We're not currently using this, and dropping it allows us to loose
a bunch of code which leads us towards the goal of having GdkWindow
only for toplevels (and reparenting makes not sense for toplevels).
We can't really support these on e.g. wayland anyway, and we're trying
to get rid of subwindow at totally in the long term, so lets drop this.
It allows us to drop a lot of complexity.
gdk_window_create_vulkan_context() now exists and will return a Vulkan
context for the given window. It even initializes the surface. But it
doesn't do anything useful yet.
... instead of a gl context.
This requires some refactoring in the way we mark the shared context as
drawing: We now call begin_frame/end_frame() on it and ignore the call
on the main context.
Unfortunately we need to do this check in all vfuncs, which sucks. But I
haven't found a better way.
Reenable GL drawing, but do it without Cairo.
Now, the context passed to gdk_window_begin_draw_frame() decides how
drawing is going to happen. If it is NULL, Cairo is used like before.
If a context is passed, Cairo may not be used for drawing and
gdk_drawing_context_get_cairo_context() is going to return NULL.
Instead, the GL renderer must draw to the GL backbuffer and
end_draw_frame() is then swapping that to the front.
The GskGLRenderer has lost the texture it used to render to and adapted
to render directly to the backbuffer instead.
The only thing missing is for GtkGLArea to gain back a performant way to
render. But it didn't have one since the introduction of GSK, this
patchset doesn't change anything about it.
The new rendering avoids two indirections (the GSK renderer's texture
and the GDK double buffering surface).
It improves icon count in the fishbowl demo by 30%.
This way, we can query the GL context's state via
gdk_gl_context_is_drawing().
Use this function to make GL contexts as attached and grant them access
to the front/backbuffer for rendering.
All of this is still unused because GL drawing is still disabled.
No visible changes as GL rendering is disabled at the moment.
What was done:
1. Move window->invalidate_for_new_frame to glcontext->begin_frame
This moves the code to where it is used (the GLContext) and prepares it
for being called where it is used when actually beginning to draw the
frame.
2. Get rid of buffer-age usage
We want to let the application render directly to the backbuffer.
Because of that, we cannot make any assumptions about the contents the
application renders outside the clip area.
In particular GskGLRenderer renders random stuff there but not actual
contents.
3. Pass the actual GL context
Previously, we passed the shared context to end_frame, now we pass the
actual GL context that the application uses for rendering. This is so
that the vfuncs could prepare the actual contexts for rendering (they
don't currently).
4. Simplify the code
The previous code set up the final drawing method in begin_frame.
Instead, we now just ensure the clip area is something we can render
and decide on the actual method in end_frame.
This is both more robust (we can change the clip area in between if we
want to) and less code.
This is a temporary switch-off of the GL dawing code that will make
things keep running. All GL related code (like the GSK renderer or
GtkGLArea will now fall back to software.
Wayland subsurfaces can have other native window parents, but those need
to be destroyed along with the rest of the window hierarchy otherwise
an assert() is reached.
https://bugzilla.gnome.org/show_bug.cgi?id=774915
gdk_window_get_toplevel() walks up the windows tree looking for the
corresponding toplevel window, but needs to account for subsurfaces as
well on Wayland.
https://bugzilla.gnome.org/show_bug.cgi?id=775319
Now that subsurfaces can be created as child of another GdkWindow (and
not just the root window), they must be placed according to the location
of their parent, i.e. the abs_x/abs_y must be updated and taken int
account when placing and moving subsurfaces under Wayland.
https://bugzilla.gnome.org/show_bug.cgi?id=774917
The functions gdk_pixbuf_get_from_window() and
gdk_cairo_set_source_window() are unreliable and depend on the windowing
system (they work great on X11 and Win32, less so on Quartz and Wayland).
With the switch to new drawing API and OpenGL, we can definitely no
longer support a generic way to snapshot windows.
People should either write windowsystem-specific code or draw their
widgets directly - like with gtk_widget_draw() - if they need to get a
rendering.
Under Wayland, a subsurface can have another surface as parent, but
gdk would not allow native windows if the parent is not the root window.
Allow native subsurface for all parent under Wayland, not just for the
root window.
https://bugzilla.gnome.org/show_bug.cgi?id=774475
These complicate a lot of GdkWindow internals to implement features
that not a lot of apps use, and will be better achieved using gsk.
So, we just drop it all.
