Add Wayland support

Not everything is yet implemented, either for Godot or personal
limitations (I don't have all hardware in the world). A brief list of
the most important issues follows:

- Single-window only: the `DisplayServer` API doesn't expose enough
information for properly creating XDG shell windows.

- Very dumb rendering loop: this is very complicated, just know that
the low consumption mode is forced to 2000 Hz and some clever hacks are
in place to overcome a specific Wayland limitation. This will be
improved to the extent possible both downstream and upstream.

- Features to implement yet: IME, touch input, native file dialog,
drawing tablet (commented out due to a refactor), screen recording.

- Mouse passthrough can't be implement through a poly API, we need a
rect-based one.

- The cursor doesn't yet support fractional scaling.

- Auto scale is rounded up when using fractional scaling as we don't
have a per-window scale query API (basically we need
`DisplayServer::window_get_scale`).

- Building with `x11=no wayland=yes opengl=yes openxr=yes` fails.

This also adds a new project property and editor setting for selecting the
default DisplayServer to start, to allow this backend to start first in
exported projects (X11 is still the default for now). The editor setting
always overrides the project setting.

Special thanks to Drew Devault, toger5, Sebastian Krzyszkowiak, Leandro
Benedet Garcia, Subhransu, Yury Zhuravlev and Mara Huldra.

1 files changed, 29 insertions, 0 deletions

diff --git a/thirdparty/wayland/COPYING b/thirdparty/wayland/COPYING
new file mode 100644
index 0000000000..eb25a4e2b3
--- /dev/null
+++ b/thirdparty/wayland/COPYING
@@ -0,0 +1,29 @@
+Copyright © 2008-2012 Kristian Høgsberg
+Copyright © 2010-2012 Intel Corporation
+Copyright © 2011 Benjamin Franzke
+Copyright © 2012 Collabora, Ltd.
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of this software and associated documentation files (the "Software"),
+to deal in the Software without restriction, including without limitation
+the rights to use, copy, modify, merge, publish, distribute, sublicense,
+and/or sell copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice (including the next
+paragraph) shall be included in all copies or substantial portions of the
+Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+DEALINGS IN THE SOFTWARE.
+
+---
+
+The above is the version of the MIT "Expat" License used by X.org:
+
+    http://cgit.freedesktop.org/xorg/xserver/tree/COPYING