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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 20:38:23 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 20:38:23 +0000 |
commit | ff6e3c025658a5fa1affd094f220b623e7e1b24b (patch) | |
tree | 9faab72d69c92d24e349d184f5869b9796f17e0c /src/gamut_mapping.c | |
parent | Initial commit. (diff) | |
download | libplacebo-ff6e3c025658a5fa1affd094f220b623e7e1b24b.tar.xz libplacebo-ff6e3c025658a5fa1affd094f220b623e7e1b24b.zip |
Adding upstream version 6.338.2.upstream/6.338.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/gamut_mapping.c')
-rw-r--r-- | src/gamut_mapping.c | 1008 |
1 files changed, 1008 insertions, 0 deletions
diff --git a/src/gamut_mapping.c b/src/gamut_mapping.c new file mode 100644 index 0000000..e80d0a7 --- /dev/null +++ b/src/gamut_mapping.c @@ -0,0 +1,1008 @@ +/* + * This file is part of libplacebo. + * + * libplacebo is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * libplacebo is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with libplacebo. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <math.h> + +#include "common.h" +#include "pl_thread.h" + +#include <libplacebo/gamut_mapping.h> + +#define fclampf(x, lo, hi) fminf(fmaxf(x, lo), hi) +static void fix_constants(struct pl_gamut_map_constants *c) +{ + c->perceptual_deadzone = fclampf(c->perceptual_deadzone, 0.0f, 1.0f); + c->perceptual_strength = fclampf(c->perceptual_strength, 0.0f, 1.0f); + c->colorimetric_gamma = fclampf(c->colorimetric_gamma, 0.0f, 10.0f); + c->softclip_knee = fclampf(c->softclip_knee, 0.0f, 1.0f); + c->softclip_desat = fclampf(c->softclip_desat, 0.0f, 1.0f); +} + +static inline bool constants_equal(const struct pl_gamut_map_constants *a, + const struct pl_gamut_map_constants *b) +{ + pl_static_assert(sizeof(*a) % sizeof(float) == 0); + return !memcmp(a, b, sizeof(*a)); +} + +bool pl_gamut_map_params_equal(const struct pl_gamut_map_params *a, + const struct pl_gamut_map_params *b) +{ + return a->function == b->function && + a->min_luma == b->min_luma && + a->max_luma == b->max_luma && + a->lut_size_I == b->lut_size_I && + a->lut_size_C == b->lut_size_C && + a->lut_size_h == b->lut_size_h && + a->lut_stride == b->lut_stride && + constants_equal(&a->constants, &b->constants) && + pl_raw_primaries_equal(&a->input_gamut, &b->input_gamut) && + pl_raw_primaries_equal(&a->output_gamut, &b->output_gamut); +} + +#define FUN(params) (params->function ? *params->function : pl_gamut_map_clip) + +static void noop(float *lut, const struct pl_gamut_map_params *params); +bool pl_gamut_map_params_noop(const struct pl_gamut_map_params *params) +{ + if (FUN(params).map == &noop) + return true; + + struct pl_raw_primaries src = params->input_gamut, dst = params->output_gamut; + if (!pl_primaries_compatible(&dst, &src)) + return true; + + bool need_map = !pl_primaries_superset(&dst, &src); + need_map |= !pl_cie_xy_equal(&src.white, &dst.white); + if (FUN(params).bidirectional) + need_map |= !pl_raw_primaries_equal(&dst, &src); + + return !need_map; +} + +// For some minimal type safety, and code cleanliness +struct RGB { + float R, G, B; +}; + +struct IPT { + float I, P, T; +}; + +struct ICh { + float I, C, h; +}; + +static inline struct ICh ipt2ich(struct IPT c) +{ + return (struct ICh) { + .I = c.I, + .C = sqrtf(c.P * c.P + c.T * c.T), + .h = atan2f(c.T, c.P), + }; +} + +static inline struct IPT ich2ipt(struct ICh c) +{ + return (struct IPT) { + .I = c.I, + .P = c.C * cosf(c.h), + .T = c.C * sinf(c.h), + }; +} + +static const float PQ_M1 = 2610./4096 * 1./4, + PQ_M2 = 2523./4096 * 128, + PQ_C1 = 3424./4096, + PQ_C2 = 2413./4096 * 32, + PQ_C3 = 2392./4096 * 32; + +enum { PQ_LUT_SIZE = 1024 }; +static const float pq_eotf_lut[1024+1] = { + 0.0000000e+00f, 4.0422718e-09f, 1.3111372e-08f, 2.6236826e-08f, 4.3151495e-08f, 6.3746885e-08f, 8.7982383e-08f, 1.1585362e-07f, + 1.4737819e-07f, 1.8258818e-07f, 2.2152586e-07f, 2.6424098e-07f, 3.1078907e-07f, 3.6123021e-07f, 4.1562821e-07f, 4.7405001e-07f, + 5.3656521e-07f, 6.0324583e-07f, 6.7416568e-07f, 7.4940095e-07f, 8.2902897e-07f, 9.1312924e-07f, 1.0017822e-06f, 1.0950702e-06f, + 1.1930764e-06f, 1.2958861e-06f, 1.4035847e-06f, 1.5162600e-06f, 1.6340000e-06f, 1.7568948e-06f, 1.8850346e-06f, 2.0185119e-06f, + 2.1574192e-06f, 2.3018509e-06f, 2.4519029e-06f, 2.6076704e-06f, 2.7692516e-06f, 2.9367449e-06f, 3.1102509e-06f, 3.2898690e-06f, + 3.4757019e-06f, 3.6678526e-06f, 3.8664261e-06f, 4.0715262e-06f, 