path: root/src/lib/libgamma-facade.c.gpp

/* -*- c -*- */
/* See LICENSE file for copyright and license details. */
#include "libgamma-facade.h"

#include "libgamma-error.h"
#include "libgamma-method.h"
#include "gamma-helper.h"


/* Initialise the general preprocessor */
$>cd src/extract
$>export PATH=".:${PATH}"

/* Some general preprocessor we will use frequently */
$<
get-methods ()
{
	./libgamma-method-extract --list --method | cut -d _ -f 1,2 --complement
}
lowercase ()
{
	echo "$*" | sed -e y/QWERTYUIOPASDFGHJKLZXCVBNM/qwertyuiopasdfghjklzxcvbnm/ | sed -e s:core_graphics:cg:g
}
$>

/* Include all adjustment methods that are enabled at compile-time. */
$>for method in $(get-methods); do
#ifdef HAVE_LIBGAMMA_METHOD_${method}
# include "gamma-$(lowercase $method | sed -e s:_:-:g).h"
# ifndef HAVE_LIBGAMMA_METHODS
#  define HAVE_LIBGAMMA_METHODS
# endif
#endif
$>done

#include <unistd.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>


/* Some things to reduce warnings when we do
 * not have any adjustment methods enabled */
#ifndef HAVE_LIBGAMMA_METHODS
# define HAVE_NO_LIBGAMMA_METHODS
# ifdef __GNUC__
#  pragma GCC diagnostic push
#  pragma GCC diagnostic ignored "-Wsuggest-attribute=const"
# endif
#endif



#ifdef HAVE_LIBGAMMA_METHODS
# ifdef HAVE_LIBGAMMA_METHOD_LINUX_DRM
/**
 * Test whether a file descriptor refers to a VT
 * 
 * @param   fd  The file descriptor
 * @return      Whether the file descriptor refers to a VT
 */
static int
libgamma_is_vt_proper(int fd)
{
	char buf[32], digit0;

	/* Get TTY */
	if (ttyname_r(fd, buf, sizeof(buf) / sizeof(char)))
		return 0;

	/* Validate TTY path */
	if (!strcmp(buf, "/dev/console"))
		return 1;
	if (strstr(buf, "/dev/tty") != buf)
		return 0;

	/* Validate TTY name */
	digit0 = buf[strlen("/dev/tty")];
	return '1' <= digit0 && digit0 <= '9';
}
# endif


/**
 * Test the availability of an adjustment method
 * 
 * @param  method     The adjustment method
 * @param  operation  Allowed values:
 *                      0: Pass if the environment suggests it will work but is not fake
 *                      1: Pass if the environment suggests it will work
 *                      2: Pass if real and not fake
 *                      3: Pass if real
 *                      4: Always pass
 *                    Other values invoke undefined behaviour
 * @return            Whether the test passed
 */
static int
libgamma_list_method_test(int method, int operation)
{
	libgamma_method_capabilities_t caps;
	libgamma_method_capabilities(&caps, method);

	switch (operation) {
	case 0:
		/* Methods that the environment suggests will work, excluding fake */
		if (caps.fake)
			return 0;
		/* fall through */

	case 1:
		/* Methods that the environment suggests will work, including fake */
		if (!caps.real)
			return 0;
#ifdef HAVE_LIBGAMMA_METHOD_LINUX_DRM
		if (method == LIBGAMMA_METHOD_LINUX_DRM) {
			return libgamma_is_vt_proper(STDIN_FILENO) ||
			       libgamma_is_vt_proper(STDOUT_FILENO) ||
			       libgamma_is_vt_proper(STDERR_FILENO);
		}
#endif
#ifdef HAVE_LIBGAMMA_METHOD_DUMMY
		if (method == LIBGAMMA_METHOD_DUMMY)
			return 0;
#endif
		return caps.default_site_known;

	case 2:
		/* All real non-fake methods */
		return caps.real && !caps.fake;

	case 3:
		/* All real methods */
		return caps.real;

	default:
		/* All methods */
		return 1;
	}
}
#endif


/**
 * 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.
 */
size_t
libgamma_list_methods(int *restrict methods, size_t buf_size, int operation)
{
#ifdef HAVE_NO_LIBGAMMA_METHODS
	(void) methods;
	(void) buf_size;
	(void) operation;
	return 0;
#else
	size_t n = 0;

