Seems that we're still missing layer clean-ups, with the touch
calibrator being one of them. Call the appropriate function when
shutting down the compositor instance.
Fixes: #603
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
The repaint_data is entirely backend specific. Moreover, it is only used by the
drm backend, while other backends ignore the repaint data.
There will always be only one repaint active, thus, there is no need to pass the
repaint data from the outside.
The repaint_data breaks with the multi-backend series, which calls repaint begin
for all backends to get the repaint_data. The repaint_data of the last backend
will then be passed to all other backend. At the moment, this works, because the
drm backend is the only backend that implements the begin_repaint call.
Another option would be to track the repaint data per backend in the compositor,
but actually, it the backend needs to track state across the calls, it's its own
responsibility.
Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Fbdev backend was deprecated in the Weston 10.0.0 release with
6338dbd581. Before that, I suggested
already in 2019 to remove it, but it was too soon then. Now it seems the
final voices asking for fbdev to be kept have been satisfied, see the
linked issue.
Fbdev-backend uses a kernel graphics UAPI (fbdev) which is sub-par for a
Wayland compositor: you cannot do GPU accelerated graphics in any
reasonable way, no hotplug support, multi-output support is tedious, and
so on. Most importantly, Linux has deprecated fbdev a long time ago due
to the UAPI fitting modern systems and use cases very poorly, but cannot
get rid of it if any users remain. Let's do here what we can to reduce
fbdev usage.
I am doing color management related additions to libweston which require
adding checks to every backend. One backend less is less churn to write
and review.
Libweston major version has already been bumped to 11, so the next
release will be Weston 11, without fbdev. enum weston_compositor_backend
entries change their numerical values.
Fixes: https://gitlab.freedesktop.org/wayland/weston/-/issues/581
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
The built-in backend of libseat requires users to enable a logging
level in order for libseat to start writing out log messages. For that
to happen we split out the info and error log level messages into the
compositor's log scope, while debug level messages go into a dedicated
scope.
With that, this patch brings in a new scope, called libseat-debug, which
users need to explicity create a subscription for it as to retrieve/have
access to debug message coming out of libseat. Note that by default we
have a subscription for the log-scope so any errors/info from libseat
would be displayed to the user.
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
We can end in `subsurface_committed()` in different scenarios
without the surface having an attached buffer. While setting
the mapped state to `true` in that case doesn't matter for
that (sub)surface itself, it triggers its own child subsurfaces
to get mapped when they shouldn't.
Closes https://gitlab.freedesktop.org/wayland/weston/-/issues/426
Signed-off-by: Robert Mader <robert.mader@collabora.com>
Zoom is a neat trick, but in its current form it's very hard to test
and maintain.
It also causes output damage to scale outside of the output's boundaries,
which leads to an extra clipping step that's only necessary when zoom
is enabled.
Remove it to simplify desktop-shell and compositor.
Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
The spec states:
> Because buffer transformation changes and damage requests may be
> interleaved in the protocol stream, it is impossible to determine
> the actual mapping between surface and buffer damage until
> wl_surface.commit time. Therefore, compositors wishing to take both
> kinds of damage into account will have to accumulate damage from the
> two requests separately and only transform from one to the other after
> receiving the wl_surface.commit.
For subsurfaces in sync mode, arguably the same is the case until the
cached state gets applied eventually. Thus, in order to keep complexity
to a sane level, just accumulate buffer damage and convert it only
when the cached state gets applied.
This mirrors how other compositors like Mutter implement cached damage
and what the spec arguably should demand.
Closes https://gitlab.freedesktop.org/wayland/weston/-/issues/446
Signed-off-by: Robert Mader <robert.mader@collabora.com>
The invariant is clearly documented in code comments, but the code
failed to ensure it in all cases. Fix it.
There is one very specific protocol sequence triggered by a development
version of the Wine Wayland driver when Chrome (win64 app) is switched
from window to fullscreen and then back by pressing F11 key. The switch
back triggered
weston: ../libweston/color.c:217: weston_paint_node_ensure_color_transform: Assertion 'it->surf_xform_valid == false' failed
For some reason, that specific protocol sequence causes
weston_compositor_build_view_list() to create a transient second view
for a sub-surface. In the Chrome traces, I have seen that happen twice
per run. The first time it works, the old view gets immediately
destroyed. The second time (during un-fullscreening) a new transient
view is create and then it fails the invariant check.
