Provided by: picom_9.1-1_amd64 
NAME
picom - a compositor for X11
SYNOPSIS
picom [OPTIONS]
DESCRIPTION
picom is a compositor based on Dana Jansens' version of xcompmgr (which itself was written
by Keith Packard). It includes some improvements over the original xcompmgr, like window
frame opacity and inactive window transparency.
OPTIONS
-h, --help
Get the usage text embedded in program code, which may be more up-to-date than this
man page.
-r, --shadow-radius=RADIUS
The blur radius for shadows, in pixels. (defaults to 12)
-o, --shadow-opacity=OPACITY
The opacity of shadows. (0.0 - 1.0, defaults to 0.75)
-l, --shadow-offset-x=OFFSET
The left offset for shadows, in pixels. (defaults to -15)
-t, --shadow-offset-y=OFFSET
The top offset for shadows, in pixels. (defaults to -15)
-I, --fade-in-step=OPACITY_STEP
Opacity change between steps while fading in. (0.01 - 1.0, defaults to 0.028)
-O, --fade-out-step=OPACITY_STEP
Opacity change between steps while fading out. (0.01 - 1.0, defaults to 0.03)
-D, --fade-delta=MILLISECONDS
The time between steps in fade step, in milliseconds. (> 0, defaults to 10)
-c, --shadow
Enabled client-side shadows on windows. Note desktop windows (windows with
_NET_WM_WINDOW_TYPE_DESKTOP) never get shadow, unless explicitly requested using the
wintypes option.
-f, --fading
Fade windows in/out when opening/closing and when opacity changes, unless
--no-fading-openclose is used.
-F
Equals to -f. Deprecated.
-i, --inactive-opacity=OPACITY
Opacity of inactive windows. (0.1 - 1.0, defaults to 1.0)
-e, --frame-opacity=OPACITY
Opacity of window titlebars and borders. (0.1 - 1.0, disabled by default)
-b, --daemon
Daemonize process. Fork to background after initialization. This option can only be
set from the command line, setting this in the configuration file will have no effect.
--log-level
Set the log level. Possible values are "TRACE", "DEBUG", "INFO", "WARN", "ERROR", in
increasing level of importance. Case doesn’t matter. If using the "TRACE" log level,
it’s better to log into a file using --log-file, since it can generate a huge stream
of logs.
--log-file
Set the log file. If --log-file is never specified, logs will be written to stderr.
Otherwise, logs will to written to the given file, though some of the early logs might
still be written to the stderr. When setting this option from the config file, it is
recommended to use an absolute path.
--experimental-backends
Use the new, reimplemented version of the backends. The new backends are HIGHLY
UNSTABLE at this point, you have been warned. This option is not available in the
config file.
--show-all-xerrors
Show all X errors (for debugging).
--config PATH
Look for configuration file at the path. See CONFIGURATION FILES section below for
where picom looks for a configuration file by default. Use /dev/null to avoid loading
configuration file.
--write-pid-path PATH
Write process ID to a file. it is recommended to use an absolute path.
--shadow-color STRING
Color of shadow, as a hex string (#000000)
--shadow-red VALUE
Red color value of shadow (0.0 - 1.0, defaults to 0).
--shadow-green VALUE
Green color value of shadow (0.0 - 1.0, defaults to 0).
--shadow-blue VALUE
Blue color value of shadow (0.0 - 1.0, defaults to 0).
--inactive-opacity-override
Let inactive opacity set by -i override the _NET_WM_WINDOW_OPACITY values of windows.
--active-opacity OPACITY
Default opacity for active windows. (0.0 - 1.0, defaults to 1.0)
--inactive-dim VALUE
Dim inactive windows. (0.0 - 1.0, defaults to 0.0)
--corner-radius VALUE
Sets the radius of rounded window corners. When > 0, the compositor will round the
corners of windows. Does not interact well with --transparent-clipping. (defaults to
0).
