This patch changes the audio mixer faders to use a non-linear algorithm
for volume control. The intention is to make Godot's audio faders be
more like those found in professional audio equipment and programs. It
is an exponential equation which intends to counter-act the logarithmic
nature of human hearing. The effect of this is a more usable audio mixer
with more emphasis on the values that make the most difference to the mix.
It also changes the audio level notch widget to be less static and
thus supports changing the scaling factor of the audio faders.
This allows more consistency in the manner we include core headers,
where previously there would be a mix of absolute, relative and
include path-dependent includes.
Using `misc/scripts/fix_headers.py` on all Godot files.
Some missing header guards were added, and the header inclusion order
was fixed in the Bullet module.
Rename user facing methods and variables as well as the corresponding
C++ methods according to the folloming changes:
* pos -> position
* rot -> rotation
* loc -> location
C++ variables are left as is.
Currently we rely on some undefined behavior when Object->cast_to() gets
called with a Null pointer. This used to work fine with GCC < 6 but
newer versions of GCC remove all codepaths in which the this pointer is
Null. However, the non-static cast_to() was supposed to be null safe.
This patch makes cast_to() Null safe and removes the now redundant Null
checks where they existed.
It is explained in this article: https://www.viva64.com/en/b/0226/
Fixes a bunch of the most spammy console errors introduced by recent refactorings:
- `AudioServerState` does not exist, this was the reference to it in the source. The surrounding code made it clear that `AudioServerLayout` was meant to be used instead.
- `StreamCSVTranslation` same here, it's the only reference. I went with `Translation` here, but I'm not 100% sure on this one.
- Some methods have been moved from `Texture` to `Image`, but the old bindings were still there.
- A few `name == ""` errors related to duplicating nodes.
