/*
 * Copyright 2016 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: AMD
 *
 */

#include "dc.h"
#include "opp.h"
#include "color_gamma.h"

/* When calculating LUT values the first region and at least one subsequent
 * region are calculated with full precision. These defines are a demarcation
 * of where the second region starts and ends.
 * These are hardcoded values to avoid recalculating them in loops.
 */
#define PRECISE_LUT_REGION_START 224
#define PRECISE_LUT_REGION_END 239

static struct hw_x_point coordinates_x[MAX_HW_POINTS + 2];

// Hardcoded table that depends on setup_x_points_distribution and sdr_level=80
// If x points are changed, then PQ Y points will be misaligned and a new
// table would need to be generated. Or use old method that calls compute_pq.
// The last point is above PQ formula range (0-125 in normalized FP16)
// The value for the last point (128) is such that interpolation from
// 120 to 128 will give 1.0 for X = 125.0
// first couple points are 0 - HW LUT is mirrored around zero, so making first
// segment 0 to 0 will effectively clip it, and these are very low PQ codes
// min nonzero value below (216825) is a little under 12-bit PQ code 1.
static const unsigned long long pq_divider = 1000000000;
static const unsigned long long pq_numerator[MAX_HW_POINTS + 1] = {
                0, 0, 0, 0, 216825, 222815,
                228691, 234460, 240128, 245702, 251187, 256587,
                261908, 267152, 272324, 277427, 282465, 292353,
                302011, 311456, 320704, 329768, 338661, 347394,
                355975, 364415, 372721, 380900, 388959, 396903,
                404739, 412471, 420104, 435089, 449727, 464042,
                478060, 491800, 505281, 518520, 531529, 544324,
                556916, 569316, 581533, 593576, 605454, 617175,
                628745, 651459, 673643, 695337, 716578, 737395,
                757817, 777869, 797572, 816947, 836012, 854782,
                873274, 891500, 909474, 927207, 944709, 979061,
                1012601, 1045391, 1077485, 1108931, 1139770, 1170042,
                1199778, 1229011, 1257767, 1286071, 1313948, 1341416,
                1368497, 1395207, 1421563, 1473272, 1523733, 1573041,
                1621279, 1668520, 1714828, 1760262, 1804874, 1848710,
                1891814, 1934223, 1975973, 2017096, 2057622, 2097578,
                2136989, 2214269, 2289629, 2363216, 2435157, 2505564,
                2574539, 2642169, 2708536, 2773711, 2837760, 2900742,
                2962712, 3023719, 3083810, 3143025, 3201405, 3315797,
                3427246, 3535974, 3642181, 3746038, 3847700, 3947305,
                4044975, 4140823, 4234949, 4327445, 4418394, 4507872,
                4595951, 4682694, 4768161, 4935487, 5098326, 5257022,
                5411878, 5563161, 5711107, 5855928, 5997812, 6136929,
                6273436, 6407471, 6539163, 6668629, 6795976, 6921304,
                7044703, 7286050, 7520623, 7748950, 7971492, 8188655,
                8400800, 8608247, 8811286, 9010175, 9205149, 9396421,
                9584186, 9768620, 9949889, 10128140, 10303513, 10646126,
                10978648, 11301874, 11616501, 11923142, 12222340, 12514578,
                12800290, 13079866, 13353659, 13621988, 13885144, 14143394,
                14396982, 14646132, 14891052, 15368951, 15832050, 16281537,
                16718448, 17143696, 17558086, 17962337, 18357092, 18742927,
                19120364, 19489877, 19851894, 20206810, 20554983, 20896745,
                21232399, 21886492, 22519276, 23132491, 23727656, 24306104,
                24869013, 25417430, 25952292, 26474438, 26984626, 27483542,
                27971811, 28450000, 28918632, 29378184, 29829095, 30706591,
                31554022, 32373894, 33168387, 33939412, 34688657, 35417620,
                36127636, 36819903, 37495502, 38155408, 38800507, 39431607,
                40049446, 40654702, 41247996, 42400951, 43512407, 44585892,
                45624474, 46630834, 47607339, 48556082, 49478931, 50377558,
                51253467, 52108015, 52942436, 53757848, 54555277, 55335659,
                56099856, 57582802, 59009766, 60385607, 61714540, 63000246,
                64245964, 65454559, 66628579, 67770304, 68881781, 69964856,
                71021203, 72052340, 73059655, 74044414, 75007782, 76874537,
                78667536, 80393312, 82057522, 83665098, 85220372, 86727167,
                88188883, 89608552, 90988895, 92332363, 93641173, 94917336,
                96162685, 97378894, 98567496, 100867409, 103072439, 105191162,
                107230989, 109198368, 111098951, 112937723, 114719105, 116447036,
                118125045, 119756307, 121343688, 122889787, 124396968, 125867388,
                127303021, 130077030, 132731849, 135278464, 137726346, 140083726,
                142357803, 144554913, 146680670, 148740067, 150737572, 152677197,
                154562560, 156396938, 158183306, 159924378, 161622632, 164899602,
                168030318, 171028513, 173906008, 176673051, 179338593, 181910502,
                184395731, 186800463, 189130216, 191389941, 193584098, 195716719,
                197791463, 199811660, 201780351, 205574133, 209192504, 212652233,
                215967720, 219151432, 222214238, 225165676, 228014163, 230767172,
                233431363, 236012706, 238516569, 240947800, 243310793, 245609544,
                247847696, 252155270, 256257056, 260173059, 263920427, 267513978,
                270966613, 274289634, 277493001, 280585542, 283575118, 286468763,
                289272796, 291992916, 294634284, 297201585, 299699091, 304500003,
                309064541, 313416043, 317574484, 321557096, 325378855, 329052864,
                332590655, 336002433, 339297275, 342483294, 345567766, 348557252,
                351457680, 354274432, 357012407, 362269536, 367260561, 372012143,
                376547060, 380884936, 385042798, 389035522, 392876185, 396576344,
                400146265, 403595112, 406931099, 410161619, 413293351, 416332348,
                419284117, 424945627, 430313203, 435416697, 440281572, 444929733,
                449380160, 453649415, 457752035, 461700854, 465507260, 469181407,
                472732388, 476168376, 479496748, 482724188, 485856764, 491858986,
                497542280, 502939446, 508078420, 512983199, 517674549, 522170569,
                526487126, 530638214, 534636233, 538492233, 542216094, 545816693,
                549302035, 552679362, 555955249, 562226134, 568156709, 573782374,
                579133244, 584235153, 589110430, 593778512, 598256421, 602559154,
                606699989, 610690741, 614541971, 618263157, 621862836, 625348729,
                628727839, 635190643, 641295921, 647081261, 652578597, 657815287,
                662814957, 667598146, 672182825, 676584810, 680818092, 684895111,
                688826974, 692623643, 696294085, 699846401, 703287935, 709864782,
                716071394, 721947076, 727525176, 732834238, 737898880, 742740485,
                747377745, 751827095, 756103063, 760218552, 764185078, 768012958,
                771711474, 775289005, 778753144, 785368225, 791604988, 797503949,
                803099452, 808420859, 813493471, 818339244, 822977353, 827424644,
                831695997, 835804619, 839762285, 843579541, 847265867, 850829815,
                854279128, 860861356, 867061719, 872921445, 878475444, 883753534,
                888781386, 893581259, 898172578, 902572393, 906795754, 910856010,
                914765057, 918533538, 922171018, 925686119, 929086644, 935571664,
                941675560, 947439782, 952899395, 958084324, 963020312, 967729662,
                972231821, 976543852, 980680801, 984656009, 988481353, 992167459,
                995723865, 999159168, 1002565681};

// these are helpers for calculations to reduce stack usage
// do not depend on these being preserved across calls

/* Helper to optimize gamma calculation, only use in translate_from_linear, in
 * particular the dc_fixpt_pow function which is very expensive
 * The idea is that our regions for X points are exponential and currently they all use
 * the same number of points (NUM_PTS_IN_REGION) and in each region every point
 * is exactly 2x the one at the same index in the previous region. In other words
 * X[i] = 2 * X[i-NUM_PTS_IN_REGION] for i>=16
 * The other fact is that (2x)^gamma = 2^gamma * x^gamma
 * So we compute and save x^gamma for the first 16 regions, and for every next region
 * just multiply with 2^gamma which can be computed once, and save the result so we
 * recursively compute all the values.
 */

/*
 * Regamma coefficients are used for both regamma and degamma. Degamma
 * coefficients are calculated in our formula using the regamma coefficients.
 */
                                                                         /*sRGB     709     2.2 2.4 P3*/
static const int32_t numerator01[] = { 31308,   180000, 0,  0,  0};
static const int32_t numerator02[] = { 12920,   4500,   0,  0,  0};
static const int32_t numerator03[] = { 55,      99,     0,  0,  0};
static const int32_t numerator04[] = { 55,      99,     0,  0,  0};
static const int32_t numerator05[] = { 2400,    2222,   2200, 2400, 2600};