--rounded-corners-exclude CONDITION
Exclude conditions for rounded corners.
--mark-wmwin-focused
Try to detect WM windows (a non-override-redirect window with no child that has
WM_STATE) and mark them as active.
--mark-ovredir-focused
Mark override-redirect windows that doesn’t have a child window with WM_STATE focused.
--no-fading-openclose
Do not fade on window open/close.
--no-fading-destroyed-argb
Do not fade destroyed ARGB windows with WM frame. Workaround of bugs in Openbox,
Fluxbox, etc.
--shadow-ignore-shaped
Do not paint shadows on shaped windows. Note shaped windows here means windows setting
its shape through X Shape extension. Those using ARGB background is beyond our
control. Deprecated, use --shadow-exclude 'bounding_shaped' or --shadow-exclude
'bounding_shaped && !rounded_corners' instead.
--detect-rounded-corners
Try to detect windows with rounded corners and don’t consider them shaped windows. The
accuracy is not very high, unfortunately.
--detect-client-opacity
Detect _NET_WM_WINDOW_OPACITY on client windows, useful for window managers not
passing _NET_WM_WINDOW_OPACITY of client windows to frame windows.
--vsync, --no-vsync
Enable/disable VSync.
--use-ewmh-active-win
Use EWMH _NET_ACTIVE_WINDOW to determine currently focused window, rather than
listening to FocusIn/FocusOut event. Might have more accuracy, provided that the WM
supports it.
--unredir-if-possible
Unredirect all windows if a full-screen opaque window is detected, to maximize
performance for full-screen windows. Known to cause flickering when
redirecting/unredirecting windows.
--unredir-if-possible-delay MILLISECONDS
Delay before unredirecting the window, in milliseconds. Defaults to 0.
--unredir-if-possible-exclude CONDITION
Conditions of windows that shouldn’t be considered full-screen for unredirecting
screen.
--shadow-exclude CONDITION
Specify a list of conditions of windows that should have no shadow.
--clip-shadow-above CONDITION
Specify a list of conditions of windows that should have no shadow painted over, such
as a dock window.
--fade-exclude CONDITION
Specify a list of conditions of windows that should not be faded.
--focus-exclude CONDITION
Specify a list of conditions of windows that should always be considered focused.
--inactive-dim-fixed
Use fixed inactive dim value, instead of adjusting according to window opacity.
--detect-transient
Use WM_TRANSIENT_FOR to group windows, and consider windows in the same group focused
at the same time.
--detect-client-leader
Use WM_CLIENT_LEADER to group windows, and consider windows in the same group focused
at the same time. This usually means windows from the same application will be
considered focused or unfocused at the same time.WM_TRANSIENT_FOR has higher priority
if --detect-transient is enabled, too.
--blur-method, --blur-size, --blur-deviation, --blur-strength
Parameters for background blurring, see the BLUR section for more information.
--blur-background
Blur background of semi-transparent / ARGB windows. Bad in performance, with
driver-dependent behavior. The name of the switch may change without prior
notifications.
--blur-background-frame
Blur background of windows when the window frame is not opaque. Implies
--blur-background. Bad in performance, with driver-dependent behavior. The name may
change.
--blur-background-fixed
Use fixed blur strength rather than adjusting according to window opacity.
--blur-kern MATRIX
Specify the blur convolution kernel, with the following format:
WIDTH,HEIGHT,ELE1,ELE2,ELE3,ELE4,ELE5...
In other words, the matrix is formatted as a list of comma separated numbers. The
first two numbers must be integers, which specify the width and height of the matrix.
They must be odd numbers. Then, the following width * height - 1 numbers specifies the
numbers in the matrix, row by row, excluding the center element.
The elements are finite floating point numbers. The decimal pointer has to be . (a
period), scientific notation is not supported.