$>for method in $(get-methods); do
#ifdef HAVE_LIBGAMMA_METHOD_${method}
	if (libgamma_list_method_test(LIBGAMMA_METHOD_${method}, operation) && n++ < buf_size)
		methods[n - 1] = LIBGAMMA_METHOD_${method};
#endif
$>done

	return n;
#endif
}


/**
 * 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
 */
int
libgamma_is_method_available(int method)
{
#ifdef HAVE_NO_LIBGAMMA_METHODS
	(void) method;
	return 0;
#else
	switch (method) {
$>for method in $(get-methods); do
#ifdef HAVE_LIBGAMMA_METHOD_${method}
	case LIBGAMMA_METHOD_${method}:
#endif
$>done
	return 1;

	default:
		return 0;
	}
#endif
}


/**
 * Call the adjustment method's implementation of the called function
 * 
 * @param  1  The adjustment method, you may use `.` instead of `->` when resolving it
 * @param  2  `return` if the function returns a value, `break` otherwise
 * @param  3  The base name of the function to call, that is, the name of the function
 *            this is expended into without the libgamma namespace prefix
 * @param  *  The function's parameters
 */
$<switch ()
$>{
  /* Read out macro's parameters */
$<method="${1//./->}"
  ctrl=$2
  fun=$3
  shift 3
  params="$*"
$>params="${params// /, }"

	switch (${method}) {
$>for adjmethod in $(get-methods); do
#ifdef HAVE_LIBGAMMA_METHOD_${adjmethod}
	case LIBGAMMA_METHOD_${adjmethod}:
	/* Call the adjustment method's implementation, either
	 * return or break after it depending on macro parameter's */
$> if [ $ctrl = return ]; then
      return
      libgamma_$(lowercase $adjmethod)_${fun}(${params});
$> elif [ ! $ctrl = return ]; then
      break;
$> fi
#endif
$>done
    
	default:
		/* If the adjustment method does not exists, either return
		 * that error, or do nothing because the function this is
		 * expanded into does return errors */
$>if [ $ctrl = return ]; then
		return LIBGAMMA_NO_SUCH_ADJUSTMENT_METHOD;
$>else
		/* Method does not exists/excluded at compile-time.
		 * We will assume that this is not done... */
		break;
$>fi
	}
$>}


/**
 * 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)
 */
void
libgamma_method_capabilities(libgamma_method_capabilities_t *restrict this, int method)
{
	memset(this, 0, sizeof(libgamma_method_capabilities_t));
$>switch method break method_capabilities this
}


/**
 * 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; this value should not be `free`:d
 */
char *
libgamma_method_default_site(int method)
{
	const char *restrict var = libgamma_method_default_site_variable(method);
	char *restrict env;

	/* Return `NULL` there is not variable to read */
	if (!var)
		return NULL;

	/* Read the variable */
	env = getenv(var);
	/* Return `NULL` if it does not exist (or is empty) */
	if (!env || !*env)
		return NULL;

	/* Return the variable's value */
	return env;
}


/**
 * 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.
 *                  This value should not be `free`:d.
 */
const char *
libgamma_method_default_site_variable(int method)
{
	switch (method) {
#ifdef HAVE_LIBGAMMA_METHOD_X_RANDR
	case LIBGAMMA_METHOD_X_RANDR:
		return "DISPLAY";
#endif
#ifdef HAVE_LIBGAMMA_METHOD_X_VIDMODE
	case LIBGAMMA_METHOD_X_VIDMODE:
		return "DISPLAY";
#endif
	default:
		return NULL;
	}
}


/**
 * 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 allocated 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
 */
int
libgamma_site_initialise(libgamma_site_state_t *restrict this, int method, char *restrict site)
{
	this->method = method;
	this->site = site;
$>switch method return site_initialise this site
}


/**
 * Release all resources held by a site state
 * 
 * @param  this  The site state
 */
void
libgamma_site_destroy(libgamma_site_state_t *restrict this)
{
$>switch this.method break site_destroy this
	free(this->site);
}


/**
 * Release all resources held by a site state
 * and free the site state pointer
 * 
 * @param  this  The site state
 */
void
libgamma_site_free(libgamma_site_state_t *restrict this)
{
	libgamma_site_destroy(this);
	free(this);
}


/**
 * Restore the gamma ramps all CRTC:s with 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
 */
int
libgamma_site_restore(libgamma_site_state_t *restrict this)
{
$>switch this.method return site_restore this
}



/**
 * 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
 */
int
libgamma_partition_initialise(libgamma_partition_state_t *restrict this, libgamma_site_state_t *restrict site, size_t partition)
{
	this->site = site;
	this->partition = partition;
$>switch site.method return partition_initialise this site partition
}


/**
 * Release all resources held by a partition state
 * 
 * @param  this  The partition state
 */
void
libgamma_partition_destroy(libgamma_partition_state_t *restrict this)
{
$>switch this.site.method break partition_destroy this
}


