libclut.c

/* See LICENSE file for copyright and license details. */
#include "libclut.h"

#include <errno.h>

#if defined(__GNUC__)
# pragma GCC diagnostic ignored "-Wunsuffixed-float-constants"
#endif


/**
 * Convert one component from [0, 1] linear sRGB to [0, 1] sRGB
 * 
 * @param   c  The linear sRGB value
 * @return     Corresponding sRGB value
 */
double
(libclut_model_linear_to_standard1)(double c)
{
	return libclut_model_linear_to_standard1(c);
}

/**
 * Convert [0, 1] linear sRGB to [0, 1] sRGB
 * 
 * @param  r  Pointer to the linear red component,
 *            and output parameter for the red component
 * @param  g  Pointer to the linear green component,
 *            and output parameter for the green component
 * @param  b  Pointer to the linear blue component,
 *            and output parameter for the blue component
 */
void
(libclut_model_linear_to_standard)(double *r, double *g, double *b)
{
	libclut_model_linear_to_standard(r, g, b);
}

/**
 * Convert one component from [0, 1] sRGB to [0, 1] linear sRGB
 * 
 * @param   c  The sRGB value
 * @return     Corresponding linear sRGB value
 */
double
(libclut_model_standard_to_linear1)(double c)
{
	return libclut_model_standard_to_linear1(c);
}

/**
 * Convert [0, 1] sRGB to [0, 1] linear sRGB
 * 
 * @param  r  Pointer to the red component, and output
 *            parameter for the linear red component
 * @param  g  Pointer to the green component, and output
 *            parameter for the linear green component
 * @param  b  Pointer to the blue component, and output
 *            parameter for the linear blue component
 */
void
(libclut_model_standard_to_linear)(double *r, double *g, double *b)
{
	libclut_model_standard_to_linear(r, g, b);
}

/**
 * Convert CIE xyY to CIE XYZ.
 * 
 * @param  x  The x parameter
 * @param  y  The y parameter
 * @param  Y  The Y parameter; this is also the Y (middle) parameter for the CIE XYZ colour
 * @param  X  Output parameter for the X parameter
 * @param  Z  Output parameter for the Z parameter
 */
void
(libclut_model_ciexyy_to_ciexyz)(double x, double y, double Y, double *X, double *Z)
{
	libclut_model_ciexyy_to_ciexyz(x, y, Y, X, Z);
}

/**
 * Convert CIE XYZ to CIE xyY
 * 
 * @param  X  The X parameter
 * @param  Y  The Y parameter; this is also the Y (last) parameter for the CIE xyY colour
 * @param  Z  The Z parameter
 * @param  x  Output parameter for the x parameter
 * @param  y  Output parameter for the y parameter
 */
void
(libclut_model_ciexyz_to_ciexyy)(double X, double Y, double Z, double *x, double *y)
{
	libclut_model_ciexyz_to_ciexyy(X, Y, Z, x, y);
}

/**
 * Convert CIE XYZ to [0, 1] linear sRGB
 * 
 * @param  X  The X parameter
 * @param  Y  The Y parameter
 * @param  Z  The Z parameter
 * @param  r  Output parameter for the red component
 * @param  g  Output parameter for the green component
 * @param  b  Output parameter for the blue component
 */
void
(libclut_model_ciexyz_to_linear)(double X, double Y, double Z, double *r, double *g, double *b)
{
	libclut_model_ciexyz_to_linear(X, Y, Z, r, g, b);
}

/**
 * Convert [0, 1] linear sRGB to CIE XYZ
 * 
 * @param  r  The red component
 * @param  g  The green component
 * @param  b  The blue component
 * @param  X  Output parameter for the X parameter
 * @param  Y  Output parameter for the Y parameter
 * @param  Z  Output parameter for the Z parameter
 */
void
(libclut_model_linear_to_ciexyz)(double r, double g, double b, double *X, double *Y, double *Z)
{
	libclut_model_linear_to_ciexyz(r, g, b, X, Y, Z);
}

/**
 * Convert [0, 1] linear sRGB to CIE xyY
 * 
 * @param  r  The red component
 * @param  g  The green component
 * @param  b  The blue component
 * @param  x  Output parameter for the x parameter
 * @param  y  Output parameter for the y parameter
 * @param  Y  Output parameter for the Y parameter
 */
void
(libclut_model_srgb_to_ciexyy)(double r, double g, double b, double *x, double *y, double *Y)
{
	libclut_model_srgb_to_ciexyy(r, g, b, x, y, Y);
}

