aboutsummaryrefslogtreecommitdiffstats
path: root/libgamma.h
diff options
context:
space:
mode:
Diffstat (limited to 'libgamma.h')
-rw-r--r--libgamma.h2474
1 files changed, 2474 insertions, 0 deletions
diff --git a/libgamma.h b/libgamma.h
new file mode 100644
index 0000000..d798f33
--- /dev/null
+++ b/libgamma.h
@@ -0,0 +1,2474 @@
+/* See LICENSE file for copyright and license details. */
+#ifndef LIBGAMMA_H
+#define LIBGAMMA_H
+
+#include <sys/types.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+
+#ifndef __GNUC__
+# define LIBGAMMA_GCC_ONLY__(X) X
+#else
+# define LIBGAMMA_GCC_ONLY__(X)
+#endif
+
+
+
+/**
+ * `errno` has be set with a standard error number
+ * to indicate the what has gone wrong
+ */
+#define LIBGAMMA_ERRNO_SET (-1)
+
+/**
+ * The selected adjustment method does not exist
+ * or has been excluded at compile-time
+ */
+#define LIBGAMMA_NO_SUCH_ADJUSTMENT_METHOD (-2) /* TODO use separate error code if disable at compile-time */
+
+/**
+ * The selected site does not exist
+ */
+#define LIBGAMMA_NO_SUCH_SITE (-3)
+
+/**
+ * The selected partition does not exist
+ */
+#define LIBGAMMA_NO_SUCH_PARTITION (-4)
+
+/**
+ * The selected CRTC does not exist
+ */
+#define LIBGAMMA_NO_SUCH_CRTC (-5)
+
+/**
+ * Counter overflowed when counting the number
+ * of available items
+ */
+#define LIBGAMMA_IMPOSSIBLE_AMOUNT (-6)
+
+/**
+ * The selected connector is disabled, it does
+ * not have a CRTC
+ */
+#define LIBGAMMA_CONNECTOR_DISABLED (-7)
+
+/**
+ * The selected CRTC could not be opened,
+ * reason unknown
+ */
+#define LIBGAMMA_OPEN_CRTC_FAILED (-8)
+
+/**
+ * The CRTC information field is not supported
+ * by the adjustment method
+ */
+#define LIBGAMMA_CRTC_INFO_NOT_SUPPORTED (-9)
+
+/**
+ * Failed to read the current gamma ramps for
+ * the selected CRTC, reason unknown
+ */
+#define LIBGAMMA_GAMMA_RAMP_READ_FAILED (-10)
+
+/**
+ * Failed to write the current gamma ramps for
+ * the selected CRTC, reason unknown
+ */
+#define LIBGAMMA_GAMMA_RAMP_WRITE_FAILED (-11)
+
+/**
+ * The specified ramp sizes does not match the
+ * ramps sizes returned by the adjustment methods
+ * in response to the query/command
+ */
+#define LIBGAMMA_GAMMA_RAMP_SIZE_CHANGED (-12)
+
+/**
+ * The specified ramp sizes are not identical
+ * which is required by the adjustment method
+ *
+ * (Only returned in debug mode)
+ */
+#define LIBGAMMA_MIXED_GAMMA_RAMP_SIZE (-13)
+
+/**
+ * The specified ramp sizes are not supported
+ * by the adjustment method
+ *
+ * (Only returned in debug mode)
+ */
+#define LIBGAMMA_WRONG_GAMMA_RAMP_SIZE (-14)
+
+/**
+ * The adjustment method reported that the gamma
+ * ramps size is 1, or perhaps even zero or negative
+ */
+#define LIBGAMMA_SINGLETON_GAMMA_RAMP (-15)
+
+/**
+ * The adjustment method failed to list
+ * available CRTC:s, reason unknown
+ */
+#define LIBGAMMA_LIST_CRTCS_FAILED (-16)
+
+/**
+ * Failed to acquire mode resources from the
+ * adjustment method
+ */
+#define LIBGAMMA_ACQUIRING_MODE_RESOURCES_FAILED (-17)
+
+/**
+ * The adjustment method reported that a negative
+ * number of partitions exists in the site
+ */
+#define LIBGAMMA_NEGATIVE_PARTITION_COUNT (-18)
+
+/**
+ * The adjustment method reported that a negative
+ * number of CRTC:s exists in the partition
+ */
+#define LIBGAMMA_NEGATIVE_CRTC_COUNT (-19)
+
+/**
+ * Device cannot be access becauses of
+ * insufficient permissions
+ */
+#define LIBGAMMA_DEVICE_RESTRICTED (-20)
+
+/**
+ * Device cannot be access, reason unknown
+ */
+#define LIBGAMMA_DEVICE_ACCESS_FAILED (-21)
+
+/**
+ * Device cannot be access, membership of the
+ * `libgamma_group_gid` (named by `libgamma_group_name`
+ * (can be `NULL`, if so `errno` may have been set
+ * to tell why)) is required
+ */
+#define LIBGAMMA_DEVICE_REQUIRE_GROUP (-22)
+
+/**
+ * The graphics card appear to have been removed
+ */
+#define LIBGAMMA_GRAPHICS_CARD_REMOVED (-23)
+
+/**
+ * The state of the requested information is unknown
+ */
+#define LIBGAMMA_STATE_UNKNOWN (-24)
+
+/**
+ * Failed to determine which connector the
+ * CRTC belongs to
+ */
+#define LIBGAMMA_CONNECTOR_UNKNOWN (-25)
+
+/**
+ * The detected connector type is not listed
+ * in this library and has to be updated
+ */
+#define LIBGAMMA_CONNECTOR_TYPE_NOT_RECOGNISED (-26)
+
+/**
+ * The detected subpixel order is not listed
+ * in this library and has to be updated
+ */
+#define LIBGAMMA_SUBPIXEL_ORDER_NOT_RECOGNISED (-27)
+
+/**
+ * The length of the EDID does not match that
+ * of any supported EDID structure revision
+ */
+#define LIBGAMMA_EDID_LENGTH_UNSUPPORTED (-28)
+
+/**
+ * The magic number in the EDID does not match
+ * that of any supported EDID structure revision
+ */
+#define LIBGAMMA_EDID_WRONG_MAGIC_NUMBER (-29)
+
+/**
+ * The EDID structure revision used by the
+ * monitor is not supported
+ */
+#define LIBGAMMA_EDID_REVISION_UNSUPPORTED (-30)
+
+/**
+ * The gamma characteristics field in the EDID
+ * is left unspecified
+ *
+ * (This could be considered a non-error)
+ */
+#define LIBGAMMA_GAMMA_NOT_SPECIFIED (-31)
+
+/**
+ * The checksum in the EDID is incorrect, all
+ * request information has been provided
+ * by you cannot count on it
+ */
+#define LIBGAMMA_EDID_CHECKSUM_ERROR (-32)
+
+/**
+ * Both of the errors `LIBGAMMA_GAMMA_NOT_SPECIFIED`
+ * and `LIBGAMMA_EDID_CHECKSUM_ERROR` have occurred
+ */
+#define LIBGAMMA_GAMMA_NOT_SPECIFIED_AND_EDID_CHECKSUM_ERROR (-33)
+
+/**
+ * Failed to query the gamma ramps size from the
+ * adjustment method, reason unknown
+ */
+#define LIBGAMMA_GAMMA_RAMPS_SIZE_QUERY_FAILED (-34)
+
+/**
+ * The selected partition could not be opened,
+ * reason unknown
+ */
+#define LIBGAMMA_OPEN_PARTITION_FAILED (-35)
+
+/**
+ * The selected site could not be opened,
+ * reason unknown
+ */