The element in the center will either be 1.0 or varying based on opacity, depending on
whether you have --blur-background-fixed. Yet the automatic adjustment of blur factor
may not work well with a custom blur kernel.
A 7x7 Gaussian blur kernel (sigma = 0.84089642) looks like:
--blur-kern '7,7,0.000003,0.000102,0.000849,0.001723,0.000849,0.000102,0.000003,0.000102,0.003494,0.029143,0.059106,0.029143,0.003494,0.000102,0.000849,0.029143,0.243117,0.493069,0.243117,0.029143,0.000849,0.001723,0.059106,0.493069,0.493069,0.059106,0.001723,0.000849,0.029143,0.243117,0.493069,0.243117,0.029143,0.000849,0.000102,0.003494,0.029143,0.059106,0.029143,0.003494,0.000102,0.000003,0.000102,0.000849,0.001723,0.000849,0.000102,0.000003'
May also be one of the predefined kernels: 3x3box (default), 5x5box, 7x7box,
3x3gaussian, 5x5gaussian, 7x7gaussian, 9x9gaussian, 11x11gaussian. All Gaussian
kernels are generated with sigma = 0.84089642 . If you find yourself needing to
generate custom blur kernels, you might want to try the new blur configuration
supported by the experimental backends (See BLUR and --experimental-backends).
--blur-background-exclude CONDITION
Exclude conditions for background blur.
--resize-damage INTEGER
Resize damaged region by a specific number of pixels. A positive value enlarges it
while a negative one shrinks it. If the value is positive, those additional pixels
will not be actually painted to screen, only used in blur calculation, and such. (Due
to technical limitations, with --use-damage, those pixels will still be incorrectly
painted to screen.) Primarily used to fix the line corruption issues of blur, in which
case you should use the blur radius value here (e.g. with a 3x3 kernel, you should use
--resize-damage 1, with a 5x5 one you use --resize-damage 2, and so on). May or may
not work with --glx-no-stencil. Shrinking doesn’t function correctly.
--invert-color-include CONDITION
Specify a list of conditions of windows that should be painted with inverted color.
Resource-hogging, and is not well tested.
--opacity-rule OPACITY:'CONDITION'
Specify a list of opacity rules, in the format PERCENT:PATTERN, like 50:name *=
"Firefox". picom-trans is recommended over this. Note we don’t make any guarantee
about possible conflicts with other programs that set _NET_WM_WINDOW_OPACITY on frame
or client windows.
--shadow-exclude-reg GEOMETRY
Specify a X geometry that describes the region in which shadow should not be painted
in, such as a dock window region. Use --shadow-exclude-reg x10+0-0, for example, if
the 10 pixels on the bottom of the screen should not have shadows painted on.
--xinerama-shadow-crop
Crop shadow of a window fully on a particular Xinerama screen to the screen.
--backend BACKEND
Specify the backend to use: xrender, glx, or xr_glx_hybrid. xrender is the default
one.
• xrender backend performs all rendering operations with X Render extension. It is
what xcompmgr uses, and is generally a safe fallback when you encounter rendering
artifacts or instability.
• glx (OpenGL) backend performs all rendering operations with OpenGL. It is more
friendly to some VSync methods, and has significantly superior performance on
color inversion (--invert-color-include) or blur (--blur-background). It requires
proper OpenGL 2.0 support from your driver and hardware. You may wish to look at
the GLX performance optimization options below. --xrender-sync-fence might be
needed on some systems to avoid delay in changes of screen contents.
• xr_glx_hybrid backend renders the updated screen contents with X Render and
presents it on the screen with GLX. It attempts to address the rendering issues
some users encountered with GLX backend and enables the better VSync of GLX
backends. --vsync-use-glfinish might fix some rendering issues with this backend.
--glx-no-stencil
GLX backend: Avoid using stencil buffer, useful if you don’t have a stencil buffer.
Might cause incorrect opacity when rendering transparent content (but never
practically happened) and may not work with --blur-background. My tests show a 15%
performance boost. Recommended.
