/* See LICENSE file for copyright and license details. */
static void to_rgb(const libcolour_colour_t *restrict from, libcolour_rgb_t *restrict to);
static void to_srgb(const libcolour_colour_t *restrict from, libcolour_srgb_t *restrict to);
static void to_ciexyy(const libcolour_colour_t *restrict from, libcolour_ciexyy_t *restrict to);
static void to_ciexyz(const libcolour_colour_t *restrict from, libcolour_ciexyz_t *restrict to);
static void to_cielab(const libcolour_colour_t *restrict from, libcolour_cielab_t *restrict to);
static void to_cieluv(const libcolour_colour_t *restrict from, libcolour_cieluv_t *restrict to);
static void to_cielchuv(const libcolour_colour_t *restrict from, libcolour_cielchuv_t *restrict to);
static void to_yiq(const libcolour_colour_t *restrict from, libcolour_yiq_t *restrict to);
static void to_ydbdr(const libcolour_colour_t *restrict from, libcolour_ydbdr_t *restrict to);
static void to_yuv(const libcolour_colour_t *restrict from, libcolour_yuv_t *restrict to);
static void to_ypbpr(const libcolour_colour_t *restrict from, libcolour_ypbpr_t *restrict to);
static void to_ycgco(const libcolour_colour_t *restrict from, libcolour_ycgco_t *restrict to);
static void to_cie1960ucs(const libcolour_colour_t *restrict from, libcolour_cie1960ucs_t *restrict to);
static void to_cieuvw(const libcolour_colour_t *restrict from, libcolour_cieuvw_t *restrict to);
#define CONV_0(MACRO, FROM, TO)\
MACRO(((const libcolour_rgb_t *)(FROM))->R,\
((const libcolour_rgb_t *)(FROM))->G,\
((const libcolour_rgb_t *)(FROM))->B,\
((libcolour_rgb_t *)(TO))->R,\
((libcolour_rgb_t *)(TO))->G,\
((libcolour_rgb_t *)(TO))->B)
#define CONV_N(MACRO, FROM, TO, ...)\
MACRO(((const libcolour_rgb_t *)(FROM))->R,\
((const libcolour_rgb_t *)(FROM))->G,\
((const libcolour_rgb_t *)(FROM))->B,\
((libcolour_rgb_t *)(TO))->R,\
((libcolour_rgb_t *)(TO))->G,\
((libcolour_rgb_t *)(TO))->B,\
__VA_ARGS__)
static void
rgb_encode(libcolour_rgb_t *restrict colour, const libcolour_rgb_t *restrict space)
{
TYPE r_sign = 1, g_sign = 1, b_sign = 1;
switch (space->encoding_type) {
case LIBCOLOUR_ENCODING_TYPE_LINEAR:
break;
case LIBCOLOUR_ENCODING_TYPE_SIMPLE:
case LIBCOLOUR_ENCODING_TYPE_REGULAR:
if (colour->R < 0) r_sign = -1, colour->R = -colour->R;
if (colour->G < 0) g_sign = -1, colour->G = -colour->G;
if (colour->B < 0) b_sign = -1, colour->B = -colour->B;
if (space->encoding_type == LIBCOLOUR_ENCODING_TYPE_SIMPLE) {
colour->R = xpow(colour->R, 1 / space->GAMMA);
colour->G = xpow(colour->G, 1 / space->GAMMA);
colour->B = xpow(colour->B, 1 / space->GAMMA);
} else {
colour->R = REGULAR(space, colour->R);
colour->G = REGULAR(space, colour->G);
colour->B = REGULAR(space, colour->B);
}
colour->R *= r_sign;
colour->G *= g_sign;
colour->B *= b_sign;
break;
case LIBCOLOUR_ENCODING_TYPE_CUSTOM:
colour->R = (space->TO_ENCODED_RED)(colour->R);
colour->G = (space->TO_ENCODED_GREEN)(colour->G);
colour->B = (space->TO_ENCODED_BLUE)(colour->B);
break;
default:
fprintf(stderr, "libcolour: invalid encoding type\n");
abort();
}
}
static void
rgb_decode(libcolour_rgb_t *restrict colour, const libcolour_rgb_t *restrict space)
{
TYPE r_sign = 1, g_sign = 1, b_sign = 1;
switch (space->encoding_type) {
case LIBCOLOUR_ENCODING_TYPE_LINEAR:
break;