+#define LIBGAMMA_OPEN_SITE_FAILED (-36)
+
+/**
+ * Failed to query the adjustment method for
+ * its protocol version, reason unknown
+ */
+#define LIBGAMMA_PROTOCOL_VERSION_QUERY_FAILED (-37)
+
+/**
+ * The adjustment method's version of its
+ * protocol is not supported
+ */
+#define LIBGAMMA_PROTOCOL_VERSION_NOT_SUPPORTED (-38)
+
+/**
+ * The adjustment method failed to list
+ * available partitions, reason unknown
+ */
+#define LIBGAMMA_LIST_PARTITIONS_FAILED (-39)
+
+/**
+ * Partition exists by index, but the partition
+ * at that index does not exist
+ */
+#define LIBGAMMA_NULL_PARTITION (-40)
+
+/**
+ * There is not monitor connected to the
+ * connector of the selected CRTC
+ */
+#define LIBGAMMA_NOT_CONNECTED (-41)
+
+/**
+ * Data extraction from a reply from the
+ * adjustment method failed, reason unknown
+ */
+#define LIBGAMMA_REPLY_VALUE_EXTRACTION_FAILED (-42)
+
+/**
+ * No EDID property was found on the output
+ */
+#define LIBGAMMA_EDID_NOT_FOUND (-43)
+
+/**
+ * Failed to list properties on the output,
+ * reason unknown
+ */
+#define LIBGAMMA_LIST_PROPERTIES_FAILED (-44)
+
+/**
+ * Failed to query a property's value from
+ * the output, reason unknown
+ */
+#define LIBGAMMA_PROPERTY_VALUE_QUERY_FAILED (-45)
+
+/**
+ * A request for information on an output
+ * failed, reason unknown
+ */
+#define LIBGAMMA_OUTPUT_INFORMATION_QUERY_FAILED (-46)
+
+/* DEVELOPERS: Remember to update LIBGAMMA_ERROR_MIN below and LIST_ERRORS in common.h when adding errors */
+
+/**
+ * The number of the libgamma error with the
+ * lowest number in the version of the library
+ * that the program is compiled against
+ */
+#define LIBGAMMA_ERROR_MIN (-46)
+
+/**
+ * The number of the libgamma error with the
+ * lowest number in the version of the library
+ * that the program is linked against
+ */
+extern const int libgamma_error_min;
+
+
+
+/**
+ * The identifier for the dummy adjustment method
+ *
+ * This method can be configured and is useful for
+ * testing your program's ability to handle errors
+ */
+#define LIBGAMMA_METHOD_DUMMY 0
+
+/**
+ * The identifier for the adjustment method with
+ * uses the RandR protocol under the X display server
+ */
+#define LIBGAMMA_METHOD_X_RANDR 1
+
+/**
+ * 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
+ * work on some drivers that are not supported by RandR,
+ * however it can only control the primary CRTC per
+ * screen (partition)
+ */
+#define LIBGAMMA_METHOD_X_VIDMODE 2
+
+/**
+ * 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 will work when you are
+ * in non-graphical mode; however a display server
+ * cannot be started while this is running, but it
+ * can be started while a display server is running
+ */
+#define LIBGAMMA_METHOD_LINUX_DRM 3
+
+/**
+ * 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
+ */
+#define LIBGAMMA_METHOD_W32_GDI 4
+
+/**
+ * The identifier for the CoreGraphics 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
+ */
+#define LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS 5
+
+/* DEVELOPERS: Remember to update LIBGAMMA_METHOD_COUNT below and LIST_METHODS in common.h when adding methods */
+
+/**
+ * The number adjustment methods provided by the
+ * version this library the program is compiled
+ * against
+ *
+ * This number includes both compile-time enabled
+ * and compile-time disabled adjustment methods
+ */
+#define LIBGAMMA_METHOD_COUNT 6
+
+/**
+ * The number adjustment methods provided by the
+ * version this library the program is linked
+ * against
+ *
+ * This number includes both compile-time enabled
+ * and compile-time disabled adjustment methods
+ */
+extern const int libgamma_method_count;
+
+
+
+/**
+ * Types for connectors
+ */
+typedef enum libgamma_connector_type {
+ /**
+ * The adjustment method does not know the connector's type
+ *
+ * (This could be considered an error)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_Unknown = 0,
+
+ /**
+ * Video Graphics Array (VGA)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_VGA,
+
+ /**
+ * Digital Visual Interface, unknown type
+ */
+ LIBGAMMA_CONNECTOR_TYPE_DVI,
+
+ /**
+ * Digital Visual Interface, integrated (DVI-I)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_DVII,
+
+ /**
+ * Digital Visual Interface, digital only (DVI-D)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_DVID,
+
+ /**
+ * Digital Visual Interface, analogue only (DVI-A)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_DVIA,
+
+ /**
+ * Composite video
+ */
+ LIBGAMMA_CONNECTOR_TYPE_Composite,
+
+ /**
+ * Separate Video (S-video)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_SVIDEO,
+
+ /**
+ * Low-voltage differential signaling (LVDS)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_LVDS,
+
+ /**
+ * Component video, usually separate cables for each channel
+ */
+ LIBGAMMA_CONNECTOR_TYPE_Component,
+
+ /**
+ * 9 pin DIN (Deutsches Institut für Normung) connector
+ */
+ LIBGAMMA_CONNECTOR_TYPE_9PinDIN,
+
+ /**
+ * DisplayPort
+ */
+ LIBGAMMA_CONNECTOR_TYPE_DisplayPort,
+
+ /**
+ * High-Definition Multimedia Interface (HDMI), unknown type
+ */
+ LIBGAMMA_CONNECTOR_TYPE_HDMI,
+
+ /**
+ * High-Definition Multimedia Interface, type A (HDMI-A)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_HDMIA,
+
+ /**
+ * High-Definition Multimedia Interface, type B (HDMI-B)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_HDMIB,
+
+ /**
+ * Television, unknown connector
+ */
+ LIBGAMMA_CONNECTOR_TYPE_TV,
+
+ /**
+ * Embedded DisplayPort (eDP)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_eDP,
+
+ /**
+ * A virtual connector
+ */
+ LIBGAMMA_CONNECTOR_TYPE_VIRTUAL,
+
+ /**
+ * Display Serial Interface (DSI)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_DSI,
+
+ /**
+ * LFP connector
+ *
+ * (What is this?)