The fix is in weston_paint_node_create() which is supposed to ensure the
invariant. However, it went through the (new) view's paint node list,
which will not contain paint nodes from other views. In hindsight this
is an obvious bug, but perhaps all views having exactly one associated
surface each somehow confused the author. Since the invariant is about
surface+output, go through the surface's paint node list instead. That
list contains all the relevant paint nodes by definition.
Fixes: https://gitlab.freedesktop.org/wayland/weston/-/issues/568
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Commit 0e4f097d broke opaque regions, and since then weston will waste
time rendering occluded areas.
I think this is because we're taking the intersection of the opaque
and scissor regions even when the scissor region isn't enabled.
An easy test is to turn on triangle fan debugging with the gl renderer,
then run weston-simple-damage and move another opaque application such as
weston-terminal over it.
Signed-off-by: Derek Foreman <derek.foreman@collabora.com>
Replaces potential corruption signal emit call sites with the more safer
weston_signal_emit_mutable().
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
This uses the more safer version of signal emission to avoid a potential
crash when the output is destroyed that will follow a surface/view
destruction for which it has a listener attached (to the output_destroy
signal).
Fixes: #734
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
This avoids crashes due to removal of notification listeners from within
invocations of other listener callbacks in the same signal emission.
Fixes: #415
Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
This adds the initial dma-buf feedback implementation, following the
changes in the dma-buf protocol extension.
The initial dma-buf feedback implementation gives support to send
default feedback and per-surface feedback. For now the per-surface
feedback support is very basic and is still not implemented in the
DRM-backend, what basically means that KMS plane's formats/modifiers are
not being exposed to clients. In the next commits of this series we add
the DRM-backend implementation.
This patch is based on previous work of Scott Anderson (@ascent).
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
Signed-off-by: Scott Anderson <scott.anderson@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
Add API to set an output's color profile. This new function can also be
called while the output is enabled. This allows changing the output
color profile even at runtime if desired.
color-noop has no way of creating weston_color_profile objects, so it
just asserts that no color profile is set.
color-lcms does not yet implement taking the output color profile into
account, so for now it just fails everything if a profile is set.
weston_surface_color_transform_fini() was previously used only prior to
freeing the struct, but now it is used also to just clear the struct,
hence it needs to reset the fields.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Move the code into a new function that either succeeds in setting all
the color transformations or does not change anything. This will be
useful when implementing output color profiles changes while the output
is enabled.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Reported in !179 adding weston_output_repaint_failed resets the output
Co-authored-by: Daniel Stone
Co-authored-by: Julius Krah
Signed-off-by: n3rdopolis <bluescreen_avenger@verizon.net>
weston_output_enable() initializes the list, but weston_output_release()
maybe be called even if the output was never enabled, triggering the
assert due to uninitialized (actually NULL) list head.
This can be triggered with a bad weston.ini, for example using an
invalid output transform value.
Check in weston_output_disable() instead, but because it too may be
called for non-enabled output, only if it was actually enabled.
Fixes: 1a4f87dec5
"libweston: introduce weston_paint_node"
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
weston_frame_callback is needed primarily to store the doubly-linked list link,
but it can be also retrieved by using the wl_resource_get_link() function.
This removes an extra heap allocation per every wl_callback object.
Signed-off-by: Vlad Zahorodnii <vlad.zahorodnii@kde.org>
Conditionally build support when libdrm is at least 2.4.107 to make use
of it. Plug it in when printing out the buffer information.
With this in, we add a hard dependecy for libweston to link against
libdrm.
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
This creates the color-lcms plugin that in the future will be using
Little CMS as the color matching module, processing ICC profiles, and
producing HDR tone mappings.
Right now, this new plugin is functionally equivalent to the no-op color
manager, except it already links to lcms2 and checks that the renderer
supports color operations.
