This adds a new `earlyInit` call which allows the overlay to register
options before actually being intialized. Also the keybind handling and
state tracking for each overlay has been moved internal to the overlay
itself.
When entering overlay mode if the cursor was previously grabbed we
should restore the state when exiting overlay mode. This will also
correct the pointer setting it to NONE or SQUARE depending on the prior
grab state.
X11 needs to calibrate to get the best possible latency, as such it
needs the scene to render so that the render time of the scene can be
accounted for in the delay calculation.
The way things were handled in EGLTexture is not only very hard to
follow, but broken. This change set breaks up EGLTexture into a modular
design making it easier to implement the various versions.
Note that DMABUF is currently broken and needs to be re-implemented.
Without configuring Wayland compositors to send frame callbacks as late as
possible, JIT rendering can increase latency by more than one frame.
For example, by default, sway asks applications to render right after a
vblank, and does its own composition right after a vblank, resulting in
~2 frame's worth of latency. If max_render_time is set on the output,
it composes that many milliseconds before the vblank, losing ~1 frame's
worth of latency. If max_render_time is set on the window also, the frame
callback is sent that many milliseconds before composition, and we achieve
perfectly low latency.
Therefore, out of the box, JIT rendering should not be enabled, as manual
compositor configuration is required for optimal results.
For reference, the following sway settings results in the best latency:
output <insert output name> max_render_time 1
for_window [app_id="looking-glass-client"] max_render_time 1
This reverts commit 3baed05728.
When requested, JIT render mode will be used if the display server supports it.
Otherwise, a warning is generated instead.
This essentially uses the signalNextFrame logic for imgui, but for everything.
We automatically enable this mode when overlay is on.
Currently, this exposes some damage tracking bugs in the EGL renderer.
We look for the client config in $XDG_CONFIG_HOME/looking-glass/client.ini.
This is done because it's more conventional, and also allows us to add
additional configuration files, e.g. for the host.
We fallback to $HOME/.config as is standard, and then as a last resort use
getpwuid(getuid())->pw_dir. This is also recommended by the getpwuid manpage:
> An application that wants to determine its user's home directory should
> inspect the value of HOME (rather than the value getpwuid(getuid())->pw_dir)
> since this allows the user to modify their notion of "the home directory"
> during a login session.
