Except for gst/gl/gstglfuncs.h
It is up to the client app to include these headers.
It is coherent with the fact that gstreamer-gl.pc does not
require any egl.pc/gles.pc. I.e. it is the responsability
of the app to search these headers within its build setup.
For example gstreamer-vaapi includes explicitly EGL/egl.h
and search for it in its configure.ac.
For example with this patch, if an app includes the headers
gst/gl/egl/gstglcontext_egl.h
gst/gl/egl/gstgldisplay_egl.h
gst/gl/egl/gstglmemoryegl.h
it will *no longer* automatically include EGL/egl.h and GLES2/gl2.h.
Which is good because the app might want to use the gstgl api only
without the need to bother about gl headers.
Also added a test: cd tests/check && make libs/gstglheaders.check
https://bugzilla.gnome.org/show_bug.cgi?id=784779
At minimum, we only need to glFlush() if we are in a shared GL context
environment. Move the glFinish() to when the actual wait is requested
which may be never. Improves the throughput on older GL systems without
GL3/GLES3 and/or fence sync objects.
CPU waits are more expensive and are only required if the CPU is ever going to
access the data. GPU waits perform inter-context synchronisation and are cheaper
as they don't require CPU intervention.
gstglsyncmeta.c -fPIC -DPIC -o .libs/libgstgl_1.0_la-gstglsyncmeta.o
gstglsyncmeta.c: In function 'gst_buffer_add_gl_sync_meta':
gstglsyncmeta.c:131:1: error: control reaches end of non-void function [-Werror=return-type]
}
^
there could be other ways/requirements for synchronising two GPU command
streams (whether GL or platform specific).
e.g. glfencesync/eglwaitnative/cond/etc
Otherwise it could stay client side without being submitted to the GL
server resulting in another context waiting on a Fence that will never
become signalled causing a deadlock.
A context can create a GLsync object that can be waited on in order
to ensure that GL resources created in one context are able to be
used in another shared context without any chance of reading invalid
data.
This meta would be placed on buffers that are known to cross from
one context to another. The receiving element would then wait
on the sync object to ensure that the data to be used is complete.
