Add support for getting hardware presentation times from KMS (Wayland
sessions). Also implement cogl_get_clock_time which is required to compare
and judge the age of presentation timestamps.
For single monitor systems this is straightforward. For multi-monitor
systems though we have to choose a display to sync to. The compositor
already partially solves this for us in the case of only one display
updating because it will only use the subset of monitors that are
changing. In the case of multiple monitors consuming the same frame
concurrently however, we choose the fastest one (in use at the time).
Note however that we also need !73 to land in order to fully realize
multiple monitors running at full speed.
Meson uses the 'dependencies' field to determine and
parallelize build steps, but that isn't entirely true
with 'link_with'; this might cause a race condition
when generating header files while trying to build
them.
Fix that by only using 'dependencies' instead of 'link_with'.
This commit adds meson build support to mutter. It takes a step away
from the three separate code bases with three different autotools setups
into a single meson build system. There are still places that can be
unified better, for example by removing various "config.h" style files
from cogl and clutter, centralizing debug C flags and other configurable
macros, and similar artifacts that are there only because they were once
separate code bases.
There are some differences between the autotools setup and the new
meson. Here are a few:
The meson setup doesn't generate wrapper scripts for various cogl and
clutter test cases. What these tests did was more or less generate a
tiny script that called an executable with a test name as the argument.
To run particular tests, just run the test executable with the name of
the test as the argument.
The meson setup doesn't install test files anymore. The autotools test
suite was designed towards working with installed tests, but it didn't
really still, and now with meson, it doesn't install anything at all,
but instead makes sure that everything runs with the uninstalled input
files, binaries and libraries when running the test suite. Installable
tests may come later.
Tests from cogl, clutter and mutter are run on 'meson test'. In
autotools, only cogl and clutter tests were run on 'make check'.