/* one-time setup of X points */
void setup_x_points_distribution(void)
{
        struct fixed31_32 region_size = dc_fixpt_from_int(128);
        int32_t segment;
        uint32_t seg_offset;
        uint32_t index;
        struct fixed31_32 increment;

        coordinates_x[MAX_HW_POINTS].x = region_size;
        coordinates_x[MAX_HW_POINTS + 1].x = region_size;

        for (segment = 6; segment > (6 - NUM_REGIONS); segment--) {
                region_size = dc_fixpt_div_int(region_size, 2);
                increment = dc_fixpt_div_int(region_size,
                                                NUM_PTS_IN_REGION);
                seg_offset = (segment + (NUM_REGIONS - 7)) * NUM_PTS_IN_REGION;
                coordinates_x[seg_offset].x = region_size;

                for (index = seg_offset + 1;
                                index < seg_offset + NUM_PTS_IN_REGION;
                                index++) {
                        coordinates_x[index].x = dc_fixpt_add
                                        (coordinates_x[index-1].x, increment);
                }
        }
}

void log_x_points_distribution(struct dal_logger *logger)
{
        int i = 0;

        if (logger != NULL) {
                LOG_GAMMA_WRITE("Log X Distribution\n");

                for (i = 0; i < MAX_HW_POINTS; i++)
                        LOG_GAMMA_WRITE("%llu\n", coordinates_x[i].x.value);
        }
}

static void compute_pq(struct fixed31_32 in_x, struct fixed31_32 *out_y)
{
        /* consts for PQ gamma formula. */
        const struct fixed31_32 m1 =
                dc_fixpt_from_fraction(159301758, 1000000000);
        const struct fixed31_32 m2 =
                dc_fixpt_from_fraction(7884375, 100000);
        const struct fixed31_32 c1 =
                dc_fixpt_from_fraction(8359375, 10000000);
        const struct fixed31_32 c2 =
                dc_fixpt_from_fraction(188515625, 10000000);
        const struct fixed31_32 c3 =
                dc_fixpt_from_fraction(186875, 10000);

        struct fixed31_32 l_pow_m1;
        struct fixed31_32 base;

        if (dc_fixpt_lt(in_x, dc_fixpt_zero))
                in_x = dc_fixpt_zero;

        l_pow_m1 = dc_fixpt_pow(in_x, m1);
        base = dc_fixpt_div(
                        dc_fixpt_add(c1,
                                        (dc_fixpt_mul(c2, l_pow_m1))),
                        dc_fixpt_add(dc_fixpt_one,
                                        (dc_fixpt_mul(c3, l_pow_m1))));
        *out_y = dc_fixpt_pow(base, m2);
}

static void compute_de_pq(struct fixed31_32 in_x, struct fixed31_32 *out_y)
{
        /* consts for dePQ gamma formula. */
        const struct fixed31_32 m1 =
                dc_fixpt_from_fraction(159301758, 1000000000);
        const struct fixed31_32 m2 =
                dc_fixpt_from_fraction(7884375, 100000);
        const struct fixed31_32 c1 =
                dc_fixpt_from_fraction(8359375, 10000000);
        const struct fixed31_32 c2 =
                dc_fixpt_from_fraction(188515625, 10000000);
        const struct fixed31_32 c3 =
                dc_fixpt_from_fraction(186875, 10000);

        struct fixed31_32 l_pow_m1;
        struct fixed31_32 base, div;
        struct fixed31_32 base2;


        if (dc_fixpt_lt(in_x, dc_fixpt_zero))
                in_x = dc_fixpt_zero;

        l_pow_m1 = dc_fixpt_pow(in_x,
                        dc_fixpt_div(dc_fixpt_one, m2));
        base = dc_fixpt_sub(l_pow_m1, c1);

        div = dc_fixpt_sub(c2, dc_fixpt_mul(c3, l_pow_m1));

        base2 = dc_fixpt_div(base, div);
        // avoid complex numbers
        if (dc_fixpt_lt(base2, dc_fixpt_zero))
                base2 = dc_fixpt_sub(dc_fixpt_zero, base2);


        *out_y = dc_fixpt_pow(base2, dc_fixpt_div(dc_fixpt_one, m1));

}


/* de gamma, non-linear to linear */
static void compute_hlg_eotf(struct fixed31_32 in_x,
                struct fixed31_32 *out_y,
                uint32_t sdr_white_level, uint32_t max_luminance_nits)
{
        struct fixed31_32 a;
        struct fixed31_32 b;
        struct fixed31_32 c;
        struct fixed31_32 threshold;
        struct fixed31_32 x;

        struct fixed31_32 scaling_factor =
                        dc_fixpt_from_fraction(max_luminance_nits, sdr_white_level);
        a = dc_fixpt_from_fraction(17883277, 100000000);
        b = dc_fixpt_from_fraction(28466892, 100000000);
        c = dc_fixpt_from_fraction(55991073, 100000000);
        threshold = dc_fixpt_from_fraction(1, 2);

        if (dc_fixpt_lt(in_x, threshold)) {
                x = dc_fixpt_mul(in_x, in_x);
                x = dc_fixpt_div_int(x, 3);
        } else {
                x = dc_fixpt_sub(in_x, c);
                x = dc_fixpt_div(x, a);
                x = dc_fixpt_exp(x);
                x = dc_fixpt_add(x, b);
                x = dc_fixpt_div_int(x, 12);
        }
        *out_y = dc_fixpt_mul(x, scaling_factor);

}

/* re gamma, linear to non-linear */
static void compute_hlg_oetf(struct fixed31_32 in_x, struct fixed31_32 *out_y,
                uint32_t sdr_white_level, uint32_t max_luminance_nits)
{
        struct fixed31_32 a;
        struct fixed31_32 b;
        struct fixed31_32 c;
        struct fixed31_32 threshold;
        struct fixed31_32 x;

        struct fixed31_32 scaling_factor =
                        dc_fixpt_from_fraction(sdr_white_level, max_luminance_nits);
        a = dc_fixpt_from_fraction(17883277, 100000000);
        b = dc_fixpt_from_fraction(28466892, 100000000);
        c = dc_fixpt_from_fraction(55991073, 100000000);
        threshold = dc_fixpt_from_fraction(1, 12);
        x = dc_fixpt_mul(in_x, scaling_factor);


        if (dc_fixpt_lt(x, threshold)) {
                x = dc_fixpt_mul(x, dc_fixpt_from_fraction(3, 1));
                *out_y = dc_fixpt_pow(x, dc_fixpt_half);
        } else {
                x = dc_fixpt_mul(x, dc_fixpt_from_fraction(12, 1));
                x = dc_fixpt_sub(x, b);
                x = dc_fixpt_log(x);
                x = dc_fixpt_mul(a, x);
                *out_y = dc_fixpt_add(x, c);
        }
}


/* one-time pre-compute PQ values - only for sdr_white_level 80 */
void precompute_pq(void)
{
        int i;
        struct fixed31_32 *pq_table = mod_color_get_table(type_pq_table);

        for (i = 0; i <= MAX_HW_POINTS; i++)
                pq_table[i] = dc_fixpt_from_fraction(pq_numerator[i], pq_divider);

        /* below is old method that uses run-time calculation in fixed pt space */
        /* pow function has problems with arguments too small */
        /*
        struct fixed31_32 x;
        const struct hw_x_point *coord_x = coordinates_x + 32;
        struct fixed31_32 scaling_factor =
                        dc_fixpt_from_fraction(80, 10000);

        for (i = 0; i < 32; i++)
                pq_table[i] = dc_fixpt_zero;

        for (i = 32; i <= MAX_HW_POINTS; i++) {
                x = dc_fixpt_mul(coord_x->x, scaling_factor);
                compute_pq(x, &pq_table[i]);
                ++coord_x;
        }
        */
}

/* one-time pre-compute dePQ values - only for max pixel value 125 FP16 */
void precompute_de_pq(void)
{
        int i;
        struct fixed31_32  y;
        uint32_t begin_index, end_index;

        struct fixed31_32 scaling_factor = dc_fixpt_from_int(125);
        struct fixed31_32 *de_pq_table = mod_color_get_table(type_de_pq_table);
        /* X points is 2^-25 to 2^7
         * De-gamma X is 2^-12 to 2^0 – we are skipping first -12-(-25) = 13 regions
         */
        begin_index = 13 * NUM_PTS_IN_REGION;
        end_index = begin_index + 12 * NUM_PTS_IN_REGION;

        for (i = 0; i <= begin_index; i++)
                de_pq_table[i] = dc_fixpt_zero;

        for (; i <= end_index; i++) {
                compute_de_pq(coordinates_x[i].x, &y);
                de_pq_table[i] = dc_fixpt_mul(y, scaling_factor);
        }

        for (; i <= MAX_HW_POINTS; i++)
                de_pq_table[i] = de_pq_table[i-1];
}
struct dividers {
        struct fixed31_32 divider1;
        struct fixed31_32 divider2;
        struct fixed31_32 divider3;
};


static bool build_coefficients(struct gamma_coefficients *coefficients,
                enum dc_transfer_func_predefined type)
{

        uint32_t i = 0;
        uint32_t index = 0;
        bool ret = true;

        if (type == TRANSFER_FUNCTION_SRGB)
                index = 0;
        else if (type == TRANSFER_FUNCTION_BT709)
                index = 1;
        else if (type == TRANSFER_FUNCTION_GAMMA22)
                index = 2;
        else if (type == TRANSFER_FUNCTION_GAMMA24)
                index = 3;
        else if (type == TRANSFER_FUNCTION_GAMMA26)
                index = 4;
        else {
                ret = false;
                goto release;
        }

        do {
                coefficients->a0[i] = dc_fixpt_from_fraction(
                        numerator01[index], 10000000);
                coefficients->a1[i] = dc_fixpt_from_fraction(
                        numerator02[index], 1000);
                coefficients->a2[i] = dc_fixpt_from_fraction(
                        numerator03[index], 1000);
                coefficients->a3[i] = dc_fixpt_from_fraction(
                        numerator04[index], 1000);
                coefficients->user_gamma[i] = dc_fixpt_from_fraction(
                        numerator05[index], 1000);