+ */
+ LIBGAMMA_CONNECTOR_TYPE_LFP
+
+ /* DEVELOPERS: Remember to update LIBGAMMA_CONNECTOR_TYPE_COUNT below
+ * and LIST_CONNECTOR_TYPES in common.h when adding methods */
+
+} libgamma_connector_type_t;
+
+/**
+ * The number of values defined in `libgamma_connector_type_t`
+ * in the version of the library the program is compiled against
+ */
+#define LIBGAMMA_CONNECTOR_TYPE_COUNT 20
+
+/**
+ * The number of values defined in `libgamma_connector_type_t`
+ * in the version of the library the program is linked against
+ */
+extern const int libgamma_connector_type_count;
+
+
+
+/**
+ * Orders for subpixels
+ *
+ * Currently the possible values are very biased
+ * to LCD, Plasma and monochrome monitors
+ */
+typedef enum libgamma_subpixel_order {
+ /**
+ * The adjustment method does not know the order of the subpixels
+ *
+ * (This could be considered an error)
+ */
+ LIBGAMMA_SUBPIXEL_ORDER_UNKNOWN = 0,
+
+ /**
+ * There are no subpixels in the monitor
+ */
+ LIBGAMMA_SUBPIXEL_ORDER_NONE,
+
+ /**
+ * The subpixels are ordered red, green and then blue, from left to right
+ */
+ LIBGAMMA_SUBPIXEL_ORDER_HORIZONTAL_RGB,
+
+ /**
+ * The subpixels are ordered blue, green and then red, from left to right
+ */
+ LIBGAMMA_SUBPIXEL_ORDER_HORIZONTAL_BGR,
+
+ /**
+ * The subpixels are ordered red, green and then blue, from the top down
+ */
+ LIBGAMMA_SUBPIXEL_ORDER_VERTICAL_RGB,
+
+ /**
+ * The subpixels are ordered blue, green and then red, from the top down
+ */
+ LIBGAMMA_SUBPIXEL_ORDER_VERTICAL_BGR
+
+ /* DEVELOPERS: Remember to update LIBGAMMA_SUBPIXEL_ORDER_COUNT below
+ * and LIST_SUBPIXEL_ORDERS in common.h when adding methods */
+
+} libgamma_subpixel_order_t;
+
+/**
+ * The number of values defined in `libgamma_subpixel_order_t`
+ * in the version of the library the program is compiled against
+ */
+#define LIBGAMMA_SUBPIXEL_ORDER_COUNT 6
+
+/**
+ * The number of values defined in `libgamma_subpixel_order_t`
+ * in the version of the library the program is linked against
+ */
+extern const int libgamma_subpixel_order_count;
+
+
+
+/**
+ * Answer enum to a decision problem
+ */
+typedef enum libgamma_decision {
+ /**
+ * The answer is negative
+ */
+ LIBGAMMA_NO = 0,
+
+ /**
+ * The answer is unknown
+ */
+ LIBGAMMA_MAYBE = 1,
+
+ /**
+ * The answer is positive
+ */
+ LIBGAMMA_YES = 2
+
+} libgamma_decision_t;
+
+
+
+/**
+ * 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
+ */
+ unsigned default_site_known : 1;
+
+ /**
+ * Whether the adjustment method supports multiple sites rather
+ * than just the default site
+ */
+ unsigned multiple_sites : 1;
+
+ /**
+ * Whether the adjustment method supports multiple partitions
+ * per site
+ */
+ unsigned multiple_partitions : 1;
+
+ /**
+ * Whether the adjustment method supports multiple CRTC:s
+ * per partition per site
+ */
+ unsigned multiple_crtcs : 1;
+
+ /**
+ * Whether the partition to graphics card is a bijection
+ */
+ unsigned partitions_are_graphics_cards : 1;
+
+ /**
+ * Whether the adjustment method supports `libgamma_site_restore`
+ */
+ unsigned site_restore : 1;
+
+ /**
+ * Whether the adjustment method supports `libgamma_partition_restore`
+ */
+ unsigned partition_restore : 1;
+
+ /**
+ * Whether the adjustment method supports `libgamma_crtc_restore`
+ */
+ unsigned 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
+ */
+ unsigned 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
+ */
+ unsigned 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
+ */
+ unsigned fixed_gamma_depth : 1;
+
+ /**
+ * Whether the adjustment method will actually perform adjustments
+ */
+ unsigned real : 1;
+
+ /**
+ * Whether the adjustment method is implement using a translation layer
+ */
+ unsigned fake : 1;
+
+ /**
+ * Whether adjustments are undone when the process disconnects from
+ * the display server
+ */
+ unsigned auto_restore : 1;
+
+} libgamma_method_capabilities_t;
+
+
+/**
+ * Site state
+ *
+ * On operating systems that integrate a graphical environment
+ * there is usually 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 usually 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;
+
+
+/**
+ * Cathode ray tube controller information data structure
+ */
+typedef struct libgamma_crtc_information {
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the values for
+ * `edid` and `edid_length` and report errors to `edid_error`
+ */
+#define LIBGAMMA_CRTC_INFO_EDID (1 << 0)
+
+ /**
+ * 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_length`.
+ */
+ 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the value
+ * for `width_mm` and report errors to `width_mm_error`
+ */
+#define LIBGAMMA_CRTC_INFO_WIDTH_MM (1 << 1)
+
+ /**
+ * 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the value
+ * for `height_mm` and report errors to `height_mm_error`
+ */
+#define LIBGAMMA_CRTC_INFO_HEIGHT_MM (1 << 2)
+
+ /**
+ * 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the value for
+ * `width_mm_edid` and report errors to `width_mm_edid_error`
+ */
+#define LIBGAMMA_CRTC_INFO_WIDTH_MM_EDID (1 << 3)
+
+ /**
+ * 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the value for
+ * `height_mm_edid` and report errors to `height_mm_edid_error`
+ */
+#define LIBGAMMA_CRTC_INFO_HEIGHT_MM_EDID (1 << 4)
+
+ /**
+ * 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;
+
+
+/**
+ * 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 LIBGAMMA_CRTC_INFO_GAMMA_SIZE (1 << 5)
+
+ /**
+ * 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the value for
+ * `gamma_depth` and report errors to `gamma_depth_error`
+ */
+#define LIBGAMMA_CRTC_INFO_GAMMA_DEPTH (1 << 6)
+
+ /**
+ * The bit-depth of the value axes of gamma ramps,
+ * -1 for single precision floating point, and -2 for
+ * double precision floating point
+ */
+ signed 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the value for
+ * `gamma_support` and report errors to `gamma_support_error`
+ */
+#define LIBGAMMA_CRTC_INFO_GAMMA_SUPPORT (1 << 7)
+
+ /**
+ * `LIBGAMMA_NO` indicates that the CRTC does not support
+ * gamma ramp adjustments. `LIBGAMMA_MAYBE` indicates that
+ * the CRTC may or may not support gamma ramp adjustments,
+ * meaning that the display server really does not know, but
+ * the protocol is available. `LIBGAMMA_NO` indicates that
+ * the CRTC does support gamma ramp adjustments.