Color-lcms is a libweston plugin that is loaded with explicit
weston_compositor API. This does not currently allow loading alternative
color manager plugins. External color manager plugins might be
considered in the future when the libweston APIs around color management
stabilize.
This libweston plugin uses the same build option as the old cms-static
Weston plugins, as they both need lcms2. The minimum version for lcms2
was chosen by what Debian Buster provides today and for no other reason.
This plugin intends to support the Wayland CM&HDR protocol extension and
hence sets supports_client_protocol to true. This will expose the
protocol extension to clients when it gets implemented.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This is needed when the compositor produces any content internally:
- the lines in triangle fan debug
- the censoring color fill (unmet HDCP requirements)
Solid color surfaces do not need this special-casing because
weston_surface is supposed to carry color space information, which will
get used in gl_shader_config_init_for_view().
This makes sure the internally produced graphics fit in, e.g on a
monitor in HDR mode.
For now, just ensure there is an identity transformation. Actual
implementations in GL-renderer will follow later.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This is needed when drawing anything internal directly to an output,
like the borders/decorations in a nested compositor setup. This makes
the assumption that the internal stuff starts in sRGB, which should be
safe. As borders are never blended with other content, this should also
be sufficient.
This patch is a reminder that that path exists, rather than a real
implementation. To be implemented when someone needs it.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This is the blending space to monitor space color transform. It needs to
be implemented in the renderers, unless a backend sets
from_blend_to_output_by_backend = true, in which case the backend does
it and the renderer does not.
The intention is that from_blend_to_output_by_backend can be toggled
frame by frame to allow backends to react to dynamic change of output
color profile.
For now, renderers just assert that they don't need to do anything for
output color transform.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
See: https://gitlab.freedesktop.org/wayland/weston/-/issues/467#note_814985
This starts building the framework required for implementing color
management.
The main new interface is struct weston_color_manager. This commit also
adds a no-op color manager implementation, which is used if no other
color manager is loaded. This no-op color manager simply provides
identity color transforms for everything, so that Weston keeps running
exactly like before.
weston_color_manager interface is incomplete and will be extended later.
Colorspace objects are not introduced in this commit. However, when
client content colorspace and output colorspace definitions are
combined, they will produce color transformations from client content to
output blending space and from output blending space to output space.
This commit introduces a placeholder struct for color transforms,
weston_color_transform. Objects of this type are expected to be heavy to
create and store, which is why they are designed to be shared as much as
possible, ideally making their instances unique. As color transform
description is intended to be generic in libweston core, renderers and
backends are expected to derive their own state for each transform
object as necessary. Creating and storing the derived state maybe be
expensive as well, more the reason to re-use these objects as much as
possible. E.g. GL-renderer might upload a 3D LUT into a texture and keep
the texture around. DRM-backend might create a KMS blob for a LUT and
keep that around.
As a color transform depends on both the surface and the output, a
transform object may need to be created for each unique pair of them.
Therefore color transforms are referenced from weston_paint_node. As
paint nodes exist for not just surface+output but surface+view+output
triplets, the code ensures that all paint nodes (having different view)
for the same surface+output have the same color transform state.
As a special case, if weston_color_transform is NULL, it means identity
transform. This short-circuits some checks and memory allocations, but
it does mean we use a separate member on weston_paint_node to know if
the color transform has been initialized or not.
Color transformations are pre-created at the weston_output
paint_node_z_order_list creation step. Currently the z order lists
contain all views globally, which means we populate color transforms we
may never need, e.g. a view is never shown on a particular output.
This problem should get fixed naturally when z order lists are
constructed "pruned" in the future: to contain only those paint nodes
that actually contribute to the output's image.
As nothing actually supports color transforms yet, both renderers and
the DRM-backend assert that they only get identity transforms. This
check has the side-effect that all surface-output pairs actually get a
weston_surface_color_transform_ref even though it points to NULL
weston_color_transform.
This design is inspired by Sebastian Wick's Weston color management
work.
