mirror of
https://gitlab.freedesktop.org/wayland/wayland.git
synced 2026-01-04 00:30:19 +01:00
read-only mirror of https://gitlab.freedesktop.org/wayland/wayland
81c57614d1
The sub-surface protocol was originally committed into Weston on May 10th, 2013, in commit 2396aec6842c709a714f3825dbad9fd88478f2e6. The design for the protocol had started in the beginning of December 2012. I think it is high time to move this into the core now. This patch copies the sub-surface protocol as it was in Weston on Nov 15th, 2013, into Wayland. Weston gets a patch to remove the protocol from there. Sub-surface is a wl_surface role. You create a wl_surface as usual, and assign it the sub-surface role and a parent wl_surface. Sub-surfaces are an integral part of the parent surface, and stay glued to the parent. For window management, a window is the union of the top-level wl_surface and all its sub-surfaces. Sub-surfaces are not clipped to the parent, and the union of the surface tree can be larger than the (top-level) wl_surface at its root. The representative use case for sub-surfaces is a video player window. When the video content is given its own wl_surface, there is no need to modify the video frame contents after decoding or copy them into a whole window sized buffer before submitting it to the compositor. This allows efficient, zero-copy video presentation paths, where video decoding hardware produces a (YUV) buffer, which eventually ends up in a (YUV-capable) hardware overlay and is scanned out directly. This can also be used for zero-copy presentation of windowed OpenGL content, where the OpenGL rendering engine does not need to draw or avoid window decorations. Sub-surfaces allow mixing different buffer types into the same window, e.g. software-rendered decorations in wl_shm buffers, and live content in EGL-based buffers. However, the sub-surface extension does not offer clipping or scaling facilities, or accurate presentation timing. Those are topics for additional extensions. Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk> |
||
|---|---|---|
| cursor | ||
| doc | ||
| m4 | ||
| protocol | ||
| spec | ||
| src | ||
| tests | ||
| .gitignore | ||
| autogen.sh | ||
| configure.ac | ||
| COPYING | ||
| Makefile.am | ||
| README | ||
| TODO | ||
| wayland-scanner.m4 | ||
| wayland-scanner.mk | ||
What is Wayland
Wayland is a project to define a protocol for a compositor to talk to
its clients as well as a library implementation of the protocol. The
compositor can be a standalone display server running on Linux kernel
modesetting and evdev input devices, an X application, or a wayland
client itself. The clients can be traditional applications, X servers
(rootless or fullscreen) or other display servers.
The wayland protocol is essentially only about input handling and
buffer management. The compositor receives input events and forwards
them to the relevant client. The clients creates buffers and renders
into them and notifies the compositor when it needs to redraw. The
protocol also handles drag and drop, selections, window management and
other interactions that must go through the compositor. However, the
protocol does not handle rendering, which is one of the features that
makes wayland so simple. All clients are expected to handle rendering
themselves, typically through cairo or OpenGL.
The weston compositor is a reference implementation of a wayland
compositor and the weston repository also includes a few example
clients.
Building the wayland libraries is fairly simple, aside from libffi,
they don't have many dependencies:
$ git clone git://anongit.freedesktop.org/wayland/wayland
$ cd wayland
$ ./autogen.sh --prefix=PREFIX
$ make
$ make install
where PREFIX is where you want to install the libraries. See
http://wayland.freedesktop.org for more complete build instructions
for wayland, weston, xwayland and various toolkits.