--glx-no-rebind-pixmap
GLX backend: Avoid rebinding pixmap on window damage. Probably could improve
performance on rapid window content changes, but is known to break things on some
drivers (LLVMpipe, xf86-video-intel, etc.). Recommended if it works.
--no-use-damage
Disable the use of damage information. This cause the whole screen to be redrawn every
time, instead of the part of the screen has actually changed. Potentially degrades the
performance, but might fix some artifacts.
--xrender-sync-fence
Use X Sync fence to sync clients' draw calls, to make sure all draw calls are finished
before picom starts drawing. Needed on nvidia-drivers with GLX backend for some users.
--glx-fshader-win SHADER
GLX backend: Use specified GLSL fragment shader for rendering window contents. See
compton-default-fshader-win.glsl and compton-fake-transparency-fshader-win.glsl in the
source tree for examples.
--force-win-blend
Force all windows to be painted with blending. Useful if you have a --glx-fshader-win
that could turn opaque pixels transparent.
--dbus
Enable remote control via D-Bus. See the D-BUS API section below for more details.
--benchmark CYCLES
Benchmark mode. Repeatedly paint until reaching the specified cycles.
--benchmark-wid WINDOW_ID
Specify window ID to repaint in benchmark mode. If omitted or is 0, the whole screen
is repainted.
--no-ewmh-fullscreen
Do not use EWMH to detect fullscreen windows. Reverts to checking if a window is
fullscreen based only on its size and coordinates.
--max-brightness
Dimming bright windows so their brightness doesn’t exceed this set value. Brightness
of a window is estimated by averaging all pixels in the window, so this could comes
with a performance hit. Setting this to 1.0 disables this behaviour. Requires
--use-damage to be disabled. (default: 1.0)
--transparent-clipping
Make transparent windows clip other windows like non-transparent windows do, instead
of blending on top of them.
FORMAT OF CONDITIONS
Some options accept a condition string to match certain windows. A condition string is
formed by one or more conditions, joined by logical operators.
A condition with "exists" operator looks like this:
<NEGATION> <TARGET> <CLIENT/FRAME> [<INDEX>] : <FORMAT> <TYPE>
With equals operator it looks like:
<NEGATION> <TARGET> <CLIENT/FRAME> [<INDEX>] : <FORMAT> <TYPE> <NEGATION> <OP QUALIFIER> <MATCH TYPE> = <PATTERN>
With greater-than/less-than operators it looks like:
<NEGATION> <TARGET> <CLIENT/FRAME> [<INDEX>] : <FORMAT> <TYPE> <NEGATION> <OPERATOR> <PATTERN>
NEGATION (optional) is one or more exclamation marks;
TARGET is either a predefined target name, or the name of a window property to match.
Supported predefined targets are id, x, y, x2 (x + widthb), y2 (like x2), width, height,
widthb (width + 2 * border_width), heightb (like widthb), border_width, fullscreen,
override_redirect, argb (whether the window has an ARGB visual), focused, wmwin (whether
the window looks like a WM window, i.e. has no child window with WM_STATE and is not
override-redirected), bounding_shaped, rounded_corners (requires
--detect-rounded-corners), client (ID of client window), window_type (window type in
string), leader (ID of window leader), name, class_g (= WM_CLASS[1]), class_i (=
WM_CLASS[0]), and role.
CLIENT/FRAME is a single @ if the window attribute should be be looked up on client
window, nothing if on frame window;
INDEX (optional) is the index number of the property to look up. For example, [2] means
look at the third value in the property. If not specified, the first value (index [0]) is
used implicitly. Use the special value [*] to perform matching against all available
property values using logical OR. Do not specify it for predefined targets.
FORMAT (optional) specifies the format of the property, 8, 16, or 32. On absence we use
format X reports. Do not specify it for predefined or string targets.