                ++i;
        } while (i != ARRAY_SIZE(coefficients->a0));
release:
        return ret;
}

static struct fixed31_32 translate_from_linear_space(
                struct translate_from_linear_space_args *args)
{
        const struct fixed31_32 one = dc_fixpt_from_int(1);

        struct fixed31_32 scratch_1, scratch_2;
        struct calculate_buffer *cal_buffer = args->cal_buffer;

        if (dc_fixpt_le(one, args->arg))
                return one;

        if (dc_fixpt_le(args->arg, dc_fixpt_neg(args->a0))) {
                scratch_1 = dc_fixpt_add(one, args->a3);
                scratch_2 = dc_fixpt_pow(
                                dc_fixpt_neg(args->arg),
                                dc_fixpt_recip(args->gamma));
                scratch_1 = dc_fixpt_mul(scratch_1, scratch_2);
                scratch_1 = dc_fixpt_sub(args->a2, scratch_1);

                return scratch_1;
        } else if (dc_fixpt_le(args->a0, args->arg)) {
                if (cal_buffer->buffer_index == 0) {
                        cal_buffer->gamma_of_2 = dc_fixpt_pow(dc_fixpt_from_int(2),
                                        dc_fixpt_recip(args->gamma));
                }
                scratch_1 = dc_fixpt_add(one, args->a3);
                /* In the first region (first 16 points) and in the
                 * region delimited by START/END we calculate with
                 * full precision to avoid error accumulation.
                 */
                if ((cal_buffer->buffer_index >= PRECISE_LUT_REGION_START &&
                        cal_buffer->buffer_index <= PRECISE_LUT_REGION_END) ||
                        (cal_buffer->buffer_index < 16))
                        scratch_2 = dc_fixpt_pow(args->arg,
                                        dc_fixpt_recip(args->gamma));
                else
                        scratch_2 = dc_fixpt_mul(cal_buffer->gamma_of_2,
                                        cal_buffer->buffer[cal_buffer->buffer_index%16]);

                if (cal_buffer->buffer_index != -1) {
                        cal_buffer->buffer[cal_buffer->buffer_index%16] = scratch_2;
                        cal_buffer->buffer_index++;
                }

                scratch_1 = dc_fixpt_mul(scratch_1, scratch_2);
                scratch_1 = dc_fixpt_sub(scratch_1, args->a2);

                return scratch_1;
        } else
                return dc_fixpt_mul(args->arg, args->a1);
}


static struct fixed31_32 translate_from_linear_space_long(
                struct translate_from_linear_space_args *args)
{
        const struct fixed31_32 one = dc_fixpt_from_int(1);

        if (dc_fixpt_lt(one, args->arg))
                return one;

        if (dc_fixpt_le(args->arg, dc_fixpt_neg(args->a0)))
                return dc_fixpt_sub(
                        args->a2,
                        dc_fixpt_mul(
                                dc_fixpt_add(
                                        one,
                                        args->a3),
                                dc_fixpt_pow(
                                        dc_fixpt_neg(args->arg),
                                        dc_fixpt_recip(args->gamma))));
        else if (dc_fixpt_le(args->a0, args->arg))
                return dc_fixpt_sub(
                        dc_fixpt_mul(
                                dc_fixpt_add(
                                        one,
                                        args->a3),
                                dc_fixpt_pow(
                                                args->arg,
                                        dc_fixpt_recip(args->gamma))),
                                        args->a2);
        else
                return dc_fixpt_mul(args->arg, args->a1);
}

static struct fixed31_32 calculate_gamma22(struct fixed31_32 arg, bool use_eetf, struct calculate_buffer *cal_buffer)
{
        struct fixed31_32 gamma = dc_fixpt_from_fraction(22, 10);
        struct translate_from_linear_space_args scratch_gamma_args;

        scratch_gamma_args.arg = arg;
        scratch_gamma_args.a0 = dc_fixpt_zero;
        scratch_gamma_args.a1 = dc_fixpt_zero;
        scratch_gamma_args.a2 = dc_fixpt_zero;
        scratch_gamma_args.a3 = dc_fixpt_zero;
        scratch_gamma_args.cal_buffer = cal_buffer;
        scratch_gamma_args.gamma = gamma;

        if (use_eetf)
                return translate_from_linear_space_long(&scratch_gamma_args);

        return translate_from_linear_space(&scratch_gamma_args);
}


static struct fixed31_32 translate_to_linear_space(
        struct fixed31_32 arg,
        struct fixed31_32 a0,
        struct fixed31_32 a1,
        struct fixed31_32 a2,
        struct fixed31_32 a3,
        struct fixed31_32 gamma)
{
        struct fixed31_32 linear;

        a0 = dc_fixpt_mul(a0, a1);
        if (dc_fixpt_le(arg, dc_fixpt_neg(a0)))

                linear = dc_fixpt_neg(
                                 dc_fixpt_pow(
                                 dc_fixpt_div(
                                 dc_fixpt_sub(a2, arg),
                                 dc_fixpt_add(
                                 dc_fixpt_one, a3)), gamma));

        else if (dc_fixpt_le(dc_fixpt_neg(a0), arg) &&
                         dc_fixpt_le(arg, a0))
                linear = dc_fixpt_div(arg, a1);
        else
                linear =  dc_fixpt_pow(
                                        dc_fixpt_div(
                                        dc_fixpt_add(a2, arg),
                                        dc_fixpt_add(
                                        dc_fixpt_one, a3)), gamma);

        return linear;
}

static struct fixed31_32 translate_from_linear_space_ex(
        struct fixed31_32 arg,
        struct gamma_coefficients *coeff,
        uint32_t color_index,
        struct calculate_buffer *cal_buffer)
{
        struct translate_from_linear_space_args scratch_gamma_args;

        scratch_gamma_args.arg = arg;
        scratch_gamma_args.a0 = coeff->a0[color_index];
        scratch_gamma_args.a1 = coeff->a1[color_index];
        scratch_gamma_args.a2 = coeff->a2[color_index];
        scratch_gamma_args.a3 = coeff->a3[color_index];
        scratch_gamma_args.gamma = coeff->user_gamma[color_index];
        scratch_gamma_args.cal_buffer = cal_buffer;

        return translate_from_linear_space(&scratch_gamma_args);
}


static inline struct fixed31_32 translate_to_linear_space_ex(
        struct fixed31_32 arg,
        struct gamma_coefficients *coeff,
        uint32_t color_index)
{
        return translate_to_linear_space(
                arg,
                coeff->a0[color_index],
                coeff->a1[color_index],
                coeff->a2[color_index],
                coeff->a3[color_index],
                coeff->user_gamma[color_index]);
}


static bool find_software_points(
        const struct dc_gamma *ramp,
        const struct gamma_pixel *axis_x,
        struct fixed31_32 hw_point,
        enum channel_name channel,
        uint32_t *index_to_start,
        uint32_t *index_left,
        uint32_t *index_right,
        enum hw_point_position *pos)
{
        const uint32_t max_number = ramp->num_entries + 3;

        struct fixed31_32 left, right;

        uint32_t i = *index_to_start;

        while (i < max_number) {
                if (channel == CHANNEL_NAME_RED) {
                        left = axis_x[i].r;

                        if (i < max_number - 1)
                                right = axis_x[i + 1].r;
                        else
                                right = axis_x[max_number - 1].r;
                } else if (channel == CHANNEL_NAME_GREEN) {
                        left = axis_x[i].g;

                        if (i < max_number - 1)
                                right = axis_x[i + 1].g;
                        else
                                right = axis_x[max_number - 1].g;
                } else {
                        left = axis_x[i].b;

                        if (i < max_number - 1)
                                right = axis_x[i + 1].b;
                        else
                                right = axis_x[max_number - 1].b;
                }

                if (dc_fixpt_le(left, hw_point) &&
                        dc_fixpt_le(hw_point, right)) {
                        *index_to_start = i;
                        *index_left = i;

                        if (i < max_number - 1)
                                *index_right = i + 1;
                        else
                                *index_right = max_number - 1;

                        *pos = HW_POINT_POSITION_MIDDLE;

                        return true;
                } else if ((i == *index_to_start) &&
                        dc_fixpt_le(hw_point, left)) {
                        *index_to_start = i;
                        *index_left = i;
                        *index_right = i;

                        *pos = HW_POINT_POSITION_LEFT;

                        return true;
                } else if ((i == max_number - 1) &&
                        dc_fixpt_le(right, hw_point)) {
                        *index_to_start = i;
                        *index_left = i;
                        *index_right = i;

                        *pos = HW_POINT_POSITION_RIGHT;

