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.
Version 3 does not send xdg_output.done events, instead guaranteeing that
all xdg_output.* events are sent before wl_output.done. This saves us from
doing the work twice.
The method used is not guaranteed to work on all Wayland compositors,
so offer a way out. We need to support it anyways in case xdg_output
or wp_viewporter protocols are not available.
Currently, we scale the desktop up to the next largest integer, and rely on
the wayland compositor to scale it back down to the correct size.
This is obviously undesirable.
In this commit, we attempt to detect the actual fractional scaling by finding
the current active mode in wl_output, and dividing it by the logical screen
size reported by xdg_output, taking into consideration screen rotation.
We then use wp_viewporter to set the exact buffer and viewport sizes if
fractional scaling is needed.
The default of [0, 50] makes sense for FPS/UPS graphs, but does not for
things like the import graph. The latter should not take more than 5 ms
for sure.
This commit allows the min/max y-axis value to be specified when registering
the graph.
Currently, we dispatch the events on the wayland display server ourselves.
This is fine when using the cairo backend of libdecor, as it does the same
thign we do, but other backends may require other things to be dispatched.
This commit lets libdecor dispatch events instead through libdecor_get_fd
and libdecor_dispatch, which should hopefully makes things less sketchy.
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.
This should fix the occasional Wayland protocol errors that arise when
the UI thread and the cursor thread race.
Example of error that is fixed:
zwp_pointer_constraints_v1@11: error 1: a pointer constraint with a wl_pointer of the same wl_seat is already on this surface
This commit restructures the Wayland clipboard handling for host->VM.
Before, we select one clipboard format and buffers the data for it, to
be presented to spice when needed.
Now, we simply offer all clipboard formats supported, and only when spice
asks for the data do we actually read the wl_data_offer. The wl_data_offer
is kept around until a new offer is presented, the offer invalidated, or
when we lose keyboard focus. This is in accordance with the specification
for wl_data_device::selection, which states that:
> The data_offer is valid until a new data_offer or NULL is received or
> until the client loses keyboard focus. The client must destroy the
> previous selection data_offer, if any, upon receiving this event.
We still buffer the entire clipboard data into memory because we have no
knowledge of the clipboard data size in advance and cannot do incremental
transfers.
Furthermore, if the user performs drag-and-drop on our window, we may have
need to handle multiple wl_data_offer objects at the same time. Therefore,
instead of storing state on the global wlCb object, we instead allocate
memory and store it as user_data on the wl_data_offer. As a result, we also
handle drag-and-drop so that we can free the memory.
Support for non-PNG types is optional in the spice agent, so we should
avoid sending those if PNG is available.
Currently, the spice VDAgent supports only PNG and BMP formats.
Instead of damaging the entire surface when rendering a cursor move,
we can use the EGL_KHR_swap_buffers_with_damage extension to only
damage the part of the window covered by the cursor. This should
reduce the cursor movement latency on Wayland.
