A:/eclipse/mhvlib/MHV_GammaCorrect.h

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/* Copyright (c) 2011, Make, Hack, Void Inc
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of the Make, Hack, Void nor the
 *    names of its contributors may be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL MAKE, HACK, VOID BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef MHV_GAMMACORRECT_H_
#define MHV_GAMMACORRECT_H_

#include <inttypes.h>
#include <math.h>
#include <avr/pgmspace.h>

const uint8_t mhv_gammaValues[] PROGMEM = {
        0,              0,              0,              0,              0,              0,              0,              0,
        0,              0,              0,              0,              0,              0,              0,              0,
        0,              0,              0,              0,              0,              0,              1,              1,
        1,              1,              1,              1,              1,              1,              1,              1,
        1,              2,              2,              2,              2,              2,              2,              2,
        2,              3,              3,              3,              3,              3,              4,              4,
        4,              4,              4,              5,              5,              5,              5,              6,
        6,              6,              6,              7,              7,              7,              7,              8,
        8,              8,              9,              9,              9,              10,             10,             10,
        11,             11,             12,             12,             12,             13,             13,             14,
        14,             15,             15,             15,             16,             16,             17,             17,
        18,             18,             19,             19,             20,             20,             21,             22,
        22,             23,             23,             24,             25,             25,             26,             26,
        27,             28,             28,             29,             30,             30,             31,             32,
        33,             33,             34,             35,             36,             36,             37,             38,
        39,             40,             40,             41,             42,             43,             44,             45,
        46,             46,             47,             48,             49,             50,             51,             52,
        53,             54,             55,             56,             57,             58,             59,             60,
        61,             62,             63,             64,             65,             67,             68,             69,
        70,             71,             72,             73,             75,             76,             77,             78,
        80,             81,             82,             83,             85,             86,             87,             89,
        90,             91,             93,             94,             95,             97,             98,             99,
        101,    102,    104,    105,    107,    108,    110,    111,
        113,    114,    116,    117,    119,    121,    122,    124,
        125,    127,    129,    130,    132,    134,    135,    137,
        139,    141,    142,    144,    146,    148,    150,    151,
        153,    155,    157,    159,    161,    163,    165,    166,
        168,    170,    172,    174,    176,    178,    180,    182,
        184,    186,    189,    191,    193,    195,    197,    199,
        201,    204,    206,    208,    210,    212,    215,    217,
        219,    221,    224,    226,    228,    231,    233,    235,
        238,    240,    243,    245,    248,    250,    253,    255
};


uint8_t mhv_calculatedGammaCorrect(uint8_t value);

/* Gamma correct a value via a lookup table
 * This uses less program memory than calculated value, and uses less clocks
 * param        value   the value to gamma correct
 * return the gamma corrected value
 */
inline uint8_t mhv_precalculatedGammaCorrect(uint8_t value) {
        return pgm_read_byte(mhv_gammaValues + value);
}

#define MHV_PRECALCULATED_GAMMA_CORRECT mhv_precalculatedGammaCorrect

#endif /* MHV_GAMMACORRECT_H_ */