.TH LIBGAMMA 7 LIBGAMMA
.SH NAME
libgamma - Display server abstraction layer for gamma ramps

.SH DESCRIPTION
.B libgamma
is a C library that aims to abstract away the display server
when adjusting the colours curves for monitors via gamma ramps.

.B libgamma
have support for the RandR (Resize and Rotate) extension for X,
the VidMode extension for X and under Linux the Direct Rendering
Manager which lets software work with graphics outside of
graphical environments. Additionally
.B libgamma
have support for Windows Graphics Device Interface (Windows GDI)
under Windows and Quartz using CoreGraphics under OS X. However
Windows GDI and Quartz/CoreGraphics do not receive first-party
testing on their target platforms but do receive first-party
testing using a compatibility layer that translates the calls to
RandR calls. Neither does
.BR libgamma ,
currently, receive testing on any of the BSD:s, it is only tested
on Linux. Furthermore
.B libgamma
provides a dummy adjustment method.


.SH JARGON
.B libgamma
uses a small jargon, parts of which is loaned from X.org
and redshift, and some is commonly used jargon.
.TP
.BR "adjustment method" " [redshift]"
A combination of the display server and a protocol used to
tell to the display server.
.TP
.BR "display server" " [X.org]"
The program used to display graphical elements to the
monitors. In
.B libgamma
we also call the non-graphical environment a display server.
.TP
.BR "display" " [X.org]"
.TQ
.BR "site" " [libgamma]"
An instance of a display server. Non-graphical environment are
only covered by \(aqsite\(aq.
.TP
.BR "screen" " [X.org]"
A group of CRTC:s within a display.
.TP
.B CRTC
.TQ
.B cathode ray tube controller
Controller for the output on monitor. The mapping from CRTC:s
to encoders is an injection.
.TP
.B monitor
The physical medium used to display text and graphics.
.TP
.BR "partition" " [libgamma]"
Umbrella term for \(aqscreen\(aq and \(aqgraphics card\(aq.
.TP
.BR "page" " [libgamma]"
The desktop workspace or virtual terminal that is displayed
on a CRTC. (This jargon is not currently used, but is reserved
for future features.)
.TP
.BR "output" " [X.org]"
A connector and its encoder.
.TP
.B connector
Physical port on the graphics card where a monitor can be
plugged in. If and only if the connector is disabled it does
not have a port and does not have a CRTC.
.TP
.B encoder
Translation layer between CRTC:s and connectors.
.TP
.B gamma ramp
.TQ
.B colour curve
.TQ
.B CLUT
.TQ
.B colour lookup table
A lookup table that translates an encoded value for a subpixel
into its output value.
.TP
.B subpixel
.TQ
.B colour channel
One of the three colours that makes up a pixel: red, green or blue.
.TP
.B gamma ramp size
.TQ
.B gamma stops
The number of possible values on the encoding axis of a gamma ramp.