/**
 * Convert CIE xyY to [0, 1] sRGB
 * 
 * @param  x  The x parameter
 * @param  y  The y parameter
 * @param  Y  The Y parameter
 * @param  r  Output parameter for the red component
 * @param  g  Output parameter for the green component
 * @param  b  Output parameter for the blue component
 */
void
(libclut_model_ciexyy_to_srgb)(double x, double y, double Y, double *r, double *g, double *b)
{
	libclut_model_ciexyy_to_srgb(x, y, Y, r, g, b);
}

/**
 * Convert from CIE XYZ to CIE L*a*b*
 * 
 * @param  X  The X parameter
 * @param  Y  The Y parameter
 * @param  Z  The Z parameter
 * @param  L  Output parameter for the L* component
 * @param  a  Output parameter for the a* component
 * @param  b  Output parameter for the b* component
 */
void
(libclut_model_ciexyz_to_cielab)(double X, double Y, double Z, double *L, double *a, double *b)
{
	libclut_model_ciexyz_to_cielab(X, Y, Z, L, a, b);
}

/**
 * Convert from CIE L*a*b* to CIE XYZ
 * 
 * @param  L  The L* component
 * @param  a  The a* component
 * @param  b  The b* component
 * @param  X  Output parameter for the X parameter
 * @param  Y  Output parameter for the Y parameter
 * @param  Z  Output parameter for the Z parameter
 */
void
(libclut_model_cielab_to_ciexyz)(double L, double a, double b, double *X, double *Y, double *Z)
{
	libclut_model_cielab_to_ciexyz(L, a, b, X, Y, Z);
}

/**
 * Convert from CIE XYZ to CIE L*u*v*
 * 
 * @param  X  The X parameter
 * @param  Y  The Y parameter
 * @param  Z  The Z parameter
 * @param  Xn  The X component of the specified white object (white point)
 * @param  Yn  The Y component of the specified white object (white point)
 * @param  Zn  The Z component of the specified white object (white point)
 * @param  L  Output parameter for the L* component
 * @param  u  Output parameter for the u* component
 * @param  v  Output parameter for the v* component
 */
void
(libclut_model_ciexyz_to_cieluv)(double X, double Y, double Z, double Xn, double Yn, double Zn, double *L, double *u, double *v)
{
	libclut_model_ciexyz_to_cieluv(X, Y, Z, Xn, Yn, Zn, L, u, v);
}

/**
 * Convert from CIE L*u*v* to CIE XYZ
 * 
 * @param  L   The L* component
 * @param  u   The u* component
 * @param  v   The v* component
 * @param  Xn  The X component of the specified white object (white point)
 * @param  Yn  The Y component of the specified white object (white point)
 * @param  Zn  The Z component of the specified white object (white point)
 * @param  X   Output parameter for the X parameter
 * @param  Y   Output parameter for the Y parameter
 * @param  Z   Output parameter for the Z parameter
 */
void
(libclut_model_cieluv_to_ciexyz)(double L, double u, double v, double Xn, double Yn, double Zn, double *X, double *Y, double *Z)
{
	libclut_model_cieluv_to_ciexyz(L, u, v, Xn, Yn, Zn, X, Y, Z);
}

/**
 * Convert from CIELCh to CIE L*u*v*
 * 
 * @param  L  The L* component
 * @param  C  The C*_uv component
 * @param  h  The h_uv component
 * @param  u  Output parameter for the u* parameter
 * @param  v  Output parameter for the v* parameter
 */
void
(libclut_model_cielch_to_cieluv)(double C, double h, double *u, double *v)
{
	libclut_model_cielch_to_cieluv(C, h, u, v);
}

/**
 * Convert from CIE L*u*v* to CIELCh
 * 
 * @param  L  The L* component
 * @param  u  The u* component
 * @param  v  The v* component
 * @param  C  Output parameter for the C*_uv parameter
 * @param  h  Output parameter for the h_uv parameter
 */
void
(libclut_model_cieluv_to_cielch)(double u, double v, double *C, double *h)
{
	libclut_model_cieluv_to_cielch(u, v, C, h);
}

/**
 * Convert from sRGB to YIQ
 * 
 * @param  r  The R component
 * @param  g  The G component
 * @param  b  The B component
 * @param  y  Output parameter for the Y parameter
 * @param  i  Output parameter for the I parameter
 * @param  q  Output parameter for the Q parameter
 */
void
(libclut_model_srgb_to_yiq)(double r, double g, double b, double *y, double *i, double *q)
{
	libclut_model_srgb_to_yiq(r, g, b, y, i, q);
}