                        return true;
                }

                ++i;
        }

        return false;
}

static bool build_custom_gamma_mapping_coefficients_worker(
        const struct dc_gamma *ramp,
        struct pixel_gamma_point *coeff,
        const struct hw_x_point *coordinates_x,
        const struct gamma_pixel *axis_x,
        enum channel_name channel,
        uint32_t number_of_points)
{
        uint32_t i = 0;

        while (i <= number_of_points) {
                struct fixed31_32 coord_x;

                uint32_t index_to_start = 0;
                uint32_t index_left = 0;
                uint32_t index_right = 0;

                enum hw_point_position hw_pos;

                struct gamma_point *point;

                struct fixed31_32 left_pos;
                struct fixed31_32 right_pos;

                if (channel == CHANNEL_NAME_RED)
                        coord_x = coordinates_x[i].regamma_y_red;
                else if (channel == CHANNEL_NAME_GREEN)
                        coord_x = coordinates_x[i].regamma_y_green;
                else
                        coord_x = coordinates_x[i].regamma_y_blue;

                if (!find_software_points(
                        ramp, axis_x, coord_x, channel,
                        &index_to_start, &index_left, &index_right, &hw_pos)) {
                        BREAK_TO_DEBUGGER();
                        return false;
                }

                if (index_left >= ramp->num_entries + 3) {
                        BREAK_TO_DEBUGGER();
                        return false;
                }

                if (index_right >= ramp->num_entries + 3) {
                        BREAK_TO_DEBUGGER();
                        return false;
                }

                if (channel == CHANNEL_NAME_RED) {
                        point = &coeff[i].r;

                        left_pos = axis_x[index_left].r;
                        right_pos = axis_x[index_right].r;
                } else if (channel == CHANNEL_NAME_GREEN) {
                        point = &coeff[i].g;

                        left_pos = axis_x[index_left].g;
                        right_pos = axis_x[index_right].g;
                } else {
                        point = &coeff[i].b;

                        left_pos = axis_x[index_left].b;
                        right_pos = axis_x[index_right].b;
                }

                if (hw_pos == HW_POINT_POSITION_MIDDLE)
                        point->coeff = dc_fixpt_div(
                                dc_fixpt_sub(
                                        coord_x,
                                        left_pos),
                                dc_fixpt_sub(
                                        right_pos,
                                        left_pos));
                else if (hw_pos == HW_POINT_POSITION_LEFT)
                        point->coeff = dc_fixpt_zero;
                else if (hw_pos == HW_POINT_POSITION_RIGHT)
                        point->coeff = dc_fixpt_from_int(2);
                else {
                        BREAK_TO_DEBUGGER();
                        return false;
                }

                point->left_index = index_left;
                point->right_index = index_right;
                point->pos = hw_pos;

                ++i;
        }

        return true;
}

static struct fixed31_32 calculate_mapped_value(
        struct pwl_float_data *rgb,
        const struct pixel_gamma_point *coeff,
        enum channel_name channel,
        uint32_t max_index)
{
        const struct gamma_point *point;

        struct fixed31_32 result;

        if (channel == CHANNEL_NAME_RED)
                point = &coeff->r;
        else if (channel == CHANNEL_NAME_GREEN)
                point = &coeff->g;
        else
                point = &coeff->b;

        if ((point->left_index < 0) || (point->left_index > max_index)) {
                BREAK_TO_DEBUGGER();
                return dc_fixpt_zero;
        }

        if ((point->right_index < 0) || (point->right_index > max_index)) {
                BREAK_TO_DEBUGGER();
                return dc_fixpt_zero;
        }

        if (point->pos == HW_POINT_POSITION_MIDDLE)
                if (channel == CHANNEL_NAME_RED)
                        result = dc_fixpt_add(
                                dc_fixpt_mul(
                                        point->coeff,
                                        dc_fixpt_sub(
                                                rgb[point->right_index].r,
                                                rgb[point->left_index].r)),
                                rgb[point->left_index].r);
                else if (channel == CHANNEL_NAME_GREEN)
                        result = dc_fixpt_add(
                                dc_fixpt_mul(
                                        point->coeff,
                                        dc_fixpt_sub(
                                                rgb[point->right_index].g,
                                                rgb[point->left_index].g)),
                                rgb[point->left_index].g);
                else
                        result = dc_fixpt_add(
                                dc_fixpt_mul(
                                        point->coeff,
                                        dc_fixpt_sub(
                                                rgb[point->right_index].b,
                                                rgb[point->left_index].b)),
                                rgb[point->left_index].b);
        else if (point->pos == HW_POINT_POSITION_LEFT) {
                BREAK_TO_DEBUGGER();
                result = dc_fixpt_zero;
        } else {
                result = dc_fixpt_one;
        }

        return result;
}

static void build_pq(struct pwl_float_data_ex *rgb_regamma,
                uint32_t hw_points_num,
                const struct hw_x_point *coordinate_x,
                uint32_t sdr_white_level)
{
        uint32_t i, start_index;

        struct pwl_float_data_ex *rgb = rgb_regamma;
        const struct hw_x_point *coord_x = coordinate_x;
        struct fixed31_32 x;
        struct fixed31_32 output;
        struct fixed31_32 scaling_factor =
                        dc_fixpt_from_fraction(sdr_white_level, 10000);
        struct fixed31_32 *pq_table = mod_color_get_table(type_pq_table);

        if (!mod_color_is_table_init(type_pq_table) && sdr_white_level == 80) {
                precompute_pq();
                mod_color_set_table_init_state(type_pq_table, true);
        }

        /* TODO: start index is from segment 2^-24, skipping first segment
         * due to x values too small for power calculations
         */
        start_index = 32;
        rgb += start_index;
        coord_x += start_index;

        for (i = start_index; i <= hw_points_num; i++) {
                /* Multiply 0.008 as regamma is 0-1 and FP16 input is 0-125.
                 * FP 1.0 = 80nits
                 */
                if (sdr_white_level == 80) {
                        output = pq_table[i];
                } else {
                        x = dc_fixpt_mul(coord_x->x, scaling_factor);
                        compute_pq(x, &output);
                }

                /* should really not happen? */
                if (dc_fixpt_lt(output, dc_fixpt_zero))
                        output = dc_fixpt_zero;

                rgb->r = output;
                rgb->g = output;
                rgb->b = output;

                ++coord_x;
                ++rgb;
        }
}

static void build_de_pq(struct pwl_float_data_ex *de_pq,
                uint32_t hw_points_num,
                const struct hw_x_point *coordinate_x)
{
        uint32_t i;
        struct fixed31_32 output;
        struct fixed31_32 *de_pq_table = mod_color_get_table(type_de_pq_table);
        struct fixed31_32 scaling_factor = dc_fixpt_from_int(125);

        if (!mod_color_is_table_init(type_de_pq_table)) {
                precompute_de_pq();
                mod_color_set_table_init_state(type_de_pq_table, true);
        }


        for (i = 0; i <= hw_points_num; i++) {
                output = de_pq_table[i];
                /* should really not happen? */
                if (dc_fixpt_lt(output, dc_fixpt_zero))
                        output = dc_fixpt_zero;
                else if (dc_fixpt_lt(scaling_factor, output))
                        output = scaling_factor;
                de_pq[i].r = output;
                de_pq[i].g = output;
                de_pq[i].b = output;
        }
}

static bool build_regamma(struct pwl_float_data_ex *rgb_regamma,
                uint32_t hw_points_num,
                const struct hw_x_point *coordinate_x,
                enum dc_transfer_func_predefined type,
                struct calculate_buffer *cal_buffer)
{
        uint32_t i;
        bool ret = false;

        struct gamma_coefficients *coeff;
        struct pwl_float_data_ex *rgb = rgb_regamma;
        const struct hw_x_point *coord_x = coordinate_x;

        coeff = kvzalloc_obj(*coeff);
        if (!coeff)
                goto release;

        if (!build_coefficients(coeff, type))
                goto release;

        memset(cal_buffer->buffer, 0, NUM_PTS_IN_REGION * sizeof(struct fixed31_32));
        cal_buffer->buffer_index = 0; // see variable definition for more info

        i = 0;
        while (i <= hw_points_num) {
                /* TODO use y vs r,g,b */
                rgb->r = translate_from_linear_space_ex(
                        coord_x->x, coeff, 0, cal_buffer);
                rgb->g = rgb->r;
                rgb->b = rgb->r;
                ++coord_x;
                ++rgb;
                ++i;
        }
        cal_buffer->buffer_index = -1;
        ret = true;
release:
        kvfree(coeff);
        return ret;
}

static void hermite_spline_eetf(struct fixed31_32 input_x,
                                struct fixed31_32 max_display,
                                struct fixed31_32 min_display,
                                struct fixed31_32 max_content,
                                struct fixed31_32 *out_x)
{
        struct fixed31_32 min_lum_pq;
        struct fixed31_32 max_lum_pq;
        struct fixed31_32 max_content_pq;
        struct fixed31_32 ks;
        struct fixed31_32 E1;
        struct fixed31_32 E2;
        struct fixed31_32 E3;
        struct fixed31_32 t;
        struct fixed31_32 t2;
        struct fixed31_32 t3;
        struct fixed31_32 two;
        struct fixed31_32 three;
        struct fixed31_32 temp1;
        struct fixed31_32 temp2;
        struct fixed31_32 a = dc_fixpt_from_fraction(15, 10);
        struct fixed31_32 b = dc_fixpt_from_fraction(5, 10);
        struct fixed31_32 epsilon = dc_fixpt_from_fraction(1, 1000000); // dc_fixpt_epsilon is a bit too small

