This has the benefit that we can refactor it and make sure we deal with
GdkDisplay::init_gl() not being called at all because
GDK_DEBUG=gl-disable had been specified.
It's not used there, but both backends have independent
immplementationgs for it.
I want to get rid of GdkGLContextX11 and moving code from it is the
first step.
Now that we have the display's context to hook into, we can use it to
construct other GL contexts and don't need a GdkSurface vfunc anymore.
This has the added benefit that backends can have different GdkGLContext
classes on the display and get new GLContexts generated from them, so
we get multiple GL backend support per GDK backend for free.
I originally wanted to make this a vfunc on GdkGLContextClass, but
it turns out all the abckends would just call g_object_new() anyway.
Instead of
Display::make_gl_context_current()
we now have
GLContext::clear_current()
GLContext::make_current()
This fits better with the backends (we can actually implement
clearCurrent on macOS now) and makes it easier to implement different GL
backends for backends (like EGL/GLX on X11).
We also pass a surfaceless boolean to make_current() so the calling code
can decide if a surface needs to be bound or not, because the backends
were all doing whatever, which was very counterproductive.
... or more exactly: Only use paint contexts with
gdk_cairo_draw_from_gl().
Instead of paint contexts being the only contexts who call swapBuffer(),
any context can be used for this, when it's used with
begin_frame()/end_frame().
This removes 2 features:
1. We no longer need a big sharing hierarchy. All contexts are now
shared with gdk_display_get_gl_context().
2. There is no longer a difference between attached and non-attached
contexts. All contexts work the same way.
The vfunc is called to initialize GL and it returns a "base" context
that GDK then uses as the context all others are shared with. So the GL
context share tree now looks like:
+ context from init_gl
- context1
- context2
...
So this is a flat tree now, the complexity is gone.
The only caveat is that backends now need to create a GL context when
initializing GL so some refactoring was needed.
Two new functions have been added:
* gdk_display_prepare_gl()
This is public API and can be used to ensure that GL has been
initialized or if not, retrieve an error to display (or debug-print).
* gdk_display_get_gl_context()
This is a private function to retrieve the base context from
init_gl(). It replaces gdk_surface_get_shared_data_context().
We try EGL first, but are very picky about what we accept.
If that fails, we try to go with GLX instead.
And if that also fails, we try EGL again, but this time accept anything.
The idea here is that EGL is the preferred method going forward, but GLX is
the tried and tested method that we know works. So if we detect issues with
EGL, we want to avoid using it in favor of GLX.
Also add a GDK_DEBUG=gl-egl option to force EGL at all costs and not try
GLX.
That way, we can give a useful error message when things break down for
users.
These error messages could still be improved in places (like looking at
the actual EGL error codes), but that seemed overkill.
Instead of going via GdkVisual, doing a preselection and letting the GL
initialization improve it, let the GL initialization pick an X Visual
directly using X Visual code directly.
The code should select the same visuals as before as it tries to apply
the same logic, but it's a rewrite, so I expect I messed something up.
There's no need to use g_object_set_data() for it.
We can also stop caching it elsewhere because we know the display has
it.
And finally, we can remove the display->have_egl boolean and use
display->egl_display != NULL instead. We initialize the display at
startup, so that variable is the perfect indicator.
We need to initialize GL to select the Visual we are going to use for
all our Windows.
As the Visual needs to be known before we know if we are even gonna use
GL later, we can't avoid initializing it.
Note that this previously happened, too. It was just hidden behind the
GdkScreen initialization.
If we want to add an EGL implementation for the X11 backend, we are
going to need to move the GLX bits into their own class. The first step
is to declare GdkX11GLContext as an abstract type, and then subclass it
into a GdkX11GLContextGLX type, which includes the whole GLX
implementation.
If cairo is a subproject, it's not necessarily installed when gtk
is built. In the source tree, cairo's headers are not stored in
a directory called 'cairo'.
It was used by all surfaces to track 'is-mapped', but still part of the
GdkToplevelState, and is now replaced with a separate boolean in the
GdkSurface structure.
It also caused issues when a widget was unmapped, and due to that
unmapped a popover which hid its corresponding surface. When this
surface was hidden, it emitted a state change event, which would then go
back into GTK and queue a resize on popover widget, which would travel
back down to the widget that was originally unmapped, causing confusino
when doing future allocations.
To summarize, one should not hide widgets during allocation, and to
avoid this, make this new is-mapped boolean asynchronous when hiding a
surface, meaning the notification event for the changed mapped state
will be emitted in an idle callback. This avoids the above described
reentry issue.