+ */
+ libgamma_decision_t 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the value for
+ * `subpixel_order` and report errors to `subpixel_order_error`
+ */
+#define LIBGAMMA_CRTC_INFO_SUBPIXEL_ORDER (1 << 8)
+
+ /**
+ * The layout of the subpixels
+ *
+ * You cannot count on this value — especially for CRT:s —
+ * but it is provided anyway as a means of distinguishing
+ * monitors
+ */
+ libgamma_subpixel_order_t 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the
+ * value for `active` and report errors to `active_error`
+ */
+#define LIBGAMMA_CRTC_INFO_ACTIVE (1 << 9)
+
+ /**
+ * Whether there is a monitor 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the value for
+ * `connector_name` and report errors to `connector_name_error`
+ */
+#define LIBGAMMA_CRTC_INFO_CONNECTOR_NAME (1 << 10)
+
+ /**
+ * 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the value for
+ * `connector_type` and report errors to `connector_type_error`
+ */
+#define LIBGAMMA_CRTC_INFO_CONNECTOR_TYPE (1 << 11)
+
+ /**
+ * The type of the connector that is associated with the CRTC
+ */
+ libgamma_connector_type_t 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;
+
+
+/**
+ * For a `libgamma_crtc_information_t` fill in the
+ * values for `gamma_red`, `gamma_green`, and `gamma_blue`
+ * and report errors to `gamma_error`
+ */
+#define LIBGAMMA_CRTC_INFO_GAMMA (1 << 12)
+
+ /**
+ * 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;
+
+ /* DEVELOPERS: Remember to update LIBGAMMA_CRTC_INFO_COUNT below and maybe
+ * also some of the list of LIBGAMMA_CRTC_INFO_* macros below */
+
+} libgamma_crtc_information_t;
+
+/**
+ * The number of `LIBGAMMA_CRTC_INFO_*` values defined in
+ * the version of the library the program is compiled against
+ *
+ * This exclude the combining macros defined below this macro
+ */
+#define LIBGAMMA_CRTC_INFO_COUNT 13
+
+/**
+ * The number of `LIBGAMMA_CRTC_INFO_*` values defined in
+ * the version of the library the program is linked against
+ */
+extern const int libgamma_crtc_info_count;
+
+/**
+ * Macro for both `libgamma_crtc_information_t` fields
+ * that can specify the size of the monitor's viewport
+ * as specified in the monitor's Extended Display
+ * Information Data
+ */
+#define LIBGAMMA_CRTC_INFO_MACRO_EDID_VIEWPORT (LIBGAMMA_CRTC_INFO_WIDTH_MM_EDID | LIBGAMMA_CRTC_INFO_HEIGHT_MM_EDID)
+
+/**
+ * Macro for all `libgamma_crtc_information_t` fields
+ * that can be filled if the adjustment method have
+ * support for reading the monitors' Extended Display
+ * Information Data
+ */
+#define LIBGAMMA_CRTC_INFO_MACRO_EDID (LIBGAMMA_CRTC_INFO_EDID | LIBGAMMA_CRTC_INFO_MACRO_EDID_VIEWPORT | LIBGAMMA_CRTC_INFO_GAMMA)
+
+/**
+ * Macro for both `libgamma_crtc_information_t` fields
+ * that can specify the size of the monitor's viewport
+ * as provided by the adjustment method without this
+ * library having to parse the monitor's Extended Display
+ * Information Data
+ */
+#define LIBGAMMA_CRTC_INFO_MACRO_VIEWPORT (LIBGAMMA_CRTC_INFO_WIDTH_MM | LIBGAMMA_CRTC_INFO_HEIGHT_MM)
+
+/**
+ * Macro for the `libgamma_crtc_information_t` fields
+ * that specifies the CRTC's gamma ramp sizes and gamma
+ * ramp depth
+ */
+#define LIBGAMMA_CRTC_INFO_MACRO_RAMP (LIBGAMMA_CRTC_INFO_GAMMA_SIZE | LIBGAMMA_CRTC_INFO_GAMMA_DEPTH)
+
+/**
+ * Macro for the `libgamma_crtc_information_t` fields
+ * that specifies the CRTC's connector type and the
+ * partition unique name of the connector
+ */
+#define LIBGAMMA_CRTC_INFO_MACRO_CONNECTOR (LIBGAMMA_CRTC_INFO_CONNECTOR_NAME | LIBGAMMA_CRTC_INFO_CONNECTOR_TYPE)
+
+/**
+ * Macro for the `libgamma_crtc_information_t` fields
+ * that required there is a monitor attached to the
+ * connector, and that status itself
+ */
+#define LIBGAMMA_CRTC_INFO_MACRO_ACTIVE (LIBGAMMA_CRTC_INFO_MACRO_EDID | LIBGAMMA_CRTC_INFO_MACRO_VIEWPORT |\
+ LIBGAMMA_CRTC_INFO_SUBPIXEL_ORDER | LIBGAMMA_CRTC_INFO_ACTIVE)
+
+
+
+/**
+ * Gamma ramp structure for 8-bit gamma ramps
+ */
+typedef struct libgamma_gamma_ramps8 {
+ /**
+ * 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
+ */
+ uint8_t *red;
+
+ /**
+ * The gamma ramp for the green channel
+ */
+ uint8_t *green;
+
+ /**
+ * The gamma ramp for the blue channel
+ */
+ uint8_t *blue;
+
+} libgamma_gamma_ramps8_t;
+
+
+/**
+ * Gamma ramp structure for 16-bit gamma ramps
+ */
+typedef struct libgamma_gamma_ramps16
+{
+ /**
+ * 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_ramps16_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;
+
+
+/**
+ * Mapping function from [0, 1] float encoding value to [0, 2⁸ − 1] integer output value
+ *
+ * @param encoding [0, 1] float encoding value
+ * @return [0, 2⁸ − 1] integer output value
+ */
+typedef uint8_t libgamma_gamma_ramps8_fun(float);
+
+/**
+ * Mapping function from [0, 1] float encoding value to [0, 2¹⁶ − 1] integer output value
+ *
+ * @param encoding [0, 1] float encoding value
+ * @return [0, 2¹⁶ − 1] integer output value
+ */
+typedef uint16_t libgamma_gamma_ramps16_fun(float);
+
+/**
+ * Mapping function from [0, 1] float encoding value to [0, 2³² − 1] integer output value
+ *
+ * @param encoding [0, 1] float encoding value
+ * @return [0, 2³² − 1] integer output value
+ */
+typedef uint32_t libgamma_gamma_ramps32_fun(float);
+
+/**
+ * Mapping function from [0, 1] float encoding value to [0, 2⁶⁴ − 1] integer output value
+ *
+ * @param encoding [0, 1] float encoding value
+ * @return [0, 2⁶⁴ − 1] integer output value
+ */
+typedef uint64_t libgamma_gamma_ramps64_fun(float);
+
+/**
+ * Mapping function from [0, 1] float encoding value to [0, 1] float output value
+ *
+ * @param encoding [0, 1] float encoding value
+ * @return [0, 1] float output value
+ */
+typedef float libgamma_gamma_rampsf_fun(float);
+
+/**
+ * Mapping function from [0, 1] double precision float encoding
+ * value to [0, 1] double precision float output value
+ *
+ * @param encoding [0, 1] float encoding value
+ * @return [0, 1] float output value
+ */
+typedef double libgamma_gamma_rampsd_fun(double);
+
+
+
+/**
+ * Prints an error to stderr in a `perror` fashion
+ *
+ * @param name The text to add at the beginning
+ * @param error_code The error code, may be an `errno` value
+ */
+void libgamma_perror(const char *, int);
+
+/**
+ * Get a description of an error
+ *
+ * @param error_code The error code, may be an `errno` value, if
+ * `LIBGAMMA_ERRNO_SET`, the current value of `errno`
+ * will be used
+ * @return The description associated with the error code,
+ * `NULL` if the error code is not recognised
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__)))
+const char *libgamma_strerror(int);
+
+/**
+ * Get a description of an error
+ *
+ * @param error_code The error code, may be an `errno` value, if
+ * `LIBGAMMA_ERRNO_SET`, the current value of `errno`
+ * will be used
+ * @param buf Buffer that shall be used if a description must be generated
+ * @param bufsize The size of `buf`, 1024 is recommended
+ * @return The description associated with the error code;
+ * can only be `NULL` if `buf` is `NULL`. If the buffer
+ * is insufficient, a truncated but NUL-terminated
+ * description is returned and `errno` is set to `ERANGE`;
+ * `errno` is otherwise unmodified
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__)))
+const char *libgamma_strerror_r(int, char[], size_t);
