.TH CG-GAMMA 1 CG-TOOLS
.SH NAME
cg-gamma - Adjust the gamma curves on the monitors
.SH SYNOPSIS
.B cg-gamma
.RB [ \-M
.IR method ]
.RB [ \-S
.IR site ]
.RB [ \-c
.IR crtc "]... ["\fB\-R\fP
.IR rule ]
.RB ( \-x
|
.RB [ \-p
.IR priority ]
.RB [ \-d ]
.RB [ \-f
.I file
|
.I all
|
.I red
.I green
.IR blue ])
.SH DESCRIPTION
.B cg-gamma
sets the gamma on the monitors to
.I all
on all channels, or
.IR red ,
.IR green ,
and
.IR blue
to the red, green, and blue channels, respectively. Alternatively,
.B cg-gamma
can change the gamma on each monitor independently by using
reading the values from
.I file
or a default file.
.P
The file is 4 column text file where empty lines and lines
starting with a '#', after any whitespace, are ignored.
The values in the columns should be, in order, a monitor's
EDID, that monitor's red gamma value, green gamma value, and
blue gamma value.
.SH OPTIONS
.TP
.B \-f " "\fIfile\fP
Read the gamma values from the selected file.
.TP
.BR \-c " "\fIcrtc\fP
Apply the filter to the CRTC with the monitor whose EDID is
.IR crtc .
By default, the filter is applied to all monitors.

If
.I crtc
is
.RB ' ? ',
all available CRTC's are listed.
.TP
.B \-d
Keep the process alive and remove the filter on death.
.TP
.BR \-M " "\fImethod\fP
Adjustment method name or number. Recognised names include:

.nf
\fBdummy\fP      Dummy method
\fBrandr\fP      X RAndR
\fBvidmode\fP    X VidMode
\fBdrm\fP        Linux DRM
\fBgdi\fP        Windows GDI
\fBquartz\fP     Quartz Core Graphics
.fi

The adjustment methods are supported via
.BR libgamma (7).
Only methods that were enabled when
.B libgamma
was compiled will be supported.

If
.I method
is
.RB ' ? ',
all available adjustment methods are printed.
.TP
.BR \-p " "\fIpriority\fP
Set the priority of the filter. Filters with lower priority
are applied before filters with higher priority. The value
must be a signed 64-bit integer (between -9223372036854775807
and 9223372036854775808).
.BR cg-gamma 's
default priority is 0.

If
.I priority
is
.RB ' ? ',
the utility's default priority is printed.
.TP
.BR \-R " "\fIrule\fP
Set the rule of of the filter to
.IR rule .
This is the last part of the filter's identifier (class).
The default rule is
.BR standard .

If
.I rule
is
.RB ' ? '
the utility's default rule is printed. If
.I rule
is
.RB ' ?? '
the utility's default class is printed.
.TP
.BR \-S " "\fIsite\fP
Select the site to which to connect. For example
.RB ' :0 ',
for local display 0 when using
.BR X .
.TP
.B \-x
Remove the currently applied filter.
.SH FILES
.TP
.B ~/.config/gamma
The default gamma table file.
.TP
.B /etc/gamma
The fallback gamma table file.
.SH "SEE ALSO"
.BR cg-tools (7)
.SH BUGS
Please report bugs to https://github.com/maandree/cg-tools/issues
or to maandree@kth.se