Not all compositors support _NET_WM_FRAME_DRAWN. In cases
where the compositor doesn't support _NET_WM_FRAME_DRAWN we don't
need to do all the fancy damage tracking and fence watching.
Furthermore, if the compositor doesn't support _NET_WM_FRAME_DRAWN,
it's possible that one frame will start before the previous frame has
made it through the pipeline, leading to a blown assertion.
This commit side-steps the unnecessary code and associated assertion
when _NET_WM_FRAME_DRAWN isn't supported.
Fixes: https://gitlab.gnome.org/GNOME/gtk/-/issues/2927
Since commit 972134abe4 we now call
glClientWaitSync for the vendor nvidia driver, to know when a frame
is ready for the compositor to process.
If a surface is hidden while a frame is still being rendered by the GPU,
the surface will never produce the damage event the code relies on to
trigger the call to glClientWaitSync. This leaves the fence dangling,
and the next time the surface is shown, it will start a fresh frame
and blow an assertion since the fence from the last frame is still
hanging around.
This commit ensures a frame gets fully wrapped up before hiding a
surface.
Commit a0f6ff101e made sure that a
context was bound before calling glClientWaitSync, but it doesn't
check that the context shares objects with the context that created
the fence.
This commit does a little more validation before deciding the current
context is good enough.
Since commit 972134abe4 we now call
glClientWaitSync for the vendor nvidia driver, to know when a frame
is ready for the compositor to process.
glClientWaitSync can be called regardless of which context is currently
bound, but if no context is bound at all, it returns 0 without
doing anything.
This commit checks for that edge case, and ensures a context gets
made current in the event no context is already current, before calling
glClientWaitSync.
When given a 0 timeout, glClientWaitSync is only supposed to return one
of three possible values:
- GL_ALREADY_SIGNALED - fence fired
- GL_WAIT_FAILED - there was an error
- GL_TIMEOUT_EXPIRED - fence hasn't fired yet
In addition, it can also return GL_CONDITION_SATISFIED if a non-zero
timeout is passed, and the fence fires while waiting on the timeout.
Since commit 972134abe4 we now call
glClientWaitSync (with a 0 timeout), but one user is reporting it's
returning some value that's not one of the above four.
This commit changes the g_assert to a g_error so we can see what
value is getting returned.
May help with https://gitlab.gnome.org/GNOME/gtk/-/issues/2858
With the vendor provided Nvidia driver there is a small window of time
after drawing to a GL surface before the updates to that surface
can be used by the compositor.
Drawing is already coordinated with the compositor through the frame
synchronization protocol detailed here:
https://fishsoup.net/misc/wm-spec-synchronization.html
Unfortunately, at the moment, GdkX11Surface tells the compositor the
frame is ready immediately after drawing to the surface, not later,
when it's consumable by the compositor.
This commit defers announcing the frame as ready until it's consumable
by the compositor. It does this by listening for the X server to announce
damage events associated with the frame drawing. It tries to find the
right damage event by waiting until fence placed at buffer swap time
signals.
We don't need the complicated wrapper system anymore,
since client-side windows are gone. This commit moves
all the vfuncs to GtkSurfaceClass, and changes the
backends to just derive their surface implementation
from GdkSurface.
As per the spec:
> The back buffer can
> either be reported as invalid (has an age of 0) or it may be
> reported to contain the contents from n frames prior to the
> current frame.
So a buffer age of 1 means that the buffer was used in the last frame.
We were handling buffer_age==1 the same as buffer_age==0, i.e. we
returned the full damage for the surface.
[1] https://www.khronos.org/registry/EGL/extensions/EXT/EGL_EXT_buffer_age.txt
We used to pass 2 regions to GdkDrawCotnext.end_frame() but code was
confusing what they meant. So we now don't do that anymore and only pass
the region that matters: The frame region.
This makes the previous gdk_draw_context_is_drawing() function public
under a new name.
I decided against the old name because we use the term "frame" for a
drawing operation, so I wanted to have this boolean flag reuse the term.
That way, we can store the right region there: The actual painted area
instead of the exposed area (which is way too small).
Also, the GL context is the only user of this data, so storing it there
seems way smarter.
This is an automatic rename of various things related
to the window->surface rename.