Co-authored-by: Sebastian Wick <sebastian@sebastianwick.net>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Fixes a definitely lost:
== 56 bytes in 1 blocks are definitely lost in loss record 16 of 45
== at 0x48450F8: malloc (vg_replace_malloc.c:309)
== by 0x4B55E93: wl_event_loop_add_timer (event-loop.c:197)
== by 0x4126CF: weston_compositor_create (in /usr/local/bin/weston)
== by 0x409997: main (in /usr/local/bin/weston)
Signed-off-by: Lujin Wang <luwang@nvidia.com>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Layers did not have a fini sequence before, which means the compositor
layer list might have stale pointers temporarily when shutting down. A
bigger problem might be having views linger after the destruction of the
layer.
These problems were not observed yet, but if they exist, this patch
should help to find them and then fix them.
The check in weston_compositor_shutdown() is not an assert yet, because
it will trigger until all components call weston_layer_fini() correctly.
Some components do not even have a tear-down function to call it from at
all, like fullscreen-shell.
The same with the check in weston_layer_fini().
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
These are all the remaining places that still use the global view_list,
and cannot avoid it. Add a comment to explain why in each.
Now all places that use view_list have been audited for paint node
lists.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Iterate paint nodes instead of the global view list. Right now this does
not change behavior.
This is a step towards using per-output view lists that can then be
optimized for the output in libweston core.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Iterate paint nodes instead of the global view list. Right now this does
not change behavior.
This is a step towards using per-output view lists that can then be
optimized for the output in libweston core.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This patch creates a per-output paint node list in the same z-order as
the global view_list in weston_compositor.
The next step is to switch output repaints and backends to use the
z-order list instead of view_list.
Having a per-output paint node list for repaints allows including only
those paint nodes that actually contribute to the output image, so that
completely occluded and out-of-screen views can be ignored in libweston
core already.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This new object is created for every surface-view-output triplet. As
there is always exactly one surface for a view and it does not change
during a view's lifetime, this is really for a view-output pair or a
surface-output pair.
The object is created on-demand as a part of preparing for an output
repaint, so it applies only to surfaces that are going through repaint.
A prerequisite for that is that the surface is mapped, which means it
has a mapped view.
When any one of surface or view gets destroyed or output gets disabled,
all related paint nodes are destroyed.
In future, paint node will be useful for caching surface-output or
view-output pair dependent data:
- damage regions for overlapping outputs
- color transformations
- backend-specific bookkeeping (e.g. DRM KMS plane assigments)
- per-output repaint lists
- surface geometry transformed into output space
Suggested by Daniel Stone in
https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/582#note_899406
PS. The call in weston_view_destroy() to
weston_compositor_build_view_list() might be so that if the view has
sub-surfaces, rebuilding the view list removes those those too and
automagically deletes their views.
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>
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>
Converting a region from global coordinates to output pixel coordinates
will become useful in GL-renderer soon, so move this function to be
shared. It is tricky to reinvent.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This adds the libweston capability bit for "color operations" which
refers to a renderer's support for operations needed for color
management. GL-renderer will grow the support while Pixman-renderer will
not, which is why the cap is needed.
To make an example use of the cap, this also adds new API:
weston_output_set_renderer_shadow_buffer(). This is a temporary API to
enable future experimental features. The first such feature will be the
renderer internal shadow buffer, the boolean variable for it taken from
Harish Krupo's "weston.ini: introduce use-shadow-fbo in output config".
Obviously this patch does not implement the renderer shadow buffer. No
renderer sets WESTON_CAP_COLOR_OPS yet so trying to enable it will fail.
The documentation here is deliberately vague, because the bits needed
for color management will come in trickling for a long time until we can
call it color management in any sense. Until then, the temporary API
shall remain, perhaps poorly named.
Cc: Harish Krupo <harishkrupo@gmail.com>
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Until now we had the test quirks initialization in wet_main(),
just after calling weston_compositor_create(). But there are
some cases that require the quirks during struct weston_compositor
creation time.
Move test quirks initialization to weston_compositor_create()
in order to cover more use cases for the test quirks mechanism.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
Until now we had struct wet_testsuite_data as an opaque
struct that should be defined by the testsuite of libweston
users. Instead, keep the data as a void * and document that
users are responsible for defining the data type.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
There are some specific cases in which we need Weston to
behave differently when running in the test suite. This
adds a new API to allow the tests to select these behaviors.