+
+/**
+ * Get the name of the definition associated with a `libgamma` error code
+ *
+ * @param value The error code
+ * @return The name of the definition associated with the error code,
+ * `NULL` if the error code does not exist
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __const__)))
+const char *libgamma_name_of_error(int);
+
+/**
+ * Get the value of a `libgamma` error definition refered to by name
+ *
+ * @param name The name of the definition associated with the error code
+ * @return The error code, zero if the name is `NULL`
+ * or does not refer to a `libgamma` error
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __pure__)))
+int libgamma_value_of_error(const char *);
+
+/**
+ * Get the group that the user needs to be a member
+ * of if `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned
+ *
+ * @return The group that the user needs to be a member of
+ * if `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned
+ */
+#ifndef __WIN32__
+gid_t libgamma_group_gid_get(void);
+#else
+short libgamma_group_gid_get(void);
+#endif
+
+/**
+ * Set the group that the user needs to be a member
+ * of if `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned
+ *
+ * @param value The group that the user needs to be a member of
+ * if `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned
+ */
+#ifndef __WIN32__
+void libgamma_group_gid_set(gid_t);
+#else
+void libgamma_group_gid_set(short);
+#endif
+
+/**
+ * Get the group that the user needs to be a member of
+ * if `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned
+ *
+ * @return The group that the user needs to be a member of if
+ * `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned, `NULL`
+ * if the name of the group `libgamma_group_gid` cannot
+ * be determined
+ */
+const char *libgamma_group_name_get(void);
+
+/**
+ * Set the group that the user needs to be a member of
+ * if `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned
+ *
+ * @param value The group that the user needs to be a member of if
+ * `LIBGAMMA_DEVICE_REQUIRE_GROUP` is returned, may be `NULL`
+ */
+void libgamma_group_name_set(const char *);
+
+
+
+
+/**
+ * Get the name of an adjustment method,
+ * for example "randr" for `LIBGAMMA_METHOD_X_RANDR`
+ *
+ * @param method The adjustment method
+ * @return The name adjustment method, `NULL` if not
+ * recognised (errno is not changed)
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __const__)))
+const char *libgamma_name_of_method(int);
+
+/**
+ * Get the name of the constant for an adjustment
+ * method, for example "LIBGAMMA_METHOD_X_RANDR"
+ * for `LIBGAMMA_METHOD_X_RANDR`
+ *
+ * @param method The adjustment method
+ * @return The name of the constant for adjustment method,
+ * `NULL` if not recognised (errno is not changed)
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __const__)))
+const char *libgamma_const_of_method(int);
+
+/**
+ * Check whether an adjustment method is available,
+ * non-existing (invalid) methods will be identified
+ * as not available under the rationale that the
+ * library may be out of date
+ *
+ * @param method The adjustment method
+ * @return Whether the adjustment method is available
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __const__)))
+int libgamma_is_method_available(int);
+
+/**
+ * Get the value of an adjustment method
+ *
+ * @param method The name of the adjustment method, for example
+ * "randr" or "LIBGAMMA_METHOD_X_RANDR"
+ * @return The adjustment method; for example `LIBGAMMA_METHOD_X_RANDR`
+ * for "randr" and "LIBGAMMA_METHOD_X_RANDR"
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __pure__)))
+int libgamma_value_of_method(const char *);
+
+
+
+/**
+ * Get the name of a connector type,
+ * for example "VGA" for `LIBGAMMA_CONNECTOR_TYPE_VGA`
+ *
+ * "Unknown" is returned for `LIBGAMMA_CONNECTOR_TYPE_Unknown`,
+ * "TV" is returned for `LIBGAMMA_CONNECTOR_TYPE_TV`,
+ * "Virtual" is returned for `LIBGAMMA_CONNECTOR_TYPE_Virtual`
+ *
+ * @param connector The connector type
+ * @return The name connector type, `NULL` if not
+ * recognised (errno is not changed)
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __const__)))
+const char *libgamma_name_of_connector_type(int);
+
+/**
+ * Get the name of the constant for a connector
+ * type, for example "LIBGAMMA_CONNECTOR_TYPE_VGA"
+ * for `LIBGAMMA_CONNECTOR_TYPE_VGA`
+ *
+ * @param connector The connector type
+ * @return The name of the constant for connector type,
+ * `NULL` if not recognised (errno is not changed)
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __const__)))
+const char *libgamma_const_of_connector_type(int);
+
+/**
+ * Get the value of a connector type
+ *
+ * @param connector The name of the connector type, for example
+ * "VGA" or "LIBGAMMA_CONNECTOR_TYPE_VGA"
+ * @return The connector type; for example `LIBGAMMA_CONNECTOR_TYPE_VGA`
+ * for "VGA" and "LIBGAMMA_CONNECTOR_TYPE_VGA"
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __pure__)))
+int libgamma_value_of_connector_type(const char *);
+
+
+
+/**
+ * Get the name of a subpixel order, for example
+ * "Horizontal RGB" for `LIBGAMMA_SUBPIXEL_ORDER_HORIZONTAL_RGB`
+ *
+ * "Unknown" is returned for `LIBGAMMA_SUBPIXEL_ORDER_UNKNOWN`,
+ * "None" is returned for `LIBGAMMA_SUBPIXEL_ORDER_NONE`
+ *
+ * @param order The subpixel order
+ * @return The name subpixel order, `NULL` if not
+ * recognised (errno is not changed)
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __const__)))
+const char *libgamma_name_of_subpixel_order(int);
+
+/**
+ * Get the name of the constant for a subpixel order,
+ * for example "LIBGAMMA_SUBPIXEL_ORDER_HORIZONTAL_RGB"
+ * for `LIBGAMMA_SUBPIXEL_ORDER_HORIZONTAL_RGB`
+ *
+ * @param order The subpixel order
+ * @return The name of the constant for subpixel order,
+ * `NULL` if not recognised (errno is not changed)
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __const__)))
+const char *libgamma_const_of_subpixel_order(int);
+
+/**
+ * Get the value of a subpixel order
+ *
+ * @param order The name of the subpixel order, for example
+ * "Horizontal RGB" or "LIBGAMMA_SUBPIXEL_ORDER_HORIZONTAL_RGB"
+ * @return The subpixel order; for example `LIBGAMMA_SUBPIXEL_ORDER_HORIZONTAL_RGB`
+ * for "Horizontal RGB" and "LIBGAMMA_SUBPIXEL_ORDER_HORIZONTAL_RGB"
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __pure__)))
+int libgamma_value_of_subpixel_order(const char *);
+
+
+
+/**
+ * Initialise a gamma ramp in the proper way that allows all adjustment
+ * methods to read from and write to it without causing segmentation violation
+ *
+ * The input must have `red_size`, `green_size`, and `blue_size` set to the
+ * sizes of the gamma ramps that should be allocated
+ *
+ * @param this The gamma ramps
+ * @return Zero on success, -1 on allocation error, `errno` will be set accordingly
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_gamma_ramps8_initialise(libgamma_gamma_ramps8_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_ramps8_initialise` or otherwise
+ * initialised in the proper manner
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_ramps8_destroy(libgamma_gamma_ramps8_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_ramps8_initialise` or otherwise
