131 lines
5.2 KiB
Plaintext
131 lines
5.2 KiB
Plaintext
What is Wayland
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Wayland is a project to define a protocol for a compositor to talk to
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its clients as well as a library implementation of the protocol. The
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compositor can be a standalone display server running on Linux kernel
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modesetting and evdev input devices, an X applications, or a wayland
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client itself. The clients can be traditional applications, X servers
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(rootless or fullscreen) or other display servers.
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The wayland protocol is essentially only about input handling and
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buffer management. The compositor receives input events and forwards
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them to the relevant client. The clients creates buffers and renders
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into them and notifies the compositor when it needs to redraw. The
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protocol also handles drag and drop, selections, window management and
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other interactions that must go throught the compositor. However, the
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protocol does not handle rendering, which is one of the features that
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makes wayland so simple. All clients are expected to handle rendering
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themselves, typically through cairo or OpenGL.
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The wayland repository includes a compositor and a few clients, but
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both the compositor and clients are essentially test cases.
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Building Instructions
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The instructions below assume some familiarity with git and building
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and running experimental software. And be prepared that this project
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isn't at all useful right now, it's still very much a prototype. When
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the instructions suggest to clone a git repo, you can of course just
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add a remote and fetch instead, if you have a clone of that repo
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around already. I usually install all software I'm working on into
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$HOME/install, so that's what I'll use in the instructions below, but
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you can use your favorite directory of course or install over your
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system copy (pass --prefix=/usr --sysconfdir=/etc, generally).
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Modesetting
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At this point, kernel modesetting is upstream for Intel, AMD and
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nVidia chipsets. Most distributions ship with kernel modesetting
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enabled by default and will work with Wayland out of the box. The
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modesetting driver must also support the page flip ioctl, which only
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the intel driver does at this point.
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Building mesa
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Wayland uses the mesa EGL stack, and all extensions required to run
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EGL on KMS are now upstream on the master branch. The 7.9 release of
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mesa will have all these extensions, but for now you'll need to build
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mesa master:
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$ git clone git://anongit.freedesktop.org/mesa/mesa
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$ cd mesa
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$ ./configure --prefix=$HOME/install --enable-egl --enable-gles2
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$ make && make install
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If you're using an intel chipset, it's best to also pass
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--disable-gallium to ./configure, since otherwise libEGL will try to
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load the gallium sw rasterizer before loading the Intel DRI driver.
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libxkbcommon
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Wayland needs libxkbcommon for translating evdev keycodes to keysyms.
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There's a couple of repos around, and we're trying to consolidate the
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development, but for wayland you'll need the repo from my git
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repository. For this you'll need development packages for xproto,
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kbproto and libX11.
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$ git clone git://people.freedesktop.org/~krh/libxkbcommon.git
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$ cd libxkbcommon/
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$ ./autogen.sh --prefix=$HOME/install
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$ make && make install
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cairo-gl
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The Wayland clients render using cairo-gl, which is an experimental
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cairo backend. It has been available since cairo 1.10. Unless your
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distribution ships cairo with the gl backend enabled, you'll need to
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compile your own version of cairo:
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$ git clone git://anongit.freedesktop.org/cairo
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$ cd cairo
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$ ./autogen.sh --prefix=$HOME/install --enable-gl
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$ make && make install
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Wayland
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With mesa and libxkbcommon in place, we can checkout and build
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Wayland. Aside from mesa, Wayland needs development packages for
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gdk-pixbuf-2.0, libudev, libdrm, xcb-dri2, xcb-fixes (for X
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compositor) cairo-gl, glib-2.0, gdk-2.0 (for poppler) and
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poppler-glib:
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$ git clone git://people.freedesktop.org/~krh/wayland
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$ ./autogen.sh --prefix=$HOME/install
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$ make && make install
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Installing into a non-/usr prefix is fine, but the 70-wayland.rules
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udev rule file has to be installed in /etc/udev/rules.d. Once
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installed, either reboot or run
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$ sudo udevadm trigger --subsystem-match=drm --subsystem-match=input
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to make udev label the devices wayland will use.
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If DISPLAY is set, the wayland compositor will run under X in a window
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and take input from X. Otherwise it will run on the KMS framebuffer
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and take input from evdev devices. Pick a background image that you
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like and copy it to the Wayland source directory as background.jpg or
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use the -b command line option:
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$ ./wayland-system-compositor -b my-image.jpg
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To run clients, switch to a different VT and run the client from
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there. Or run it under X and start up the clients from a terminal
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window. There are a few demo clients available, but they are all
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pretty simple and mostly for testing specific features in the wayland
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protocol: 'terminal' is a simple terminal emulator, not very compliant
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at all, but works well enough for bash
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'flower' moves a flower around the screen, testing the frame protocol
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'gears' glxgears, but for wayland, currently broken
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'image' loads the image files passed on the command line and shows them
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'view' does the same for pdf files, but needs file URIs
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(file:///path/to/pdf)
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