case LIBCOLOUR_ENCODING_TYPE_SIMPLE:
case LIBCOLOUR_ENCODING_TYPE_REGULAR:
if (colour->R < 0) r_sign = -1, colour->R = -colour->R;
if (colour->G < 0) g_sign = -1, colour->G = -colour->G;
if (colour->B < 0) b_sign = -1, colour->B = -colour->B;
if (space->encoding_type == LIBCOLOUR_ENCODING_TYPE_SIMPLE) {
colour->R = xpow(colour->R, space->GAMMA);
colour->G = xpow(colour->G, space->GAMMA);
colour->B = xpow(colour->B, space->GAMMA);
} else {
colour->R = INVREGULAR(space, colour->R);
colour->G = INVREGULAR(space, colour->G);
colour->B = INVREGULAR(space, colour->B);
}
colour->R *= r_sign;
colour->G *= g_sign;
colour->B *= b_sign;
break;
case LIBCOLOUR_ENCODING_TYPE_CUSTOM:
colour->R = (space->TO_DECODED_RED)(colour->R);
colour->G = (space->TO_DECODED_GREEN)(colour->G);
colour->B = (space->TO_DECODED_BLUE)(colour->B);
break;
default:
fprintf(stderr, "libcolour: invalid encoding type\n");
abort();
}
}
static int
rgb_same_transfer(const libcolour_rgb_t *restrict a, const libcolour_rgb_t *restrict b)
{
if (a->encoding_type != b->encoding_type)
return 0;
switch (a->encoding_type) {
case LIBCOLOUR_ENCODING_TYPE_SIMPLE:
return a->GAMMA == b->GAMMA;
case LIBCOLOUR_ENCODING_TYPE_REGULAR:
return a->GAMMA == b->GAMMA &&
a->OFFSET == b->OFFSET &&
a->SLOPE == b->SLOPE &&
a->TRANSITION == b->TRANSITION;
case LIBCOLOUR_ENCODING_TYPE_CUSTOM:
return a->TO_ENCODED_RED == b->TO_ENCODED_RED &&
a->TO_ENCODED_GREEN == b->TO_ENCODED_GREEN &&
a->TO_ENCODED_BLUE == b->TO_ENCODED_BLUE &&
a->TO_DECODED_RED == b->TO_DECODED_RED &&
a->TO_DECODED_GREEN == b->TO_DECODED_GREEN &&
a->TO_DECODED_BLUE == b->TO_DECODED_BLUE;
default:
return 1;
}
}
static void
to_rgb(const libcolour_colour_t *restrict from, libcolour_rgb_t *restrict to)
{
int have_transfer = 0, with_transfer = to->with_transfer;
libcolour_ciexyz_t tmp;
switch (from->model) {
case LIBCOLOUR_RGB:
if (!memcmp(from->rgb.M, to->M, sizeof(TYPE[3][3]))) {
have_transfer = from->rgb.with_transfer;
to->R = from->rgb.R;
to->G = from->rgb.G;
to->B = from->rgb.B;
if (have_transfer && with_transfer && !rgb_same_transfer(&from->rgb, to))
rgb_decode(to, &from->rgb), have_transfer = 0;
break;
}
/* fall through */
default:
tmp.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp);
from = (const void *)&tmp;
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_N(CIEXYZ_TO_RGB, from, to, to->Minv);
break;
}
if (have_transfer != with_transfer) {
if (with_transfer)
rgb_encode(to, to);
else
rgb_decode(to, &from->rgb);
}
}
static void
to_srgb(const libcolour_colour_t *restrict from, libcolour_srgb_t *restrict to)
{
libcolour_srgb_t tmp_srgb;
libcolour_ciexyz_t tmp_ciexyz;
switch (from->model) {
default:
tmp_ciexyz.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp_ciexyz);
from = (const void *)&tmp_ciexyz;
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_0(CIEXYZ_TO_SRGB, from, to);
break;
case LIBCOLOUR_SRGB:
srgb_to_srgb:
if (from->srgb.with_transfer == to->with_transfer) {
*to = from->srgb;
} else if (to->with_transfer) {
to->R = srgb_encode(from->srgb.R);
to->G = srgb_encode(from->srgb.G);
to->B = srgb_encode(from->srgb.B);
} else {
to->R = srgb_decode(from->srgb.R);
to->G = srgb_decode(from->srgb.G);
to->B = srgb_decode(from->srgb.B);
}
return;
case LIBCOLOUR_YIQ:
CONV_0(YIQ_TO_SRGB, from, to);
