The rendering logic before was somewhat complex. We had three independent
cases to take into account when doing rendering:
* X11 compositor. In this case, we're a traditional X11 compositor,
not a Wayland compositor. We use XCompositeNameWindowPixmap to get
the backing pixmap for the window, and deal with the COMPOSITE
extension messiness.
In this case, meta_is_wayland_compositor() is FALSE.
* Wayland clients. In this case, we're a Wayland compositor managing
Wayland surfaces. The rendering for this is fairly straightforward,
as Cogl handles most of the complexity with EGL and SHM buffers...
Wayland clients give us the input and opaque regions through
wl_surface.
In this case, meta_is_wayland_compositor() is TRUE and
priv->window->client_type == META_WINDOW_CLIENT_TYPE_WAYLAND.
* XWayland clients. In this case, we're a Wayland compositor, like
above, and XWayland hands us Wayland surfaces. XWayland handles
the COMPOSITE extension messiness for us, and hands us a buffer
like any other Wayland client. We have to fetch the input and
opaque regions from the X11 window ourselves.
In this case, meta_is_wayland_compositor() is TRUE and
priv->window->client_type == META_WINDOW_CLIENT_TYPE_X11.
We now split the rendering logic into two subclasses, which are:
* MetaSurfaceActorX11, which handles the X11 compositor case, in that
it uses XCompositeNameWindowPixmap to get the backing pixmap, and
deal with all the COMPOSITE extension messiness.
* MetaSurfaceActorWayland, which handles the Wayland compositor case
for both native Wayland clients and XWayland clients. XWayland handles
COMPOSITE for us, and handles pushing a surface over through the
xf86-video-wayland DDX.
Frame sync is still in MetaWindowActor, as it needs to work for both the
X11 compositor and XWayland client cases. When Wayland's video display
protocol lands, this will need to be significantly overhauled, as it would
have to work for any wl_surface, including subsurfaces, so we would need
surface-level discretion.
https://bugzilla.gnome.org/show_bug.cgi?id=720631
It's mostly equivalent to the case where we've already detached
the pixmap, *except* for the x11_size_changed case. We can simply
detach the pixmap at the time the window changes size, though.
https://bugzilla.gnome.org/show_bug.cgi?id=720631
We guarantee ourselves that a valid pixmap will appear any time
that the window is painted. The window actor will be scheduled
for a repaint if it's added / removed from the scene graph, like
during construction, if the size changes, or if we receive damage,
which are the existing use cases where this function is called.
So, I can't see any reason that we queue a redraw in here.
With the split into surface actors, we don't have an easy place
we can use to queue a redraw, and since it's unnecessary, we can
just drop it on the floor.
https://bugzilla.gnome.org/show_bug.cgi?id=720631
We can never have a window actor that represents either the X root
window or the stage window, so it doesn't make sense to bail out
early in case we do.
I'd imagine that this came from a much earlier version of the code
where the compositor was much separate and had its own MapNotify
handling.
Since the unredirected window MetaWindowActor is stacked on top, it
will naturally get culled out of the process, so we can remove the
special casing here. Unfortunately, with the way that the code is
currently structured, it's too difficult to actually prevent setting
the clip / visible regions if the window is redirected, so just let
those be set for unredirected windows for now.
The input region was set on the shaped texture, but the shaped texture
was never picked properly, as it was never set to be reactive. Move the
pick implementation and reactivity to the MetaSurfaceActor, and update
the code everywhere else to expect a MetaSurfaceActor.
Traditionally, WMs unmap windows when minimizing them, and map them
when restoring them or wanting to show them for other reasons, like
upon creation.
However, as metacity morphed into mutter, we optionally chose to keep
windows mapped for the lifetime of the window under the user option
"live-window-previews", which makes the code keep windows mapped so it
can show window preview for minimized windows in other places, like
Alt-Tab and Expose.
I removed this preference two years ago mechanically, by removing all
the if statements, but never went through and cleaned up the code so
that windows are simply mapped for the lifetime of the window -- the
"architecture" of the old code that maps and unmaps on show/hide was
still there.
Remove this now.
The one case we still need to be careful of is shaded windows, in which
we do still unmap the client window. In the future, we might want to
show previews of shaded windows in the overview and Alt-Tab. In that
we'd also keep shaded windows mapped, and could remove all unmap logic,
but we'd need a more complex method of showing the shaded titlebar, such
as using a different actor.