/**
 * Convert from YIQ to sRGB
 * 
 * @param  y  The Y component
 * @param  i  The I component
 * @param  q  The Q component
 * @param  r  Output parameter for the R parameter
 * @param  g  Output parameter for the G parameter
 * @param  b  Output parameter for the B parameter
 */
void
(libclut_model_yiq_to_srgb)(double y, double i, double q, double *r, double *g, double *b)
{
	libclut_model_yiq_to_srgb(y, i, q, r, g, b);
}

/**
 * Convert from sRGB to YDbDr
 * 
 * @param  r   The R component
 * @param  g   The G component
 * @param  b   The B component
 * @param  y   Output parameter for the Y parameter
 * @param  db  Output parameter for the Db parameter
 * @param  dr  Output parameter for the Dr parameter
 */
void
(libclut_model_srgb_to_ydbdr)(double r, double g, double b, double *y, double *db, double *dr)
{
	libclut_model_srgb_to_ydbdr(r, g, b, y, db, dr);
}

/**
 * Convert from YDbDr to sRGB
 * 
 * @param  y   The Y component
 * @param  db  The Db component
 * @param  dr  The Dr component
 * @param  r   Output parameter for the R parameter
 * @param  g   Output parameter for the G parameter
 * @param  b   Output parameter for the B parameter
 */
void
(libclut_model_ydbdr_to_srgb)(double y, double db, double dr, double *r, double *g, double *b)
{
	libclut_model_ydbdr_to_srgb(y, db, dr, r, g, b);
}

/**
 * Convert from YUV to YDbDr
 * 
 * @param  u   The U component
 * @param  v   The V component
 * @param  db  Output parameter for the Db parameter
 * @param  dr  Output parameter for the Dr parameter
 */
void
(libclut_model_yuv_to_ydbdr)(double u, double v, double *db, double *dr)
{
	libclut_model_yuv_to_ydbdr(u, v, db, dr);
}

/**
 * Convert from YDbDr to YUV
 * 
 * @param  db  The Db component
 * @param  dr  The Dr component
 * @param  u   Output parameter for the U parameter
 * @param  v   Output parameter for the V parameter
 */
void
(libclut_model_ydbdr_to_yuv)(double db, double dr, double *u, double *v)
{
	libclut_model_ydbdr_to_yuv(db, dr, u, v);
}

/**
 * Convert from sRGB to YPbPr
 * 
 * @param  r   The R component
 * @param  g   The G component
 * @param  b   The B component
 * @param  y   Output parameter for the Y parameter
 * @param  pb  Output parameter for the Pb parameter
 * @param  pr  Output parameter for the Pr parameter
 */
void
(libclut_model_srgb_to_ypbpr)(double r, double g, double b, double *y, double *pb, double *pr)
{
	libclut_model_srgb_to_ypbpr(r, g, b, y, pb, pr);
}

/**
 * Convert from YPbPr to sRGB
 * 
 * @param  y   The Y component
 * @param  pb  The Pb component
 * @param  pr  The Pr component
 * @param  r   Output parameter for the R parameter
 * @param  g   Output parameter for the G parameter
 * @param  b   Output parameter for the B parameter
 */
void
(libclut_model_ypbpr_to_srgb)(double y, double pb, double pr, double *r, double *g, double *b)
{
	libclut_model_ypbpr_to_srgb(y, pb, pr, r, g, b);
}

/**
 * Convert from sRGB to YCgCo
 * 
 * @param  r   The R component
 * @param  g   The G component
 * @param  b   The B component
 * @param  y   Output parameter for the Y parameter
 * @param  cg  Output parameter for the Cg parameter
 * @param  co  Output parameter for the Co parameter
 */
void
(libclut_model_srgb_to_ycgco)(double r, double g, double b, double *y, double *cg, double *co)
{
	libclut_model_srgb_to_ycgco(r, g, b, y, cg, co);
}

/**
 * Convert from YCgCo to sRGB
 * 
 * @param  y   The Y component
 * @param  cg  The Cg component
 * @param  co  The Co component
 * @param  r   Output parameter for the R parameter
 * @param  g   Output parameter for the G parameter
 * @param  b   Output parameter for the B parameter
 */
void
(libclut_model_ycgco_to_srgb)(double y, double cg, double co, double *r, double *g, double *b)
{
	libclut_model_ycgco_to_srgb(y, cg, co, r, g, b);
}

