For an unknwon reason when LG is on another desktop (hidden) and the
user switches to that desktop, the first attempt to grab the pointer
results in a GrabFrozen result. This adds some simple retry logic to
attempt again after a short (100ms) delay which seems to resolve the
issue.
The Linux OpenGL ABI does not guarantee that glXSwapIntervalEXT will be
exported statically from any library, and indeed on some systems this
function does not link at load time, e.g. with amdgpu-pro. All other
GLX functions that we use are from GLX 1.0, which is guaranteed to be
exported statically.
This commit solves this issue by using glXGetProcAddressARB to load the
function. Note that only the ARB version of glXGetProcAddress is
guaranteed to exist by the Linux OpenGL ABI, which is why we must use
it.
External events like launching other applications can cause latency
spikes while X11 initializes the application, we should only start
adjusting our delay if we see excessive skips over a 1s period.
Invalidating the entire window on an Expose event causes poor WM
performance when dragging the window around. Instead flag to redraw and
wait for the expose events to stop for 100ms before doing it.
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.
XPresent doesn't give us the time before presentation, but the time just
after. This code calculates and calibrates a delay to sleep for before
signaling the wait event for render when using jitRender
The imgui overlay requires input even if the display is not captured and
operating in raw mode. XInput2 correctly only sends
XI_Press/ReleaseButton events if the device has not been captured, as
such it's safe to handle both raw and non raw buttons events at the same
time.
This commit creates a new utility library, eglutil.h, which contains code
to detect and use EGL_KHR_swap_buffers_with_damage or its EXT equivalent.
This logic used to be duplicated between the X11 and Wayland display servers,
which is not ideal.
Drawing to the front buffer directly requires special handling to
prevent seeing the draw progress (avoiding glClear, etc) and as a result
the output is quite bad unless a compositor is running. Also vsync if
enabled will not function without double buffering enabled.
As OpenGL is the legacy fallback, there are no plans to implement clean
front buffer draw support, so just enable double buffering.