/**
 * Release all resources held by a partition state
 * and free the partition state pointer
 * 
 * @param  this  The partition state
 */
void
libgamma_partition_free(libgamma_partition_state_t *restrict this)
{
	libgamma_partition_destroy(this);
	free(this);
}


/**
 * Restore the gamma ramps all CRTC:s with 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
 */
int
libgamma_partition_restore(libgamma_partition_state_t *restrict this)
{
$>switch this.site.method return partition_restore this
}



/**
 * 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
 */
int
libgamma_crtc_initialise(libgamma_crtc_state_t *restrict this, libgamma_partition_state_t *restrict partition, size_t crtc)
{
	this->partition = partition;
	this->crtc = crtc;
$>switch partition.site.method return crtc_initialise this partition crtc
}


/**
 * Release all resources held by a CRTC state
 * 
 * @param  this  The CRTC state
 */
void
libgamma_crtc_destroy(libgamma_crtc_state_t *restrict this)
{
$>switch this.partition.site.method break crtc_destroy this
}


/**
 * Release all resources held by a CRTC state
 * and free the CRTC state pointer
 * 
 * @param  this  The CRTC state
 */
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
 */
int
libgamma_crtc_restore(libgamma_crtc_state_t *restrict this)
{
$>switch this.partition.site.method return crtc_restore this
}



/**
 * 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`
 */
int
libgamma_get_crtc_information(libgamma_crtc_information_t *restrict this, libgamma_crtc_state_t *restrict crtc, int32_t fields)
{
#ifdef HAVE_NO_LIBGAMMA_METHODS
	(void) fields;
#endif
	this->edid = NULL;
	this->connector_name = NULL;
$>switch crtc.partition.site.method return get_crtc_information this crtc fields
}


/**
 * Release all resources in an information data structure for a CRTC
 * 
 * @param  this  The CRTC information
 */
void
libgamma_crtc_information_destroy(libgamma_crtc_information_t *restrict this)
{
	free(this->edid);
	free(this->connector_name);
}


/**
 * Release all resources in an information data structure for a CRTC
 * and free the data structure pointer
 * 
 * @param  this  The CRTC information
 */
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 hexadecimal representation
 * 
 * @param   1       Casing name
 * @param   2       The hexadecimal alphabet
 * @param   edid    The EDID in raw representation
 * @param   length  The length of `edid`
 * @return          The EDID in hexadecimal representation
 *                  `NULL` on allocation error, `errno` will be set accordingly
 */
$>behex_edid ()
$>{
char *
libgamma_behex_edid_${1}(const unsigned char *restrict edid, size_t length)
{
	char *restrict out;
	size_t i;

	/* Allocate memory area for the output string */
	out = malloc((length * 2 + 1) * sizeof(char));
	if (!out)
		return NULL;

	/* Translate from raw octets to hexadecimal */
	for (i = 0; i < length; i++) {
		out[i * 2 + 0] = "${2}"[(edid[i] >> 4) & 15];
		out[i * 2 + 1] = "${2}"[(edid[i] >> 0) & 15];
	}
	/* NUL-terminate the output string */
	out[length * 2] = '\0';

	return out;
}
$>}


/**
 * 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
 */
$>behex_edid lowercase 0123456789abcdef


/**
 * 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
 */
$>behex_edid uppercase 0123456789ABCDEF


/**
 * 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
 */
unsigned char *
libgamma_unhex_edid(const char *restrict edid)
{
#define not_range(lower, V, upper) (V < lower || upper < V)
#define is_not_hex(V)              (not_range('0', V, '9') && not_range('a', V, 'f') && not_range('A', V, 'F'))

	unsigned char *restrict out;
	size_t i, n = strlen(edid);
	char a, b;

	/* Check that the length of the strings is even,
	 * otherwise it cannot represent bytes */
	if (n & 1) {
		errno = EINVAL;
		return NULL;
	}

	/* Allocate memory area for output octet array */
	n /= 2 * sizeof(unsigned char);
	out = malloc(n);
	if (!out)
		return NULL;

	/* Convert to raw octet array */
	for (i = 0; i < n; i++) {
		/* Get the next character pair that, it represents an octet. */
		a = edid[i * 2 + 0];
		b = edid[i * 2 + 1];

		/* Verify that the input is in hexadecimal */
		if (is_not_hex(a) || is_not_hex(b)) {
			free(out);
			errno = EINVAL;
			return NULL;
		}