TYPE is a single character representing the type of the property to match for: c for
CARDINAL, a for ATOM, w for WINDOW, d for DRAWABLE, s for STRING (and any other string
types, such as UTF8_STRING). Do not specify it for predefined targets.
OP QUALIFIER (optional), applicable only for equals operator, could be ? (ignore-case).
MATCH TYPE (optional), applicable only for equals operator, could be nothing (exact
match), * (match anywhere), ^ (match from start), % (wildcard), or ~ (PCRE regular
expression).
OPERATOR is one of = (equals), <, >, <=, =>, or nothing (exists). Exists operator checks
whether a property exists on a window (but for predefined targets, exists means != 0
then).
PATTERN is either an integer or a string enclosed by single or double quotes.
Python-3-style escape sequences and raw string are supported in the string format.
Supported logical operators are && (and) and || (or). && has higher precedence than ||,
left-to-right associativity. Use parentheses to change precedence.
Examples:
# If the window is focused
focused
focused = 1
# If the window is not override-redirected
!override_redirect
override_redirect = false
override_redirect != true
override_redirect != 1
# If the window is a menu
window_type *= "menu"
_NET_WM_WINDOW_TYPE@:a *= "MENU"
# If the window is marked hidden: _NET_WM_STATE contains _NET_WM_STATE_HIDDEN
_NET_WM_STATE@[*]:a = "_NET_WM_STATE_HIDDEN"
# If the window is marked sticky: _NET_WM_STATE contains an atom that contains
# "sticky", ignore case
_NET_WM_STATE@[*]:a *?= "sticky"
# If the window name contains "Firefox", ignore case
name *?= "Firefox"
_NET_WM_NAME@:s *?= "Firefox"
# If the window name ends with "Firefox"
name %= "*Firefox"
name ~= "Firefox$"
# If the window has a property _COMPTON_SHADOW with value 0, type CARDINAL,
# format 32, value 0, on its frame window
_COMPTON_SHADOW:32c = 0
# If the third value of _NET_FRAME_EXTENTS is less than 20, or there's no
# _NET_FRAME_EXTENTS property on client window
_NET_FRAME_EXTENTS@[2]:32c < 20 || !_NET_FRAME_EXTENTS@:32c
# The pattern here will be parsed as "dd4"
name = "\x64\x64\o64"
# The pattern here will be parsed as "\x64\x64\x64"
name = r"\x64\x64\o64"
LEGACY FORMAT OF CONDITIONS
This is the old condition format we once used. Support of this format might be removed in
the future.
condition = TARGET:TYPE[FLAGS]:PATTERN
TARGET is one of "n" (window name), "i" (window class instance), "g" (window general
class), and "r" (window role).
TYPE is one of "e" (exact match), "a" (match anywhere), "s" (match from start), "w"
(wildcard), and "p" (PCRE regular expressions, if compiled with the support).
FLAGS could be a series of flags. Currently the only defined flag is "i" (ignore case).
PATTERN is the actual pattern string.
CONFIGURATION FILES
picom could read from a configuration file if libconfig support is compiled in. If
--config is not used, picom will seek for a configuration file in
$XDG_CONFIG_HOME/picom.conf (~/.config/picom.conf, usually), then
$XDG_CONFIG_HOME/picom/picom.conf, then $XDG_CONFIG_DIRS/picom.conf (often
/etc/xdg/picom.conf), then $XDG_CONFIG_DIRS/picom/picom.conf.
picom uses general libconfig configuration file format. A sample configuration file is
available as picom.sample.conf in the source tree. Most of commandline switches can be
used as options in configuration file as well. For example, --vsync option documented
above can be set in the configuration file using `vsync = `. Command line options will
always overwrite the settings in the configuration file.