/**
 * Convert from CIE 1960 UCS to CIE XYZ
 * 
 * @param  u  The u component
 * @param  v  The v component
 * @param  Y  The Y component
 * @param  x  Output parameter for the X parameter
 * @param  y  Output parameter for the Y parameter
 * @param  z  Output parameter for the Z parameter
 */
void
(libclut_model_cie_1960_ucs_to_ciexyz)(double u, double v, double Y, double *x, double *y, double *z)
{
	libclut_model_cie_1960_ucs_to_ciexyz(u, v, Y, x, y, z);
}

/**
 * Convert from CIE XYZ to CIE 1960 UCS
 * 
 * @param  x  The X component
 * @param  y  The Y component
 * @param  z  The Z component
 * @param  u  Output parameter for the u parameter
 * @param  v  Output parameter for the v parameter
 * @param  Y  Output parameter for the Y parameter
 */
void
(libclut_model_ciexyz_to_cie_1960_ucs)(double x, double y, double z, double *u, double *v, double *Y)
{
	libclut_model_ciexyz_to_cie_1960_ucs(x, y, z, u, v, Y);
}

/**
 * Convert from CIEUVW to CIE 1960 UCS
 * 
 * @param  U   The U* component
 * @param  V   The V* component
 * @param  W   The W* component
 * @param  u0  The u parameter for the white point
 * @param  v0  The v parameter for the white point
 * @param  u   Output parameter for the u parameter
 * @param  v   Output parameter for the v parameter
 * @param  Y   Output parameter for the Y parameter
 */
void
(libclut_model_cieuvw_to_cie_1960_ucs)(double U, double V, double W, double u0, double v0, double *u, double *v, double *Y)
{
	libclut_model_cieuvw_to_cie_1960_ucs(U, V, W, u0, v0, u, v, Y);
}

/**
 * Convert from CIE 1960 UCS to CIEUVW
 * 
 * Requires linking with `-lm`
 * 
 * @param  u   The u component
 * @param  v   The v component
 * @param  Y   The Y component
 * @param  u0  The u parameter for the white point
 * @param  v0  The v parameter for the white point
 * @param  U   Output parameter for the U* parameter
 * @param  V   Output parameter for the V* parameter
 * @param  W   Output parameter for the W* parameter
 */
void
(libclut_model_cie_1960_ucs_to_cieuvw)(double u, double v, double Y, double u0, double v0, double *U, double *V, double *W)
{
	libclut_model_cie_1960_ucs_to_cieuvw(u, v, Y, u0, v0, U, V, W);
}

/**
 * Divide all values in a row by a divisor
 * 
 * @param  m  The first part of the row
 * @param  a  The second part of the row
 * @param  d  The divisor
 */
static void
divrow(double m[3], double a[3], double d)
{
	m[0] /= d, m[1] /= d, m[2] /= d;
	a[0] /= d, a[1] /= d, a[2] /= d;
}

/**
 * Subtract all values in a row by corresponding value
 * in another row multiplied by a common value
 * 
 * @param  a1  The first part of the minuend/difference row
 * @param  a2  The second part of the minuend/difference row
 * @param  b1  The first part of the subtrahend row
 * @param  b2  The second part of the subtrahend row
 * @param  m   The multiplier
 */
static void
subrow(double a1[3], double a2[3], double b1[3], double b2[3], double m)
{
	a1[0] -= b1[0] * m, a1[1] -= b1[1] * m, a1[2] -= b1[2] * m;
	a2[0] -= b2[0] * m, a2[1] -= b2[1] * m, a2[2] -= b2[2] * m;
}

/**
 * Invert a matrix
 * 
 * @param   M  The matrix to invert, will be modified to an
 *             identity matrix, possibly with reordered rows
 * @param   A  The inversion of M (as input)
 * @return     1 on success, 0 if the matrix is not invertible
 */
static int
invert(libclut_colour_space_conversion_matrix_t M, libclut_colour_space_conversion_matrix_t A)
{
	int r0 = 0, r1 = 1, r2 = 2, t, swapped = 0;
	libclut_colour_space_conversion_matrix_t T;

