Use the real name of the seat instead of calling each seat 'default'. This makes
it easier to identify the current seat in a multi-seat environment.
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
This change fixes the "touch-up" operation to clear "data_source"
by setting "seat" to NULL. This operation is done in the mouse button
release operation, but seems to have been forgotten in the "touch up"
case.
Forgetting this operation causes weston to send a "premature finish
request" error to the client which causes the client to exit.
This issue can be reproduced with the "weston-dnd" program by performing
a drag-and-drop operation with a touch input device. Once the drag
is released, the weston-dnd program will exit with an error.
Signed-off-by: Jonathan Marler <johnnymarler@gmail.com>
If sprites_are_broken, then we will only ever arrive in renderer_only
mode, so this case will be caught by the checks above.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Avoids an user-after-free when destroying the surface, like in the
following ASAN message:
==25180==ERROR: AddressSanitizer: heap-use-after-free on address 0x6060000589d8 at pc 0x7ff70a4f7102 bp 0x7fff8f7e13b0 sp 0x7fff8f7e13a8
READ of size 8 at 0x6060000589d8 thread T0
#0 0x7ff70a4f7101 in weston_schedule_surface_protection_update ../libweston/compositor.c:1163
#1 0x7ff70a4f743b in weston_surface_update_output_mask ../libweston/compositor.c:1212
#2 0x7ff70a4f7a47 in weston_surface_assign_output ../libweston/compositor.c:1298
#3 0x7ff70a4f7f44 in weston_view_assign_output ../libweston/compositor.c:1348
#4 0x7ff70a4fa12f in weston_view_update_transform ../libweston/compositor.c:1589
#5 0x7ff70a4ffc20 in view_list_add ../libweston/compositor.c:2657
#6 0x7ff70a5000ee in weston_compositor_build_view_list ../libweston/compositor.c:2688
#7 0x7ff70a4fd577 in weston_view_destroy ../libweston/compositor.c:2202
#8 0x7ff70a4fd7df in weston_surface_destroy ../libweston/compositor.c:2239
#9 0x7ff70a4fdbb0 in destroy_surface ../libweston/compositor.c:2285
#10 0x7ff70a4a2d3e in destroy_resource ../src/wayland-server.c:723
#11 0x7ff70a4a8940 in for_each_helper ../src/wayland-util.c:372
#12 0x7ff70a4a8e1f in wl_map_for_each ../src/wayland-util.c:385
#13 0x7ff70a4a3748 in wl_client_destroy ../src/wayland-server.c:882
#14 0x7ff6fe04e866 in shell_destroy ../desktop-shell/shell.c:5004
#15 0x7ff70a4ee923 in wl_signal_emit /home/mvlad/install-amd64/include/wayland-server-core.h:481
#16 0x7ff70a51598d in weston_compositor_destroy ../libweston/compositor.c:7903
#17 0x7ff70a903a58 in wet_main ../compositor/main.c:3493
#18 0x560de7b3b179 in main ../compositor/executable.c:33
#19 0x7ff70a73ecc9 in __libc_start_main ../csu/libc-start.c:308
#20 0x560de7b3b099 in _start (/home/mvlad/install-amd64/bin/weston+0x1099)
0x6060000589d8 is located 56 bytes inside of 64-byte region [0x6060000589a0,0x6060000589e0)
freed by thread T0 here:
#0 0x7ff70a9d3b6f in __interceptor_free (/usr/lib/x86_64-linux-gnu/libasan.so.6+0xa9b6f)
#1 0x7ff70a5167d2 in cp_destroy_listener ../libweston/content-protection.c:193
#2 0x7ff70a4ee923 in wl_signal_emit /home/mvlad/install-amd64/include/wayland-server-core.h:481
#3 0x7ff70a51598d in weston_compositor_destroy ../libweston/compositor.c:7903
#4 0x7ff70a903a58 in wet_main ../compositor/main.c:3493
#5 0x560de7b3b179 in main ../compositor/executable.c:33
#6 0x7ff70a73ecc9 in __libc_start_main ../csu/libc-start.c:308
previously allocated by thread T0 here:
#0 0x7ff70a9d4037 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.6+0xaa037)
#1 0x7ff70a5160aa in zalloc ../include/libweston/zalloc.h:38
#2 0x7ff70a516cda in weston_compositor_enable_content_protection ../libweston/content-protection.c:329
#3 0x7ff7070247e0 in drm_backend_create ../libweston/backend-drm/drm.c:3180
#4 0x7ff707024cae in weston_backend_init ../libweston/backend-drm/drm.c:3250
#5 0x7ff70a515d02 in weston_compositor_load_backend ../libweston/compositor.c:7999
#6 0x7ff70a8fbcfb in load_drm_backend ../compositor/main.c:2614
#7 0x7ff70a900b46 in load_backend ../compositor/main.c:3103
#8 0x7ff70a902ecd in wet_main ../compositor/main.c:3380
#9 0x560de7b3b179 in main ../compositor/executable.c:33
#10 0x7ff70a73ecc9 in __libc_start_main ../csu/libc-start.c:308
SUMMARY: AddressSanitizer: heap-use-after-free ../libweston/compositor.c:1163 in weston_schedule_surface_protection_update
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Weston internals and Wayland clients assume that output presentation
clock cannot go backwards. Therefore require unconditionally that KMS
uses the monotonic clock.