        if (dc_fixpt_eq(max_content, dc_fixpt_zero)) {
                *out_x = dc_fixpt_zero;
                return;
        }

        compute_pq(input_x, &E1);
        compute_pq(dc_fixpt_div(min_display, max_content), &min_lum_pq);
        compute_pq(dc_fixpt_div(max_display, max_content), &max_lum_pq);
        compute_pq(dc_fixpt_one, &max_content_pq); // always 1? DAL2 code is weird
        a = dc_fixpt_div(dc_fixpt_add(dc_fixpt_one, b), max_content_pq); // (1+b)/maxContent
        ks = dc_fixpt_sub(dc_fixpt_mul(a, max_lum_pq), b); // a * max_lum_pq - b

        if (dc_fixpt_lt(E1, ks))
                E2 = E1;
        else if (dc_fixpt_le(ks, E1) && dc_fixpt_le(E1, dc_fixpt_one)) {
                if (dc_fixpt_lt(epsilon, dc_fixpt_sub(dc_fixpt_one, ks)))
                        // t = (E1 - ks) / (1 - ks)
                        t = dc_fixpt_div(dc_fixpt_sub(E1, ks),
                                        dc_fixpt_sub(dc_fixpt_one, ks));
                else
                        t = dc_fixpt_zero;

                two = dc_fixpt_from_int(2);
                three = dc_fixpt_from_int(3);

                t2 = dc_fixpt_mul(t, t);
                t3 = dc_fixpt_mul(t2, t);
                temp1 = dc_fixpt_mul(two, t3);
                temp2 = dc_fixpt_mul(three, t2);

                // (2t^3 - 3t^2 + 1) * ks
                E2 = dc_fixpt_mul(ks, dc_fixpt_add(dc_fixpt_one,
                                dc_fixpt_sub(temp1, temp2)));

                // (-2t^3 + 3t^2) * max_lum_pq
                E2 = dc_fixpt_add(E2, dc_fixpt_mul(max_lum_pq,
                                dc_fixpt_sub(temp2, temp1)));

                temp1 = dc_fixpt_mul(two, t2);
                temp2 = dc_fixpt_sub(dc_fixpt_one, ks);

                // (t^3 - 2t^2 + t) * (1-ks)
                E2 = dc_fixpt_add(E2, dc_fixpt_mul(temp2,
                                dc_fixpt_add(t, dc_fixpt_sub(t3, temp1))));
        } else
                E2 = dc_fixpt_one;

        temp1 = dc_fixpt_sub(dc_fixpt_one, E2);
        temp2 = dc_fixpt_mul(temp1, temp1);
        temp2 = dc_fixpt_mul(temp2, temp2);
        // temp2 = (1-E2)^4

        E3 =  dc_fixpt_add(E2, dc_fixpt_mul(min_lum_pq, temp2));
        compute_de_pq(E3, out_x);

        *out_x = dc_fixpt_div(*out_x, dc_fixpt_div(max_display, max_content));
}

static bool build_freesync_hdr(struct pwl_float_data_ex *rgb_regamma,
                uint32_t hw_points_num,
                const struct hw_x_point *coordinate_x,
                const struct hdr_tm_params *fs_params,
                struct calculate_buffer *cal_buffer)
{
        uint32_t i;
        struct pwl_float_data_ex *rgb = rgb_regamma;
        const struct hw_x_point *coord_x = coordinate_x;
        const struct hw_x_point *prv_coord_x = coord_x;
        struct fixed31_32 scaledX = dc_fixpt_zero;
        struct fixed31_32 scaledX1 = dc_fixpt_zero;
        struct fixed31_32 max_display;
        struct fixed31_32 min_display;
        struct fixed31_32 max_content;
        struct fixed31_32 clip = dc_fixpt_one;
        struct fixed31_32 output = dc_fixpt_zero;
        bool use_eetf = false;
        bool is_clipped = false;
        struct fixed31_32 sdr_white_level;
        struct fixed31_32 coordX_diff;
        struct fixed31_32 out_dist_max;
        struct fixed31_32 bright_norm;

        if (fs_params->max_content == 0 ||
                        fs_params->max_display == 0)
                return false;

        max_display = dc_fixpt_from_int(fs_params->max_display);
        min_display = dc_fixpt_from_fraction(fs_params->min_display, 10000);
        max_content = dc_fixpt_from_int(fs_params->max_content);
        sdr_white_level = dc_fixpt_from_int(fs_params->sdr_white_level);

        if (fs_params->min_display > 1000) // cap at 0.1 at the bottom
                min_display = dc_fixpt_from_fraction(1, 10);
        if (fs_params->max_display < 100) // cap at 100 at the top
                max_display = dc_fixpt_from_int(100);

        // only max used, we don't adjust min luminance
        if (fs_params->max_content > fs_params->max_display)
                use_eetf = true;
        else
                max_content = max_display;

        if (!use_eetf)
                cal_buffer->buffer_index = 0; // see var definition for more info
        rgb += 32; // first 32 points have problems with fixed point, too small
        coord_x += 32;

        for (i = 32; i <= hw_points_num; i++) {
                if (!is_clipped) {
                        if (use_eetf) {
                                /* max content is equal 1 */
                                scaledX1 = dc_fixpt_div(coord_x->x,
                                                dc_fixpt_div(max_content, sdr_white_level));
                                hermite_spline_eetf(scaledX1, max_display, min_display,
                                                max_content, &scaledX);
                        } else
                                scaledX = dc_fixpt_div(coord_x->x,
                                                dc_fixpt_div(max_display, sdr_white_level));

                        if (dc_fixpt_lt(scaledX, clip)) {
                                if (dc_fixpt_lt(scaledX, dc_fixpt_zero))
                                        output = dc_fixpt_zero;
                                else
                                        output = calculate_gamma22(scaledX, use_eetf, cal_buffer);

                                // Ensure output respects reasonable boundaries
                                output = dc_fixpt_clamp(output, dc_fixpt_zero, dc_fixpt_one);

                                rgb->r = output;
                                rgb->g = output;
                                rgb->b = output;
                        } else {
                                /* Here clipping happens for the first time */
                                is_clipped = true;

                                /* The next few lines implement the equation
                                 * output = prev_out +
                                 * (coord_x->x - prev_coord_x->x) *
                                 * (1.0 - prev_out) /
                                 * (maxDisp/sdr_white_level - prevCoordX)
                                 *
                                 * This equation interpolates the first point
                                 * after max_display/80 so that the slope from
                                 * hw_x_before_max and hw_x_after_max is such
                                 * that we hit Y=1.0 at max_display/80.
                                 */

                                coordX_diff = dc_fixpt_sub(coord_x->x, prv_coord_x->x);
                                out_dist_max = dc_fixpt_sub(dc_fixpt_one, output);
                                bright_norm = dc_fixpt_div(max_display, sdr_white_level);

                                output = dc_fixpt_add(
                                        output, dc_fixpt_mul(
                                                coordX_diff, dc_fixpt_div(
                                                        out_dist_max,
                                                        dc_fixpt_sub(bright_norm, prv_coord_x->x)
                                                )
                                        )
                                );

                                /* Relaxing the maximum boundary to 1.07 (instead of 1.0)
                                 * because the last point in the curve must be such that
                                 * the maximum display pixel brightness interpolates to
                                 * exactly 1.0. The worst case scenario was calculated
                                 * around 1.057, so the limit of 1.07 leaves some safety
                                 * margin.
                                 */
                                output = dc_fixpt_clamp(output, dc_fixpt_zero,
                                        dc_fixpt_from_fraction(107, 100));

                                rgb->r = output;
                                rgb->g = output;
                                rgb->b = output;
                        }
                } else {
                        /* Every other clipping after the first
                         * one is dealt with here
                         */
                        rgb->r = clip;
                        rgb->g = clip;
                        rgb->b = clip;
                }

                prv_coord_x = coord_x;
                ++coord_x;
                ++rgb;
        }
        cal_buffer->buffer_index = -1;

        return true;
}

static bool build_degamma(struct pwl_float_data_ex *curve,
                uint32_t hw_points_num,
                const struct hw_x_point *coordinate_x, enum dc_transfer_func_predefined type)
{
        uint32_t i;
        struct gamma_coefficients coeff;
        uint32_t begin_index, end_index;
        bool ret = false;

        if (!build_coefficients(&coeff, type))
                goto release;

        i = 0;