Window-type-specific settings are exposed only in configuration file and has the following
format:
wintypes:
{
WINDOW_TYPE = { fade = BOOL; shadow = BOOL; opacity = FLOAT; focus = BOOL; blur-background = BOOL; full-shadow = BOOL; clip-shadow-above = BOOL; redir-ignore = BOOL; };
};
WINDOW_TYPE is one of the 15 window types defined in EWMH standard: "unknown", "desktop",
"dock", "toolbar", "menu", "utility", "splash", "dialog", "normal", "dropdown_menu",
"popup_menu", "tooltip", "notification", "combo", and "dnd".
Following per window-type options are available:
fade, shadow
Controls window-type-specific shadow and fade settings.
opacity
Controls default opacity of the window type.
focus
Controls whether the window of this type is to be always considered focused. (By
default, all window types except "normal" and "dialog" has this on.)
blur-background
Controls wether the window of this type will have its transparent background
blurred.
full-shadow
Controls whether shadow is drawn under the parts of the window that you normally
won’t be able to see. Useful when the window has parts of it transparent, and you
want shadows in those areas.
clip-shadow-above
Controls wether shadows that would have been drawn above the window should be
clipped. Useful for dock windows that should have no shadow painted on top.
redir-ignore
Controls whether this type of windows should cause screen to become redirected
again after been unredirected. If you have --unredir-if-possible set, and doesn’t
want certain window to cause unnecessary screen redirection, you can set this to
true.
BLUR
You can configure how the window background is blurred using a blur section in your
configuration file. Here is an example:
blur:
{
method = "gaussian";
size = 10;
deviation = 5.0;
};
Available options of the blur section are:
method
A string. Controls the blur method. Corresponds to the --blur-method command line
option. Available choices are: none to disable blurring; gaussian for gaussian
blur; box for box blur; kernel for convolution blur with a custom kernel;
dual_kawase for dual-filter kawase blur. Note: gaussian, box and dual_kawase blur
methods are only supported by the experimental backends. (default: none)
size
An integer. The size of the blur kernel, required by gaussian and box blur
methods. For the kernel method, the size is included in the kernel. Corresponds to
the --blur-size command line option (default: 3).
deviation
A floating point number. The standard deviation for the gaussian blur method.
Corresponds to the --blur-deviation command line option (default: 0.84089642).
strength
An integer in the range 0-20. The strength of the dual_kawase blur method.
Corresponds to the --blur-strength command line option. If set to zero, the value
requested by --blur-size is approximated (default: 5).
kernel
A string. The kernel to use for the kernel blur method, specified in the same
format as the --blur-kerns option. Corresponds to the --blur-kerns command line
option.
SIGNALS
• picom reinitializes itself upon receiving SIGUSR1.
D-BUS API
It’s possible to control picom via D-Bus messages, by running picom with --dbus and send
messages to com.github.chjj.compton.<DISPLAY>. <DISPLAY> is the display used by picom,
with all non-alphanumeric characters transformed to underscores. For DISPLAY=:0.0 you
should use com.github.chjj.compton._0_0, for example.
The D-Bus methods and signals are not yet stable, thus undocumented right now.
EXAMPLES
• Disable configuration file parsing:
$ picom --config /dev/null
• Run picom with client-side shadow and fading:
$ picom -cf
• Same thing as above, plus making inactive windows 80% transparent, making frame 80%
transparent, don’t fade on window open/close, and fork to background:
$ picom -bcf -i 0.8 -e 0.8 --no-fading-openclose
• Draw white shadows:
$ picom -c --shadow-red 1 --shadow-green 1 --shadow-blue 1
• Avoid drawing shadows on wbar window:
$ picom -c --shadow-exclude 'class_g = "wbar"'
• Enable VSync with GLX backend:
$ picom --backend glx --vsync
BUGS
Please submit bug reports to https://github.com/yshui/picom.
Out dated information in this man page is considered a bug.
RESOURCES
Homepage: https://github.com/yshui/picom
SEE ALSO
xcompmgr(1), picom-trans(1)