	A[0][0] = A[1][1] = A[2][2] = 1;
	A[0][1] = A[0][2] = A[1][0] = A[1][2] = A[2][0] = A[2][1] = 0;
  
	if (libclut_0__(M[r0][0])) {
		if (libclut_0__(M[r1][0])) {
			if (libclut_0__(M[r2][0]))
				return 0;
			t = r0, r0 = r2, r2 = t;
		} else {
			t = r0, r0 = r1, r1 = t;
		}
		swapped = 1;
	}

	divrow(M[r0], A[r0], M[r0][0]);
	subrow(M[r1], A[r1], M[r0], A[r0], M[r1][0]);
	subrow(M[r2], A[r2], M[r0], A[r0], M[r2][0]);

	if (libclut_0__(M[r1][1])) {
		if (libclut_0__(M[r2][1]))
			return 0;
		t = r1, r1 = r2, r2 = t;
		swapped = 1;
	}

	divrow(M[r1], A[r1], M[r1][1]);
	subrow(M[r2], A[r2], M[r1], A[r1], M[r2][1]);

	if (libclut_0__(M[r2][2]))
		return 0;

	divrow(M[r2], A[r2], M[r2][2]);

	subrow(M[r1], A[r1], M[r2], A[r2], M[r1][2]);
	subrow(M[r0], A[r0], M[r2], A[r2], M[r0][2]);

	subrow(M[r0], A[r0], M[r1], A[r1], M[r0][1]);

	if (swapped) {
		memcpy(T, A, sizeof(T));
		memcpy(A[0], T[r0], sizeof(*T));
		memcpy(A[1], T[r1], sizeof(*T));
		memcpy(A[2], T[r2], sizeof(*T));
	}

	return 1;
}

/**
 * Create an RGB to CIE XYZ conversion matrix
 * 
 * @param   cs  The colour space
 * @param   M   The output matrix
 * @return      Zero on success, -1 on error
 * 
 * @throws  EINVAL  The colour space cannot be used
 */
static int
get_conversion_matrix(const libclut_rgb_colour_space_t *cs, libclut_colour_space_conversion_matrix_t M)
{
#define XYY_TO_XYZ(x, y, Y, Xp, Yp, Zp)\
	(libclut_0__(Y)) ?\
	 (*(Xp) = *(Zp) = *(Yp) = (Y)) :\
	 (*(Xp) = (x) * (Y) / (y),\
	  *(Yp) = (Y),\
	  *(Zp) = (1 - (x) - (y)) * (Y) / (y))

	double Xr, Yr, Zr, Xg, Yg, Zg, Xb, Yb, Zb, Xw, Yw, Zw, Sr, Sg, Sb;
	libclut_colour_space_conversion_matrix_t M2;

	XYY_TO_XYZ(cs->red_x,   cs->red_y,   1,           &Xr, &Yr, &Zr);
	XYY_TO_XYZ(cs->green_x, cs->green_y, 1,           &Xg, &Yg, &Zg);
	XYY_TO_XYZ(cs->blue_x,  cs->blue_y,  1,           &Xb, &Yb, &Zb);
	XYY_TO_XYZ(cs->white_x, cs->white_y, cs->white_Y, &Xw, &Yw, &Zw);

	M2[0][0] = Xr, M2[0][1] = Xg, M2[0][2] = Xb;
	M2[1][0] = Yr, M2[1][1] = Yg, M2[1][2] = Yb;
	M2[2][0] = Zr, M2[2][1] = Zg, M2[2][2] = Zb;

	if (!invert(M2, M))
		return errno = EINVAL, -1;

	Sr = M[0][0] * Xw + M[0][1] * Yw + M[0][2] * Zw;
	Sg = M[1][0] * Xw + M[1][1] * Yw + M[1][2] * Zw;
	Sb = M[2][0] * Xw + M[2][1] * Yw + M[2][2] * Zw;

	M[0][0] = Sr * Xr, M[0][1] = Sg * Xg, M[0][2] = Sb * Xb;
	M[1][0] = Sr * Yr, M[1][1] = Sg * Yg, M[1][2] = Sb * Yb;
	M[2][0] = Sr * Zr, M[2][1] = Sg * Zg, M[2][2] = Sb * Zb;

	return 0;

#undef XYY_TO_XYZ
}

/**
 * Create a matrix for converting values between
 * two RGB colour spaces
 * 
 * @param   from  The input colour space, the Y-component is only necessary
 *                for the white point, `NULL` for CIE XYZ
 * @param   to    The output colour space, the Y-component is only necessary
 *                for the white point, `NULL` for CIE XYZ
 * @param   M     Output matrix for conversion from `from` to `to`
 * @param   Minv  Output matrix for conversion from `to` to `from`, may be `NULL`
 * @return        Zero on success, -1 on error
 * 
 * @throws  EINVAL  The colour space cannot be used
 */
int
libclut_model_get_rgb_conversion_matrix(const libclut_rgb_colour_space_t *from,
                                        const libclut_rgb_colour_space_t *to,
                                        libclut_colour_space_conversion_matrix_t M,
                                        libclut_colour_space_conversion_matrix_t Minv)
{
	libclut_colour_space_conversion_matrix_t A, B;

