/**
* libgamma — Display server abstraction layer for gamma ramp adjustments
* Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef LIBGAMMA_METHOD_H
#define LIBGAMMA_METHOD_H
#include <stddef.h>
#include <stdint.h>
/**
* The identifier for the dummy adjustment method.
* This method can be configured and is useful for
* testing your program's ability to handle errors.
*/
#ifdef HAVE_GAMMA_METHOD_DUMMY
# define GAMMA_METHOD_DUMMY 0
#endif
/**
* The identifier for the adjustment method with
* uses the RandR protocol under the X display server.
*/
#ifdef HAVE_GAMMA_METHOD_X_RANDR
# define GAMMA_METHOD_X_RANDR 1
#endif
/**
* The identifier for the adjustment method with
* uses the VidMode protocol under the X display server.
* This is an older alternative to RandR that can
* [not verified] work on some drivers that are not
* supported by RandR, however it can only control the
* primary CRTC per screen (partition).
*/
#ifdef HAVE_GAMMA_METHOD_X_VIDMODE
# define GAMMA_METHOD_X_VIDMODE 2
#endif
/**
* The identifier for the Direct Rendering Manager
* adjustment method that is available in Linux
* (built in to the Linux kernel with a userland
* library for access) and is a part of the
* Direct Rendering Infrastructure. This adjustment
* method all work when you are in non-graphical
* mode; however a display server cannnot be
* started while this is running, but it can be
* started while a display server is running.
*/
#ifdef HAVE_GAMMA_METHOD_LINUX_DRM
# define GAMMA_METHOD_LINUX_DRM 3
#endif
/**
* The identifier for the Graphics Device Interface
* adjustment method that is available in Windows.
* This method is not well tested; it can be compiled
* to be available under X.org using a translation layer.
*/
#ifdef HAVE_GAMMA_METHOD_W32_GDI
# define GAMMA_METHOD_W32_GDI 4
#endif
/**
* The identifier for the Core Graphics adjustment
* method that is available in Mac OS X that can
* adjust gamma ramps under the Quartz display server.
* This method is not well tested; it can be compiled
* to be available under X.org using a translation layer.
*/
#ifdef HAVE_GAMMA_METHOD_QUARTZ_CORE_GRAPHICS
# define GAMMA_METHOD_QUARTZ_CORE_GRAPHICS 5
#endif
/**
* The index of the last gamma method, neither it
* nor any index before it may actually be supported
* as it could have been disabled at compile-time
*/
#define GAMMA_METHOD_MAX 5
/**
* Capabilities of adjustment methods
*/
typedef struct libgamma_method_capabilities {
/**
* OR of the CRTC information fields in `libgamma_crtc_information_t`
* that may (but can fail) be read successfully
*/
int32_t crtc_information;
/**
* Whether the default site is known, if true the site is integrated
* to the system or can be determined using environment variables
*/
int default_site_known : 1;
/**
* Whether the adjustment method supports multiple sites rather
* than just the default site
*/
int multiple_sites : 1;
/**
* Whether the adjustment method supports multiple partitions
* per site
*/
int multiple_partitions : 1;
/**
* Whether the adjustment method supports multiple CRTC:s
* per partition per site
*/
int multiple_crtcs : 1;
/**
* Whether the partition to graphics card is a bijection
*/
int partitions_are_graphics_cards : 1;
/**
* Whether the adjustment method supports `libgamma_site_restore`
*/
int site_restore : 1;
/**
* Whether the adjustment method supports `libgamma_partition_restore`
*/
int partition_restore : 1;
/**
* Whether the adjustment method supports `libgamma_crtc_restore`
*/
int crtc_restore : 1;
/**
* Whether the `red_gamma_size`, `green_gamma_size` and `blue_gamma_size`
* fields in `libgamma_crtc_information_t` will always have the same
* values as each other for the adjustment method
*/
int identical_gamma_sizes : 1;
/**
* Whether the `red_gamma_size`, `green_gamma_size` and `blue_gamma_size`
* fields in `libgamma_crtc_information_t` will always be filled with the
* same value for the adjustment method
*/
int fixed_gamma_size : 1;
/**
* Whether the `gamma_depth` field in `libgamma_crtc_information_t`
* will always be filled with the same value for the adjustment method
*/
int fixed_gamma_depth : 1;
/**
* Whether the adjustment method will actually perform adjustments
*/
int real : 1;
/**
* Whether the adjustment method is implement using a translation layer
*/
int fake : 1;
} libgamma_method_capabilities_t;
/**
* Site state
*
* On operating systems that integrate a graphical environment
* there is usally just one site. However, one systems with
* pluggable graphics, like Unix-like systems such as GNU/Linux
* and the BSD:s, there can usually be any (feasible) number of
* sites. In X.org parlance they are called displays.