For instance, in the DRM backend we plan to add a writeback
connector screenshooter. In case it fails for some
reason, it should fallback to the renderer screenshooter
that all other backends use. But if we add a test to
ensure the correctness of the writeback screenshooter,
we don't want it to fallback to the renderer one, we
want it to fail. With this new API we can choose to
disable the fallback behavior specifically for this test.
Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>
The opaque region is used to determine where the views underneath the current
view must be drawn. If the opaque is not clipped, then the area that is part of
the opaque region but not part of the scissor area is not drawn at all.
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
Subsurfaces inherit the scissor region from the parent surface. Currently
the region is updated at the end of weston_view_update_transform(). As a
result, the old region is used to clip the transform.boundingbox of the
subsurface.
Change the order to update the scissor region after the transform.matrix is
updated but before it is used.
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
As from commit b7e5f10bf4, weston_view_is_opaque() is called from
debug_scene_graph_cb(), which on its own represents a (different)
scope. By default, we already have a subscriber for the 'log' scope,
which will cause a harmless, yet spurious, message.
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
compositor_accumulate_damage() is called for each output during repaint.
The DRM backend will only set keep_buffer for the surfaces that are visible on
the current output. So a buffer_ref is released that may still be needed. When
the output that shows the surface is repainted, the buffer_ref is gone and the
surface cannot be put on a plane.
Ignore all surfaces that are not visible on the current output to avoid this.
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
Currently the debug output for 'drm-backend' can be confusing. In the output of
debug_scene_view_print() views may be listed as 'not opaque' but later, during
plane assignment, other views underneath such a view is reported as 'occluded on
our output'.
This happens because weston_view_is_opaque() has some extra checks to determine
if a view is fully opaque, such as 'is_opaque' provided by the renderer for
formats that have no alpha channel.
Use weston_view_is_opaque() in debug_scene_view_print() as well to get more
accurate results.
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
All timeline event timestamps are in CLOCK_MONOTONIC already. DRM KMS
timestamps are practically guaranteed to be CLOCK_MONOTONIC too, even though
presentation clock could theoretically be something else. For other backends,
the presentation clock is likely CLOCK_MONOTONIC_RAW due to
weston_compositor_set_presentation_clock_software().
This patch ensures that the recorded vblank timestamp is in CLOCK_MONOTONIC.
Otherwise interpreting the timeline traces might be difficult to do accurately,
since it would be hard to recover the relationship between the presentation
clock and timeline event timestamps.
The time conversion routine is the simplest possible, I don't think we need any
more accurate conversion for timeline purposes. Besides, DRM-backend is the
only backend where the timings actually matter, the other backends are
software-timed anyway.
Since the clock domain of the "vblank" attribute potentially changes, the
attribute is renamed. Wesgr never used this attribute.
Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
If a surface has subsurfaces then the surface itself is in the subsurface
list. To avoid printing it again there is a check to skip the child view,
if it is the same as the current view.
However, this fails when a surface with subsurfaces has two (or more) views:
The check to skip the parent fails for the other view and the two views are
printed again and again until a stack overflow occurs.
So instead check if the parent view of the subsurface view is the current
view. This way, any view that does not belong to a real subsurface is
skipped.
As a side effect, this ensures that each view of the subsurfaces is only
printed once at the correct place in the hierarchy.
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
Like physical size, subpixel arrangement, etc, transform advises of a
physical transform of a head, if present.
This commit adds the transform member and setter to weston_head, however
it is currently unused.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
[daniels: Extracted from one of Lucas's patches.]
Signed-off-by: Daniel Stone <daniels@collabora.com>
Marius Vlad
Michael Tretter
Pekka Paalanen
Robert Mader
Derek Foreman
Alexandros Frantzis
Leandro Ribeiro
nerdopolis
Emmanuel Gil Peyrot
Vlad Zahorodnii
Lujin Wang
Maxime Roussin-Bélanger
Michael Olbrich
Lucas Stach