4.2832601e-06f, 4.5017354e-06f, 4.7270617e-06f, 4.9593473e-06f, + 5.1987040e-06f, 5.4452441e-06f, 5.6990819e-06f, 5.9603301e-06f, 6.2291055e-06f, 6.5055251e-06f, 6.7897080e-06f, 7.0817717e-06f, + 7.3818379e-06f, 7.6900283e-06f, 8.0064675e-06f, 8.3312774e-06f, 8.6645849e-06f, 9.0065169e-06f, 9.3572031e-06f, 9.7167704e-06f, + 1.0085351e-05f, 1.0463077e-05f, 1.0850082e-05f, 1.1246501e-05f, 1.1652473e-05f, 1.2068130e-05f, 1.2493614e-05f, 1.2929066e-05f, + 1.3374626e-05f, 1.3830439e-05f, 1.4296648e-05f, 1.4773401e-05f, 1.5260848e-05f, 1.5759132e-05f, 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8.6543786e-03f, 8.7399153e-03f, 8.8262362e-03f, 8.9133482e-03f, 9.0012582e-03f, 9.0899733e-03f, 9.1795005e-03f, + 9.2698470e-03f, 9.3610199e-03f, 9.4530265e-03f, 9.5458741e-03f, 9.6395701e-03f, 9.7341219e-03f, 9.8295370e-03f, 9.9258231e-03f, + 1.0022988e-02f, 1.0121039e-02f, 1.0219984e-02f, 1.0319830e-02f, 1.0420587e-02f, 1.0522261e-02f, 1.0624862e-02f, 1.0728396e-02f, + 1.0832872e-02f, 1.0938299e-02f, 1.1044684e-02f, 1.1152036e-02f, 1.1260365e-02f, 1.1369677e-02f, 1.1479982e-02f, 1.1591288e-02f, + 1.1703605e-02f, 1.1816941e-02f, 1.1931305e-02f, 1.2046706e-02f, 1.2163153e-02f, 1.2280656e-02f, 1.2399223e-02f, 1.2518864e-02f, + 1.2639596e-02f, 1.2761413e-02f, 1.2884333e-02f, 1.3008365e-02f, 1.3133519e-02f, 1.3259804e-02f, 1.3387231e-02f, 1.3515809e-02f, + 1.3645549e-02f, 1.3776461e-02f, 1.3908555e-02f, 1.4041841e-02f, 1.4176331e-02f, 1.4312034e-02f, 1.4448961e-02f, 1.4587123e-02f, + 1.4726530e-02f, 1.4867194e-02f, 1.5009126e-02f, 1.5152336e-02f, 1.5296837e-02f, 1.5442638e-02f, 1.5589753e-02f, 1.5738191e-02f, + 1.5887965e-02f, 1.6039087e-02f, 1.6191567e-02f, 1.6345419e-02f, 1.6500655e-02f, 1.6657285e-02f, 1.6815323e-02f, 1.6974781e-02f, + 1.7135672e-02f, 1.7298007e-02f, 1.7461800e-02f, 1.7627063e-02f, 1.7793810e-02f, 1.7962053e-02f, 1.8131805e-02f, 1.8303080e-02f, + 1.8475891e-02f, 1.8650252e-02f, 1.8826176e-02f, 1.9003676e-02f, 1.9182767e-02f, 1.9363463e-02f, 1.9545777e-02f, 1.9729724e-02f, + 1.9915319e-02f, 2.0102575e-02f, 2.0291507e-02f, 2.0482131e-02f, 2.0674460e-02f, 2.0868510e-02f, 2.1064296e-02f, 2.1261833e-02f, + 2.1461136e-02f, 2.1662222e-02f, 2.1865105e-02f, 2.2069802e-02f, 2.2276328e-02f, 2.2484700e-02f, 2.2694934e-02f, 2.2907045e-02f, + 2.3121064e-02f, 2.3336982e-02f, 2.3554827e-02f, 2.3774618e-02f, 2.3996370e-02f, 2.4220102e-02f, 2.4445831e-02f, 2.4673574e-02f, + 2.4903349e-02f, 2.5135174e-02f, 2.5369067e-02f, 2.5605046e-02f, 2.5843129e-02f, 2.6083336e-02f, 2.6325684e-02f, 2.6570192e-02f, + 2.6816880e-02f, 2.7065767e-02f, 2.7316872e-02f, 2.7570215e-02f, 2.7825815e-02f, 2.8083692e-02f, 2.8343867e-02f, 2.8606359e-02f, + 2.8871189e-02f, 2.9138378e-02f, 2.9407946e-02f, 2.9679914e-02f, 2.9954304e-02f, 3.0231137e-02f, 3.0510434e-02f, 3.0792217e-02f, + 3.1076508e-02f, 3.1363330e-02f, 3.1652704e-02f, 3.1944653e-02f, 3.2239199e-02f, 3.2536367e-02f, 3.2836178e-02f, 3.3138657e-02f, + 3.3443826e-02f, 3.3751710e-02f, 3.4062333e-02f, 3.4375718e-02f, 3.4691890e-02f, 3.5010874e-02f, 3.5332694e-02f, 3.5657377e-02f, + 3.5984946e-02f, 3.6315428e-02f, 3.6648848e-02f, 3.6985233e-02f, 3.7324608e-02f, 3.7667000e-02f, 3.8012436e-02f, 3.8360942e-02f, + 3.8712547e-02f, 3.9067276e-02f, 3.9425159e-02f, 3.9786223e-02f, 4.0150496e-02f, 4.0518006e-02f, 4.0888783e-02f, 4.1262855e-02f, + 4.1640274e-02f, 4.2021025e-02f, 4.2405159e-02f, 4.2792707e-02f, 4.3183699e-02f, 4.3578166e-02f, 4.3976138e-02f, 4.4377647e-02f, + 4.4782724e-02f, 4.5191401e-02f, 4.5603709e-02f, 4.6019681e-02f, 4.6439350e-02f, 4.6862749e-02f, 4.7289910e-02f, 4.7720867e-02f, + 4.8155654e-02f, 4.8594305e-02f, 4.9036854e-02f, 4.9483336e-02f, 4.9933787e-02f, 5.0388240e-02f, 5.0846733e-02f, 5.1309301e-02f, + 5.1775981e-02f, 5.2246808e-02f, 5.2721821e-02f, 5.3201056e-02f, 5.3684551e-02f, 5.4172344e-02f, 5.4664473e-02f, 5.5160978e-02f, + 5.5661897e-02f, 5.6167269e-02f, 5.6677135e-02f, 5.7191535e-02f, 5.7710508e-02f, 5.8234097e-02f, 5.8762342e-02f, 5.9295285e-02f, + 5.9832968e-02f, 6.0375433e-02f, 6.0922723e-02f, 6.1474882e-02f, 6.2031952e-02f, 6.2593979e-02f, 6.3161006e-02f, 6.3733078e-02f, + 6.4310241e-02f, 6.4892540e-02f, 6.5480021e-02f, 6.6072730e-02f, 6.6670715e-02f, 6.7274023e-02f, 6.7882702e-02f, 6.8496800e-02f, + 6.9116365e-02f, 6.9741447e-02f, 7.0372096e-02f, 7.1008361e-02f, 7.1650293e-02f, 7.2297942e-02f, 7.2951361e-02f, 7.3610602e-02f, + 7.4275756e-02f, 7.4946797e-02f, 7.5623818e-02f, 7.6306873e-02f, 7.6996016e-02f, 7.7691302e-02f, 7.8392787e-02f, 