The kernel unconditionally supports DRM_CAP_TIMESTAMP_MONOTONIC. See:
commit 25e1a79874eb3821d93310c908cc0a81b47af060
Author: Arnd Bergmann <arnd@arndb.de>
Date: Wed Oct 11 17:20:13 2017 +0200
drm: vblank: remove drm_timestamp_monotonic parameter
That one removed the final possibility of DRM_CAP_TIMESTAMP_MONOTONIC
being false, by removing the module option. But even before that, all
drivers have been supporting monotonic, since
commit c61eef726a78ae77b6ce223d01ea2130f465fe5c
Author: Imre Deak <imre.deak@intel.com>
Date: Tue Oct 23 18:53:26 2012 +0000
drm: add support for monotonic vblank timestamps
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This drops the software presentation clocks that could jump backwards.
See the previous commit "libweston: assert frame times never go
backwards" for the rationale.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Adding this check was prompted by
https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/609
There is no reason to allow frame times jump backwards, and apparently
we already have code that makes that assumption.
DRM KMS uses CLOCK_MONOTONIC as the vblank and page flip timestamps,
which by definition cannot go backwards. Other backends call
weston_compositor_set_presentation_clock_software().
Frame times are also reported directly to Wayland clients via
presentation-time extension, and clients too will not expect that the
timestamp could go backwards.
So make sure time can never go backwards.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
As observed in #420 (Running Weston under Weston's kiosk shell with
multiple outputs causes the scrollback to go nuts), not
being able to cope with (a correct) resize of the parent surface would
cause the client weston instance to spin forever. If dispatching
failed, just exit.
Fixes#420
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
As an in-flight resize call might cause a call to
wayland_output_destroy_shm_buffers() to go over a list of free_buffers
list. Just initialize the lists before attempting to create the parent
surface to avoid it.
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
fb->format is *pixel_format_info, whereas fb->format->format is the
actual DRM/wl_shm format code we want to see here. Fix the drm_debug()
call accordingly.
Signed-off-by: Bastian Krause <bst@pengutronix.de>
In "backend-drm: simplify compile time array copy", ARRAY_COPY was
introduced to be used by the DRM-backend.
In this patch we expand its usage to other code where hardcoded arrays
are being copied.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
In drm_fb_get_from_dmabuf() we have some compile time array copies, and
multiple static_assert() calls are needed (for safety). This makes the
code unpleasant to read.
Add ARRAY_COPY macro, to simplify the code.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
EGL implementations have no way to tell that implicit modifiers are not
supported. So Weston must consider that implicit modifiers are
supported. Always add DRM_FORMAT_MOD_INVALID to formats that we query
from EGL.
The implication is that clients using dmabuf extension may pick
DRM_FORMAT_MOD_INVALID to allocate their buffers, and so these buffers
will not be directly imported to KMS and placed in planes. See commit
"backend-drm: do not import dmabuf buffers with no modifiers to KMS" for
more details.
But we should not avoid advertising DRM_FORMAT_MOD_INVALID in the dmabuf
protocol just because we hope that the client don't choose it, it's not
our choice.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
In commit "libweston: add struct weston_drm_format" struct
weston_drm_format and its helper functions were added to libweston.
The functions query_dmabuf_formats and query_dmabuf_modifiers are very
specific to GL-renderer and its internals. So instead of exposing them
in libweston, query and store DRM formats and modifiers internally in
GL-renderer. Also, add a vfunction to struct weston_renderer in order
to retrieve the formats.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
In commit "backend-drm: do not import dmabuf buffers with no modifiers
to KMS" we've stopped to import dmabuf with no modifiers to KMS.
