Last October, our last look at graphics focused on the plans laid at September's X Developer's Conference. In the three months since then, these plans have come to fruition, reasserting the continuing relevance of X.org compared with Wayland and other compositing display servers.

Indeed, while Wayland continues to show solid progress in development, adoption by users and distros remains light, with efforts focused around niche areas (e.g. automotive). That said, this quarter saw interesting progress at increasing Wayland's flexibility, which may enable it to enter a wider array of niches and use cases.

The X.org project saw a prolific quarter, with several packages receiving some major new releases:

• The Intel video driver (xf86-video-intel) has had several release candidates in their run up to their 3.0 release. Version 3.0 will feature switching to using the Sandybridge New Acceleration (SNA) by default. SNA is the latest 2D acceleration method from Intel, and promises faster rendering performance and better power usage than the current UXA acceleration method. SNA has undergone extensive testing over the past few years, and has been shipping as the default in distros like Ubuntu. Another new feature is tear-free rendering on transformed/rotated outputs. The 3.0 series also brings in bunches of hardware enablement fixes, build fixes, performance tunings, fixes for graphical glitches, and other stabilization work.
• mesa achieved version 10.0. The major new feature is the implementation of the OpenGL 3.3 API. The API is implemented for the Intel driver; OpenGL 3.3 support for the Open Source Radeon and Nouveau video drivers will be filled in by those projects over time. Along with this comes fixes for a number of rendering problems encountered by games, demos, and h264 video playback. This was followed by a 10.0.1 release which corrected a regression preventing Mesa 10.0 from working with released versions of the X server.
• xorg-server released 1.15.0 just before the end of the year, on December 27th. This release brings the Direct Rendering Infrastructure 3 (DRI3) and the Present Extension, which provides an efficient rendering path for direct rendering applications like games and video players when operating in a composited environment. This brings Wayland-like rendering performance to X.org and solves some major longstanding glitch/tearing type bugs. Beyond DRI3, this release also introduces a major GLX code re-write. A notably missing feature is any support for XWayland or XMir, so both of those projects will need to continue carrying their own X11 compatibility patches.
• xorg-server also saw several stable releases of the previous 1.14.x branch, most notably being fixes for passive/active grabs, touch listeners, and pointer syncing in 1.14.3 and 1.14.4, and a series of randr fixes for 1.14.5.
• The release of presentproto 1.0 and dri3proto 1.0 marks a major release of Keith Packard's Present extension work. This adds a new protocol and API to give clients a better way of redirecting rendering data to hardware while in a composited environment.

The Wayland project is comprised of two code trees: 'Wayland', which is just the protocol definition, and 'Weston', the demo compositor that implements the backend server for the protocol. This past quarter saw a 1.3.0 release for Wayland, and 1.3.0 and 1.3.1 releases for Weston.

With the Wayland protocol largely considered stable now, the Wayland 1.3 release was relatively light. One notable enhancement was the addition of language binding support, which allows writing clients in higher level languages.

Weston 1.3 brings quite a few changes:

• Realtime h.264 screen capture using libva. Potentially will be replaced by gstreamer later. This might serve as the base for a network streaming functionality.
• libhybris support, so weston can be used with Android EGL/GLES2 drivers.
• Better multi-resource input device support, allowing different subsystems can receive events from any number of pointers, keyboards, or touch resources.
• Drag-and-drop from X to wayland.
• RGB565 pixel format for clients using gl or pixman buffers.
• Various fixes and improvements for touch device support.

The Weston 1.3.1 release was an important bugfix release since 1.3.0 was released with a list of known issues. This fixes several severe crashes and hangs, and addresses several functional gaps.

Wayland Development News

The XDG Shell Protocol has received a large amount of attention the past few months, and some preliminary prototyping is underway as 'westoy' - an intra-project fork of weston with the new protocol inserted between weston core and the shell. This protocol is intended to standardize compositor calls that shells need to make, such that weston could be swapped out for a different but protocol-compliant compositor, with no modifications required of the shell.

The Wayland/Weston 1.4 release is scheduled for mid-January, with the first alpha release (1.3.91) posted on Dec 17th. A few of the features being included in this release are:

• Moving subsurface and input methods into wayland, and scaling of subsurfaces. Subsurfaces provide a more efficient design for applications that use sub-windows for displaying video content, such as a web browser with a video player or game embedded in it.
• logind backend.
• Surface/view split, with scaling and cropping support.
• Output cloning and per-output multi-texture borders.
• Fix for wl_shm buffer truncate exploit.
• eglSwapInterval(0).
• Nested wl_buffer pass-through.
• Touch grabs to enable touch-to-focus.
• Use gstreamer or libva helper library instead of direct libva use for weston encoding.
• Run-time switchable renderer backends (e.g. Pixman vs. OpenGL)
• An ExposÈ feature.

Upcoming Events

• linux.conf.au, Perth, Australia, Jan 6-10, 2014
• FOSDEM 2014, Brussels, Belgium, Feb 1-2, 2014
• LibreGraphics Meeting: LGM2014 - April 2-5, 2014: Leipzig, Germany

2013 has been a dramatic and controversial year for graphics in Linux, yet actual changes to the overall graphics stack have so far been more incremental than revolutionary. But with us closing in on several Linux distributions' Long-Term Support releases this is to be expected, as stability weighs stronger than novelty among consumers of these products. This next summer may be a safer window for distros to undertake major transitions; we should expect to see major graphics system transitions in desktop distros at that point. The landing of XWayland support in the X server can be seen as an early indicator of a Wayland desktop future, since it's a crucial prerequisite.

We'll check in again next quarter, when hopefully the distros will have established their post-LTS plans, and we'll be able to forecast the future for X.org and Wayland. Meanwhile, follow us on Twitter @SamsungOSG.