/*

 * copyright (c) 2005 Michael Niedermayer <michaelni@gmx.at>

 *

 * This file is part of Libav.

 *

 * Libav 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.

 *

 * Libav 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 Libav; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#ifndef AVUTIL_MATHEMATICS_H

#define AVUTIL_MATHEMATICS_H

#include <stdint.h>

#include <math.h>

#include "attributes.h"

#include "rational.h"

#include "intfloat.h"

#ifndef M_LOG2_10

#define M_LOG2_10      3.32192809488736234787  /* log_2 10 */

#endif

#ifndef M_PHI

#define M_PHI          1.61803398874989484820   /* phi / golden ratio */

#endif

#ifndef NAN

#define NAN            av_int2float(0x7fc00000)

#endif

#ifndef INFINITY

#define INFINITY       av_int2float(0x7f800000)

#endif

/**

 * @addtogroup lavu_math

 * @{

 */

enum AVRounding {

    AV_ROUND_ZERO     = 0, ///< Round toward zero.

    AV_ROUND_INF      = 1, ///< Round away from zero.

    AV_ROUND_DOWN     = 2, ///< Round toward -infinity.

    AV_ROUND_UP       = 3, ///< Round toward +infinity.

    AV_ROUND_NEAR_INF = 5, ///< Round to nearest and halfway cases away from zero.

};

/**

 * Return the greatest common divisor of a and b.

 * If both a and b are 0 or either or both are <0 then behavior is

 * undefined.

 */

int64_t av_const av_gcd(int64_t a, int64_t b);

/**

 * Rescale a 64-bit integer with rounding to nearest.

 * A simple a*b/c isn't possible as it can overflow.

 */

int64_t av_rescale(int64_t a, int64_t b, int64_t c) av_const;

/**

 * Rescale a 64-bit integer with specified rounding.

 * A simple a*b/c isn't possible as it can overflow.

 */

int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding) av_const;

/**

 * Rescale a 64-bit integer by 2 rational numbers.

 */

int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq) av_const;

/**

 * Rescale a 64-bit integer by 2 rational numbers with specified rounding.

 */

int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq,

                         enum AVRounding) av_const;

/**

 * Compare 2 timestamps each in its own timebases.

 * The result of the function is undefined if one of the timestamps

 * is outside the int64_t range when represented in the others timebase.

 * @return -1 if ts_a is before ts_b, 1 if ts_a is after ts_b or 0 if they represent the same position

 */

int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b);

/**

 * Compare 2 integers modulo mod.

 * That is we compare integers a and b for which only the least

 * significant log2(mod) bits are known.

 *

 * @param mod must be a power of 2

 * @return a negative value if a is smaller than b

 *         a positive value if a is greater than b

 *         0                if a equals          b

 */

int64_t av_compare_mod(uint64_t a, uint64_t b, uint64_t mod);

/**

 * @}

 */

#endif /* AVUTIL_MATHEMATICS_H */