        /* X points is 2^-25 to 2^7
         * De-gamma X is 2^-12 to 2^0 – we are skipping first -12-(-25) = 13 regions
         */
        begin_index = 13 * NUM_PTS_IN_REGION;
        end_index = begin_index + 12 * NUM_PTS_IN_REGION;

        while (i != begin_index) {
                curve[i].r = dc_fixpt_zero;
                curve[i].g = dc_fixpt_zero;
                curve[i].b = dc_fixpt_zero;
                i++;
        }

        while (i != end_index) {
                curve[i].r = translate_to_linear_space_ex(
                                coordinate_x[i].x, &coeff, 0);
                curve[i].g = curve[i].r;
                curve[i].b = curve[i].r;
                i++;
        }
        while (i != hw_points_num + 1) {
                curve[i].r = dc_fixpt_one;
                curve[i].g = dc_fixpt_one;
                curve[i].b = dc_fixpt_one;
                i++;
        }
        ret = true;
release:
        return ret;
}





static void build_hlg_degamma(struct pwl_float_data_ex *degamma,
                uint32_t hw_points_num,
                const struct hw_x_point *coordinate_x,
                uint32_t sdr_white_level, uint32_t max_luminance_nits)
{
        uint32_t i;

        struct pwl_float_data_ex *rgb = degamma;
        const struct hw_x_point *coord_x = coordinate_x;

        i = 0;
        // check when i == 434
        while (i != hw_points_num + 1) {
                compute_hlg_eotf(coord_x->x, &rgb->r, sdr_white_level, max_luminance_nits);
                rgb->g = rgb->r;
                rgb->b = rgb->r;
                ++coord_x;
                ++rgb;
                ++i;
        }
}


static void build_hlg_regamma(struct pwl_float_data_ex *regamma,
                uint32_t hw_points_num,
                const struct hw_x_point *coordinate_x,
                uint32_t sdr_white_level, uint32_t max_luminance_nits)
{
        uint32_t i;

        struct pwl_float_data_ex *rgb = regamma;
        const struct hw_x_point *coord_x = coordinate_x;

        i = 0;

        // when i == 471
        while (i != hw_points_num + 1) {
                compute_hlg_oetf(coord_x->x, &rgb->r, sdr_white_level, max_luminance_nits);
                rgb->g = rgb->r;
                rgb->b = rgb->r;
                ++coord_x;
                ++rgb;
                ++i;
        }
}

static void scale_gamma(struct pwl_float_data *pwl_rgb,
                const struct dc_gamma *ramp,
                struct dividers dividers)
{
        const struct fixed31_32 max_driver = dc_fixpt_from_int(0xFFFF);
        const struct fixed31_32 max_os = dc_fixpt_from_int(0xFF00);
        struct fixed31_32 scaler = max_os;
        uint32_t i;
        struct pwl_float_data *rgb = pwl_rgb;
        struct pwl_float_data *rgb_last = rgb + ramp->num_entries - 1;

        i = 0;

        do {
                if (dc_fixpt_lt(max_os, ramp->entries.red[i]) ||
                        dc_fixpt_lt(max_os, ramp->entries.green[i]) ||
                        dc_fixpt_lt(max_os, ramp->entries.blue[i])) {
                        scaler = max_driver;
                        break;
                }
                ++i;
        } while (i != ramp->num_entries);

        i = 0;

        do {
                rgb->r = dc_fixpt_div(
                        ramp->entries.red[i], scaler);
                rgb->g = dc_fixpt_div(
                        ramp->entries.green[i], scaler);
                rgb->b = dc_fixpt_div(
                        ramp->entries.blue[i], scaler);

                ++rgb;
                ++i;
        } while (i != ramp->num_entries);

        rgb->r = dc_fixpt_mul(rgb_last->r,
                        dividers.divider1);
        rgb->g = dc_fixpt_mul(rgb_last->g,
                        dividers.divider1);
        rgb->b = dc_fixpt_mul(rgb_last->b,
                        dividers.divider1);

        ++rgb;

        rgb->r = dc_fixpt_mul(rgb_last->r,
                        dividers.divider2);
        rgb->g = dc_fixpt_mul(rgb_last->g,
                        dividers.divider2);
        rgb->b = dc_fixpt_mul(rgb_last->b,
                        dividers.divider2);

        ++rgb;

        rgb->r = dc_fixpt_mul(rgb_last->r,
                        dividers.divider3);
        rgb->g = dc_fixpt_mul(rgb_last->g,
                        dividers.divider3);
        rgb->b = dc_fixpt_mul(rgb_last->b,
                        dividers.divider3);
}

static void scale_gamma_dx(struct pwl_float_data *pwl_rgb,
                const struct dc_gamma *ramp,
                struct dividers dividers)
{
        uint32_t i;
        struct fixed31_32 min = dc_fixpt_zero;
        struct fixed31_32 max = dc_fixpt_one;

        struct fixed31_32 delta = dc_fixpt_zero;
        struct fixed31_32 offset = dc_fixpt_zero;

        for (i = 0 ; i < ramp->num_entries; i++) {
                if (dc_fixpt_lt(ramp->entries.red[i], min))
                        min = ramp->entries.red[i];

                if (dc_fixpt_lt(ramp->entries.green[i], min))
                        min = ramp->entries.green[i];

                if (dc_fixpt_lt(ramp->entries.blue[i], min))
                        min = ramp->entries.blue[i];

                if (dc_fixpt_lt(max, ramp->entries.red[i]))
                        max = ramp->entries.red[i];

                if (dc_fixpt_lt(max, ramp->entries.green[i]))
                        max = ramp->entries.green[i];

                if (dc_fixpt_lt(max, ramp->entries.blue[i]))
                        max = ramp->entries.blue[i];
        }

        if (dc_fixpt_lt(min, dc_fixpt_zero))
                delta = dc_fixpt_neg(min);

        offset = dc_fixpt_add(min, max);

        for (i = 0 ; i < ramp->num_entries; i++) {
                pwl_rgb[i].r = dc_fixpt_div(
                        dc_fixpt_add(
                                ramp->entries.red[i], delta), offset);
                pwl_rgb[i].g = dc_fixpt_div(
                        dc_fixpt_add(
                                ramp->entries.green[i], delta), offset);
                pwl_rgb[i].b = dc_fixpt_div(
                        dc_fixpt_add(
                                ramp->entries.blue[i], delta), offset);

        }

        pwl_rgb[i].r =  dc_fixpt_sub(dc_fixpt_mul_int(
                                pwl_rgb[i-1].r, 2), pwl_rgb[i-2].r);
        pwl_rgb[i].g =  dc_fixpt_sub(dc_fixpt_mul_int(
                                pwl_rgb[i-1].g, 2), pwl_rgb[i-2].g);
        pwl_rgb[i].b =  dc_fixpt_sub(dc_fixpt_mul_int(
                                pwl_rgb[i-1].b, 2), pwl_rgb[i-2].b);
        ++i;
        pwl_rgb[i].r =  dc_fixpt_sub(dc_fixpt_mul_int(
                                pwl_rgb[i-1].r, 2), pwl_rgb[i-2].r);
        pwl_rgb[i].g =  dc_fixpt_sub(dc_fixpt_mul_int(
                                pwl_rgb[i-1].g, 2), pwl_rgb[i-2].g);
        pwl_rgb[i].b =  dc_fixpt_sub(dc_fixpt_mul_int(
                                pwl_rgb[i-1].b, 2), pwl_rgb[i-2].b);
}

/*
 * RS3+ color transform DDI - 1D LUT adjustment is composed with regamma here
 * Input is evenly distributed in the output color space as specified in
 * SetTimings
 *
 * Interpolation details:
 * 1D LUT has 4096 values which give curve correction in 0-1 float range
 * for evenly spaced points in 0-1 range. lut1D[index] gives correction
 * for index/4095.
 * First we find index for which:
 *      index/4095 < regamma_y < (index+1)/4095 =>
 *      index < 4095*regamma_y < index + 1
 * norm_y = 4095*regamma_y, and index is just truncating to nearest integer
 * lut1 = lut1D[index], lut2 = lut1D[index+1]
 *
 * adjustedY is then linearly interpolating regamma Y between lut1 and lut2
 *
 * Custom degamma on Linux uses the same interpolation math, so is handled here
 */
static void apply_lut_1d(
                const struct dc_gamma *ramp,
                uint32_t num_hw_points,
                struct dc_transfer_func_distributed_points *tf_pts)
{
        int i = 0;
        int color = 0;
        struct fixed31_32 *regamma_y;
        struct fixed31_32 norm_y;
        struct fixed31_32 lut1;
        struct fixed31_32 lut2;
        const int max_lut_index = 4095;
        const struct fixed31_32 penult_lut_index_f =
                        dc_fixpt_from_int(max_lut_index-1);
        const struct fixed31_32 max_lut_index_f =
                        dc_fixpt_from_int(max_lut_index);
        int32_t index = 0, index_next = 0;
        struct fixed31_32 index_f;
        struct fixed31_32 delta_lut;
        struct fixed31_32 delta_index;

        if (ramp->type != GAMMA_CS_TFM_1D && ramp->type != GAMMA_CUSTOM)
                return; // this is not expected

        for (i = 0; i < num_hw_points; i++) {
                for (color = 0; color < 3; color++) {
                        if (color == 0)
                                regamma_y = &tf_pts->red[i];
                        else if (color == 1)
                                regamma_y = &tf_pts->green[i];
                        else
                                regamma_y = &tf_pts->blue[i];

                        norm_y = dc_fixpt_mul(max_lut_index_f,
                                                   *regamma_y);
                        index = dc_fixpt_floor(norm_y);
                        index_f = dc_fixpt_from_int(index);

                        if (index < 0)
                                continue;

                        if (index <= max_lut_index)
                                index_next = (index == max_lut_index) ? index : index+1;
                        else {
                                /* Here we are dealing with the last point in the curve,
                                 * which in some cases might exceed the range given by
                                 * max_lut_index. So we interpolate the value using
                                 * max_lut_index and max_lut_index - 1.
                                 */
                                index = max_lut_index - 1;
                                index_next = max_lut_index;
                                index_f = penult_lut_index_f;
                        }

