This should prevent the looking-glass-client window from having an alpha
channel. On Wayland, the alpha channel is used to compose the window onto
the desktop, so the wallpaper would bleed through unless set to complete
opaque.
We worked around this by using constant alpha for rendering, but it was
not sustainable. Instead, we should just ask for 24-bit context.
We ask for 32-bit colour buffer when creating the EGL context. On Wayland,
this sometimes give contexts with alpha channels, resulting in unwanted
transparency. So we clear the alpha channel in the desktop shader.
We also switch to using constant alpha for blending the splash, which
avoids more alpha issues.
This effectively reverts 4bceaf5.
Upstream ticket: https://gitlab.freedesktop.org/mesa/mesa/-/issues/4180
Commit 941c651 makes working around the hang in LG itself not as
annoying as before.
In the future, we can bypass this entire issue by implementing our own
swapchain and listening to frame callbacks ourselves.
Build failed with _FORTIFY_SOURCE enabled because the compiler couldn't
ensure the switch statements didn't hit the default arm and thus wouldn't
define the variables. Adding a statically failing assert makes sure that
all code paths either define the variables or fail early.
$ cd client
$ env CFLAGS='-O1 -D_FORTIFY_SOURCE=1' cmake -B build/
$ make -C build
[...]
client/renderers/EGL/egl.c: In function ‘egl_calc_mouse_size’:
client/renderers/EGL/egl.c:299:36: error: ‘h’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
299 | (this->mouseHeight * (1.0f / h)) * this->scaleY
| ~~~~~~^~~~
As the screen output rotation can be changed on the fly, if it has been
rotated to 90 or 270 the nearest flag will be incorrect, so we perform
this check here and override the provided value.
If the guest has it's output rotated (ie, landscape) we must rotate and
translate the pointer draw location, as well as all the translations of
cursor coordinate spaces based on the rotation, along with any local
rotations that may also be applied.
This makes it a compile-time error to call a function that semantically
takes no parameters with a nonzero number of arguments.
Previously, such code would still compile, but risk blowing up the stack
if a compiler chose to use something other than caller-cleanup calling
conventions.
This commit makes Looking Glass always use the OpenGL renderer when
running on Wayland. The EGL renderer is broken on Wayland and can't
reasonably be fixed until SDL is dropped entirely (as per
https://github.com/gnif/LookingGlass/issues/306).
Until that time, the OpenGL renderer provides a much better
Wayland-native experience.
eglSwapBuffers is allowed to block when called with a nonzero interval
parameter. On Wayland, Mesa will block until a frame callback arrives.
If an application is not visible, a compositor is free to not schedule
frame callbacks (in order to save CPU time rendering something that is
entirely invisible).
Currently, starting Looking Glass from a terminal, hiding it
entirely, and sending ^C will cause Looking Glass to hang joining the
render thread until the window is made visible again.
Calling eglDestroySurface is insufficient to unblock eglSwapBuffers, as
it attempts to grab the same underlying mutex.
Instead, this commit makes it so that we pass a 0 interval to
eglSwapBuffers when running on Wayland, such that we don't block waiting
for a frame callback. This is not entirely ideal as it *does* mean
Looking Glass submits buffers while hidden, but it seems better than
hanging on exit.
It also forces opengl:vsync and egl:vsync flags to off when running on
Wayland, as they are meaningless there.
Note: This only works with the KVMFR kernel module in a VM->VM
configuration. If this causes issues it can be disabled with the new
option `app:allowDMA`