.SH SEE ALSO
.BR libgamma_behex_edid (3),
.br
.BR libgamma_behex_edid_lowercase (3),
.br
.BR libgamma_behex_edid_uppercase (3),
.br
.BR libgamma_connector_type_count (3),
.br
.BR libgamma_const_of_connector_type (3),
.br
.BR libgamma_const_of_method (3),
.br
.BR libgamma_const_of_subpixel_order (3),
.br
.BR libgamma_crtc_destroy (3),
.br
.BR libgamma_crtc_free (3),
.br
.BR libgamma_crtc_get_gamma_ramps8 (3),
.br
.BR libgamma_crtc_get_gamma_ramps16 (3),
.br
.BR libgamma_crtc_get_gamma_ramps32 (3),
.br
.BR libgamma_crtc_get_gamma_ramps64 (3),
.br
.BR libgamma_crtc_get_gamma_rampsf (3),
.br
.BR libgamma_crtc_get_gamma_rampsd (3),
.br
.BR libgamma_crtc_info_count (3),
.br
.BR libgamma_crtc_information_destroy (3),
.br
.BR libgamma_crtc_information_free (3),
.br
.BR libgamma_crtc_initialise (3),
.br
.BR libgamma_crtc_restore (3),
.br
.BR libgamma_crtc_set_gamma_ramps8 (3),
.br
.BR libgamma_crtc_set_gamma_ramps16 (3),
.br
.BR libgamma_crtc_set_gamma_ramps32 (3),
.br
.BR libgamma_crtc_set_gamma_ramps64 (3),
.br
.BR libgamma_crtc_set_gamma_rampsf (3),
.br
.BR libgamma_crtc_set_gamma_rampsd (3),
.br
.BR libgamma_crtc_set_gamma_ramps8_f (3),
.br
.BR libgamma_crtc_set_gamma_ramps16_f (3),
.br
.BR libgamma_crtc_set_gamma_ramps32_f (3),
.br
.BR libgamma_crtc_set_gamma_ramps64_f (3),
.br
.BR libgamma_crtc_set_gamma_rampsf_f (3),
.br
.BR libgamma_crtc_set_gamma_rampsd_f (3),
.br
.BR libgamma_error_min (3),
.br
.BR libgamma_gamma_ramps8_destroy (3),
.br
.BR libgamma_gamma_ramps16_destroy (3),
.br
.BR libgamma_gamma_ramps32_destroy (3),
.br
.BR libgamma_gamma_ramps64_destroy (3),
.br
.BR libgamma_gamma_rampsf_destroy (3),
.br
.BR libgamma_gamma_rampsd_destroy (3),
.br
.BR libgamma_gamma_ramps8_free (3),
.br
.BR libgamma_gamma_ramps16_free (3),
.br
.BR libgamma_gamma_ramps32_free (3),
.br
.BR libgamma_gamma_ramps64_free (3),
.br
.BR libgamma_gamma_rampsf_free (3),
.br
.BR libgamma_gamma_rampsd_free (3),
.br
.BR libgamma_gamma_ramps8_initialise (3),
.br
.BR libgamma_gamma_ramps16_initialise (3),
.br
.BR libgamma_gamma_ramps32_initialise (3),
.br
.BR libgamma_gamma_ramps64_initialise (3),
.br
.BR libgamma_gamma_rampsf_initialise (3),
.br
.BR libgamma_gamma_rampsd_initialise (3),
.br
.BR libgamma_get_crtc_information (3),
.br
.BR libgamma_group_gid (3),
.br
.BR libgamma_group_name (3),
.br
.BR libgamma_is_method_available (3),
.br
.BR libgamma_list_methods (3),
.br
.BR libgamma_method_capabilities (3),
.br
.BR libgamma_method_count (3),
.br
.BR libgamma_method_default_site (3),
.br
.BR libgamma_method_default_site_variable (3),
.br
.BR libgamma_name_of_connector_type (3),
.br
.BR libgamma_name_of_error (3),
.br
.BR libgamma_name_of_method (3),
.br
.BR libgamma_name_of_subpixel_order (3),
.br
.BR libgamma_partition_destroy (3),
.br
.BR libgamma_partition_free (3),
.br
.BR libgamma_partition_initialise (3),
.br
.BR libgamma_partition_restore (3),
.br
.BR libgamma_perror (3),
.br
.BR libgamma_site_destroy (3),
.br
.BR libgamma_site_free (3),
.br
.BR libgamma_site_initialise (3),
.br
.BR libgamma_site_restore (3),
.br
.BR libgamma_strerror (3),
.br
.BR libgamma_strerror_r (3),
.br
.BR libgamma_subpixel_order_count (3),
.br
.BR libgamma_unhex_edid (3),
.br
.BR libgamma_value_of_connector_type (3),
.br
.BR libgamma_value_of_error (3),
.br
.BR libgamma_value_of_method (3),
.br
.BR libgamma_value_of_subpixel_order (3)