break;
case LIBCOLOUR_YDBDR:
CONV_0(YDBDR_TO_SRGB, from, to);
break;
case LIBCOLOUR_YPBPR:
CONV_0(YPBPR_TO_SRGB, from, to);
break;
case LIBCOLOUR_YUV:
CONV_0(YUV_TO_SRGB, from, to);
break;
case LIBCOLOUR_YCGCO:
CONV_0(YCGCO_TO_SRGB, from, to);
break;
}
if (to->with_transfer) {
tmp_srgb = *to;
tmp_srgb.with_transfer = 0;
from = (const void *)&tmp_srgb;
goto srgb_to_srgb;
}
}
static void
to_ciexyy(const libcolour_colour_t *restrict from, libcolour_ciexyy_t *restrict to)
{
libcolour_srgb_t tmp1;
libcolour_ciexyz_t tmp2;
switch (from->model) {
case LIBCOLOUR_CIEXYY:
*to = from->ciexyy;
break;
case LIBCOLOUR_SRGB:
tmp1.model = LIBCOLOUR_SRGB;
if (from->srgb.with_transfer) {
tmp1.with_transfer = 0;
to_srgb((const libcolour_colour_t *)from, &tmp1);
} else {
tmp1 = from->srgb;
}
if (tmp1.R == 0 && tmp1.G == 0 && tmp1.B == 0) {
to->x = D(0.31272660439158);
to->y = D(0.32902315240275);
to->Y = 0;
break;
} else {
from = (const void *)&tmp1;
}
/* fall through */
default:
tmp2.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp2);
from = (const void *)&tmp2;
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_0(CIEXYZ_TO_CIEXYY, from, to);
break;
}
}
static void
to_ciexyz(const libcolour_colour_t *restrict from, libcolour_ciexyz_t *restrict to)
{
libcolour_colour_t tmp;
libcolour_srgb_t tmp_srgb;
TYPE R, G, B;
switch (from->model) {
case LIBCOLOUR_RGB:
if (from->rgb.with_transfer) {
tmp.rgb = from->rgb;
tmp.rgb.with_transfer = 0;
to_rgb(from, &tmp.rgb);
R = tmp.rgb.R, G = tmp.rgb.G, B = tmp.rgb.B;
} else {
R = from->rgb.R, G = from->rgb.G, B = from->rgb.B;
}
RGB_TO_CIEXYZ(R, G, B, to->X, to->Y, to->Z, from->rgb.M);
break;
default:
tmp.srgb.model = LIBCOLOUR_SRGB;
tmp.srgb.with_transfer = 0;
to_srgb(from, &tmp.srgb);
from = (const void *)&tmp.srgb;
/* fall through */
case LIBCOLOUR_SRGB:
if (from->srgb.with_transfer) {
tmp_srgb.model = LIBCOLOUR_SRGB;
tmp_srgb.with_transfer = 0;
to_srgb(from, &tmp_srgb);
R = tmp_srgb.R, G = tmp_srgb.G, B = tmp_srgb.B;
} else {
R = from->srgb.R, G = from->srgb.G, B = from->srgb.B;
}
SRGB_TO_CIEXYZ(R, G, B, to->X, to->Y, to->Z);
break;
case LIBCOLOUR_CIEXYY:
CONV_0(CIEXYY_TO_CIEXYZ, from, to);
break;
case LIBCOLOUR_CIEXYZ:
*to = from->ciexyz;
break;
case LIBCOLOUR_CIELAB:
CONV_0(CIELAB_TO_CIEXYZ, from, to);
break;
case LIBCOLOUR_CIELCHUV:
tmp.cieluv.model = LIBCOLOUR_CIELUV;
tmp.cieluv.white = from->cielchuv.white;
to_cieluv(from, &tmp.cieluv);
from = (const void *)&tmp.cieluv;
/* fall through */
case LIBCOLOUR_CIELUV:
CONV_N(CIELUV_TO_CIEXYZ, from, to, from->cieluv.white.X, from->cieluv.white.Y, from->cieluv.white.Z);
break;
case LIBCOLOUR_YIQ:
CONV_0(YIQ_TO_CIEXYZ, from, to);
break;
case LIBCOLOUR_YDBDR:
CONV_0(YDBDR_TO_CIEXYZ, from, to);
break;
case LIBCOLOUR_YUV:
CONV_0(YUV_TO_CIEXYZ, from, to);
break;
case LIBCOLOUR_YPBPR:
CONV_0(YPBPR_TO_CIEXYZ, from, to);
break;
case LIBCOLOUR_YCGCO:
CONV_0(YCGCO_TO_CIEXYZ, from, to);
break;
case LIBCOLOUR_CIEUVW:
tmp.cie1960ucs.model = LIBCOLOUR_CIE1960UCS;
to_cie1960ucs(from, &tmp.cie1960ucs);
from = (const void *)&tmp.cie1960ucs;
/* fall through */
case LIBCOLOUR_CIE1960UCS:
CONV_0(CIE1960UCS_TO_CIEXYZ, from, to);
break;
}
}
static void
to_cielab(const libcolour_colour_t *restrict from, libcolour_cielab_t *restrict to)
{
