.TH 12to11
.SH NAME
12to11 - Wayland to X protocol translator
.SH SYNOPSIS
.B 12to11
.SH DESCRIPTION
.I 12to11
starts a Wayland compositor on the next available socket;
Wayland programs will then be displayed through the X server.
.SH OPTIONS
None.
.SH ENVIRONMENT
Several environment variables exist that modify the behavior of the
protocol translator in one way or another.  Most of these are used for
debugging, but some may be relevant to users as well.
.PP
The
.B USE_BUILTIN_RESIZE
environment variable, if set, forces the use of the built-in
drag-to-resize support provided by the protocol translator, even if
the X window manager provides its own.
.PP
The
.B DEBUG_REFRESH_PREDICTION
environment variable, if set, forces the frame clock to predict the
presentation deadline of the X compositing manager.  This is used to
debug code that is otherwise not run without subsurfaces being
present.
.PP
The
.B DISABLE_FRAME_SYNCHRONIZATION
environment variable, if set, disables frame synchronization with the
X compositing manager.  Setting this variable is probably not a good
idea.
.PP
The
.B SYNCHRONIZE
environment variable, if set, causes the X library to check for errors
immediately after issuing a request.  The resulting backtraces from
the error handler then reflect the protocol request that actually
caused the error, instead of some unpredictable request in the future.
.PP
The
.B APPLY_STATE_WORKAROUND
environment variable, if set, causes the protocol translator to handle
toplevel window state changes differently.  If Wayland programs do not
make the transition between fullscreen and maximized states correctly,
try setting this variable.
.PP
The
.B GLOBAL_SCALE
environment variable, if set to an integer, overrides the global
program scale factor normally provided by the
.I Gdk/WindowScalingFactor
X setting.
.PP
The
.B OUTPUT_SCALE
environment variable, if set to an integer, overrides the output scale
factor that is otherwise set to the global program scale factor.
Setting this option is only useful to debug Wayland program
downscaling.
.PP
The
.B DIRECT_STATE_CHANGES
variable, if set, forces ConfigureNotify events from the window
manager to be handled directly, without waiting some time for a
corresponding _NET_WM_STATE event to arrive.  This is only
useful for debugging the window resizing logic.
.PP
The
.B RENDERER
variable, if set, controls the rendering backend used by the
protocol translator.  When set to
.I help
it prints a list of available rendering backends instead.
.PP
The
.B RENDER_VISUAL
variable, if set to a number, contains the ID of the visual used
when the EGL rendering backend is in use.
.SH BUGS
There is a hard to catch bug where Wayland programs leaving the
fullscreen or maximized state may abruptly return to their maximized
size.  Setting the
.B APPLY_STATE_WORKAROUND
environment variable may help.
.PP
Mozilla Firefox also does not work correctly.  Resizing the Firefox
window leads to screen tearing, and Firefox often resizes its toplevel
windows outside their normal boundaries, causing invalid screen
contents to be displayed over other applications.
.PP
Using this protocol translator under a window manager that does not at
least support the
.B _NET_WM_SYNC_REQUEST
and
.B _NET_WM_STATE
window manager hints will result in Wayland programs running
incorrectly.
.SH "SEE ALSO"
X(1), Xorg(1)
.SH AUTHOR
Various contributors.