*/
typedef struct libgamma_site_state {
/**
* Adjustment method implementation specific data.
* You as a user of this library should not touch this.
*/
void* data;
/**
* This field specifies, for the methods if this library,
* which adjustment method (display server and protocol)
* is used to adjust the gamma ramps.
*/
int method;
/**
* The site identifier. It can either be `NULL` or a string.
* `NULL` indicates the default site. On systems like the
* Unix-like systems, where the graphics are pluggable, this
* is usally resolved by an environment variable, such as
* "DISPLAY" for X.org.
*/
char* site;
/**
* The number of partitions that is available on this site.
* Probably the majority of display server only one partition
* per site. However, X.org can, and traditional used to have
* on multi-headed environments, multiple partitions per site.
* In X.org partitions are called 'screens'. It is not to be
* confused with monitor. A screen is a collection of monitors,
* and the mapping from monitors to screens is a surjection.
* On hardware-level adjustment methods, such as Direct
* Rendering Manager, a partition is a graphics card.
*/
size_t partitions_available;
} libgamma_site_state_t;
/**
* Partition state
*
* Probably the majority of display server only one partition
* per site. However, X.org can, and traditional used to have
* on multi-headed environments, multiple partitions per site.
* In X.org partitions are called 'screens'. It is not to be
* confused with monitor. A screen is a collection of monitors,
* and the mapping from monitors to screens is a surjection.
* On hardware-level adjustment methods, such as Direct
* Rendering Manager, a partition is a graphics card.
*/
typedef struct libgamma_partition_state {
/**
* Adjustment method implementation specific data.
* You as a user of this library should not touch this.
*/
void* data;
/**
* The site this partition belongs to
*/
libgamma_site_state_t* site;
/**
* The index of the partition
*/
size_t partition;
/**
* The number of CRTC:s that are available under this
* partition. Note that the CRTC:s are not necessarily
* online.
*/
size_t crtcs_available;
} libgamma_partition_state_t;
/**
* Cathode ray tube controller state
*
* The CRTC controls the gamma ramps for the
* monitor that is plugged in to the connector
* that the CRTC belongs to
*/
typedef struct libgamma_crtc_state {
/**
* Adjustment method implementation specific data.
* You as a user of this library should not touch this.
*/
void* data;
/**
* The partition this CRTC belongs to
*/
libgamma_partition_state_t* partition;
/**
* The index of the CRTC within its partition.
*/
size_t crtc;
} libgamma_crtc_state_t;
/**
* For a `libgamma_crtc_information_t` fill in the
* values for `edid` and `edid_length` and report errors to `edid_error`
*/
#define CRTC_INFO_EDID (1 << 0)
/**
* For a `libgamma_crtc_information_t` fill in the
* value for `width_mm` and report errors to `width_mm_error`
*/
#define CRTC_INFO_WIDTH_MM (1 << 1)
/**
* For a `libgamma_crtc_information_t` fill in the
* value for `height_mm` and report errors to `height_mm_error`
*/
#define CRTC_INFO_HEIGHT_MM (1 << 2)
/**
* For a `libgamma_crtc_information_t` fill in the
* value for `width_mm_edid` and report errors to `width_mm_edid_error`
*/
#define CRTC_INFO_WIDTH_MM_EDID (1 << 3)
/**
* For a `libgamma_crtc_information_t` fill in the
* value for `height_mm_edid` and report errors to `height_mm_edid_error`
*/
#define CRTC_INFO_HEIGHT_MM_EDID (1 << 4)
/**
* For a `libgamma_crtc_information_t` fill in the
* values for `red_gamma_size`, `green_gamma_size` and `blue_gamma_size`
* and report errors to `gamma_size_error`
*/
#define CRTC_INFO_GAMMA_SIZE (1 << 5)
/**
* For a `libgamma_crtc_information_t` fill in the
* value for `gamma_depth` and report errors to `gamma_depth_error`
*/
#define CRTC_INFO_GAMMA_DEPTH (1 << 6)
/**
* For a `libgamma_crtc_information_t` fill in the
* value for `gamma_support` and report errors to `gamma_support_error`
*/
#define CRTC_INFO_GAMMA_SUPPORT (1 << 7)