libcolour_ciexyz_t tmp;
switch (from->model) {
default:
tmp.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp);
from = (const void *)&tmp;
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_0(CIEXYZ_TO_CIELAB, from, to);
break;
case LIBCOLOUR_CIELAB:
*to = from->cielab;
break;
}
}
static void
to_cieluv(const libcolour_colour_t *restrict from, libcolour_cieluv_t *restrict to)
{
libcolour_ciexyz_t tmp;
libcolour_cielchuv_t tmp2;
TYPE L, C, h;
switch (from->model) {
case LIBCOLOUR_CIELCHUV:
if (to->white.X != from->cielchuv.white.X ||
to->white.Y != from->cielchuv.white.Y ||
to->white.Z != from->cielchuv.white.Z) {
tmp.model = LIBCOLOUR_CIEXYZ;
tmp2.model = LIBCOLOUR_CIELCHUV;
tmp2.white = to->white;
tmp2.one_revolution = PI2;
to_ciexyz(from, &tmp);
to_cielchuv((const libcolour_colour_t *)&tmp, &tmp2);
L = tmp2.L, C = tmp2.C, h = tmp2.h;
} else {
L = from->cielchuv.L;
C = from->cielchuv.C;
h = from->cielchuv.h * PI2 / from->cielchuv.one_revolution;
}
CIELCHUV_TO_CIELUV(L, C, h, to->L, to->u, to->v);
break;
case LIBCOLOUR_CIELUV:
if (to->white.X == from->cieluv.white.X &&
to->white.Y == from->cieluv.white.Y &&
to->white.Z == from->cieluv.white.Z) {
*to = from->cieluv;
break;
}
/* fall through */
default:
tmp.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp);
from = (const void *)&tmp;
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_N(CIEXYZ_TO_CIELUV, from, to, to->white.X, to->white.Y, to->white.Z);
break;
}
}
static void
to_cielchuv(const libcolour_colour_t *restrict from, libcolour_cielchuv_t *restrict to)
{
libcolour_cieluv_t tmp1, tmp2;
TYPE one_revolution;
switch (from->model) {
case LIBCOLOUR_CIELCHUV:
if (to->white.X == from->cielchuv.white.X &&
to->white.Y == from->cielchuv.white.Y &&
to->white.Z == from->cielchuv.white.Z) {
if (to->one_revolution == from->cielchuv.one_revolution) {
*to = from->cielchuv;
} else {
one_revolution = to->one_revolution;
*to = from->cielchuv;
to->one_revolution = one_revolution;
to->h = to->h / from->cielchuv.one_revolution * one_revolution;
}
break;
}
/* fall through */
default:
tmp1.model = LIBCOLOUR_CIELUV;
tmp1.white = to->white;
to_cieluv(from, &tmp1);
from = (const void *)&tmp1;
/* fall through */
case LIBCOLOUR_CIELUV:
if (to->white.X != from->cieluv.white.X ||
to->white.Y != from->cieluv.white.Y ||
to->white.Z != from->cieluv.white.Z) {
tmp2.model = LIBCOLOUR_CIELUV;
tmp2.white = to->white;
to_cieluv(from, &tmp2);
from = (const void *)&tmp2;
}
CONV_N(CIELUV_TO_CIELCHUV, from, to, to->one_revolution);
break;
}
}
static void
to_yiq(const libcolour_colour_t *restrict from, libcolour_yiq_t *restrict to)
{
libcolour_colour_t tmp = *from;
switch (from->model) {
case LIBCOLOUR_YIQ:
*to = from->yiq;
break;
case LIBCOLOUR_SRGB:
if (tmp.srgb.with_transfer) {
tmp.srgb.with_transfer = 0;
to_srgb(from, &tmp.srgb);
}
CONV_0(SRGB_TO_YIQ, &tmp, to);
break;
default:
tmp.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp.ciexyz);
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_0(CIEXYZ_TO_YIQ, &tmp, to);
break;
}
}
static void
to_ydbdr(const libcolour_colour_t *restrict from, libcolour_ydbdr_t *restrict to)
{
libcolour_colour_t tmp = *from;
switch (from->model) {
case LIBCOLOUR_YDBDR:
*to = from->ydbdr;
break;
case LIBCOLOUR_SRGB:
if (tmp.srgb.with_transfer) {