In this patch we document why we can still import wl_drm buffers with no
modifiers to KMS.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
We can't tell the layout of a buffer that has been allocated with no
modifiers. Although usually drivers use linear layouts to allocate in
these cases, it is not a rule. It can use a tiling layout, for instance,
under the hood.
So it is not safe to import a buffer with no modifiers to KMS, as it
can't tell the buffer layout and this may result in garbage being
displayed. In this patch we start to require explicit modifiers to
import buffers to KMS.
In most cases things just work as expected, but just because both sides
(display and render driver) usually end up using the linear layout when
modifiers are not exposed. It also works on systems where the display
and render devices are tied (desktops with Intel or AMD, for instance),
as there's only one driver and it knows the layout of the buffer (no
need to guess).
But in SoC's where the display and render device are split, things can
go wrong. It is better to lose performance and not break things. To
solve the problem, drivers should be updated to expose modifiers (even
if only DRM_FORMAT_MOD_LINEAR), as the concept of implicit modifiers is
the root of the problem.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
In commit "backend-drm: add DRM_FORMAT_MOD_INVALID to modifier sets when
no modifiers are supported" we've changed the code that iterates through
the IN_FORMATS blob property. Now it adds DRM_FORMAT_MOD_INVALID for
formats exposed without modifiers.
But the thing is that there shouldn't be formats in the IN_FORMATS blob
exposed without modifiers, as the blob has been added after the
introduction of the explicit modifiers API in the kernel. For now,
there's nothing in the kernel to ensure this correct behavior. So
instead of adding DRM_FORMAT_MOD_INVALID in this case, ignore these
formats, as userspace can't do much in this case.
In the future this may be fixed by the kernel. Or maybe the following MR
in libdrm, which adds an iterator API for the IN_FORMATS blob:
https://gitlab.freedesktop.org/mesa/drm/-/merge_requests/146
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
From now on, when we can't know the modifiers supported for a certain
format, we add DRM_FORMAT_MOD_INVALID to its modifier set.
There is some parts where nothing is being added an others where
DRM_FORMAT_MOD_LINEAR is being added, so fix them.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
In create_gbm_surface() we may allocate with no modifiers in the
following situations:
1. old GBM version, so HAVE_GBM_MODIFIERS is false;
2. the KMS driver does not support modifiers;
3. if allocating with modifiers failed, what can happen when the KMS
display device supports modifiers but the GBM driver does not, e.g.
the old i915 Mesa driver.
The comment was only stating the third situation, so add the other two.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
The function drm_output_init_egl() is too big, so move the code to
create the gbm surface to a separate function: create_gbm_surface().
Also made some minor style changes to the code that has been moved, in
order to improve readability.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
In commit "libweston: add struct weston_drm_format" struct
weston_drm_format and its helper functions were added to libweston.
Also, unit tests for this API have been added in commit "tests: add unit
tests for struct weston_drm_format".
Start to use this API in the DRM-backend, as it enhances the code by
avoiding repetition and ensuring correctness.
Signed-off-by: Scott Anderson <scott.anderson@collabora.com>
Co-authored-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
Add struct weston_drm_format, which contains a DRM format and a list of
modifiers. The patch also adds struct weston_drm_format_array and some
helper functions to handle these two new structs: init/fini, find
elements, add elements, etc.
This will be useful in the next commits in which we add support to
dmabuf-hints. It also allows a cleanup in the DRM-backend, where we
currently have a similar struct in drm_plane but with no helper
functions, so the code to handle it is scattered throughout the
functions and there is a lot of repetition.
This patch is based on previous work of Scott Anderson (@ascent).
Signed-off-by: Scott Anderson <scott.anderson@collabora.com>
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
In drm_output_prepare_plane_view() we iterate the list of planes and add
them as candidates to promote the view to one of them.
Cursor planes do not support buffers other than wl_shm (at least for
now). So when we have a dmabuf or an EGL buffer in the view, the
function drm_output_plane_cursor_has_valid_format() returns false and
the cursor plane is not added to the candidate list.
In this patch we move the responsibility of doing this from
drm_output_plane_cursor_has_valid_format() to
drm_output_prepare_plane_view() itself, as the incompatibility between
other types of buffers and cursor planes is different from the
incompatibility between formats. This makes the code easier to read
and also documents the current incompatibility between cursor planes
and buffers that are not created through wl_shm.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
In the absence of universal planes support,
drm_output_find_special_plane() sets the plane format to zero as a
placeholder. Then in drm_output_init_planes() it sets the format to
output->gbm_format.