                        if (color == 0) {
                                lut1 = ramp->entries.red[index];
                                lut2 = ramp->entries.red[index_next];
                        } else if (color == 1) {
                                lut1 = ramp->entries.green[index];
                                lut2 = ramp->entries.green[index_next];
                        } else {
                                lut1 = ramp->entries.blue[index];
                                lut2 = ramp->entries.blue[index_next];
                        }

                        // we have everything now, so interpolate
                        delta_lut = dc_fixpt_sub(lut2, lut1);
                        delta_index = dc_fixpt_sub(norm_y, index_f);

                        *regamma_y = dc_fixpt_add(lut1,
                                dc_fixpt_mul(delta_index, delta_lut));
                }
        }
}

static void build_evenly_distributed_points(
        struct gamma_pixel *points,
        uint32_t numberof_points,
        struct dividers dividers)
{
        struct gamma_pixel *p = points;
        struct gamma_pixel *p_last;

        uint32_t i = 0;

        // This function should not gets called with 0 as a parameter
        ASSERT(numberof_points > 0);
        p_last = p + numberof_points - 1;

        do {
                struct fixed31_32 value = dc_fixpt_from_fraction(i,
                        numberof_points - 1);

                p->r = value;
                p->g = value;
                p->b = value;

                ++p;
                ++i;
        } while (i < numberof_points);

        p->r = dc_fixpt_div(p_last->r, dividers.divider1);
        p->g = dc_fixpt_div(p_last->g, dividers.divider1);
        p->b = dc_fixpt_div(p_last->b, dividers.divider1);

        ++p;

        p->r = dc_fixpt_div(p_last->r, dividers.divider2);
        p->g = dc_fixpt_div(p_last->g, dividers.divider2);
        p->b = dc_fixpt_div(p_last->b, dividers.divider2);

        ++p;

        p->r = dc_fixpt_div(p_last->r, dividers.divider3);
        p->g = dc_fixpt_div(p_last->g, dividers.divider3);
        p->b = dc_fixpt_div(p_last->b, dividers.divider3);
}

static inline void copy_rgb_regamma_to_coordinates_x(
                struct hw_x_point *coordinates_x,
                uint32_t hw_points_num,
                const struct pwl_float_data_ex *rgb_ex)
{
        struct hw_x_point *coords = coordinates_x;
        uint32_t i = 0;
        const struct pwl_float_data_ex *rgb_regamma = rgb_ex;

        while (i <= hw_points_num + 1) {
                coords->regamma_y_red = rgb_regamma->r;
                coords->regamma_y_green = rgb_regamma->g;
                coords->regamma_y_blue = rgb_regamma->b;

                ++coords;
                ++rgb_regamma;
                ++i;
        }
}

static bool calculate_interpolated_hardware_curve(
        const struct dc_gamma *ramp,
        struct pixel_gamma_point *coeff128,
        struct pwl_float_data *rgb_user,
        const struct hw_x_point *coordinates_x,
        const struct gamma_pixel *axis_x,
        uint32_t number_of_points,
        struct dc_transfer_func_distributed_points *tf_pts)
{

        const struct pixel_gamma_point *coeff = coeff128;
        uint32_t max_entries = 3 - 1;

        uint32_t i = 0;

        for (i = 0; i < 3; i++) {
                if (!build_custom_gamma_mapping_coefficients_worker(
                                ramp, coeff128, coordinates_x, axis_x, i,
                                number_of_points))
                        return false;
        }

        i = 0;
        max_entries += ramp->num_entries;

        /* TODO: float point case */

        while (i <= number_of_points) {
                tf_pts->red[i] = calculate_mapped_value(
                        rgb_user, coeff, CHANNEL_NAME_RED, max_entries);
                tf_pts->green[i] = calculate_mapped_value(
                        rgb_user, coeff, CHANNEL_NAME_GREEN, max_entries);
                tf_pts->blue[i] = calculate_mapped_value(
                        rgb_user, coeff, CHANNEL_NAME_BLUE, max_entries);

                ++coeff;
                ++i;
        }

        return true;
}

static void build_new_custom_resulted_curve(
        uint32_t hw_points_num,
        struct dc_transfer_func_distributed_points *tf_pts)
{
        uint32_t i = 0;

        while (i != hw_points_num + 1) {
                tf_pts->red[i] = dc_fixpt_clamp(
                        tf_pts->red[i], dc_fixpt_zero,
                        dc_fixpt_one);
                tf_pts->green[i] = dc_fixpt_clamp(
                        tf_pts->green[i], dc_fixpt_zero,
                        dc_fixpt_one);
                tf_pts->blue[i] = dc_fixpt_clamp(
                        tf_pts->blue[i], dc_fixpt_zero,
                        dc_fixpt_one);

                ++i;
        }
}

static bool map_regamma_hw_to_x_user(
        const struct dc_gamma *ramp,
        struct pixel_gamma_point *coeff128,
        struct pwl_float_data *rgb_user,
        struct hw_x_point *coords_x,
        const struct gamma_pixel *axis_x,
        const struct pwl_float_data_ex *rgb_regamma,
        uint32_t hw_points_num,
        struct dc_transfer_func_distributed_points *tf_pts,
        bool map_user_ramp,
        bool do_clamping)
{
        /* setup to spare calculated ideal regamma values */

        int i = 0;
        struct hw_x_point *coords = coords_x;
        const struct pwl_float_data_ex *regamma = rgb_regamma;

        if (ramp && map_user_ramp) {
                copy_rgb_regamma_to_coordinates_x(coords,
                                hw_points_num,
                                rgb_regamma);

                calculate_interpolated_hardware_curve(
                        ramp, coeff128, rgb_user, coords, axis_x,
                        hw_points_num, tf_pts);
        } else {
                /* just copy current rgb_regamma into  tf_pts */
                while (i <= hw_points_num) {
                        tf_pts->red[i] = regamma->r;
                        tf_pts->green[i] = regamma->g;
                        tf_pts->blue[i] = regamma->b;

                        ++regamma;
                        ++i;
                }
        }

        if (do_clamping) {
                /* this should be named differently, all it does is clamp to 0-1 */
                build_new_custom_resulted_curve(hw_points_num, tf_pts);
        }

        return true;
}

#define _EXTRA_POINTS 3

bool mod_color_calculate_degamma_params(struct dc_color_caps *dc_caps,
                struct dc_transfer_func *input_tf,
                const struct dc_gamma *ramp, bool map_user_ramp)
{
        struct dc_transfer_func_distributed_points *tf_pts = &input_tf->tf_pts;
        struct dividers dividers;
        struct pwl_float_data *rgb_user = NULL;
        struct pwl_float_data_ex *curve = NULL;
        struct gamma_pixel *axis_x = NULL;
        struct pixel_gamma_point *coeff = NULL;
        enum dc_transfer_func_predefined tf;
        uint32_t i;
        bool ret = false;

        if (input_tf->type == TF_TYPE_BYPASS)
                return false;

        /* we can use hardcoded curve for plain SRGB TF
         * If linear, it's bypass if no user ramp
         */
        if (input_tf->type == TF_TYPE_PREDEFINED) {
                if ((input_tf->tf == TRANSFER_FUNCTION_SRGB ||
                                input_tf->tf == TRANSFER_FUNCTION_LINEAR) &&
                                !map_user_ramp)
                        return true;

                if (dc_caps != NULL &&
                        dc_caps->dpp.dcn_arch == 1) {

                        if (input_tf->tf == TRANSFER_FUNCTION_PQ &&
                                        dc_caps->dpp.dgam_rom_caps.pq == 1)
                                return true;

                        if (input_tf->tf == TRANSFER_FUNCTION_GAMMA22 &&
                                        dc_caps->dpp.dgam_rom_caps.gamma2_2 == 1)
                                return true;

                        // HLG OOTF not accounted for
                        if (input_tf->tf == TRANSFER_FUNCTION_HLG &&
                                        dc_caps->dpp.dgam_rom_caps.hlg == 1)
                                return true;
                }
        }

        input_tf->type = TF_TYPE_DISTRIBUTED_POINTS;

        if (map_user_ramp && ramp && ramp->type == GAMMA_RGB_256) {
                rgb_user = kvzalloc_objs(*rgb_user,
                                         ramp->num_entries + _EXTRA_POINTS);
                if (!rgb_user)
                        goto rgb_user_alloc_fail;

                axis_x = kvzalloc_objs(*axis_x,
                                       ramp->num_entries + _EXTRA_POINTS);
                if (!axis_x)
                        goto axis_x_alloc_fail;

                dividers.divider1 = dc_fixpt_from_fraction(3, 2);
                dividers.divider2 = dc_fixpt_from_int(2);
                dividers.divider3 = dc_fixpt_from_fraction(5, 2);

                build_evenly_distributed_points(
                                axis_x,
                                ramp->num_entries,
                                dividers);

                scale_gamma(rgb_user, ramp, dividers);
        }

        curve = kvzalloc_objs(*curve, MAX_HW_POINTS + _EXTRA_POINTS);
        if (!curve)
                goto curve_alloc_fail;

        coeff = kvzalloc_objs(*coeff, MAX_HW_POINTS + _EXTRA_POINTS);
        if (!coeff)
                goto coeff_alloc_fail;

        tf = input_tf->tf;

