This is needed for using GstGL with ANGLE as the GLES implementation
in Universal Windows Platform apps that use the Windows Runtime
(WinRT) instead of Win32, which is deprecated and not allowed in
Windows Store apps.
This has been tested with Servo on the Microsoft HoloLens 2, and seems
to work quite well.
By passing NULL to `g_signal_new` instead of a marshaller, GLib will
actually internally optimize the signal (if the marshaller is available
in GLib itself) by also setting the valist marshaller. This makes the
signal emission a bit more performant than the regular marshalling,
which still needs to box into `GValue` and call libffi in case of a
generic marshaller.
Note that for custom marshallers, one would use
`g_signal_set_va_marshaller()` with the valist marshaller instead.
Doing so involves retrieving the current viewport from OpenGL which as
with any glGet operation, is expensive.
This means that the various sinks need to reset the viewport on draw.
In the process, fix resizing on cocoa.
Make a bunch of symbols private that are currently leaked
accidentally because they have a gst_* prefix and are used
internally. We mark those we can't make static with
G_GNUC_INTERNAL so that they get hidden with the autotools
build as well (although we could just pass -fvisibility=hidden
there too).
No-one's using/depending on it (it would have criticalled and not worked)
and it's causing more problems than it's solving. Store the GMainContext
in the public struct instead for subclasses to optionally use instead of
relying on the push/pop state to be correct.
https://bugzilla.gnome.org/show_bug.cgi?id=775970
Calling g_main_context_push_thread and then g_main_context_invoke()
(used by gst_gl_window_send_message_async()) in the same thread will
cause the invoked function to run immediately instead of being delayed.
This had implications for the creation of the OpenGL context not waiting
until the main loop had completely started up and as a result would
sometimes deadlock in short create/destroy scenarios.
https://bugzilla.gnome.org/show_bug.cgi?id=775171
Using g_thread_join() in _finalize() handlers may result in a deadlock
joining the current thread when the last reference is held by a signal
handler.
e.g.:
error 'Resource deadlock avoided' during 'pthread_join (pt->system_thread, NULL)'
The backtrace looks like this:
[...]
g_thread_join ()
gst_gl_window_finalize ()
gst_gl_window_x11_finalize ()
g_object_unref ()
g_value_unset ()
g_signal_emit_valist ()
g_signal_emit ()
gst_gl_window_send_mouse_event ()
gst_gl_window_mouse_event_cb ()
g_main_dispatch ()
[..]
g_main_loop_run ()
gst_gl_window_navigation_thread ()
g_thread_proxy ()
start_thread ()
clone ()
Makes infinitely more sense and implementation were expecting that behaviour
anyway and would enter a resize, draw, resize, draw, ... cycle instead of only
resizing once.
Don't create many short lived locks/conds in gst_gl_window_send_message. This is
a micro optimization to save a bunch of pthread_* calls which are expensive on
OSX/iOS and possibly other platforms.
Useful when gst_gl_window.c::gst_gl_window_new is not used.
This is the case when using a custom GstGLWindow.
(ex: GstGLWindowGPUProcess from Chromium)
Exposing the navigation thread's main context, GSourceFuncs and structs called
key_event and mouse_event is exposing a bit too much of the internals. Let's
just go with two functions to asynchronously send navigation events on the
window with the same API as the synchronous ones.
- glimagesink needs to be able to resize the viewport on aspect ratio
changes resulting from either caps changes or 3d output mode changes.
- Performing a glViewport outside the GstGLWindow::resize callback
will not have the winsys' stack of viewports required to correctly
place the output frame.
Provide a function to request a resize on the next draw event from the
winsys.
Also track size changes inside the base GstGLWindow class rather
than in each subclass.
https://bugzilla.gnome.org/show_bug.cgi?id=755111