As output->gbm_format is already set by the time we call
drm_output_find_special_plane(), simply set the plane format to it
directly in this function. This makes the code clearer, as there is no
reason to use the placeholder.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
get_vt is used to check if VTs are enabled, by verifying that a VT greater than
0 is returned.
libseat always implements switching, with switch to an active session
currently being a noop in all backends. libseat does not currently have
a get_vt implementation. Make get_vt errors more explicit, and allow VT
switching anyway if the error is ENOSYS.
Signed-off-by: Kenny Levinsen <kl@kl.wtf>
This adds support for libseat as a seat backend. libseat provides seatd,
(e)logind and direct seat backends as compile-time and runtime options.
The backend is currently disabled by default. It can be enabled through the
launcher-libseat option.
Signed-off-by: Kenny Levinsen <kl@kl.wtf>
In some situations, like positioning a sub-surface that exceeds the
output's dimensions we would adjust the plane state dimensions to some
lower values to that of the buffer. That would ultimately trip the cursor
update function because the buffer itself actually exceeds the maximum
size/dimension of the cursor.
The plane state destination co-ordinates is the area of the view which
is visible on the output, which in some situations, would actually be
smaller than the original buffer dimensions (making it so that it will
pass the cropping/scaling check), but depending on of
how large is the surface buffer, it would tripping the assert wrt to
cursor width/height dimensions.
This hasn't been seen so far due to the fact that until recently we had
a cursor surface that always reached the cursor plane and that was
already being set-up by default (with desktop-shell, which is no longer
the case), and also because kiosk-shell, which doesn't set-up a cursor
surface, was not available.
This adds a check to skip placing the view in the cursor plane if the
buffer dimensions exceed the cursor permitted width/height.
(Suggested-by Daniel Stone).
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
fixes issue #484 (race condition with message to/from weston launch)
The race condition occurs after weston sends the WESTON_LAUNCHER_OPEN
message to weston-launch. The race is between when weston-launch replies
with the fd handle versus weston-launch sending an activation message. If
weston-launch sends an activation message before sending the fd handle,
then weston will be in an invalid state.
To fix this, I modified the fd handle reply that weston-launch sends to
include a message id at the beginning, which I called
WESTON_LAUNCHER_OPEN_REPLY. Along with this, weston now inspects the
first part of any reply to determine whether it is an activation message
or a reply to the OPEN message. In the newly handled case that it's an
activation message, it tracks whether the latest result is a deactivate
message and stores it in a flag to be handled once the open function has
completed.
Signed-off-by: Jonathan Marler <johnnymarler@gmail.com>
Now that pieces of color management implementation start to land, the
fallback shader becomes even more special than before. It is the only
case where the compositor ignores color management.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
The texture target can be uniquely inferred from the shader variant, so
do not store texture target separately.
Shortens the code a bit.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Replace the shader_requirements with just shader_variant. The variant is
the only thing gl_surface_state will actually carry. All the other
requirements fields are always unused.
Co-authored-by: Sebastian Wick <sebastian@sebastianwick.net>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This patch gathers all values to be loaded to shader uniforms into a new
struct gl_shader_config along with texture target and filter
information. Struct gl_shader becomes opaque outside of gl-shaders.c.
Everything that used or open-coded these are converted.
The aim is to make gl-renderer.c easier to read. Previously, uniform
values were loaded up in various places, texture units were set up in
one place, textures were bound into units in different places. Stuff was
all over the place.
Now, shader requirements and associated uniform data is stored in a
single struct. The data is loaded into a shader program in one function
only.
That makes it easy for things like maybe_censor_override() to replace
the whole config rather than poke only the shader requirements. This may
not look like much right now, but when color management adds more
uniforms and even hardcoded color need to go through the proper color
pipeline, doing things the old way would become intractable.
Similar simplification can be seen in draw_view(), where the RGBA->RGBX
override becomes more contained. There is no longer a need to "pre-load"
the shader used by triangle fan debug. Triangle fan debug no longer
needs to play tricks with saving and restoring the current shader.
The real benefit of this change will probably come when almost all
shader operations need to take color spaces into account. That means
filling in gl_shader_config parts based on a color transformation.
This is based on an idea Sebastian already used in his Weston color
management work.
Co-authored-by: Sebastian Wick <sebastian@sebastianwick.net>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Avoid looking up 'gr' from view->compositor by passing it explicitly
into the functions needing it.
Also fixes the whitespace in repaint_region() signature.
