Allow to use the opengl context sharing feature if the original
context has been used already.
This is only possible on win32 with wglShareLists because on other
backends, the sharing is made when a context is created.
This new feature is only usefull when using external context
because gst-gl internally makes sure that the orginal context is not
already used when sharing it.
Fix bug #611067
First, inactivate shared gl contexts known by each sink pad.
Then, destroy the gl context known by the glmixer.
Finally, re-activate shared gl contexts.
This is to satisfy the fact that no shared gl context must be current
when an opengl context is destroyed.
Moreover the application may hang or crash without those steps.
For now only identity, mirror and squeeze effects are available.
Maybe some factorization is needed about compilation shader
before to put the other effects since only a copy/past is needed,
at least until effect number 9: heat.
The effects from 10:sepia to 15:glow require more work.
qglwtextureshare now works again. In this example,
the pipeline is src ! glupload ! fakesink.
So in this case the glupload element is a sink in
terms of gl chain.
But the problem is still there if the pipeline is
src ! glupload ! glfilter ! fakesink
(it's the case in sdlshare and cluttershare examples)
because since recent changes about how the gstgldisplay
is transmitted to the gl element, the context is usually
created by the sink in terms of gl chain.
A solution would be to also install this property on glfilter.
The background image needs to be scaled to fit current texture size.
Previously this was done by gdk_pixbuf_scale_simple but that's been
removed.
Create a texture from the background pixbuf with correct dimensions and
use interpolation shader to scale it to the right size. Interpolation
fragment shader doesn't have too much sense if all the textures don't
have the same size so this seemed the most natural place to do the
scaling. It could probably be done with some custom texture mapping
outside the shader but it involved more code.
Fixes bug #599883.
Before, the window size was given at its creation. Now, it's done at
the drawing step because it's only relevant when there is a glimagesink
element in the pipeline.
glmixer can be seen as a glfilter except it handles N requested
sink pads.
Each sink pad and the src pad are video/x-raw-gl.
glmixer is responsible for managing different framerates from inputs.
It uses OpenGL context sharing. It means that each input is in its
own OpenGL context shared together and shared with the OpenGL context
of the ouput gl chain.
Also add a glmosaic which is an example of implementation of glmixer.
For now glmosaic is a cube but it will be fixed in the next commits.
For now the glmixer has some weird behaviours in some configurations
but it will be improved in the next commits.
The autotools builds is temporarly broken since those changes
have been made on win32.
Before, a gstgldisplay was instancied by the gl src in terms of gl chain.
And then the next element got it through the first gstglbuffer.
Now, this is done though queries.
All glelements get their ref on a gstgldisplay in READY state.
This rewrite is mainly a first step to be able to share OpenGL context hold
by the gstgldisplay using more complex glelements.
For example, with a glvideomixer. The associated gstgldisplay of each gl chain
of the sink pads will share their OpenGL context.
A texture is not destroyed when when we are done with it.
This texture is just added to the texture pool in order to be
re-used. In this case no OpenGL code is executed so we do not need to
request gl thread.
Add a pkg-config check for opengl and if not found assume opengl-es. If user has
none of both one still get build error later on (there is no pkg-config for
opengl-es).
Add more files to EXTRA dist and build the opengles variant if selected.
Simmilar changes could be done for the winCE backend.
Default implementation of NSOpenglView::update is not safe because it
just calls update on the opengl context whereas we are not in the gl thread.
Also fix the white flickering when resizing, because now we need to call
the draw callback manually when resizing.