+ * initialised in the proper manner, as well as release the pointer
+ * to the structure
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_ramps8_free(libgamma_gamma_ramps8_t *restrict);
+
+
+/**
+ * Initialise a gamma ramp in the proper way that allows all adjustment
+ * methods to read from and write to it without causing segmentation violation
+ *
+ * The input must have `red_size`, `green_size`, and `blue_size` set to the
+ * sizes of the gamma ramps that should be allocated
+ *
+ * @param this The gamma ramps
+ * @return Zero on success, -1 on allocation error, `errno` will be set accordingly
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_gamma_ramps16_initialise(libgamma_gamma_ramps16_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_ramps16_initialise` or otherwise
+ * initialised in the proper manner
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_ramps16_destroy(libgamma_gamma_ramps16_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_ramps16_initialise` or otherwise
+ * initialised in the proper manner, as well as release the pointer
+ * to the structure
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_ramps16_free(libgamma_gamma_ramps16_t *restrict);
+
+
+/**
+ * Initialise a gamma ramp in the proper way that allows all adjustment
+ * methods to read from and write to it without causing segmentation violation
+ *
+ * The input must have `red_size`, `green_size`, and `blue_size` set to the
+ * sizes of the gamma ramps that should be allocated.
+ *
+ * @param this The gamma ramps
+ * @return Zero on success, -1 on allocation error, `errno` will be set accordingly
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_gamma_ramps32_initialise(libgamma_gamma_ramps32_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_ramps32_initialise` or otherwise
+ * initialised in the proper manner
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_ramps32_destroy(libgamma_gamma_ramps32_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_ramps32_initialise` or otherwise
+ * initialised in the proper manner, as well as release the pointer
+ * to the structure
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_ramps32_free(libgamma_gamma_ramps32_t *restrict);
+
+
+/**
+ * Initialise a gamma ramp in the proper way that allows all adjustment
+ * methods to read from and write to it without causing segmentation violation.
+ *
+ * The input must have `red_size`, `green_size`, and `blue_size` set to the
+ * sizes of the gamma ramps that should be allocated.
+ *
+ * @param this The gamma ramps
+ * @return Zero on success, -1 on allocation error, `errno` will be set accordingly
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_gamma_ramps64_initialise(libgamma_gamma_ramps64_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_ramps64_initialise` or otherwise
+ * initialised in the proper manner
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_ramps64_destroy(libgamma_gamma_ramps64_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_ramps64_initialise` or otherwise
+ * initialised in the proper manner, as well as release the pointer
+ * to the structure
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_ramps64_free(libgamma_gamma_ramps64_t *restrict);
+
+
+/**
+ * Initialise a gamma ramp in the proper way that allows all adjustment
+ * methods to read from and write to it without causing segmentation violation
+ *
+ * The input must have `red_size`, `green_size`, and `blue_size` set to the
+ * sizes of the gamma ramps that should be allocated
+ *
+ * @param this The gamma ramps
+ * @return Zero on success, -1 on allocation error, `errno` will be set accordingly
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_gamma_rampsf_initialise(libgamma_gamma_rampsf_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_rampsf_initialise` or otherwise
+ * initialised in the proper manner
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_rampsf_destroy(libgamma_gamma_rampsf_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_rampsf_initialise` or otherwise
+ * initialised in the proper manner, as well as release the pointer
+ * to the structure
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_rampsf_free(libgamma_gamma_rampsf_t *restrict);
+
+
+/**
+ * Initialise a gamma ramp in the proper way that allows all adjustment
+ * methods to read from and write to it without causing segmentation violation
+ *
+ * The input must have `red_size`, `green_size`, and `blue_size` set to the
+ * sizes of the gamma ramps that should be allocated
+ *
+ * @param this The gamma ramps
+ * @return Zero on success, -1 on allocation error, `errno` will be set accordingly
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_gamma_rampsd_initialise(libgamma_gamma_rampsd_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_rampsd_initialise` or otherwise
+ * initialised in the proper manner
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_rampsd_destroy(libgamma_gamma_rampsd_t *restrict);
+
+/**
+ * Release resources that are held by a gamma ramp strcuture that
+ * has been allocated by `libgamma_gamma_rampsd_initialise` or otherwise
+ * initialised in the proper manner, as well as release the pointer
+ * to the structure
+ *
+ * @param this The gamma ramps
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_gamma_rampsd_free(libgamma_gamma_rampsd_t *restrict);
+
+
+
+/**
+ * List available adjustment methods by their order of preference based on the environment
+ *
+ * @param methods Output array of methods, should be able to hold `LIBGAMMA_METHOD_COUNT` elements
+ * @param buf_size The number of elements that fits in `methods`, it should be `LIBGAMMA_METHOD_COUNT`,
+ * This is used to avoid writing outside the output buffer if this library adds new
+ * adjustment methods without the users of the library recompiling
+ * @param operation Allowed values:
+ * 0: Methods that the environment suggests will work, excluding fake
+ * 1: Methods that the environment suggests will work, including fake
+ * 2: All real non-fake methods
+ * 3: All real methods
+ * 4: All methods
+ * Other values invoke undefined behaviour
+ * @return The number of element that have been stored in `methods`, or should
+ * have been stored if the buffer was large enough
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__)))
+size_t libgamma_list_methods(int *restrict, size_t, int);
+
+/**
+ * Return the capabilities of an adjustment method
+ *
+ * @param this The data structure to fill with the method's capabilities
+ * @param method The adjustment method (display server and protocol)
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+int libgamma_method_capabilities(libgamma_method_capabilities_t *restrict, int);
+
+/**
+ * Return the default site for an adjustment method
+ *
+ * @param method The adjustment method (display server and protocol)
+ * @return The default site, `NULL` if it cannot be determined or
+ * if multiple sites are not supported by the adjustment
+ * method
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__)))
+const char *libgamma_method_default_site(int);
+
+/**
+ * Return the default variable that determines
+ * the default site for an adjustment method
+ *
+ * @param method The adjustment method (display server and protocol)
+ * @return The environ variables that is used to determine the
