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
8082aa980e