Clarifies code by removing local variables, but also future changes will
need 'gr' more.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
A future change will call this function from draw_view(), so move it
upwards to avoid adding a function declaration.
No functional or even cosmetic change.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
These functions are related to shaders, so they are more at home in
gl-shaders.c. gl-renderer.c is too long already.
This allows making a couple functions static while the moved functions
become non-static. Future changes turn some of these functions into
static again, with the ultimate goal of making struct gl_shader opaque.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Tearing down the drm-backend when there are no input devices, would call
for the gbm device destruction before compositor shutdown. The latter
would call into the renderer detroy function and assume that the
EGLDisplay, which was created using the before-mentioned gbm device, is
still available. This patch re-orders the gbm destruction after the
compositor shutdown when no one would make use of it.
Fixes: #314
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Suggested-by: Daniel Stone <daniel.stone@collabora.com>
Everywhere else uses #ifdef, this used just #if. When the next commit
adds -Wundef to the compiler options, this #if here will start failing
as ENABLE_EGL is undefined.
It would be much better to use Meson's set10() for ENABLE_EGL and change
all #ifdef into #if, but I opted for the smaller change for now.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This adds a heuristic for freeing shader programs that have not been
needed for a while. The intention is to stop Weston accumulating shader
programs indefinitely, especially in the future when color management
will explode the number of possible different shader programs.
Shader programs that have not been used in the past minute are freed,
except always keep the ten most recently used shader programs anyway.
The former rule is to ensure we keep shader programs that are actively
used regardless of how many. The latter rule is to prevent freeing too
many shader programs after Weston has been idle for a long time and then
repaints just a small area. Many of the shader programs could still be
relevant even though not needed in the first repaint after idle.
The numbers ten and one minute in the above are arbitrary and not based
on anything.
These heuristics are simpler to implement than e.g. views taking
references on shader programs. Expiry by time allows shader programs to
survive a while even after their last user is gone, with the hope of
being re-used soon. Tracking actual use instead of references also
adapts to what is actually visible rather than what merely exists.
Keeping the shader list in most recently used order might also make
gl_renderer_get_program() more efficient on average.
last_repaint_start time is used for shader timestamp to avoid calling
clock_gettime() more often. Adding that variable is an ABI break, but
libweston major has already been bumped to 10 since last release.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This is useful for seeing that the shader program garbage collection
works in a future patch.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
One more thing is coming to need this, so add the compositor pointer and
migrate existing places to use it where it simplifies things.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
I have verified that the conversion here follows ITU-R BT.601 except for
the offsets 16/256 and 128/256 which should be 16/255 and 128/255
respectively.
I used to following octave script to verify this:
rf = 0.299;
gf = 0.587;
bf = 0.114;
crdiv = 1.402;
cbdiv = 1.772;
M = [ rf, gf, bf ;
-rf / cbdiv, -gf / cbdiv, (1 - bf) / cbdiv;
(1 - rf) / crdiv, -gf / crdiv, -bf / crdiv ];
YCbCr = [ 'Y'; 'Cb'; 'Cr' ];
RGB = [ 'R'; 'G'; 'B' ];
eq = [ ' '; '='; ' ' ];
l = [ ' [ '; ' [ '; ' [ ' ];
r = [ ' ] '; ' ] '; ' ] ' ];
mat = [
sprintf('%9f %9f %9f', M(1,:));
sprintf('%9f %9f %9f', M(2,:));
sprintf('%9f %9f %9f', M(3,:));
];
[ l YCbCr r eq l mat r l RGB r ]
R = inv(M);
mat = [
sprintf('%9f %9f %9f', R(1,:));
sprintf('%9f %9f %9f', R(2,:));
sprintf('%9f %9f %9f', R(3,:));
];
[ l RGB r eq l mat r l YCbCr r ]
[ R(:,1), R(:,2:3) .* (255/224) ]
The final matrix printed is what the shader uses down to +/- one digit,
so at least 7 correct decimals.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Sampling input texture has nothing to do with view alpha. This clarifies
the code structure.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Reading the input texture is just one part of the future color pipeline,
so separate it into a function of its own. This makes it easier to add
more steps to the pipeline, and shows the green tint is separate as
well.
Making use of early returns, reducing the if-else ladder should help
with readability. Sharing the call to yuva2rgba() likewise.
Setting yuva.w = alpha is not shared though, in case support for AYUV
format might be added in the future.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Do not call texture2D() in the shader when we already have the result.
Simpler code, maybe even a little bit faster?
Suggested-by: Harish Krupo <harishkrupo@gmail.com>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
