We want to completely clear the background framebuffer when switching
back to ACTOR mode to make sure the `background_fb.framebuffer` check
will fail in `update_background_fbo` when switching to BACKGROUND mode
again. Otherwise the checks in `update_background_fbo` will return TRUE
and we will keep using the background framebuffer that was created
before switchig to ACTOR mode.
While at it, also clear the background framebuffer completely when
changing the actor to avoid the same issue here.
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/1000
When blurring only the actor (ACTOR mode), we don't want to apply any
scale, it looks fine without using the resource scale and it also seems
like `clutter_actor_continue_paint` in `paint_actor_offscreen` only
draws an unscaled texture anyway (ie. if the resource scale is 2, only a
quarter of the framebuffer is being drawn to).
In BACKGROUND mode though, we need to scale the framebuffer using the
scale factor of the stage view (ie. the final scale factor for the
monitor) because the content of the framebuffer we blit is scaled using
that factor. Also, since the framebuffer we blit belongs to a stage view
and only includes the contents of this view, we need to adjust the
stage-coordinates of the actor to be relative to the stage-view.
To make sure we don't have to get the transformed actor size or position
multiple times during one paint-run and don't have to carefully floor()
or ceil() widths and positions, store the size of the actor (which is
also the size of the framebuffer) and its position relative to the stage
view inside a ClutterActorBox.
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/1000
A ClutterEffect is being painted as part of the paint cycle of
ClutterActor, where _clutter_effect_paint() is called before painting
the actual actor. With that, it's impossible that an effect gets painted
while it's disabled, so remove the check whether the ClutterActorMeta is
enabled before painting.
Also if everything works fine in Clutter, the ClutterActorMeta should
have an actor set and we've been notified about that actor in
shell_blur_effect_set_actor(), so assert that our cached actor is set
when painting the effect.
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/1000
If we modify the paint volume to make it larger and include the blur
radius, we should also use the gained size and draw something there.
Since the framebuffers are only the size of the actor to blur, we're not
doing that right now anyway, so remove the vfunc override.
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/991
Use the shader for linear sampling and incremental calculation of the
gaussian kernel values as it was implemented by Patrick Walton in
webrender.
The sigma value for the blur (the standard deviation) is calculated by
taking the blur radius and dividing it by 3, this value is used by most
implementations of gaussian blurs since it covers a high percentage of
the gaussian shape.
The linear sampling optimization is implemented by skipping every second
texel (i += 2) in the for-loop that's sampling adjacent texels.
https://github.com/servo/webrender/blob/master/webrender/res/cs_blur.glsl38ec7db6f1https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/991
Floor the downscaled size of the new framebuffer to make sure we don't
initialize a framebuffer with a floating point value that might be
interpreted wrong by `cogl_texture_2d_new_with_size` and end up with a
slightly wrong aspect ratio of the framebuffer.
This fixes situations where the widths or heights of downscaled
framebuffers sometimes miss some pixels at the border.
While at it, remove the `downscale_factor` argument from
`setup_projection_matrix` since that function doesn't need the initial
size of the actor anyway.
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/991
The brightness property of ShellBlurEffect is of float type, but
we are calling g_value_set_int() in the GObject::get_property()
handler, which throws warnings when trying to set the property
via g_object_set() and family.
Use g_value_set_float() instead.
https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/924
This is a moderately fast two-pass gaussian blur implementation.
It downscales the framebuffer dynamically before applying the
gaussian shader, which cuts down rendering time quite considerably.
The blur shader takes 2 uniforms as input: the blur radius; and
whether to blur vertically or horizontally.
The blur radius is treated as an integer in C land to simplify
calculations. The vertical parameter is treated as an integer by
the shader simply due to Cogl not having proper boolean support
in snippets.
At last, brightness is also added to avoid needing to use an extra
effect to achieve that. Brightness is applied in a different pipeline
than blur, so we can control it more tightly.
ShellBlurEffect also implements a "background" mode, where the contents
beneath the actor are blurred, but not the actor itself. This mode is
performance-heavy.
Related: https://gitlab.gnome.org/GNOME/gnome-shell/issues/1848https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/864
