/* See LICENSE file for copyright and license details. */
#include <math.h>

#define D65_XYY_X 0.312726871026564878786047074755
#define D65_XYY_Y 0.329023206641284038376227272238

#define D65_XYZ_X (D65_XYY_X / D65_XYY_Y)
#define D65_XYZ_Z (1 / D65_XYY_Y - 1 - D65_XYZ_X)

static inline double
srgb_encode(double t)
{
	double sign = 1;
	if (t < 0) {
		t = -t;
		sign = -1;
	}
	t = t <= 0.0031306684425217108
		? 12.92 * t
		: 1.055 * pow(t, 1 / 2.4) - 0.055;
	return t * sign;
}

static inline float
srgb_encode_f(float t)
{
	float sign = 1;
	if (t < 0) {
		t = -t;
		sign = -1;
	}
	t = t <= (float)0.0031306684425217108
		? (float)12.92 * t
		: (float)1.055 * powf(t, 1 / (float)2.4) - (float)0.055;
	return t * sign;
}

static inline double
srgb_decode(double t)
{
	double sign = 1;
	if (t < 0) {
		t = -t;
		sign = -1;
	}
	t = t <= 0.0031306684425217108 * 12.92
		? t / 12.92
		: pow((t + 0.055) / 1.055, 2.4);
	return t * sign;
}

static inline float
srgb_decode_f(float t)
{
	float sign = 1;
	if (t < 0) {
		t = -t;
		sign = -1;
	}
	t = t <= (float)0.0031306684425217108 * (float)12.92
		? t / (float)12.92
		: powf((t + (float)0.055) / (float)1.055, (float)2.4);
	return t * sign;
}

static inline void
yuv_to_srgb(double y, double u, double v, double *r, double *g, double *b)
{
#define MULTIPLY(CY, CU, CV)  ((CY) * y + (CU) * u + (CV) * v)
	*r = MULTIPLY(1,  0.00028328010485821202317155420580263580632163211703,  1.14070449590558520291949662350816652178764343261719);
	*g = MULTIPLY(1, -0.39630886669497211727275498560629785060882568359375, -0.58107364288228224857846271333983168005943298339844);
	*b = MULTIPLY(1,  2.03990003507541306504435851820744574069976806640625,  0.00017179031692307700847528739718228507626918144524);
#undef MULTIPLY
}

static inline void
yuv_to_srgb_f(float y, float u, float v, float *r, float *g, float *b)
{
#define MULTIPLY(CY, CU, CV)  ((float)(CY) * y + (float)(CU) * u + (float)(CV) * v)
	*r = MULTIPLY(1,  0.00028328010485821202317155420580263580632163211703,  1.14070449590558520291949662350816652178764343261719);
	*g = MULTIPLY(1, -0.39630886669497211727275498560629785060882568359375, -0.58107364288228224857846271333983168005943298339844);
	*b = MULTIPLY(1,  2.03990003507541306504435851820744574069976806640625,  0.00017179031692307700847528739718228507626918144524);
#undef MULTIPLY
}

static inline void
srgb_to_yuv(double r, double g, double b, double *y, double *u, double *v)
{
#define MULTIPLY(CR, CG, CB) ((CR) * r + (CG) * g + (CB) * b)
	*y = MULTIPLY(0.299, 0.587, 0.114);
	*u = MULTIPLY(-0.14662756598240470062854967636667424812912940979004,
		      -0.28771586836102963635752871596196200698614120483398,
		       0.43434343434343436474165400795754976570606231689453);
	*v = MULTIPLY( 0.61456892577224520035628074765554629266262054443359,
		      -0.51452282157676354490405401520547457039356231689453,
		      -0.10004610419548178035231700278018251992762088775635);
#undef MULTIPLY
}

static inline void
srgb_to_yuv_f(float r, float g, float b, float *y, float *u, float *v)
{
#define MULTIPLY(CR, CG, CB) ((float)(CR) * r + (float)(CG) * g + (float)(CB) * b)
	*y = MULTIPLY(0.299, 0.587, 0.114);
	*u = MULTIPLY(-0.14662756598240470062854967636667424812912940979004,
		      -0.28771586836102963635752871596196200698614120483398,
		       0.43434343434343436474165400795754976570606231689453);
	*v = MULTIPLY( 0.61456892577224520035628074765554629266262054443359,
		      -0.51452282157676354490405401520547457039356231689453,
		      -0.10004610419548178035231700278018251992762088775635);
#undef MULTIPLY
}

static inline void
ciexyz_to_srgb(double x, double y, double z, double *r, double *g, double *b)
{
#define MULTIPLY(CX, CY, CZ)  ((CX) * x + (CY) * y + (CZ) * z)
	*r = MULTIPLY(3.240446254647737500675930277794, -1.537134761820080575134284117667, -0.498530193022728718155178739835);
	*g = MULTIPLY(-0.969266606244679751469561779231, 1.876011959788370209167851498933, 0.041556042214430065351304932619);
	*b = MULTIPLY(0.055643503564352832235773149705, -0.204026179735960239147729566866, 1.057226567722703292062647051353);
#undef MULTIPLY
}

