Unify the X11 and Wayland EGL contexts.
This is a bit ugly to implement, because I don't want to create an
interface and I can't make them inherit from the same object, because
one needs to inherit from X11GLContext and the other from
WaylandGLContext.
So we have to put the code in GdkGLContext and make sure non-EGL
contexts can't accidentally run it. This is rather easy because we can
just check for priv->egl_context != NULL.
We have a global GdkGLBackendType now, just set it.
This way, using the variable forces the backend type, and we don't need
special code handling the env vars in the backends.
It also means setting the env var will now "work" on GDK backends that
don't even support that GL backend and simualte another GDK backend
having registered that GL backend already. So you can run
GDK_DEBUG=gl-wgl gtk4-demo
on test what Wayland will do when WGL is in use.
Print the extensions one per line, and sort them
alphabetically, so it is actually possible to find
something in the list.
Also print a short description of the chosen config.
Print the extensions one per line, and sort them
alphabetically, so it is actually possible to find
something in the list.
Also print a short description of the chosen config.
Include the appropriate headers as some function prototypes were moved lately.
Also, re-order the include order of the gdk/*private.h headers alphabetically
in the files that were updated.
Creative people managed to create an X11 display and a Wayland display
at once, thereby getting EGL and GLX involved in a fight to the death
over the ownership of the glFoo() symbolspace.
A way to force such a fight with available tools here is (on Wayland)
running something like:
GTK_INSPECTOR_DISPLAY=:1 GTK_DEBUG=interactive gtk4-demo
Related: xdg-desktop-portal-gnome#5
On Windows, GLES is not that widely available unless one installs wrapper
libraries such as libANGLE, so GLES/EGL support on Windows is used more like
a fallback mode if Desktop OpenGL (WGL) support is inadequate on the system.
Hence, unless one forces WGL or EGL, we will first try to initialize WGL, and
then try to initialize GLES if enabled and if WGL initialization failed, and
then just return whatever the last result we can obtain from these
initialization attempts, since unlike X11 EGL contexts, we do not have
separate modes for WGL except for legacy and non-legacy contexts.
We were setting the WGL pixel format in GdkWin32Display too early, so the code
does not bail out correctly when we retry establishing the WGL context.
Fix this by pushing back setting the WGL pixel format only after it passes the
shader availability check.
Should fix issue #4257.
