... 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.
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.
This is an attempt to get rid of gdk_window_new() for more specific use
cases. These 2 are for client-side windows - regular ones and input-only
ones resepectively.
So far all those functions just call into gdk_window_new().
The update tracking code was ugly and using deprecated drawing APIs. It
was also in the wrong place.
So instead of trying to keep it working, I'll remove it. We need to find
a better way to put it and make it work there.
And with it, gtk_widget_get_visual() and gtk_widget_set_visual() are
gone.
We now always use the RGBA visual (if available) and otherwise fall back
to the system visual.
The cursor was set using gdk_window_set_cursor() even in
gdk_window_new().
So instead of having yet another flag, just make the users of that flag
call gdk_window_set_cursor() directly after the window was created.
X11 was the only backend to support it and people can just override it
using XSetClassHint() directly.
The docs already advertised the function as "Do not use".
Keep the existing call to XSetClassHint() in place, so that we keep
setting the same values as in GTK3.
Instead of giving out Cairo contexts, GdkWindow should provide a
"drawing context", which can then create Cairo contexts on demand; this
allows us to future proof the API for when we're going to use a
different rendering pipeline, like OpenGL.
https://bugzilla.gnome.org/show_bug.cgi?id=766675
Existing code drawing on a GDK window has to handle the direct drawing
and the buffered drawing by itself, by checking the window type and
whether or not the window is backed by a native windowing surface. After
that, the calling code has to create a Cairo context from the window and
keep an association between the context and the window itself.
This is completely unnecessary: GDK can determine whether or not it
should use a backing store to draw on a GdkWindow as well as create a
Cairo context, and keep track of it.
This allows to simplify the calling code, and enforce some of the
drawing behavior we want to guarantee to users.
https://bugzilla.gnome.org/show_bug.cgi?id=766675
An pass_through window is something you can draw in but does not
affect event handling. Normally if a window has with no event mask set
for a particular event then input events in it go to its parent window
(X11 semantics), whereas if pass_through is enabled the window below
the window will get the event. The later mode is useful when the
window is partially transparent. Note that an pass-through windows can
have child windows that are not pass-through so they can still get events
on some parts.
Semantically, this behaves the same as an regular window with
gdk_window_set_child_input_shapes() called on it (and re-called any
time a child is changed), but its far more efficient and easy to use.
This allows us to fix the testoverlay input stacking test.
https://bugzilla.gnome.org/show_bug.cgi?id=750568https://bugs.freedesktop.org/show_bug.cgi?id=90917
Now that we have a two-stages GL context creation sequence, we can move
the profile to a pre-realize option, like the debug and forward
compatibility bits, or the GL version to use.
One of the major requests by OpenGL users has been the ability to
specify settings when creating a GL context, like the version to use
or whether the debug support should be enabled.
We have a couple of requirements in terms of API:
• avoid, if at all possible, the "C arrays of integers with
attribute, value pairs", which are hard to write and hard
to bind in non-C languages.
• allow failing in a recoverable way.
• do not make the GL context creation API a mess of arguments.
Looking at prior art, it seems that a common pattern is to split the
construction phase in two:
• a first phase that creates a GL context wrapper object and
does preliminary checks on the environment.
• a second phase that creates the backend-specific GL object.
We adopted a similar pattern:
• gdk_window_create_gl_context() creates a GdkGLContext
• gdk_gl_context_realize() creates the underlying resources
Calling gdk_gl_context_make_current() also realizes the context, so
simple GL users do not need to care. Advanced users will want to
call gdk_window_create_gl_context(), set up the optional requirements,
and then call gdk_gl_context_realize(). If either of these two steps
fails, it's possible to recover by changing the requirements, or simply
creating a new GdkGLContext instance.
https://bugzilla.gnome.org/show_bug.cgi?id=741946
This adds the new type GdkGLContext that wraps an OpenGL context for a
particular native window. It also adds support for the gdk paint
machinery to use OpenGL to draw everything. As soon as anyone creates
a GL context for a native window we create a "paint context" for that
GdkWindow and switch to using GL for painting it.
This commit contains only an implementation for X11 (using GLX).
The way painting works is that all client gl contexts draw into
offscreen buffers rather than directly to the back buffer, and the
way something gets onto the window is by using gdk_cairo_draw_from_gl()
to draw part of that buffer onto the draw cairo context.
As a fallback (if we're doing redirected drawing or some effect like a
cairo_push_group()) we read back the gl buffer into memory and composite
using cairo. This means that GL rendering works in all cases, including
rendering to a PDF. However, this is not particularly fast.
In the *typical* case, where we're drawing directly to the window in
the regular paint loop we hit the fast path. The fast path uses opengl
to draw the buffer to the window back buffer, either by blitting or
texturing. Then we track the region that was drawn, and when the draw
ends we paint the normal cairo surface to the window (using
texture-from-pixmap in the X11 case, or texture from cairo image
otherwise) in the regions where there is no gl painted.
There are some complexities wrt layering of gl and cairo areas though:
* We track via gdk_window_mark_paint_from_clip() whenever gtk is
painting over a region we previously rendered with opengl
(flushed_region). This area (needs_blend_region) is blended
rather than copied at the end of the frame.
* If we're drawing a gl texture with alpha we first copy the current
cairo_surface inside the target region to the back buffer before
we blend over it.
These two operations allow us full stacking of transparent gl and cairo
regions.
This is a new function that gets called every time we're drawing
some area in the Gtk paint machinery. It is a no-op right now, but
it will be required later to keep track of what areas which
we previously rendered with GL was overwritten with cairo contents.
This avoids a bunch of policy problems with deciding how to lay
out the window menu under different WMs.
For now, we use the special event _GTK_SHOW_WINDOW_MENU, but we
hope to have this standardized in wm-spec quite soon, as KDE wants
it as well.