		/* Convert each chararacter to raw format */
		a = (char)((a & 15) + (a > '9' ? 9 : 0));
		b = (char)((b & 15) + (b > '9' ? 9 : 0));

		/* Combine the two characters into one octet */
		out[i] = (unsigned char)((a << 4) | b);
	}

	return out;

#undef is_hex
#undef not_range
}


/**
 * 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
 */
int
libgamma_crtc_get_gamma_ramps16(libgamma_crtc_state_t *restrict this, libgamma_gamma_ramps16_t *restrict ramps)
{
	libgamma_gamma_ramps_any_t ramps_;

#ifdef HAVE_NO_LIBGAMMA_METHODS
	(void) ramps;
#endif

	switch (this->partition->site->method) {
	/* Methods other than Quartz/CoreGraphics uses 16-bit integers */
$>for method in $(get-methods | grep -v QUARTZ_CORE_GRAPHICS); do
#ifdef HAVE_LIBGAMMA_METHOD_${method}
	case LIBGAMMA_METHOD_${method}:
		return libgamma_$(lowercase $method)_crtc_get_gamma_ramps16(this, ramps);
#endif

	/* The Quartz/CoreGraphics method uses single precision float */
$>done
#ifdef HAVE_LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS
	case LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS:
		ramps_.bits16 = *ramps;
		return libgamma_translated_ramp_get(this, &ramps_, 16, -1, libgamma_crtc_get_gamma_rampsf);
#endif

	/* The selected method does not exist */
	default:
		return LIBGAMMA_NO_SUCH_ADJUSTMENT_METHOD;
	}
}


/**
 * 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
 */
int
libgamma_crtc_set_gamma_ramps16(libgamma_crtc_state_t *restrict this, libgamma_gamma_ramps16_t ramps)
{
	libgamma_gamma_ramps_any_t ramps_;

#ifdef HAVE_NO_LIBGAMMA_METHODS
	(void) ramps;
#endif
  
	switch (this->partition->site->method) {
	/* Methods other than Quartz/CoreGraphics uses 16-bit integers */
$>for method in $(get-methods | grep -v QUARTZ_CORE_GRAPHICS); do
#ifdef HAVE_LIBGAMMA_METHOD_${method}
	case LIBGAMMA_METHOD_${method}:
		return libgamma_$(lowercase $method)_crtc_set_gamma_ramps16(this, ramps);
#endif
$>done
     
	/* The Quartz/CoreGraphics method uses single precision float */
#ifdef HAVE_LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS
	case LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS:
		ramps_.bits16 = ramps;
		return libgamma_translated_ramp_set(this, ramps_, 16, -1, libgamma_crtc_set_gamma_rampsf);
#endif

	/* The selected method does not exist. */
	default:
		return LIBGAMMA_NO_SUCH_ADJUSTMENT_METHOD;
	}
}



/**
 * Set or get the gamma ramps for a CRTC, non-16-bit gamma-depth version
 * 
 * @param   1      Either `get` or `set`, for the action that the name of value implies
 * @param   2      The `ramp*` pattern for the ramp structure and function to call
 * @param   3      Either of `bit8`, `bit16`, `bit32`, `bit64`, `float_single`, `float_double`;
 *                 rather self-explanatory
 * @param   4      The number of bits in the gamma depth, -1 for single precision float,
 *                 (`float`) and -2 for double percition float (`double`)
 * @param   this   The CRTC state
 * @param   ramps  The gamma ramps to apply, or
 *                 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
 */
$>crtc_set_get_gamma_ramps ()
$>{
$<action=$1
  ramps=$2
  type=$3
  bits=$4
  p=
  if [ $action = get ]; then
    p='*'
  fi
$>
int
libgamma_crtc_${action}_gamma_${ramps}(libgamma_crtc_state_t *restrict this, libgamma_gamma_${ramps}_t${p:+* restrict} ramps)
{
	libgamma_gamma_ramps_any_t ramps_;
	switch (this->partition->site->method) {
	/* The dummy method supports all ramp depths */
#ifdef HAVE_LIBGAMMA_METHOD_DUMMY
	case LIBGAMMA_METHOD_DUMMY:
		return libgamma_dummy_crtc_${action}_gamma_${ramps}(this, ramps);
#endif

	/* The Quartz/CoreGraphics method uses single precision float */
#ifdef HAVE_LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS
	case LIBGAMMA_METHOD_QUARTZ_CORE_GRAPHICS:
$>if [ $bits = -1 ]; then
		/* Single precision float is used */
		return libgamma_quartz_cg_crtc_${action}_gamma_${ramps}(this, ramps);
$>else
		/* Something else is used and we convert to Single precision float */
		ramps_.${type} = ${p}ramps;
		return libgamma_translated_ramp_${action}(this, ${p:+&}ramps_, ${bits}, -1, libgamma_crtc_${action}_gamma_rampsf);
$>fi
#endif