Public symbols changed by this is:
GDK_MODE_WINDOW
gdk_device_get_window_at_position
gdk_device_get_window_at_position_double
gdk_device_get_last_event_window
gdk_display_get_monitor_at_window
gdk_drag_context_get_source_window
gdk_drag_context_get_dest_window
gdk_drag_context_get_drag_window
gdk_draw_context_get_window
gdk_drawing_context_get_window
gdk_gl_context_get_window
gdk_synthesize_window_state
gdk_surface_get_window_type
gdk_x11_display_set_window_scale
gsk_renderer_new_for_window
gsk_renderer_get_window
gtk_text_view_buffer_to_window_coords
gtk_tree_view_convert_widget_to_bin_window_coords
gtk_tree_view_convert_tree_to_bin_window_coords
The commands that generated this are:
git sed -f g "GDK window" "GDK surface"
git sed -f g window_impl surface_impl
(cd gdk; git sed -f g impl_window impl_surface)
git sed -f g WINDOW_IMPL SURFACE_IMPL
git sed -f g GDK_MODE_WINDOW GDK_MODE_SURFACE
git sed -f g gdk_draw_context_get_window gdk_draw_context_get_surface
git sed -f g gdk_drawing_context_get_window gdk_drawing_context_get_surface
git sed -f g gdk_gl_context_get_window gdk_gl_context_get_surface
git sed -f g gsk_renderer_get_window gsk_renderer_get_surface
git sed -f g gsk_renderer_new_for_window gsk_renderer_new_for_surface
(cd gdk; git sed -f g window_type surface_type)
git sed -f g gdk_surface_get_window_type gdk_surface_get_surface_type
git sed -f g window_at_position surface_at_position
git sed -f g event_window event_surface
git sed -f g window_coord surface_coord
git sed -f g window_state surface_state
git sed -f g window_cursor surface_cursor
git sed -f g window_scale surface_scale
git sed -f g window_events surface_events
git sed -f g monitor_at_window monitor_at_surface
git sed -f g window_under_pointer surface_under_pointer
(cd gdk; git sed -f g for_window for_surface)
git sed -f g window_anchor surface_anchor
git sed -f g WINDOW_IS_TOPLEVEL SURFACE_IS_TOPLEVEL
git sed -f g native_window native_surface
git sed -f g source_window source_surface
git sed -f g dest_window dest_surface
git sed -f g drag_window drag_surface
git sed -f g input_window input_surface
git checkout NEWS* po-properties po docs/reference/gtk/migrating-3to4.xml
Rename all *window.[ch] source files.
This is an automatic operation, done by the following commands:
for i in $(git ls-files gdk | grep window); do
git mv $i $(echo $i | sed s/window/surface/);
git sed -f g $(basename $i) $(basename $i | sed s/window/surface/) ;
done
git checkout NEWS* po-properties po
This renames the GdkWindow class and related classes (impl, backend
subclasses) to surface. Additionally it renames related types:
GdkWindowAttr, GdkWindowPaint, GdkWindowWindowClass, GdkWindowType,
GdkWindowTypeHint, GdkWindowHints, GdkWindowState, GdkWindowEdge
This is an automatic conversion using the below commands:
git sed -f g GdkWindowWindowClass GdkSurfaceSurfaceClass
git sed -f g GdkWindow GdkSurface
git sed -f g "gdk_window\([ _\(\),;]\|$\)" "gdk_surface\1" # Avoid hitting gdk_windowing
git sed -f g "GDK_WINDOW\([ _\(]\|$\)" "GDK_SURFACE\1" # Avoid hitting GDK_WINDOWING
git sed "GDK_\([A-Z]*\)IS_WINDOW\([_ (]\|$\)" "GDK_\1IS_SURFACE\2"
git sed GDK_TYPE_WINDOW GDK_TYPE_SURFACE
git sed -f g GdkPointerWindowInfo GdkPointerSurfaceInfo
git sed -f g "BROADWAY_WINDOW" "BROADWAY_SURFACE"
git sed -f g "broadway_window" "broadway_surface"
git sed -f g "BroadwayWindow" "BroadwaySurface"
git sed -f g "WAYLAND_WINDOW" "WAYLAND_SURFACE"
git sed -f g "wayland_window" "wayland_surface"
git sed -f g "WaylandWindow" "WaylandSurface"
git sed -f g "X11_WINDOW" "X11_SURFACE"
git sed -f g "x11_window" "x11_surface"
git sed -f g "X11Window" "X11Surface"
git sed -f g "WIN32_WINDOW" "WIN32_SURFACE"
git sed -f g "win32_window" "win32_surface"
git sed -f g "Win32Window" "Win32Surface"
git sed -f g "QUARTZ_WINDOW" "QUARTZ_SURFACE"
git sed -f g "quartz_window" "quartz_surface"
git sed -f g "QuartzWindow" "QuartzSurface"
git checkout NEWS* po-properties
Remove all the old 2.x and 3.x version annotations.
GTK+ 4 is a new start, and from the perspective of a
GTK+ 4 developer all these APIs have been around since
the beginning.
As far as possible, use per-display debug flags.
This will minimize the debug spew that we get from
the inspector if it is running on a separate display.