+ * default site, `NULL` if there is none, that is, if
+ * the method does not support multiple sites
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__)))
+const char *libgamma_method_default_site_variable(int);
+
+
+
+/**
+ * Initialise an allocated site state
+ *
+ * @param this The site state to initialise
+ * @param method The adjustment method (display server and protocol)
+ * @param site The site identifier, unless it is `NULL` it must a
+ * `free`:able. Once the state is destroyed the library
+ * will attempt to free it. There you should not free
+ * it yourself, and it must not be a string constant
+ * or allocate on the stack. Note however that it will
+ * not be `free`:d if this function fails.
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__(1))))
+int libgamma_site_initialise(libgamma_site_state_t *restrict, int, char *restrict);
+
+/**
+ * Release all resources held by a site state
+ *
+ * @param this The site state
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_site_destroy(libgamma_site_state_t *restrict);
+
+/**
+ * Release all resources held by a site state
+ * and free the site state pointer
+ *
+ * @param this The site state
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+inline void
+libgamma_site_free(libgamma_site_state_t *restrict this__)
+{
+ libgamma_site_destroy(this__);
+ free(this__);
+}
+
+/**
+ * Restore the gamma ramps all CRTC:s within a site to the system settings
+ *
+ * @param this The site state
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_site_restore(libgamma_site_state_t *restrict);
+
+
+
+/**
+ * Initialise an allocated partition state
+ *
+ * @param this The partition state to initialise
+ * @param site The site state for the site that the partition belongs to
+ * @param partition The index of the partition within the site
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_partition_initialise(libgamma_partition_state_t *restrict, libgamma_site_state_t *restrict, size_t);
+
+/**
+ * Release all resources held by a partition state
+ *
+ * @param this The partition state
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_partition_destroy(libgamma_partition_state_t *restrict);
+
+/**
+ * Release all resources held by a partition state
+ * and free the partition state pointer
+ *
+ * @param this The partition state
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+inline void
+libgamma_partition_free(libgamma_partition_state_t *restrict this__)
+{
+ libgamma_partition_destroy(this__);
+ free(this__);
+}
+
+/**
+ * Restore the gamma ramps all CRTC:s within a partition to the system settings
+ *
+ * @param this The partition state
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_partition_restore(libgamma_partition_state_t *restrict);
+
+
+
+/**
+ * Initialise an allocated CRTC state
+ *
+ * @param this The CRTC state to initialise
+ * @param partition The partition state for the partition that the CRTC belongs to
+ * @param crtc The index of the CRTC within the partition
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_initialise(libgamma_crtc_state_t *restrict, libgamma_partition_state_t *restrict, size_t);
+
+/**
+ * Release all resources held by a CRTC state
+ *
+ * @param this The CRTC state
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_crtc_destroy(libgamma_crtc_state_t *restrict);
+
+/**
+ * Release all resources held by a CRTC state
+ * and free the CRTC state pointer
+ *
+ * @param this The CRTC state
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+inline void
+libgamma_crtc_free(libgamma_crtc_state_t *restrict this__)
+{
+ libgamma_crtc_destroy(this__);
+ free(this__);
+}
+
+/**
+ * Restore the gamma ramps for a CRTC to the system settings for that CRTC
+ *
+ * @param this The CRTC state
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_restore(libgamma_crtc_state_t *restrict);
+
+
+/**
+ * Read information about a CRTC
+ *
+ * @param this Instance of a data structure to fill with the information about the CRTC
+ * @param crtc The state of the CRTC whose information should be read
+ * @param fields OR:ed identifiers for the information about the CRTC that should be read
+ * @return Zero on success, -1 on error; on error refer to the error reports in `this`
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_get_crtc_information(libgamma_crtc_information_t *restrict, libgamma_crtc_state_t *restrict, int32_t);
+
+/**
+ * Release all resources in an information data structure for a CRTC
+ *
+ * @param this The CRTC information
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+void libgamma_crtc_information_destroy(libgamma_crtc_information_t *restrict);
+
+/**
+ * Release all resources in an information data structure for a CRTC
+ * and free the data structure pointer
+ *
+ * @param this The CRTC information
+ */
+inline void
+libgamma_crtc_information_free(libgamma_crtc_information_t *restrict this__)
+{
+ libgamma_crtc_information_destroy(this__);
+ free(this__);
+}
+
+
+/**
+ * Convert a raw representation of an EDID to a lowercase hexadecimal representation
+ *
+ * @param edid The EDID in raw representation
+ * @param length The length of `edid`
+ * @return The EDID in lowercase hexadecimal representation
+ * `NULL` on allocation error, `errno` will be set accordingly
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__)))
+char *libgamma_behex_edid_lowercase(const unsigned char *restrict, size_t);
+
+/**
+ * Convert a raw representation of an EDID to an uppercase hexadecimal representation
+ *
+ * @param edid The EDID in raw representation
+ * @param length The length of `edid`
+ * @return The EDID in uppercase hexadecimal representation,
+ * NULL` on allocation error, `errno` will be set accordingly
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__)))
+char *libgamma_behex_edid_uppercase(const unsigned char *restrict, size_t);
+
+/**
+ * Convert a raw representation of an EDID to a lowercase hexadecimal representation
+ *
+ * @param edid:const unsigned char* The EDID in raw representation
+ * @param length:size_t The length of `edid`
+ * @return :char* The EDID in lowercase hexadecimal representation,
+ * `NULL` on allocation error, `errno` will be set accordingly
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__)))
+inline char *
+libgamma_behex_edid(const unsigned char *restrict edid__, size_t length__)
+{
+ return libgamma_behex_edid_lowercase(edid__, length__);
+}
+
+/**
+ * Convert an hexadecimal representation of an EDID to a raw representation
+ *
+ * @param edid The EDID in hexadecimal representation
+ * @return The EDID in raw representation, it will be half the length
+ * of `edid` (the input value); `NULL` on allocation error or
+ * if the EDID is malformated, `errno` will be set accordingly
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__warn_unused_result__, __nonnull__)))
+unsigned char *libgamma_unhex_edid(const char *restrict);
+
+
+
+/**
+ * Get the current gamma ramps for a CRTC, 8-bit gamma-depth version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to fill with the current values
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_get_gamma_ramps8(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps8_t *restrict);
+
+/**
+ * Set the gamma ramps for a CRTC, 8-bit gamma-depth version.