	/* Other methods use 16-bit integers. */
	default:
		ramps_.${type} = ${p}ramps;
		return libgamma_translated_ramp_${action}(this, ${p:+&}ramps_, ${bits}, 16, libgamma_crtc_${action}_gamma_ramps16);
	}
}
$>}



/**
 * 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
 */
$>crtc_set_get_gamma_ramps get ramps8 bits8 8


/**
 * 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
 */
$>crtc_set_get_gamma_ramps set ramps8 bits8 8



/**
 * 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
 */
$>crtc_set_get_gamma_ramps get ramps32 bits32 32


/**
 * 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
 */
$>crtc_set_get_gamma_ramps set ramps32 bits32 32



/**
 * 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
 */
$>crtc_set_get_gamma_ramps get ramps64 bits64 64


/**
 * 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
 */
$>crtc_set_get_gamma_ramps set ramps64 bits64 64


/**
 * 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
 */
$>crtc_set_get_gamma_ramps get rampsf float_single -1


/**
 * 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
 */
$>crtc_set_get_gamma_ramps set rampsf float_single -1



/**
 * 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
 */
$>crtc_set_get_gamma_ramps get rampsd float_double -2


/**
 * 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
 */
$>crtc_set_get_gamma_ramps set rampsd float_double -2



/**
 * Set the gamma ramps for a CRTC
 * 
 * Note that this will probably involve the library allocating temporary data
 * 
 * @param   1               The data type for the ramp stop elements
 * @param   2               The `ramp*` pattern for the ramp structure and function to call
 * @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
 */
$>crtc_set_gamma_ramps_f ()
$>{
int
libgamma_crtc_set_gamma_${2}_f(libgamma_crtc_state_t *restrict this, libgamma_gamma_${2}_fun *red_function,
                               libgamma_gamma_${2}_fun *green_function, libgamma_gamma_${2}_fun *blue_function)
{
	libgamma_crtc_information_t info;
	libgamma_gamma_${2}_t ramps;
	size_t i, n;
	int e;

	/* Get the size of the gamma ramps */
	if (libgamma_get_crtc_information(&info, this, LIBGAMMA_CRTC_INFO_GAMMA_SIZE)) {
		e = info.gamma_size_error;
		if (e < 0)
			return e;
		errno = e;
		return LIBGAMMA_ERRNO_SET;
	}

	/* Copy the size of the gamma ramps and calculte the grand size */
	n  = ramps.  red_size = info.  red_gamma_size;
	n += ramps.green_size = info.green_gamma_size;
	n += ramps. blue_size = info. blue_gamma_size;

	/* Allocate gamma ramps */
	ramps.  red = malloc(n * sizeof(${1}));
	ramps.green = &ramps.  red[ramps.  red_size];
	ramps. blue = &ramps.green[ramps.green_size];
	if (!ramps.red)
		return LIBGAMMA_ERRNO_SET;

	/* Generate the gamma ramp for the red chennel */
	for (i = 0, n = ramps.red_size; i < n; i++)
		ramps.red[i] = red_function((float)i / (float)(n - 1));

	/* Generate the gamma ramp for the green chennel */
	for (i = 0, n = ramps.green_size; i < n; i++)
		ramps.green[i] = green_function((float)i / (float)(n - 1));

	/* Generate the gamma ramp for the blue chennel */
	for (i = 0, n = ramps.blue_size; i < n; i++)
		ramps.blue[i] = blue_function((float)i / (float)(n - 1));

	/* Apply the gamma ramps */
	e = libgamma_crtc_set_gamma_${2}(this, ramps);
	free(ramps.red);
	return e;
}
$>}


/**
 * 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
 */
$>crtc_set_gamma_ramps_f uint8_t ramps8


/**
 * 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
 */
$>crtc_set_gamma_ramps_f uint16_t ramps16


/**
 * 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
 */
$>crtc_set_gamma_ramps_f uint32_t ramps32


/**
 * 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
 */
$>crtc_set_gamma_ramps_f uint64_t ramps64


/**
 * 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
 */
$>crtc_set_gamma_ramps_f float rampsf


/**
 * 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
 */
$>crtc_set_gamma_ramps_f double rampsd



#ifdef HAVE_NO_LIBGAMMA_METHODS
# ifdef __GNUC__
#  pragma GCC diagnostic pop
# endif
#endif