/**
* For a `libgamma_crtc_information_t` fill in the
* value for `subpixel_order` and report errors to `subpixel_order_error`
*/
#define CRTC_INFO_SUBPIXEL_ORDER (1 << 8)
/**
* For a `libgamma_crtc_information_t` fill in the
* value for `active` and report errors to `active_error`
*/
#define CRTC_INFO_ACTIVE (1 << 9)
/**
* For a `libgamma_crtc_information_t` fill in the
* value for `connector_name` and report errors to `connector_name_error`
*/
#define CRTC_INFO_CONNECTOR_NAME (1 << 10)
/**
* For a `libgamma_crtc_information_t` fill in the
* value for `connector_type` and report errors to `connector_type_error`
*/
#define CRTC_INFO_CONNECTOR_TYPE (1 << 11)
/**
* For a `libgamma_crtc_information_t` fill in the
* values for `gamma_red`, `gamma_green` and `gamma_blue`
* and report errors to `connector_type_error`
*/
#define CRTC_INFO_GAMMA (1 << 12)
/**
* Cathode ray tube controller information data structure
*/
typedef struct libgamma_crtc_information {
/**
* The Extended Display Identification Data associated with
* the attached monitor. This is raw byte array that is usually
* 128 bytes long. It is not NUL-terminate, rather its length
* is stored in `edid_size`.
*/
unsigned char* edid;
/**
* The length of `edid`
*/
size_t edid_length;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int edid_error;
/**
* The phyical width, in millimetres, of the viewport of the
* attached monitor, as reported by the adjustment method. This
* value may be incorrect, which is a known issue with the X
* server where it is the result of the X server attempting
* the estimate the size on its own.
* Zero means that its is not applicable, which is the case
* for projectors.
*/
size_t width_mm;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int width_mm_error;
/**
* The phyical height, in millimetres, of the viewport of the
* attached monitor, as reported by the adjustment method. This
* value may be incorrect, which is a known issue with the X
* server where it is the result of the X server attempting
* the estimate the size on its own.
* Zero means that its is not applicable, which is the case
* for projectors.
*/
size_t height_mm;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int height_mm_error;
/**
* The phyical width, in millimetres, of the viewport of the
* attached monitor, as reported by it the monitor's Extended
* Display Information Data. This value can only contain whole
* centimetres, which means that the result is always zero
* modulus ten. However, this could change with revisions of
* the EDID structure.
* Zero means that its is not applicable, which is the case
* for projectors.
*/
size_t width_mm_edid;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int width_mm_edid_error;
/**
* The phyical height, in millimetres, of the viewport of the
* attached monitor, as reported by it the monitor's Extended
* Display Information Data. This value can only contain whole
* centimetres, which means that the result is always zero
* modulus ten. However, this could change with revisions of
* the EDID structure.
* Zero means that its is not applicable, which is the case
* for projectors.
*/
size_t height_mm_edid;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int height_mm_edid_error;
/**
* The size of the encoding axis of the red gamma ramp
*/
size_t red_gamma_size;
/**
* The size of the encoding axis of the green gamma ramp
*/
size_t green_gamma_size;
/**
* The size of the encoding axis of the blue gamma ramp
*/
size_t blue_gamma_size;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int gamma_size_error;
/**
* The bit-depth of the value axes of gamma ramps
*/
size_t gamma_depth;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int gamma_depth_error;
/**
* Non-zero gamma ramp adjustments are supported
*/
int gamma_support;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int gamma_support_error;
/**
* The layout of the subpixels.
* You cannot count on this value, but it is provided
* anyway as a means of distinguishing monitors.
