TODO

 - sync-to-vblank

 - how does clients move their surfaces? set a full tri-mesh every
   time? probably just go back to x and y position, let the compositor
   do the fancy stuff.  How does the server apply transformations to a
   surface behind the clients back? (wobbly, minimize, zoom) Maybe
   wobble is client side?

 - switch scanout when top surface is full screen

    - what about cursors then?  maybe use hw cursors if the cursor
      satisfies hw limitations (64x64, only one cursor), switch to
      composited cursors if not.

 - multihead, screen geometry and crtc layout protocol, hotplug

 - input device discovery, hotplug

    - Advertise axes as part of the discovery, use something like
      "org.wayland.input.x" to identify the axes.

    - keyboard state, layout events at connect time and when it
      changes

    - relative events

    - input handling - keyboard focus, multiple input devices,
      multiple pointers, multi touch.

 - wayland-system-compositor

    - device kit/libudev/console kit integration to discover seats,
      that is, groups of input devices and outputs that provide a
      means for one user to interact with the system.  That is,
      typically a mouse, keyboard and a screen.  The input devices
      will just be evdev devices, the outputs will be a drm device
      filename and the specific outputs accessible throught that drm
      device.

 - send drm device in connection info, probably just udev path.

 - cairo-drm; wayland needs cairo-drm one way or another:

    - chris wilson (ickle) is doing cairo-drm for i915 now, basically
      the pixman-drm idean, but inside cairo instead.

    - pixman-drm; move the ddx driver batchbuffer logic into libdrm
      and write native, direct rendering acceleration code in
      pixman-drm.  is a clean approach in that we avoid the mess of
      the global GL context leaking through to applications, and we
      can bootstrap this project by pulling in the EXA hooks from the
      DDX drivers.

    - use open gl behind the scenes a la glitz.

    - should be possible to provide a realistic api and then stub out
      the implementation with pwrite and pread so gtk+ port can proceed.

 - XKB like client side library for translating keyboard events to
   more useful keycodes and modifiers etc.  Will probably be shared
   between toolkits as a low-level library.

 - port gtk+

    - eek, so much X legacy stuff there...

    - draw window decorations in gtkwindow.c

    - start from alexl's client-side-windows branch

    - Details about pointer grabs. wayland doesn't have active grabs,
      menus will behave subtly different.  Under X, clicking a menu
      open grabs the pointer and clicking outside the window pops down
      the menu and swallows the click.  without active grabs we can't
      swallow the click.  I'm sure there much more...

 - Port Qt?  There's already talk about this on the list.

 - X on Wayland

    - move most of the code from xf86-video-intel into a Xorg wayland
      module.

    - don't ask KMS for available output and modes, use the info from
      the wayland server.  then stop mooching off of drmmode.c.

    - map multiple wayland input devices to MPX in Xorg.

    - rootless; avoid allocating and setting the front buffer, draw
      window decorations in the X server (!), how to map input?

 - gnome-shell as a wayland session compositor

    - runs as a client of the wayland session compositor, uses
      clutter+egl on wayland

    - talks to an Xorg server as the compositing and window manager
      for that server and renders the output to a wayland surface.
      the Xorg server should be modified to take input from the system
      compositor through gnome-shell, but not allocate a front buffer.

    - make gnome-shell itself a nested wayland server and allow native
      wayland clients to connect and can native wayland windows with
      the windows from the X server.

 - qemu as a wayland client; session surface as X case

    - qemu has too simple acceleration, so a Wayland backend like the
      SDL/VNC ones it has now is trivial.

    - paravirt: forward wayland screen info as mmio, expose gem ioctls as mmio

    - mapping vmem is tricky, should try to only use ioctl (pwrite+pread)

    - not useful for Windows without a windows paravirt driver.

    - two approaches: 1) do a toplevel qemu window, or 2) expose a
      wayland server in the guest that forwards to the host wayland
      server, ie a "remote" compositor, but with the gem buffers
      shared.  could do a wl_connection directly on mmio memory, with
      head and tail pointers.  use an alloc_head register to indicate
      desired data to write, if it overwrites tail, block guest.  just
      a socket would be easier.

 - moblin as a wayland compositor

    - clutter as a wayland compositors

    - argh, mutter

 - make libwayland-client less ghetto

 - sparse based idl compiler

    - crack?

    - xml based description instead?

 - actually make batch/commit batch up commands

 - protocol for setting the cursor image

    - should we have a mechanism to attach surface to cursor for
      guaranteed non-laggy drag?

    - drawing cursors, moving them, cursor themes, attaching surfaces
      to cursors.  How do you change cursors when you mouse over a
      text field if you don't have subwindows?  This is what we do: a
      client can set a cursor for a surface and wayland will set that
      on enter and revert to default on leave

 - server should be able to discard surfaces, and send a re-render
   event to clients to get them to render and provide the surface
   again.  for wayland system compositor vt switcing, for example, to
   be able to throw away the surfaces in the session we're switching
   away from.  for minimized windows that we don't want live thumb
   nails for. etc.

 - auth; We need to generate a random socket name and advertise that
   on dbus along with a connection cookie.  Something like a method
   that returns the socket name and a connection cookie.  The
   connection cookie is just another random string that the client
   must pass to the wayland server to become authenticated.  The
   Wayland server generates the cookie on demand when the dbus method
   is called and expires it after 5s or so.

    - or just pass the fd over dbus

 - drm bo access control, authentication, flink_to

 - enter/leave events from the input devices

 - gain, lose keyboard focus events; this event carries information
   about which keys are currently held down as a surface gains focus
   so the client can deduce modifier state.

 - Range protocol may not be sufficient... if a server cycles through
   2^32 object IDs we don't have a way to handle wrapping.  And since
   we hand out a range of 256 IDs to each new clients, we're just
   talking about 2^24 clients.  That's 31 years with a new client
   every minute...  Maybe just use bigger ranges, then it's feasible
   to track and garbage collect them when a client dies.

 - multi gpu, needs queue and seqno to wait on in requests

 - opaque region, window rect

 - save and restore state on crash, clients reconnect, re-render
   buffers

 - how do apps share the glyph cache?  what is the glyph cache, how
   does it work?  pixbuf cache?

 - synaptics, 3-button emulation, scim

 - what to do when protocol out buffer fills up?  Just block on write
   would work I guess.  Clients are supposed to throttle using the
   bread crumb events, so we shouldn't get into this situation.

 - when a surface is the size of the screen and on top, we can set the
   scanout buffer to that surface directly.  Like compiz unredirect
   top-level window feature.  Except it won't have any protocol state
   side-effects and the client that owns the surface won't know.  We
   lose control of updates.  Should work well for X server root window
   under wayland.