The new Framebuffer::Session::sync_source RPC function allows for the
selection of a specific source of sync signals in the presence of
multiple capture clients at the GUI server.
This patch contains only the extension of the interface. The information
is not evaluated by the GUI server yet.
Issue #5347
By enhancing the Framebuffer::Session interface by the new RPC functions
'blit' and 'panning', GUI clients become able to attain tearing-free
output. Two modes of operations are supported.
1. Atomic back-to-front blitting
GUI clients that partially update their user interface like regular
application dialogs, can now implement double buffering by placing
both the back buffer and front buffer within the GUI session's
framebuffer and configuring a view that shows only the front buffer.
The 'blit' operation allows the client to atomically flush pixels
from the back buffer to the front buffer.
2. Atomic buffer flipping
GUI clients that always update all pixels like a media player or
a game can now use the 'panning' feature to atomically redirect the
displayed pixels to a different portion of the GUI session's virtual
frame buffer. The virtual framebuffer always contains two frames,
the displayed one and the next one. Once the next frame is complete,
the client changes the panning position to the portion containing
the next frame.
Issue #5350
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082