tmp.srgb.with_transfer = 0;
to_srgb(from, &tmp.srgb);
}
CONV_0(SRGB_TO_YDBDR, &tmp, to);
break;
case LIBCOLOUR_YUV:
CONV_0(YUV_TO_YDBDR, &tmp, to);
break;
default:
tmp.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp.ciexyz);
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_0(CIEXYZ_TO_YDBDR, &tmp, to);
break;
}
}
static void
to_yuv(const libcolour_colour_t *restrict from, libcolour_yuv_t *restrict to)
{
libcolour_colour_t tmp = *from;
switch (from->model) {
case LIBCOLOUR_YUV:
*to = from->yuv;
break;
case LIBCOLOUR_YDBDR:
CONV_0(YDBDR_TO_YUV, from, to);
break;
case LIBCOLOUR_SRGB:
if (tmp.srgb.with_transfer) {
tmp.srgb.with_transfer = 0;
to_srgb(from, &tmp.srgb);
}
CONV_0(SRGB_TO_YUV, &tmp, to);
break;
default:
tmp.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp.ciexyz);
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_0(CIEXYZ_TO_YUV, &tmp, to);
break;
}
}
static void
to_ypbpr(const libcolour_colour_t *restrict from, libcolour_ypbpr_t *restrict to)
{
libcolour_colour_t tmp = *from;
switch (from->model) {
case LIBCOLOUR_YPBPR:
*to = from->ypbpr;
break;
case LIBCOLOUR_SRGB:
if (tmp.srgb.with_transfer) {
tmp.srgb.with_transfer = 0;
to_srgb(from, &tmp.srgb);
}
CONV_0(SRGB_TO_YPBPR, &tmp, to);
break;
default:
tmp.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp.ciexyz);
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_0(CIEXYZ_TO_YPBPR, &tmp, to);
break;
}
}
static void
to_ycgco(const libcolour_colour_t *restrict from, libcolour_ycgco_t *restrict to)
{
libcolour_colour_t tmp = *from;
switch (from->model) {
case LIBCOLOUR_YCGCO:
*to = from->ycgco;
break;
case LIBCOLOUR_SRGB:
if (tmp.srgb.with_transfer) {
tmp.srgb.with_transfer = 0;
to_srgb(from, &tmp.srgb);
}
CONV_0(SRGB_TO_YCGCO, &tmp, to);
break;
default:
tmp.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp.ciexyz);
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_0(CIEXYZ_TO_YCGCO, &tmp, to);
break;
}
}
static void
to_cie1960ucs(const libcolour_colour_t *restrict from, libcolour_cie1960ucs_t *restrict to)
{
libcolour_colour_t tmp = *from;
switch (from->model) {
case LIBCOLOUR_CIE1960UCS:
*to = from->cie1960ucs;
return;
case LIBCOLOUR_CIEUVW:
CONV_N(CIEUVW_TO_CIE1960UCS, from, to, from->cieuvw.u0, from->cieuvw.v0);
return;
default:
tmp.model = LIBCOLOUR_CIEXYZ;
to_ciexyz(from, &tmp.ciexyz);
/* fall through */
case LIBCOLOUR_CIEXYZ:
CONV_0(CIEXYZ_TO_CIE1960UCS, &tmp, to);
return;
}
}
static void
to_cieuvw(const libcolour_colour_t *restrict from, libcolour_cieuvw_t *restrict to)
{
libcolour_colour_t tmp = *from;
switch (from->model) {
case LIBCOLOUR_CIEUVW:
CONV_N(CIEUVW_TO_CIEUVW, from, to, from->cieuvw.u0, from->cieuvw.v0, to->u0, to->v0);
break;
default:
tmp.model = LIBCOLOUR_CIE1960UCS;
to_cie1960ucs(from, &tmp.cie1960ucs);
/* fall through */
case LIBCOLOUR_CIE1960UCS:
CONV_N(CIE1960UCS_TO_CIEUVW, &tmp, to, to->u0, to->v0);
break;
}
}
int
libcolour_convert(const libcolour_colour_t *restrict from, libcolour_colour_t *restrict to)
{
#define X(C, T, N) 1 +
if (from->model < 0 || from->model > LIST_MODELS(X) 0) {
#undef X
errno = EINVAL;
return -1;
}
switch (to->model) {
#define X(C, T, N) case C: to_##N(from, &to->N); break;
LIST_MODELS(X)
#undef X
default:
errno = EINVAL;
return -1;
}
return 0;
}