        if (tf == TRANSFER_FUNCTION_PQ)
                build_de_pq(curve,
                                MAX_HW_POINTS,
                                coordinates_x);
        else if (tf == TRANSFER_FUNCTION_SRGB ||
                tf == TRANSFER_FUNCTION_BT709 ||
                tf == TRANSFER_FUNCTION_GAMMA22 ||
                tf == TRANSFER_FUNCTION_GAMMA24 ||
                tf == TRANSFER_FUNCTION_GAMMA26)
                build_degamma(curve,
                                MAX_HW_POINTS,
                                coordinates_x,
                                tf);
        else if (tf == TRANSFER_FUNCTION_HLG)
                build_hlg_degamma(curve,
                                MAX_HW_POINTS,
                                coordinates_x,
                                80, 1000);
        else if (tf == TRANSFER_FUNCTION_LINEAR) {
                // just copy coordinates_x into curve
                i = 0;
                while (i != MAX_HW_POINTS + 1) {
                        curve[i].r = coordinates_x[i].x;
                        curve[i].g = curve[i].r;
                        curve[i].b = curve[i].r;
                        i++;
                }
        } else
                goto invalid_tf_fail;

        tf_pts->end_exponent = 0;
        tf_pts->x_point_at_y1_red = 1;
        tf_pts->x_point_at_y1_green = 1;
        tf_pts->x_point_at_y1_blue = 1;

        if (input_tf->tf == TRANSFER_FUNCTION_PQ) {
                /* just copy current rgb_regamma into  tf_pts */
                struct pwl_float_data_ex *curvePt = curve;
                int i = 0;

                while (i <= MAX_HW_POINTS) {
                        tf_pts->red[i]   = curvePt->r;
                        tf_pts->green[i] = curvePt->g;
                        tf_pts->blue[i]  = curvePt->b;
                        ++curvePt;
                        ++i;
                }
        } else {
                // clamps to 0-1
                map_regamma_hw_to_x_user(ramp, coeff, rgb_user,
                                coordinates_x, axis_x, curve,
                                MAX_HW_POINTS, tf_pts,
                                map_user_ramp && ramp && ramp->type == GAMMA_RGB_256,
                                true);
        }



        if (ramp && ramp->type == GAMMA_CUSTOM)
                apply_lut_1d(ramp, MAX_HW_POINTS, tf_pts);

        ret = true;

invalid_tf_fail:
        kvfree(coeff);
coeff_alloc_fail:
        kvfree(curve);
curve_alloc_fail:
        kvfree(axis_x);
axis_x_alloc_fail:
        kvfree(rgb_user);
rgb_user_alloc_fail:

        return ret;
}

static bool calculate_curve(enum dc_transfer_func_predefined trans,
                                struct dc_transfer_func_distributed_points *points,
                                struct pwl_float_data_ex *rgb_regamma,
                                const struct hdr_tm_params *fs_params,
                                uint32_t sdr_ref_white_level,
                                struct calculate_buffer *cal_buffer)
{
        uint32_t i;
        bool ret = false;

        if (trans == TRANSFER_FUNCTION_UNITY ||
                trans == TRANSFER_FUNCTION_LINEAR) {
                points->end_exponent = 0;
                points->x_point_at_y1_red = 1;
                points->x_point_at_y1_green = 1;
                points->x_point_at_y1_blue = 1;

                for (i = 0; i <= MAX_HW_POINTS ; i++) {
                        rgb_regamma[i].r = coordinates_x[i].x;
                        rgb_regamma[i].g = coordinates_x[i].x;
                        rgb_regamma[i].b = coordinates_x[i].x;
                }

                ret = true;
        } else if (trans == TRANSFER_FUNCTION_PQ) {
                points->end_exponent = 7;
                points->x_point_at_y1_red = 125;
                points->x_point_at_y1_green = 125;
                points->x_point_at_y1_blue = 125;

                build_pq(rgb_regamma,
                                MAX_HW_POINTS,
                                coordinates_x,
                                sdr_ref_white_level);

                ret = true;
        } else if (trans == TRANSFER_FUNCTION_GAMMA22 &&
                        fs_params != NULL && fs_params->skip_tm == 0) {
                build_freesync_hdr(rgb_regamma,
                                MAX_HW_POINTS,
                                coordinates_x,
                                fs_params,
                                cal_buffer);

                ret = true;
        } else if (trans == TRANSFER_FUNCTION_HLG) {
                points->end_exponent = 4;
                points->x_point_at_y1_red = 12;
                points->x_point_at_y1_green = 12;
                points->x_point_at_y1_blue = 12;

                build_hlg_regamma(rgb_regamma,
                                MAX_HW_POINTS,
                                coordinates_x,
                                80, 1000);

                ret = true;
        } else {
                // trans == TRANSFER_FUNCTION_SRGB
                // trans == TRANSFER_FUNCTION_BT709
                // trans == TRANSFER_FUNCTION_GAMMA22
                // trans == TRANSFER_FUNCTION_GAMMA24
                // trans == TRANSFER_FUNCTION_GAMMA26
                points->end_exponent = 0;
                points->x_point_at_y1_red = 1;
                points->x_point_at_y1_green = 1;
                points->x_point_at_y1_blue = 1;

                build_regamma(rgb_regamma,
                                MAX_HW_POINTS,
                                coordinates_x,
                                trans,
                                cal_buffer);

                ret = true;
        }

        return ret;
}

bool mod_color_calculate_regamma_params(struct dc_transfer_func *output_tf,
                                        const struct dc_gamma *ramp,
                                        bool map_user_ramp,
                                        bool can_rom_be_used,
                                        const struct hdr_tm_params *fs_params,
                                        struct calculate_buffer *cal_buffer)
{
        struct dc_transfer_func_distributed_points *tf_pts = &output_tf->tf_pts;
        struct dividers dividers;

        struct pwl_float_data *rgb_user = NULL;
        struct pwl_float_data_ex *rgb_regamma = NULL;
        struct gamma_pixel *axis_x = NULL;
        struct pixel_gamma_point *coeff = NULL;
        enum dc_transfer_func_predefined tf;
        bool do_clamping = true;
        bool ret = false;

        if (output_tf->type == TF_TYPE_BYPASS)
                return false;

        /* we can use hardcoded curve for plain SRGB TF */
        if (output_tf->type == TF_TYPE_PREDEFINED && can_rom_be_used == true &&
                        output_tf->tf == TRANSFER_FUNCTION_SRGB) {
                if (ramp == NULL)
                        return true;
                if ((ramp->is_identity && ramp->type != GAMMA_CS_TFM_1D) ||
                    (!map_user_ramp && ramp->type == GAMMA_RGB_256))
                        return true;
        }

        output_tf->type = TF_TYPE_DISTRIBUTED_POINTS;

        if (ramp && ramp->type != GAMMA_CS_TFM_1D &&
            (map_user_ramp || ramp->type != GAMMA_RGB_256)) {
                rgb_user = kvzalloc_objs(*rgb_user,
                                         ramp->num_entries + _EXTRA_POINTS);
                if (!rgb_user)
                        goto rgb_user_alloc_fail;

                axis_x = kvzalloc_objs(*axis_x, ramp->num_entries + 3);
                if (!axis_x)
                        goto axis_x_alloc_fail;

                dividers.divider1 = dc_fixpt_from_fraction(3, 2);
                dividers.divider2 = dc_fixpt_from_int(2);
                dividers.divider3 = dc_fixpt_from_fraction(5, 2);

                build_evenly_distributed_points(
                                axis_x,
                                ramp->num_entries,
                                dividers);

                if (ramp->type == GAMMA_RGB_256 && map_user_ramp)
                        scale_gamma(rgb_user, ramp, dividers);
                else if (ramp->type == GAMMA_RGB_FLOAT_1024)
                        scale_gamma_dx(rgb_user, ramp, dividers);
        }

        rgb_regamma = kvzalloc_objs(*rgb_regamma, MAX_HW_POINTS + _EXTRA_POINTS);
        if (!rgb_regamma)
                goto rgb_regamma_alloc_fail;

        coeff = kvzalloc_objs(*coeff, MAX_HW_POINTS + _EXTRA_POINTS);
        if (!coeff)
                goto coeff_alloc_fail;

        tf = output_tf->tf;

        ret = calculate_curve(tf,
                        tf_pts,
                        rgb_regamma,
                        fs_params,
                        output_tf->sdr_ref_white_level,
                        cal_buffer);

        if (ret) {
                do_clamping = !(output_tf->tf == TRANSFER_FUNCTION_PQ) &&
                                !(output_tf->tf == TRANSFER_FUNCTION_GAMMA22 &&
                                fs_params != NULL && fs_params->skip_tm == 0);

                map_regamma_hw_to_x_user(ramp, coeff, rgb_user,
                                         coordinates_x, axis_x, rgb_regamma,
                                         MAX_HW_POINTS, tf_pts,
                                         (map_user_ramp || (ramp && ramp->type != GAMMA_RGB_256)) &&
                                         (ramp && ramp->type != GAMMA_CS_TFM_1D),
                                         do_clamping);

                if (ramp && ramp->type == GAMMA_CS_TFM_1D)
                        apply_lut_1d(ramp, MAX_HW_POINTS, tf_pts);
        }

        kvfree(coeff);
coeff_alloc_fail:
        kvfree(rgb_regamma);
rgb_regamma_alloc_fail:
        kvfree(axis_x);
axis_x_alloc_fail:
        kvfree(rgb_user);
rgb_user_alloc_fail:
        return ret;
}