7.9100526e-02f, + 7.9814576e-02f, 8.0534993e-02f, 8.1261837e-02f, 8.1995163e-02f, 8.2735032e-02f, 8.3481501e-02f, 8.4234632e-02f, 8.4994483e-02f, + 8.5761116e-02f, 8.6534592e-02f, 8.7314974e-02f, 8.8102323e-02f, 8.8896702e-02f, 8.9698176e-02f, 9.0506809e-02f, 9.1322665e-02f, + 9.2145810e-02f, 9.2976310e-02f, 9.3814232e-02f, 9.4659643e-02f, 9.5512612e-02f, 9.6373206e-02f, 9.7241496e-02f, 9.8117550e-02f, + 9.9001441e-02f, 9.9893238e-02f, 1.0079301e-01f, 1.0170084e-01f, 1.0261679e-01f, 1.0354094e-01f, 1.0447337e-01f, 1.0541414e-01f, + 1.0636334e-01f, 1.0732104e-01f, 1.0828731e-01f, 1.0926225e-01f, 1.1024592e-01f, 1.1123841e-01f, 1.1223979e-01f, 1.1325016e-01f, + 1.1426958e-01f, 1.1529814e-01f, 1.1633594e-01f, 1.1738304e-01f, 1.1843954e-01f, 1.1950552e-01f, 1.2058107e-01f, 1.2166627e-01f, + 1.2276122e-01f, 1.2386601e-01f, 1.2498072e-01f, 1.2610544e-01f, 1.2724027e-01f, 1.2838531e-01f, 1.2954063e-01f, 1.3070635e-01f, + 1.3188262e-01f, 1.3306940e-01f, 1.3426686e-01f, 1.3547509e-01f, 1.3669420e-01f, 1.3792428e-01f, 1.3916544e-01f, 1.4041778e-01f, + 1.4168140e-01f, 1.4295640e-01f, 1.4424289e-01f, 1.4554098e-01f, 1.4685078e-01f, 1.4817238e-01f, 1.4950591e-01f, 1.5085147e-01f, + 1.5220916e-01f, 1.5357912e-01f, 1.5496144e-01f, 1.5635624e-01f, 1.5776364e-01f, 1.5918375e-01f, 1.6061670e-01f, 1.6206260e-01f, + 1.6352156e-01f, 1.6499372e-01f, 1.6647920e-01f, 1.6797811e-01f, 1.6949059e-01f, 1.7101676e-01f, 1.7255674e-01f, 1.7411067e-01f, + 1.7567867e-01f, 1.7726087e-01f, 1.7885742e-01f, 1.8046844e-01f, 1.8209406e-01f, 1.8373443e-01f, 1.8538967e-01f, 1.8705994e-01f, + 1.8874536e-01f, 1.9044608e-01f, 1.9216225e-01f, 1.9389401e-01f, 1.9564150e-01f, 1.9740486e-01f, 1.9918426e-01f, 2.0097984e-01f, + 2.0279175e-01f, 2.0462014e-01f, 2.0646517e-01f, 2.0832699e-01f, 2.1020577e-01f, 2.1210165e-01f, 2.1401481e-01f, 2.1594540e-01f, + 2.1789359e-01f, 2.1985954e-01f, 2.2184342e-01f, 2.2384540e-01f, 2.2586565e-01f, 2.2790434e-01f, 2.2996165e-01f, 2.3203774e-01f, + 2.3413293e-01f, 2.3624714e-01f, 2.3838068e-01f, 2.4053372e-01f, 2.4270646e-01f, 2.4489908e-01f, 2.4711177e-01f, 2.4934471e-01f, + 2.5159811e-01f, 2.5387214e-01f, 2.5616702e-01f, 2.5848293e-01f, 2.6082007e-01f, 2.6317866e-01f, 2.6555888e-01f, 2.6796095e-01f, + 2.7038507e-01f, 2.7283145e-01f, 2.7530031e-01f, 2.7779186e-01f, 2.8030631e-01f, 2.8284388e-01f, 2.8540479e-01f, 2.8798927e-01f, + 2.9059754e-01f, 2.9322983e-01f, 2.9588635e-01f, 2.9856736e-01f, 3.0127308e-01f, 3.0400374e-01f, 3.0675959e-01f, 3.0954086e-01f, + 3.1234780e-01f, 3.1518066e-01f, 3.1803969e-01f, 3.2092512e-01f, 3.2383723e-01f, 3.2677625e-01f, 3.2974246e-01f, 3.3273611e-01f, + 3.3575747e-01f, 3.3880680e-01f, 3.4188437e-01f, 3.4499045e-01f, 3.4812533e-01f, 3.5128926e-01f, 3.5448255e-01f, 3.5770546e-01f, + 3.6095828e-01f, 3.6424131e-01f, 3.6755483e-01f, 3.7089914e-01f, 3.7427454e-01f, 3.7768132e-01f, 3.8111979e-01f, 3.8459027e-01f, + 3.8809304e-01f, 3.9162844e-01f, 3.9519678e-01f, 3.9879837e-01f, 4.0243354e-01f, 4.0610261e-01f, 4.0980592e-01f, 4.1354380e-01f, + 4.1731681e-01f, 4.2112483e-01f, 4.2496844e-01f, 4.2884798e-01f, 4.3276381e-01f, 4.3671627e-01f, 4.4070572e-01f, 4.4473253e-01f, + 4.4879706e-01f, 4.5289968e-01f, 4.5704076e-01f, 4.6122068e-01f, 4.6543981e-01f, 4.6969854e-01f, 4.7399727e-01f, 4.7833637e-01f, + 4.8271625e-01f, 4.8713731e-01f, 4.9159995e-01f, 4.9610458e-01f, 5.0065162e-01f, 5.0524147e-01f, 5.0987457e-01f, 5.1455133e-01f, + 5.1927219e-01f, 5.2403759e-01f, 5.2884795e-01f, 5.3370373e-01f, 5.3860537e-01f, 5.4355333e-01f, 5.4854807e-01f, 5.5359004e-01f, + 5.5867972e-01f, 5.6381757e-01f, 5.6900408e-01f, 5.7423972e-01f, 5.7952499e-01f, 5.8486037e-01f, 5.9024637e-01f, 5.9568349e-01f, + 6.0117223e-01f, 6.0671311e-01f, 6.1230664e-01f, 6.1795336e-01f, 6.2365379e-01f, 6.2940847e-01f, 6.3521793e-01f, 6.4108273e-01f, + 6.4700342e-01f, 6.5298056e-01f, 6.5901471e-01f, 6.6510643e-01f, 6.7125632e-01f, 6.7746495e-01f, 6.8373290e-01f, 6.9006078e-01f, + 6.9644918e-01f, 7.0289872e-01f, 7.0941001e-01f, 7.1598366e-01f, 7.2262031e-01f, 7.2932059e-01f, 7.3608513e-01f, 7.4291460e-01f, + 7.4981006e-01f, 7.5677134e-01f, 7.6379952e-01f, 7.7089527e-01f, 7.7805929e-01f, 7.8529226e-01f, 7.9259489e-01f, 7.9996786e-01f, + 8.0741191e-01f, 8.1492774e-01f, 8.2251609e-01f, 8.3017769e-01f, 8.3791329e-01f, 8.4572364e-01f, 8.5360950e-01f, 8.6157163e-01f, + 8.6961082e-01f, 8.7772786e-01f, 8.8592352e-01f, 8.9419862e-01f, 9.0255397e-01f, 9.1099038e-01f, 9.1950869e-01f, 9.2810973e-01f, + 9.3679435e-01f, 9.4556340e-01f, 9.5441776e-01f, 