At the same time, simplify the compositor interface by removing
meta_compositor_window_[un]mapped API, and instead adding/removing the
window on-demand.
https://bugzilla.gnome.org/show_bug.cgi?id=720631
We want to remove a bunch of auxilliary duties from the MetaWindowActor
and MetaSurfaceActor, including some details of how culling is done.
Move the unobscured region culling code to the MetaShapedTexture, which
helps the actor become "more independent".
https://bugzilla.gnome.org/show_bug.cgi?id=720631
When we traversed down to reset the culling state, previously we
would just skip any actors that wanted culling. In order to properly
reset the unobscured_region before painting, we need to traverse down
to these places as well. Do this by calling cull_out with NULL regions
for both arguments, and adapt existing cull_out implementations to
match.
https://bugzilla.gnome.org/show_bug.cgi?id=720631
I know it's confusing with the triple negative, but unredirected is how
we track it elsewhere: we have an 'unredirected' flag, and 'should_unredirect'.
https://bugzilla.gnome.org/show_bug.cgi?id=720631
We currently ignore the unobscured region when we have mapped clones in
meta_window_actor_process_damage and meta_window_actor_damage_all but
use it unconditionally when computing the paint volume.
This is wrong. We should ignore it there as well or we will end up with
empty clones if the cloned window is completly obscured
(like the tray icons in gnome-shell).
https://bugzilla.gnome.org/show_bug.cgi?id=721596
We need to do this for XWayland windows, since we only get the event
telling us they're an XWayland window after the compositor knows about
the window.
I know it's confusing with the triple negative, but unredirected is how
we track it elsewhere: we have an 'unredirected' flag, and 'should_unredirect'.
https://bugzilla.gnome.org/show_bug.cgi?id=720631
We no longer unmap the toplevel windows during normal operation. The
toplevel state is tied to the window's lifetime.
Call meta_compositor_add_window / meta_compositor_remove_window instead...
Traditionally, WMs unmap windows when minimizing them, and map them
when restoring them or wanting to show them for other reasons, like
upon creation.
However, as metacity morphed into mutter, we optionally chose to keep
windows mapped for the lifetime of the window under the user option
"live-window-previews", which makes the code keep windows mapped so it
can show window preview for minimized windows in other places, like
Alt-Tab and Expose.
I removed this preference two years ago mechanically, by removing all
the if statements, but never went through and cleaned up the code so
that windows are simply mapped for the lifetime of the window -- the
"architecture" of the old code that maps and unmaps on show/hide was
still there.
Remove this now.
The one case we still need to be careful of is shaded windows, in which
we do still unmap the client window. Theoretically, we might want to
show previews of shaded windows in the overview and Alt-Tab, so we remove
the complex unmap tracking for this later.
We need to set the number of components on the CoglTextureRectangle to
prevent wasting too much GPU memory. As we need to do this before we call
cogl_texture_set_region, just remove the meta_texture_rectangle_new wrapper,
and make callers call cogl_texture_rectangle_new_with_size directly.
The shadow is added in the paint step, not as a separate actor,
so the raise is a no-op. It also gets rid of an annoying misspelling
that's driving me crazy.
Since subsurfaces won't have toplevel MetaWindowActors, we need to
use MetaSurfaceActor instead. These are embedded in the MetaWindowActor,
just like MetaShapedTexture was (in fact, MetaSurfaceActor now contains
a MetaShapedTexture)
Make MetaWindowActor chain up to the generic default MetaCullable
implementation, and remove the helper methods for MetaSurfaceActor
and MetaShapedTexture.
Instead of hardcoded knowledge of certain classes in MetaWindowGroup,
create a generic interface that all actors can implement to get parts of
their regions culled out during redraw, without needing any special
knowledge of how to handle a specific actor.
The names now are a bit suspect. MetaBackgroundGroup is a simple
MetaCullable that knows how to cull children, and MetaWindowGroup is the
"toplevel" cullable that computes the initial two regions. A future
cleanup here could be to merge MetaWindowGroup / MetaBackgroundGroup so
that we only have a generic MetaSimpleCullable, and move the "toplevel"
cullability to be a MetaCullableToplevel.
https://bugzilla.gnome.org/show_bug.cgi?id=714706