static inline void
ciexyz_to_srgb_f(float x, float y, float z, float *r, float *g, float *b)
{
#define MULTIPLY(CX, CY, CZ)  ((float)(CX) * x + (float)(CY) * y + (float)(CZ) * z)
	*r = MULTIPLY(3.240446254647737500675930277794, -1.537134761820080575134284117667, -0.498530193022728718155178739835);
	*g = MULTIPLY(-0.969266606244679751469561779231, 1.876011959788370209167851498933, 0.041556042214430065351304932619);
	*b = MULTIPLY(0.055643503564352832235773149705, -0.204026179735960239147729566866, 1.057226567722703292062647051353);
#undef MULTIPLY
}

static inline void
srgb_to_ciexyz(double r, double g, double b, double *x, double *y, double *z)
{
#define MULTIPLY(CR, CG, CB) ((CR) * r + (CG) * g + (CB) * b)
	*x = MULTIPLY(0.412457445582367576708548995157, 0.357575865245515878143578447634, 0.180437247826399665973085006954);
	*y = MULTIPLY(0.212673370378408277403536885686, 0.715151730491031756287156895269, 0.072174899130559869164791564344);
	*z = MULTIPLY(0.019333942761673460208893260415, 0.119191955081838593666354597644, 0.950302838552371742508739771438);
#undef MULTIPLY
}

static inline void
srgb_to_ciexyz_f(float r, float g, float b, float *x, float *y, float *z)
{
#define MULTIPLY(CR, CG, CB) ((float)(CR) * r + (float)(CG) * g + (float)(CB) * b)
	*x = MULTIPLY(0.412457445582367576708548995157, 0.357575865245515878143578447634, 0.180437247826399665973085006954);
	*y = MULTIPLY(0.212673370378408277403536885686, 0.715151730491031756287156895269, 0.072174899130559869164791564344);
	*z = MULTIPLY(0.019333942761673460208893260415, 0.119191955081838593666354597644, 0.950302838552371742508739771438);
#undef MULTIPLY
}

static inline void
scaled_yuv_to_ciexyz(double y, double u, double v, double *xp, double *yp, double *zp)
{
#define MULTIPLY(CY, CU, CV) ((CY) * y + (CU) * u + (CV) * v)
	*xp = MULTIPLY( 0.00001450325106667098632156481796684488472237717360,
		        0.00000345586790639342739093228633329157872822179343,
		        0.00000400923398630552893485111398685916128670214675);
	*yp = MULTIPLY( 0.00001525902189669641837040624243737596543724066578,
		       -0.00000207722814409390653614547427030512238843584782,
		       -0.00000263898607692305410302407824019166326934282552);
	*zp = MULTIPLY( 0.00001661446153041708825425643025752719950105529279,
		        0.00002885925752619118069149627137104374696718878113,
			-0.00000071781086875769179526501342566979779746816348);
#undef MULTIPLY
}

static inline void
scaled_yuv_to_ciexyz_f(float y, float u, float v, float *xp, float *yp, float *zp)
{
#define MULTIPLY(CY, CU, CV) ((float)(CY) * y + (float)(CU) * u + (float)(CV) * v)
	*xp = MULTIPLY( 0.00001450325106667098632156481796684488472237717360,
		        0.00000345586790639342739093228633329157872822179343,
		        0.00000400923398630552893485111398685916128670214675);
	*yp = MULTIPLY( 0.00001525902189669641837040624243737596543724066578,
		       -0.00000207722814409390653614547427030512238843584782,
		       -0.00000263898607692305410302407824019166326934282552);
	*zp = MULTIPLY( 0.00001661446153041708825425643025752719950105529279,
		        0.00002885925752619118069149627137104374696718878113,
			-0.00000071781086875769179526501342566979779746816348);
#undef MULTIPLY
}

static inline void
ciexyz_to_scaled_yuv(double x, double y, double z, double *yp, double *up, double *vp)
{
#define MULTIPLY(CX, CY, CZ) ((CX) * x + (CY) * y + (CZ) * z)
	*yp = MULTIPLY(  26625.38231027395886485464870929718017578125,
		         40524.0090949436053051613271236419677734375,
		          -271.5313105642117079696618020534515380859375);
	*up = MULTIPLY( -11278.3751445417292416095733642578125,
		        -26409.91773157499847002327442169189453125,
		         34100.5706543184860493056476116180419921875);
	*vp = MULTIPLY( 162829.60100012840121053159236907958984375,
		       -123829.313212639070115983486175537109375,
			-28411.65702312920984695665538311004638671875);
#undef MULTIPLY
}

static inline void
ciexyz_to_scaled_yuv_f(float x, float y, float z, float *yp, float *up, float *vp)
{
#define MULTIPLY(CX, CY, CZ) ((float)(CX) * x + (float)(CY) * y + (float)(CZ) * z)
	*yp = MULTIPLY(  26625.38231027395886485464870929718017578125,
		         40524.0090949436053051613271236419677734375,
		          -271.5313105642117079696618020534515380859375);
	*up = MULTIPLY( -11278.3751445417292416095733642578125,
		        -26409.91773157499847002327442169189453125,
		         34100.5706543184860493056476116180419921875);
	*vp = MULTIPLY( 162829.60100012840121053159236907958984375,
		       -123829.313212639070115983486175537109375,
			-28411.65702312920984695665538311004638671875);
#undef MULTIPLY
}