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to apply
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_set_gamma_ramps8(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps8_t);
+
+/**
+ * Set the gamma ramps for a CRTC, 8-bit gamma-depth function version
+ *
+ * Note that this will probably involve the library allocating temporary data
+ *
+ * @param this The CRTC state
+ * @param red_function The function that generates the gamma ramp for the red channel
+ * @param green_function The function that generates the gamma ramp for the green channel
+ * @param blue_function The function that generates the gamma ramp for the blue channel
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_set_gamma_ramps8_f(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps8_fun *,
+ libgamma_gamma_ramps8_fun *, libgamma_gamma_ramps8_fun *);
+
+
+/**
+ * Get the current gamma ramps for a CRTC, 16-bit gamma-depth version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to fill with the current values
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__, __hot__)))
+int libgamma_crtc_get_gamma_ramps16(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps16_t *restrict);
+
+/**
+ * Set the gamma ramps for a CRTC, 16-bit gamma-depth version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to apply
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__, __hot__)))
+int libgamma_crtc_set_gamma_ramps16(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps16_t);
+
+/**
+ * Set the gamma ramps for a CRTC, 16-bit gamma-depth function version
+ *
+ * Note that this will probably involve the library allocating temporary data
+ *
+ * @param this The CRTC state
+ * @param red_function The function that generates the gamma ramp for the red channel
+ * @param green_function The function that generates the gamma ramp for the green channel
+ * @param blue_function The function that generates the gamma ramp for the blue channel
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__, __hot__)))
+int libgamma_crtc_set_gamma_ramps16_f(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps16_fun *,
+ libgamma_gamma_ramps16_fun *, libgamma_gamma_ramps16_fun *);
+
+
+/**
+ * Get the current gamma ramps for a CRTC, 32-bit gamma-depth version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to fill with the current values
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_get_gamma_ramps32(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps32_t *restrict);
+
+/**
+ * Set the gamma ramps for a CRTC, 32-bit gamma-depth version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to apply
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_set_gamma_ramps32(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps32_t);
+
+/**
+ * Set the gamma ramps for a CRTC, 32-bit gamma-depth function version
+ *
+ * Note that this will probably involve the library allocating temporary data
+ *
+ * @param this The CRTC state
+ * @param red_function The function that generates the gamma ramp for the red channel
+ * @param green_function The function that generates the gamma ramp for the green channel
+ * @param blue_function The function that generates the gamma ramp for the blue channel
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_set_gamma_ramps32_f(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps32_fun *,
+ libgamma_gamma_ramps32_fun *, libgamma_gamma_ramps32_fun *);
+
+
+/**
+ * Get the current gamma ramps for a CRTC, 64-bit gamma-depth version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to fill with the current values
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_get_gamma_ramps64(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps64_t *restrict);
+
+/**
+ * Set the gamma ramps for a CRTC, 64-bit gamma-depth version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to apply
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_set_gamma_ramps64(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps64_t);
+
+/**
+ * Set the gamma ramps for a CRTC, 64-bit gamma-depth function version
+ *
+ * Note that this will probably involve the library allocating temporary data
+ *
+ * @param this The CRTC state
+ * @param red_function The function that generates the gamma ramp for the red channel
+ * @param green_function The function that generates the gamma ramp for the green channel
+ * @param blue_function The function that generates the gamma ramp for the blue channel
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_set_gamma_ramps64_f(libgamma_crtc_state_t *restrict, libgamma_gamma_ramps64_fun *,
+ libgamma_gamma_ramps64_fun *, libgamma_gamma_ramps64_fun *);
+
+
+/**
+ * Set the gamma ramps for a CRTC, `float` version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to apply
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_set_gamma_rampsf(libgamma_crtc_state_t *restrict, libgamma_gamma_rampsf_t);
+
+/**
+ * Get the current gamma ramps for a CRTC, `float` version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to fill with the current values
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_get_gamma_rampsf(libgamma_crtc_state_t *restrict, libgamma_gamma_rampsf_t *restrict);
+
+/**
+ * Set the gamma ramps for a CRTC, `float` function version
+ *
+ * Note that this will probably involve the library allocating temporary data
+ *
+ * @param this The CRTC state
+ * @param red_function The function that generates the gamma ramp for the red channel
+ * @param green_function The function that generates the gamma ramp for the green channel
+ * @param blue_function The function that generates the gamma ramp for the blue channel
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_set_gamma_rampsf_f(libgamma_crtc_state_t *restrict, libgamma_gamma_rampsf_fun *,
+ libgamma_gamma_rampsf_fun *, libgamma_gamma_rampsf_fun *);
+
+
+/**
+ * Get the current gamma ramps for a CRTC, `double` version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to fill with the current values
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_get_gamma_rampsd(libgamma_crtc_state_t *restrict, libgamma_gamma_rampsd_t *restrict);
+
+/**
+ * Set the gamma ramps for a CRTC, `double` version
+ *
+ * @param this The CRTC state
+ * @param ramps The gamma ramps to apply
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+int libgamma_crtc_set_gamma_rampsd(libgamma_crtc_state_t *restrict, libgamma_gamma_rampsd_t);
+
+/**
+ * Set the gamma ramps for a CRTC, `double` function version
+ *
+ * Note that this will probably involve the library allocating temporary data
+ *
+ * @param this The CRTC state
+ * @param red_function The function that generates the gamma ramp for the red channel
+ * @param green_function The function that generates the gamma ramp for the green channel
+ * @param blue_function The function that generates the gamma ramp for the blue channel
+ * @return Zero on success, otherwise (negative) the value of an
+ * error identifier provided by this library
+ */
+LIBGAMMA_GCC_ONLY__(__attribute__((__nonnull__)))
+int libgamma_crtc_set_gamma_rampsd_f(libgamma_crtc_state_t *restrict, libgamma_gamma_rampsd_fun *,
+ libgamma_gamma_rampsd_fun *, libgamma_gamma_rampsd_fun *);
+
+
+
+#undef LIBGAMMA_GCC_ONLY__
+#endif