*/
int subpixel_order;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int subpixel_order_error;
/**
* Whether there is a monitors connected to the CRTC
*/
int active;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int active_error;
/**
* The name of the connector as designated by the display
* server or as give by this library in case the display
* server lacks this feature
*/
char* connector_name;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int connector_name_error;
/**
* The type of the connector that is associated with the CRTC
*/
int connector_type;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int connector_type_error;
/**
* The gamma characteristics of the monitor as reported
* in its Extended Display Information Data. The value
* holds the value for the red channel. If you do not have
* and more accurate measurement of the gamma for the
* monitor this could be used to give a rought gamma
* correction; simply divide the value with 2.2 and use
* the result for the red channel in the gamma correction.
*/
float gamma_red;
/**
* The gamma characteristics of the monitor as reported
* in its Extended Display Information Data. The value
* holds the value for the green channel. If you do not have
* and more accurate measurement of the gamma for the
* monitor this could be used to give a rought gamma
* correction; simply divide the value with 2.2 and use
* the result for the green channel in the gamma correction.
*/
float gamma_green;
/**
* The gamma characteristics of the monitor as reported
* in its Extended Display Information Data. The value
* holds the value for the blue channel. If you do not have
* and more accurate measurement of the gamma for the
* monitor this could be used to give a rought gamma
* correction; simply divide the value with 2.2 and use
* the result for the blue channel in the gamma correction.
*/
float gamma_blue;
/**
* Zero on success, positive it holds the value `errno` had
* when the reading failed, otherwise (negative) the value
* of an error identifier provided by this library
*/
int gamma_error;
} libgamma_crtc_information_t;
/**
* Gamma ramp structure for 16-bit gamma ramps
*/
typedef struct libgamma_gamma_ramps
{
/**
* The size of `red`
*/
size_t red_size;
/**
* The size of `green`
*/
size_t green_size;
/**
* The size of `blue`
*/
size_t blue_size;
/**
* The gamma ramp for the red channel
*/
uint16_t* red;
/**
* The gamma ramp for the green channel
*/
uint16_t* green;
/**
* The gamma ramp for the blue channel
*/
uint16_t* blue;
} libgamma_gamma_ramps_t;
/**
* Gamma ramp structure for 32-bit gamma ramps
*/
typedef struct libgamma_gamma_ramps32
{
/**
* The size of `red`
*/
size_t red_size;
/**
* The size of `green`
*/
size_t green_size;
/**
* The size of `blue`
*/
size_t blue_size;
/**
* The gamma ramp for the red channel
*/
uint32_t* red;
/**
* The gamma ramp for the green channel
*/
uint32_t* green;
/**
* The gamma ramp for the blue channel
*/
uint32_t* blue;
} libgamma_gamma_ramps32_t;
/**
* Gamma ramp structure for 64-bit gamma ramps
*/
typedef struct libgamma_gamma_ramps64
{
/**
* The size of `red`
*/
size_t red_size;
/**
* The size of `green`
*/
size_t green_size;
/**
* The size of `blue`
*/
size_t blue_size;
/**
* The gamma ramp for the red channel
*/
uint64_t* red;
/**
* The gamma ramp for the green channel
*/
uint64_t* green;
/**
* The gamma ramp for the blue channel
*/
uint64_t* blue;
} libgamma_gamma_ramps64_t;
/**
* Gamma ramp structure for `float` gamma ramps
*/
typedef struct libgamma_gamma_rampsf
{
/**
* The size of `red`
*/
size_t red_size;
/**
* The size of `green`
*/
size_t green_size;
/**
* The size of `blue`
*/
size_t blue_size;
/**
* The gamma ramp for the red channel
*/
float* red;
/**
* The gamma ramp for the green channel
*/
float* green;
/**
* The gamma ramp for the blue channel
*/
float* blue;
} libgamma_gamma_rampsf_t;
/**
* Gamma ramp structure for `double` gamma ramps
*/
typedef struct libgamma_gamma_rampsd
{
/**
* The size of `red`
*/
size_t red_size;
/**
* The size of `green`
*/
size_t green_size;
/**
* The size of `blue`
*/
size_t blue_size;
/**
* The gamma ramp for the red channel
*/
double* red;
/**
* The gamma ramp for the green channel
*/
double* green;
/**
* The gamma ramp for the blue channel
*/
double* blue;
} libgamma_gamma_rampsd_t;
#endif
