kwin/plugins/platforms/drm
Vlad Zahorodnii b8a70e62d5 Introduce RenderLoop
At the moment, our frame scheduling infrastructure is still heavily
based on Xinerama-style rendering. Specifically, we assume that painting
is driven by a single timer, etc.

This change introduces a new type - RenderLoop. Its main purpose is to
drive compositing on a specific output, or in case of X11, on the
overlay window.

With RenderLoop, compositing is synchronized to vblank events. It
exposes the last and the next estimated presentation timestamp. The
expected presentation timestamp can be used by effects to ensure that
animations are synchronized with the upcoming vblank event.

On Wayland, every outputs has its own render loop. On X11, per screen
rendering is not possible, therefore the platform exposes the render
loop for the overlay window. Ideally, the Scene has to expose the
RenderLoop, but as the first step towards better compositing scheduling
it's good as is for the time being.

The RenderLoop tries to minimize the latency by delaying compositing as
close as possible to the next vblank event. One tricky thing about it is
that if compositing is too close to the next vblank event, animations
may become a little bit choppy. However, increasing the latency reduces
the choppiness.

Given that, there is no any "silver bullet" solution for the choppiness
issue, a new option has been added in the Compositing KCM to specify the
amount of latency. By default, it's "Medium," but if a user is not
satisfied with the upstream default, they can tweak it.
2021-01-06 16:59:29 +00:00
..
abstract_egl_drm_backend.cpp Introduce RenderLoop 2021-01-06 16:59:29 +00:00
abstract_egl_drm_backend.h
CMakeLists.txt
drm.json
drm_backend.cpp Introduce RenderLoop 2021-01-06 16:59:29 +00:00
drm_backend.h
drm_buffer.cpp
drm_buffer.h
drm_buffer_gbm.cpp
drm_buffer_gbm.h
drm_gpu.cpp Introduce RenderLoop 2021-01-06 16:59:29 +00:00
drm_gpu.h Introduce RenderLoop 2021-01-06 16:59:29 +00:00
drm_inputeventfilter.cpp
drm_inputeventfilter.h
drm_object.cpp
drm_object.h
drm_object_connector.cpp
drm_object_connector.h
drm_object_crtc.cpp
drm_object_crtc.h
drm_object_plane.cpp
drm_object_plane.h
drm_output.cpp Introduce RenderLoop 2021-01-06 16:59:29 +00:00
drm_output.h Introduce RenderLoop 2021-01-06 16:59:29 +00:00
drm_pointer.h
edid.cpp
edid.h
egl_gbm_backend.cpp
egl_gbm_backend.h
egl_multi_backend.cpp Introduce RenderLoop 2021-01-06 16:59:29 +00:00
egl_multi_backend.h
egl_stream_backend.cpp
egl_stream_backend.h
gbm_dmabuf.cpp
gbm_dmabuf.h
gbm_surface.cpp
gbm_surface.h
logging.cpp
logging.h
scene_qpainter_drm_backend.cpp
scene_qpainter_drm_backend.h