	if (from) {
		if (get_conversion_matrix(from, A))
			return -1;
	} else {
		A[0][0] = A[1][1] = A[2][2] = 1;
		A[0][1] = A[1][0] = A[2][0] = 0;
		A[0][2] = A[1][2] = A[2][1] = 0;
	}

	if (to) {
		if (get_conversion_matrix(to, M))
			return -1;
		if (!invert(M, B)) {
			errno = EINVAL;
			return -1;
		}

		if (from) {
			M[0][0] = B[0][0] * A[0][0] + B[0][1] * A[1][0] + B[0][2] * A[2][0];
			M[0][1] = B[0][0] * A[0][1] + B[0][1] * A[1][1] + B[0][2] * A[2][1];
			M[0][2] = B[0][0] * A[0][2] + B[0][1] * A[1][2] + B[0][2] * A[2][2];

			M[1][0] = B[1][0] * A[0][0] + B[1][1] * A[1][0] + B[1][2] * A[2][0];
			M[1][1] = B[1][0] * A[0][1] + B[1][1] * A[1][1] + B[1][2] * A[2][1];
			M[1][2] = B[1][0] * A[0][2] + B[1][1] * A[1][2] + B[1][2] * A[2][2];

			M[2][0] = B[2][0] * A[0][0] + B[2][1] * A[1][0] + B[2][2] * A[2][0];
			M[2][1] = B[2][0] * A[0][1] + B[2][1] * A[1][1] + B[2][2] * A[2][1];
			M[2][2] = B[2][0] * A[0][2] + B[2][1] * A[1][2] + B[2][2] * A[2][2];
		} else {
			memcpy(M, B, sizeof(B));
		}
	} else {
		memcpy(M, A, sizeof(A));
	}

	if (Minv) {
		memcpy(A, M, sizeof(A));
		if (!invert(A, Minv)) {
			errno = EINVAL;
			return -1;
		}
	}

	return 0;
}

/**
 * Convert an RGB colour into another RGB colour space
 * 
 * Both RGB colour spaces must have same gamma functions as sRGB
 * 
 * @param  r      The red component of the colour to convert
 * @param  g      The green component of the colour to convert
 * @param  b      The blue component of the colour to convert
 * @param  M      Conversion matrix, create with `libclut_model_get_rgb_conversion_matrix`
 * @param  out_r  Output parameter for the new red component
 * @param  out_g  Output parameter for the new green component
 * @param  out_b  Output parameter for the new blue component
 */
void
(libclut_model_convert_rgb)(double r, double g, double b, libclut_colour_space_conversion_matrix_t M,
                            double *out_r, double *out_g, double *out_b)
{
	libclut_model_convert_rgb(r, g, b, M, out_r, out_g, out_b);
}

/**
 * Convert an RGB colour of a custom RGB colour space to CIE XYZ
 * 
 * The RGB colour space must have same gamma functions as sRGB
 * 
 * @param  r  The red component
 * @param  g  The green component
 * @param  b  The blue component
 * @param  M  Conversion matrix, create with `libclut_model_get_rgb_conversion_matrix`
 * @param  x  Output parameter for the X component
 * @param  y  Output parameter for the Y component
 * @param  z  Output parameter for the Z component
 */
void
(libclut_model_rgb_to_ciexyz)(double r, double g, double b, libclut_colour_space_conversion_matrix_t M,
                              double *x, double *y, double *z)
{
	libclut_model_rgb_to_ciexyz(r, g, b, M, x, y, z);
}

/**
 * Convert a CIE XYZ colour to a custom RGB colour space
 * 
 * The RGB colour space must have same gamma functions as sRGB
 * 
 * @param  x  The X component
 * @param  y  The Y component
 * @param  z  The Z component
 * @param  M  Conversion matrix, create with `libclut_model_get_rgb_conversion_matrix`
 * @param  r  Output parameter for the red component
 * @param  g  Output parameter for the green component
 * @param  b  Output parameter for the blue component
 */
void
(libclut_model_ciexyz_to_rgb)(double x, double y, double z, libclut_colour_space_conversion_matrix_t M,
                              double *r, double *g, double *b)
{
	libclut_model_ciexyz_to_rgb(x, y, z, M, r, g, b);
}