The ClientBuffer type is empty now, most of the things have been
upstreamed to the GraphicsBuffer type. So let's drop it to simplify the
type hierarchy.
ClientBufferIntegration was introduced to work around the fact that some
client buffers are not created by us.
In addition to that, DisplayPrivate::registerClientBuffer() was
introduced to register client buffers created by us.
This change get rids of the ClientBufferIntegration type and further
simplifies the ClientBuffer type to make wayland-specific client buffer
code less messier.
The main motivation is to avoid scattering graphics buffer things around
kwin.
DmaBufParams struct has been moved to the OutputBackend, but with the
introduction of buffer allocators, we need to port screencasting code to
the new abstractions some time in the future.
A client can specify the following flags when creating a linux dmabuf
client buffer:
- y_invert
- interlaced
- bottom_first
Only the y_invert flag is supported by kwin. The interlaced and the
bottom_first flags are ignored. On the other hand, most clients don't
specify the dmabuf flags. For example, neither EGL nor Vulkan WSIs
use the y_invert flag.
The y_invert flag is undesired because it also blocks optimizations such
as direct scanout because DRM assumes that the origin is in the top left
corner.
Therefore, this change drops the support for linux dmabuf flags. From
the protocol perspective, this is fine. It can be viewed as buffer
import failing with the specified flags.
LinuxDmaBufV1ClientBuffer contains properties (formats, and flags) that
are not available in the base GraphicsBuffer type and there's no reason
to move it there.
In order to get rid of those properties (and eventually hide the
LinuxDmaBufV1ClientBuffer type from the public api), this change adds a
DmaBufAttributes getter in the GraphicsBuffer.
At the moment, the render backend provides its specific implementation
of LinuxDmaBufV1ClientBuffer. This has some of its limitations. For
example, due to the strong coupling, compositing restarts must be
handled carefully. It's hard to have a generic code path to import
dmabufs, which would be nice to have in order to unify graphics buffer
allocation across various backends; currently, it's all scattered.
To make the code simpler, this change drops the commented out YUV import
code path for now. Given that Mesa implicitly handles it, the need for
it is no longer so urgent.
At the moment, dmabuf importing is scattered all over the place in kwin.
It would be great if we had one function that takes dma-buf attributes
and returns an EGLImage if successful.
As the first step, make linux-dmabuf-v1 implementation provide dmabuf
attrs compatible with KWin::DmaBufAttributes.
This makes KWin switch to in-tree copy of KWaylandServer codebase.
KWaylandServer namespace has been left as is. It will be addressed later
by renaming classes in order to fit in the KWin namespace.
dmabuf-feedback allows the compositor to give the client feedback on what
formats and modifiers are best to use, and for which devices it needs to
allocate its buffers, which improves performance and efficiency.
Currently, the BufferInterface encapsulates all the kinds of client
buffers. This has become a somewhat annoying issue as we want to
reference the shm pool if a shm buffer is destroyed, or have custom
buffer readiness logic for linux dma-buf client buffers.
Implementing all of that with the current abstractions will be
challenging as there's no good separation between different client
buffer types.
This change splits the BufferInterface class in three sub-classes -
DrmClientBuffer, LinuxDmaBufV1ClientBuffer, and ShmClientBuffer.
In addition to that, this change fixes the broken buffer ref'ing api.