9.6335829e-01f, 9.7238588e-01f, 9.8150143e-01f, 9.9070583e-01f, 1.0000000e+00f, + 1.0f, // extra padding to avoid out of bounds access +}; + +static inline float pq_eotf(float x) +{ + float idxf = fminf(fmaxf(x, 0.0f), 1.0f) * (PQ_LUT_SIZE - 1); + int ipart = floorf(idxf); + float fpart = idxf - ipart; + return PL_MIX(pq_eotf_lut[ipart], pq_eotf_lut[ipart + 1], fpart); +} + +static inline float pq_oetf(float x) +{ + x = powf(fmaxf(x, 0.0f), PQ_M1); + x = (PQ_C1 + PQ_C2 * x) / (1.0f + PQ_C3 * x); + return powf(x, PQ_M2); +} + +// Helper struct containing pre-computed cached values describing a gamut +struct gamut { + pl_matrix3x3 lms2rgb; + pl_matrix3x3 rgb2lms; + float min_luma, max_luma; // pq + float min_rgb, max_rgb; // 10k normalized + struct ICh *peak_cache; // 1-item cache for computed peaks (per hue) +}; + +struct cache { + struct ICh src_cache; + struct ICh dst_cache; +}; + +static void get_gamuts(struct gamut *dst, struct gamut *src, struct cache *cache, + const struct pl_gamut_map_params *params) +{ + const float epsilon = 1e-6; + memset(cache, 0, sizeof(*cache)); + struct gamut base = { + .min_luma = params->min_luma, + .max_luma = params->max_luma, + .min_rgb = pq_eotf(params->min_luma) - epsilon, + .max_rgb = pq_eotf(params->max_luma) + epsilon, + }; + + if (dst) { + *dst = base; + dst->lms2rgb = dst->rgb2lms = pl_ipt_rgb2lms(¶ms->output_gamut); + dst->peak_cache = &cache->dst_cache; + pl_matrix3x3_invert(&dst->lms2rgb); + } + + if (src) { + *src = base; + src->lms2rgb = src->rgb2lms = pl_ipt_rgb2lms(¶ms->input_gamut); + src->peak_cache = &cache->src_cache; + pl_matrix3x3_invert(&src->lms2rgb); + } +} + +static inline struct IPT rgb2ipt(struct RGB c, struct gamut gamut) +{ + const float L = gamut.rgb2lms.m[0][0] * c.R + + gamut.rgb2lms.m[0][1] * c.G + + gamut.rgb2lms.m[0][2] * c.B; + const float M = gamut.rgb2lms.m[1][0] * c.R + + gamut.rgb2lms.m[1][1] * c.G + + gamut.rgb2lms.m[1][2] * c.B; + const float S = gamut.rgb2lms.m[2][0] * c.R + + gamut.rgb2lms.m[2][1] * c.G + + gamut.rgb2lms.m[2][2] * c.B; + const float Lp = pq_oetf(L); + const float Mp = pq_oetf(M); + const float Sp = pq_oetf(S); + return (struct IPT) { + .I = 0.4000f * Lp + 0.4000f * Mp + 0.2000f * Sp, + .P = 4.4550f * Lp - 4.8510f * Mp + 0.3960f * Sp, + .T = 0.8056f * Lp + 0.3572f * Mp - 1.1628f * Sp, + }; +} + +static inline struct RGB ipt2rgb(struct IPT c, struct gamut gamut) +{ + const float Lp = c.I + 0.0975689f * c.P + 0.205226f * c.T; + const float Mp = c.I - 0.1138760f * c.P + 0.133217f * c.T; + const float Sp = c.I + 0.0326151f * c.P - 0.676887f * c.T; + const float L = pq_eotf(Lp); + const float M = pq_eotf(Mp); + const float S = pq_eotf(Sp); + return (struct RGB) { + .R = gamut.lms2rgb.m[0][0] * L + + gamut.lms2rgb.m[0][1] * M + + gamut.lms2rgb.m[0][2] * S, + .G = gamut.lms2rgb.m[1][0] * L + + gamut.lms2rgb.m[1][1] * M + + gamut.lms2rgb.m[1][2] * S, + .B = gamut.lms2rgb.m[2][0] * L + + gamut.lms2rgb.m[2][1] * M + + gamut.lms2rgb.m[2][2] * S, + }; +} + +static inline bool ingamut(struct IPT c, struct gamut gamut) +{ + const float Lp = c.I + 0.0975689f * c.P + 0.205226f * c.T; + const float Mp = c.I - 0.1138760f * c.P + 0.133217f * c.T; + const float Sp = c.I + 0.0326151f * c.P - 0.676887f * c.T; + if (Lp < gamut.min_luma || Lp > gamut.max_luma || + Mp < gamut.min_luma || Mp > gamut.max_luma || + Sp < gamut.min_luma || Sp > gamut.max_luma) + { + // Early exit for values outside legal LMS range + return false; + } + + const float L = pq_eotf(Lp); + const float M = pq_eotf(Mp); + const float S = pq_eotf(Sp); + struct RGB rgb = { + .R = gamut.lms2rgb.m[0][0] * L + + gamut.lms2rgb.m[0][1] * M + + gamut.lms2rgb.m[0][2] * S, + .G = gamut.lms2rgb.m[1][0] * L + + gamut.lms2rgb.m[1][1] * M + + gamut.lms2rgb.m[1][2] * S, + .B = gamut.lms2rgb.m[2][0] * L + + gamut.lms2rgb.m[2][1] * M + + gamut.lms2rgb.m[2][2] * S, + }; + return rgb.R >= gamut.min_rgb && rgb.R <= gamut.max_rgb && + rgb.G >= gamut.min_rgb && rgb.G <= gamut.max_rgb && + rgb.B >= gamut.min_rgb && rgb.B <= gamut.max_rgb; +} + +struct generate_args { + const struct pl_gamut_map_params *params; + float *out; + int start; + int count; +}; + +static PL_THREAD_VOID generate(void *priv) +{ + const struct generate_args *args = priv; + const struct pl_gamut_map_params *params = args->params; + + float *in = args->out; + const int end = args->start + args->count; + for (int h = args->start; h < end; h++) { + for (int C = 0; C < params->lut_size_C; C++) { + for (int I = 0; I < params->lut_size_I; I++) { + float Ix = (float) I / (params->lut_size_I - 1); + float Cx = (float) C / (params->lut_size_C - 1); + float hx = (float) h / (params->lut_size_h - 1); + struct IPT ipt = ich2ipt((struct ICh) { + .I = PL_MIX(params->min_luma, params->max_luma, Ix), + .C = PL_MIX(0.0f, 0.5f, Cx), + .h = PL_MIX(-M_PI, M_PI, hx), + }); + in[0] = ipt.I; + in[1] = ipt.P; + in[2] = ipt.T; + in += params->lut_stride; + } + } + } + + struct pl_gamut_map_params fixed = *params; + fix_constants(&fixed.constants); + fixed.lut_size_h = args->count; + FUN(params).map(args->out, &fixed); + PL_THREAD_RETURN(); +} + +void pl_gamut_map_generate(float *out, const struct pl_gamut_map_params *params) +{ + enum { MAX_WORKERS = 32 }; + struct generate_args args[MAX_WORKERS]; + + const int num_per_worker = PL_DIV_UP(params->lut_size_h, MAX_WORKERS); + const int num_workers = PL_DIV_UP(params->lut_size_h, num_per_worker); + for (int i = 0; i < num_workers; i++) { + const int start = i * num_per_worker; + const int count = PL_MIN(num_per_worker, params->lut_size_h - start); + args[i] = (struct generate_args) { + .params = params, + .out = out, + .start = start, + .count = count, + }; + out += count * params->lut_size_C * params->lut_size_I * params->lut_stride; + } + + pl_thread workers[MAX_WORKERS] = {0}; + for (int i = 0; i < num_workers; i++) { + if (pl_thread_create(&workers[i], generate, &args[i]) != 0) + generate(&args[i]); // fallback + } + + for (int i = 0; i < num_workers; i++) { + if (!workers[i]) + continue; + if (pl_thread_join(workers[i]) != 0) + generate(&args[i]); // fallback + } +} + +void pl_gamut_map_sample(float x[3], const struct pl_gamut_map_params *params) +{ + struct pl_gamut_map_params fixed = *params; + fix_constants(&fixed.constants); + fixed.lut_size_I = fixed.lut_size_C = fixed.lut_size_h = 1; + fixed.lut_stride = 3; + + FUN(params).map(x, &fixed); +} + +#define LUT_SIZE(p) (p->lut_size_I * p->lut_size_C * p->lut_size_h * p->lut_stride) +#define FOREACH_LUT(lut, C) \ + for (struct IPT *_i = (struct IPT *) lut, \ + *_end = (struct IPT *) (lut + LUT_SIZE(params)), \ + C; \ + _i < _end && ( C = *_i, 1 ); \ + *_i = C, _i = (struct IPT *) ((float *) _i + params->lut_stride)) + +// Something like PL_MIX(base, c, x) but follows an exponential curve, note +// that this can be used to extend 'c' outwards for x > 1 +static inline struct ICh mix_exp(struct ICh c, float x, float gamma, float base) +{ + return (struct ICh) { + .I = base + (c.I - base) * powf(x, gamma), + .C = c.C * x, + .h = c.h, + }; +} + +// Drop gamma for colors approaching black and achromatic to avoid numerical +// instabilities, and excessive brightness boosting of grain, while also +// strongly boosting gamma for values exceeding the target peak +static inline float scale_gamma(float gamma, struct ICh ich, struct ICh peak, + struct gamut gamut) +{ + const float Imin = gamut.min_luma; + const float Irel = fmaxf((ich.I - Imin) / (peak.I - Imin), 0.0f); + return gamma * powf(Irel, 3) * fminf(ich.C / peak.C, 1.0f); +} + +static const float maxDelta = 5e-5f; + +// Find gamut intersection using specified bounds +static inline struct ICh +desat_bounded(float I, float h, float Cmin, float Cmax, struct gamut gamut) +{ + if (I <= gamut.min_luma) + return (struct ICh) { .I = gamut.min_luma, .C = 0, .h = h }; + if (I >= gamut.max_luma) + return (struct ICh) { .I = gamut.max_luma, .C = 0, .h = h }; + + const float maxDI = I * maxDelta; + struct ICh res = { .I = I, .C = (Cmin + Cmax) / 2, .h = h }; + do { + if (ingamut(ich2ipt(res), gamut)) { + Cmin = res.C; + } else { + Cmax = res.C; + } + res.C = (Cmin + Cmax) / 2; + } while (Cmax - Cmin > maxDI); + + return res; +} + +// Finds maximally saturated in-gamut color (for given hue) +static inline struct ICh saturate(float hue, struct gamut gamut) +{ + if (gamut.peak_cache->I && fabsf(gamut.peak_cache->h - hue) < 1e-3) + return *gamut.peak_cache; + + static const float invphi = 0.6180339887498948f; + static const float invphi2 = 0.38196601125010515f; + + struct ICh lo = { .I = gamut.min_luma, .h = hue }; + struct ICh hi = { .I = gamut.max_luma, .h = hue }; + float de = hi.I - lo.I; + struct ICh a = { .I = lo.I + invphi2 * de }; + struct ICh b = { .I = lo.I + invphi * de }; + a = desat_bounded(a.I, hue, 0.0f, 0.5f, gamut); + b = desat_bounded(b.I, hue, 0.0f, 0.5f, gamut); + + while (de > maxDelta) { + de *= invphi; + if (a.C > b.C) { + hi = b; + b = a; + a.I = lo.I + invphi2 * de; + a = desat_bounded(a.I, hue, lo.C - maxDelta, 0.5f, gamut); + } else { + lo = a; + a = b; + b.I = lo.I + invphi * de; + b = desat_bounded(b.I, hue, hi.C - maxDelta, 0.5f, gamut); + } + } + + struct ICh peak = a.C > b.C ? a : b; + *gamut.peak_cache = peak; + return peak; +} + +// Clip a color along the exponential curve given by `gamma` +static inline struct IPT +clip_gamma(struct IPT ipt, float gamma, struct gamut gamut) +{ + if (ipt.I <= gamut.min_luma) + return (struct IPT) { .I = gamut.min_luma }; + if (ingamut(ipt, gamut)) + return ipt; + + struct ICh ich = ipt2ich(ipt); + if (!gamma) + return ich2ipt(desat_bounded(ich.I, ich.h, 0.0f, ich.C, gamut)); + + const float maxDI = fmaxf(ich.I * maxDelta, 1e-7f); + struct ICh peak = saturate(ich.h, gamut); + gamma = scale_gamma(gamma, ich, peak, gamut); + float lo = 0.0f, hi = 1.0f, x = 0.5f; + do { + struct ICh test = mix_exp(ich, x, gamma, peak.I); + if (ingamut(ich2ipt(test), gamut)) { + lo = x; + } else { + hi = x; + } + x = (lo + hi) / 2.0f; + } while (hi - lo > maxDI); + + return ich2ipt(mix_exp(ich, x, gamma, peak.I)); +} + +static float softclip(float value, float source, float target, + const struct pl_gamut_map_constants *c) +{ + if (!target) + return 0.0f; + const float peak = source / target; + const float x = fminf(value / target, peak); + const float j = c->softclip_knee; + if (x <= j || peak <= 1.0) + return value; + // Apply simple mobius function + const float a = -j*j * (peak - 1.0f) / (j*j - 2.0f * j + peak); + const float b = (j*j - 2.0f * j * peak + peak) / + fmaxf(1e-6f, peak - 1.0f); + const float scale = (b*b + 2.0f * b*j + j*j) / (b - a); + return scale * (x + a) / (x + b) * target; +} + +static int cmp_float(const void *a, const void *b) +{ + float fa = *(const float*) a; + float fb = *(const float*) b; + return PL_CMP(fa, fb); +} + +static float wrap(float h) +{ + if (h > M_PI) { + return h - 2 * M_PI; + } else if (h < -M_PI) { + return h + 2 * M_PI; + } else { + return h; + } +} + +enum { + S = 12, // number of hue shift vertices + N = S + 2, // +2 for the endpoints +}; + +// Hue-shift helper struct +struct hueshift { + float dh[N]; + float dddh[N]; + float K[N]; + float prev_hue; + float prev_shift; + struct { float hue, delta; } hueshift[N]; +}; + +static void hueshift_prepare(struct hueshift *s, struct gamut src, struct gamut dst) +{ + const float O = pq_eotf(src.min_luma), X = pq_eotf(src.max_luma); + const float M = (O + X) / 2.0f; + const struct RGB refpoints[S] = { + {X, O, O}, {O, X, O}, {O, O, X}, + {O, X, X}, {X, O, X}, {X, X, O}, + {O, X, M}, {X, O, M}, {X, M, O}, + {O, M, X}, {M, O, X}, {M, X, O}, + }; + + memset(s, 0, sizeof(*s)); + for (int i = 0; i < S; i++) { + struct ICh ich_src = ipt2ich(rgb2ipt(refpoints[i], src)); + struct ICh ich_dst = ipt2ich(rgb2ipt(refpoints[i], dst)); + const float delta = wrap(ich_dst.h - ich_src.h); + s->hueshift[i+1].hue = ich_src.h; + s->hueshift[i+1].delta = delta; + } + + // Sort and wrap endpoints + qsort(s->hueshift + 1, S, sizeof(*s->hueshift), cmp_float); + s->hueshift[0] = s->hueshift[S]; + s->hueshift[S+1] = s->hueshift[1]; + s->hueshift[0].hue -= 2 * M_PI; + s->hueshift[S+1].hue += 2 * M_PI; + + // Construction of cubic spline coefficients + float tmp[N][N] = {0}; + for (int i = N - 1; i > 0; i--) { + s->dh[i-1] = s->hueshift[i].hue - s->hueshift[i-1].hue; + s->dddh[i] = (s->hueshift[i].delta - s->hueshift[i-1].delta) / s->dh[i-1]; + } + for (int i = 1; i < N - 1; i++) { + tmp[i][i] = 2 * (s->dh[i-1] + s->dh[i]); + if (i != 1) + tmp[i][i-1] = tmp[i-1][i] = s->dh[i-1]; + tmp[i][N-1] = 6 * (s->dddh[i+1] - s->dddh[i]); + } + for (int i = 1; i < N - 2; i++) { + const float q = (tmp[i+1][i] / tmp[i][i]); + for (int j = 1; j <= N - 1; j++) + tmp[i+1][j] -= q * tmp[i][j]; + } + for (int i = N - 2; i > 0; i--) { + float sum = 0.0f; + for (int j = i; j <= N - 2; j++) + sum += tmp[i][j] * s->K[j]; + s->K[i] = (tmp[i][N-1] - sum) / tmp[i][i]; + } + + s->prev_hue = -10.0f; +} + +static struct ICh hueshift_apply(struct hueshift *s, struct ICh ich) +{ + if (fabsf(ich.h - s->prev_hue) < 1e-6f) + goto done; + + // Determine perceptual hue shift delta by interpolation of refpoints + for (int i = 0; i < N - 1; i++) { + if (s->hueshift[i+1].hue > ich.h) { + pl_assert(s->hueshift[i].hue <= ich.h); + float a = (s->K[i+1] - s->K[i]) / (6 * s->dh[i]); + float b = s->K[i] / 2; + float c = s->dddh[i+1] - (2 * s->dh[i] * s->K[i] + s->K[i+1] * s->dh[i]) / 6; + float d = s->hueshift[i].delta; + float x = ich.h - s->hueshift[i].hue; + float delta = ((a * x + b) * x + c) * x + d; + s->prev_shift = ich.h + delta; + s->prev_hue = ich.h; + break; + } + } + +done: + return (struct ICh) { + .I = ich.I, + .C = ich.C, + .h = s->prev_shift, + }; +} + +static void perceptual(float *lut, const struct pl_gamut_map_params *params) +{ + const struct pl_gamut_map_constants *c = ¶ms->constants; + struct cache cache; + struct gamut dst, src; + get_gamuts(&dst, &src, &cache, params); + + FOREACH_LUT(lut, ipt) { + struct ICh ich = ipt2ich(ipt); + struct ICh src_peak = saturate(ich.h, src); + struct ICh dst_peak = saturate(ich.h, dst); + struct IPT mapped = rgb2ipt(ipt2rgb(ipt, src), dst); + + // Protect in gamut region + const float maxC = fmaxf(src_peak.C, dst_peak.C); + float k = pl_smoothstep(c->perceptual_deadzone, 1.0f, ich.C / maxC); + k *= c->perceptual_strength; + ipt.I = PL_MIX(ipt.I, mapped.I, k); + ipt.P = PL_MIX(ipt.P, mapped.P, k); + ipt.T = PL_MIX(ipt.T, mapped.T, k); + + struct RGB rgb = ipt2rgb(ipt, dst); + const float maxRGB = fmaxf(rgb.R, fmaxf(rgb.G, rgb.B)); + rgb.R = fmaxf(softclip(rgb.R, maxRGB, dst.max_rgb, c), dst.min_rgb); + rgb.G = fmaxf(softclip(rgb.G, maxRGB, dst.max_rgb, c), dst.min_rgb); + rgb.B = fmaxf(softclip(rgb.B, maxRGB, dst.max_rgb, c), dst.min_rgb); + ipt = rgb2ipt(rgb, dst); + } +} + +const struct pl_gamut_map_function pl_gamut_map_perceptual = { + .name = "perceptual", + .description = "Perceptual mapping", + .bidirectional = true, + .map = perceptual, +}; + +static void softclip_map(float *lut, const struct pl_gamut_map_params *params) +{ + const struct pl_gamut_map_constants *c = ¶ms->constants; + + // Separate cache after hueshift, because this invalidates previous cache + struct cache cache_pre, cache_post; + struct gamut dst_pre, src_pre, src_post, dst_post; + struct hueshift hueshift; + get_gamuts(&dst_pre, &src_pre, &cache_pre, params); + get_gamuts(&dst_post, &src_post, &cache_post, params); + hueshift_prepare(&hueshift, src_pre, dst_pre); + + FOREACH_LUT(lut, ipt) { + struct gamut src = src_pre; + struct gamut dst = dst_pre; + + if (ipt.I <= dst.min_luma) { + ipt.P = ipt.T = 0.0f; + continue; + } + + struct ICh ich = ipt2ich(ipt); + if (ich.C <= 1e-2f) + continue; // Fast path for achromatic colors + + float margin = 1.0f; + struct ICh shifted = hueshift_apply(&hueshift, ich); + if (fabsf(shifted.h - ich.h) >= 1e-3f) { + struct ICh src_border = desat_bounded(ich.I, ich.h, 0.0f, 0.5f, src); + struct ICh dst_border = desat_bounded(ich.I, ich.h, 0.0f, 0.5f, dst); + const float k = pl_smoothstep(dst_border.C * c->softclip_knee, + src_border.C, ich.C); + ich.h = PL_MIX(ich.h, shifted.h, k); + src = src_post; + dst = dst_post; + + // Expand/contract chromaticity margin to correspond to the altered + // size of the hue leaf after applying the hue delta + struct ICh shift_border = desat_bounded(ich.I, ich.h, 0.0f, 0.5f, src); + margin *= fmaxf(1.0f, src_border.C / shift_border.C); + } + + // Determine intersections with source and target gamuts, and + // apply softclip to the chromaticity + struct ICh source = saturate(ich.h, src); + struct ICh target = saturate(ich.h, dst); + struct ICh border = desat_bounded(ich.I, ich.h, 0.0f, target.C, dst); + const float chromaticity = PL_MIX(target.C, border.C, c->softclip_desat); + ich.C = softclip(ich.C, margin * source.C, chromaticity, c); + + // Soft-clip the resulting RGB color. This will generally distort + // hues slightly, but hopefully in an aesthetically pleasing way. + struct ICh saturated = { ich.I, chromaticity, ich.h }; + struct RGB peak = ipt2rgb(ich2ipt(saturated), dst); + struct RGB rgb = ipt2rgb(ich2ipt(ich), dst); + rgb.R = fmaxf(softclip(rgb.R, peak.R, dst.max_rgb, c), dst.min_rgb); + rgb.G = fmaxf(softclip(rgb.G, peak.G, dst.max_rgb, c), dst.min_rgb); + rgb.B = fmaxf(softclip(rgb.B, peak.B, dst.max_rgb, c), dst.min_rgb); + ipt = rgb2ipt(rgb, dst); + } +} + +const struct pl_gamut_map_function pl_gamut_map_softclip = { + .name = "softclip", + .description = "Soft clipping", + .map = softclip_map, +}; + +static void relative(float *lut, const struct pl_gamut_map_params *params) +{ + const struct pl_gamut_map_constants *c = ¶ms->constants; + struct cache cache; + struct gamut dst; + get_gamuts(&dst, NULL, &cache, params); + + FOREACH_LUT(lut, ipt) + ipt = clip_gamma(ipt, c->colorimetric_gamma, dst); +} + +const struct pl_gamut_map_function pl_gamut_map_relative = { + .name = "relative", + .description = "Colorimetric clip", + .map = relative, +}; + +static void desaturate(float *lut, const struct pl_gamut_map_params *params) +{ + struct cache cache; + struct gamut dst; + get_gamuts(&dst, NULL, &cache, params); + + FOREACH_LUT(lut, ipt) + ipt = clip_gamma(ipt, 0.0f, dst); +} + +const struct pl_gamut_map_function pl_gamut_map_desaturate = { + .name = "desaturate", + .description = "Desaturating clip", + .map = desaturate, +}; + +static void saturation(float *lut, const struct pl_gamut_map_params *params) +{ + struct cache cache; + struct gamut dst, src; + get_gamuts(&dst, &src, &cache, params); + + FOREACH_LUT(lut, ipt) + ipt = rgb2ipt(ipt2rgb(ipt, src), dst); +} + +const struct pl_gamut_map_function pl_gamut_map_saturation = { + .name = "saturation", + .description = "Saturation mapping", + .bidirectional = true, + .map = saturation, +}; + +static void absolute(float *lut, const struct pl_gamut_map_params *params) +{ + const struct pl_gamut_map_constants *c = ¶ms->constants; + struct cache cache; + struct gamut dst; + get_gamuts(&dst, NULL, &cache, params); + pl_matrix3x3 m = pl_get_adaptation_matrix(params->output_gamut.white, + params->input_gamut.white); + + FOREACH_LUT(lut, ipt) { + struct RGB rgb = ipt2rgb(ipt, dst); + pl_matrix3x3_apply(&m, (float *) &rgb); + ipt = rgb2ipt(rgb, dst); + ipt = clip_gamma(ipt, c->colorimetric_gamma, dst); + } +} + +const struct pl_gamut_map_function pl_gamut_map_absolute = { + .name = "absolute", + .description = "Absolute colorimetric clip", + .map = absolute, +}; + +static void highlight(float *lut, const struct pl_gamut_map_params *params) +{ + struct cache cache; + struct gamut dst; + get_gamuts(&dst, NULL, &cache, params); + + FOREACH_LUT(lut, ipt) { + if (!ingamut(ipt, dst)) { + ipt.I = fminf(ipt.I + 0.1f, 1.0f); + ipt.P = fclampf(-1.2f * ipt.P, -0.5f, 0.5f); + ipt.T = fclampf(-1.2f * ipt.T, -0.5f, 0.5f); + } + } +} + +const struct pl_gamut_map_function pl_gamut_map_highlight = { + .name = "highlight", + .description = "Highlight out-of-gamut pixels", + .map = highlight, +}; + +static void linear(float *lut, const struct pl_gamut_map_params *params) +{ + struct cache cache; + struct gamut dst, src; + get_gamuts(&dst, &src, &cache, params); + + float gain = 1.0f; + for (float hue = -M_PI; hue < M_PI; hue += 0.1f) + gain = fminf(gain, saturate(hue, dst).C / saturate(hue, src).C); + + FOREACH_LUT(lut, ipt) { + struct ICh ich = ipt2ich(ipt); + ich.C *= gain; + ipt = ich2ipt(ich); + } +} + +const struct pl_gamut_map_function pl_gamut_map_linear = { + .name = "linear", + .description = "Linear desaturate", + .map = linear, +}; + +static void darken(float *lut, const struct pl_gamut_map_params *params) +{ + const struct pl_gamut_map_constants *c = ¶ms->constants; + struct cache cache; + struct gamut dst, src; + get_gamuts(&dst, &src, &cache, params); + + static const struct RGB points[6] = { + {1, 0, 0}, {0, 1, 0}, {0, 0, 1}, + {0, 1, 1}, {1, 0, 1}, {1, 1, 0}, + }; + + float gain = 1.0f; + for (int i = 0; i < PL_ARRAY_SIZE(points); i++) { + const struct RGB p = ipt2rgb(rgb2ipt(points[i], src), dst); + const float maxRGB = PL_MAX3(p.R, p.G, p.B); + gain = fminf(gain, 1.0 / maxRGB); + } + + FOREACH_LUT(lut, ipt) { + struct RGB rgb = ipt2rgb(ipt, dst); + rgb.R *= gain; + rgb.G *= gain; + rgb.B *= gain; + ipt = rgb2ipt(rgb, dst); + ipt = clip_gamma(ipt, c->colorimetric_gamma, dst); + } +} + +const struct pl_gamut_map_function pl_gamut_map_darken = { + .name = "darken", + .description = "Darken and clip", + .map = darken, +}; + +static void noop(float *lut, const struct pl_gamut_map_params *params) +{ + return; +} + +const struct pl_gamut_map_function pl_gamut_map_clip = { + .name = "clip", + .description = "No gamut mapping (hard clip)", + .map = noop, +}; + +const struct pl_gamut_map_function * const pl_gamut_map_functions[] = { + &pl_gamut_map_clip, + &pl_gamut_map_perceptual, + &pl_gamut_map_softclip, + &pl_gamut_map_relative, + &pl_gamut_map_saturation, + &pl_gamut_map_absolute, + &pl_gamut_map_desaturate, + &pl_gamut_map_darken, + &pl_gamut_map_highlight, + &pl_gamut_map_linear, + NULL +}; + +const int pl_num_gamut_map_functions = PL_ARRAY_SIZE(pl_gamut_map_functions) - 1; + +const struct pl_gamut_map_function *pl_find_gamut_map_function(const char *name) +{ + for (int i = 0; i < pl_num_gamut_map_functions; i++) { + if (strcmp(name, pl_gamut_map_functions[i]->name) == 0) + return pl_gamut_map_functions[i]; + } + + return NULL; +} |