never got replaced.
Now sustained voices are preferentially replaced when there are no free
voices.
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.
