openjpeg/src/lib/openjp2/opj_intmath.h

/*
 * Copyright (c) 2002-2007, Communications and Remote Sensing Laboratory, Universite catholique de Louvain (UCL), Belgium
 * Copyright (c) 2002-2007, Professor Benoit Macq
 * Copyright (c) 2001-2003, David Janssens
 * Copyright (c) 2002-2003, Yannick Verschueren
 * Copyright (c) 2003-2007, Francois-Olivier Devaux and Antonin Descampe
 * Copyright (c) 2005, Herve Drolon, FreeImage Team
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * 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 THE COPYRIGHT OWNER OR CONTRIBUTORS 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 __INT_H
#define __INT_H
/**
@file opj_intmath.h
@brief Implementation of operations on integers (INT)

The functions in OPJ_INTMATH.H have for goal to realize operations on integers.
*/

/** @defgroup OPJ_INTMATH OPJ_INTMATH - Implementation of operations on integers */
/*@{*/

/** @name Exported functions (see also openjpeg.h) */
/*@{*/
/* ----------------------------------------------------------------------- */
/**
Get the minimum of two integers
@return Returns a if a < b else b
*/
static INLINE OPJ_INT32 opj_int_min(OPJ_INT32 a, OPJ_INT32 b) {
	return a < b ? a : b;
}

/**
Get the minimum of two integers
@return Returns a if a < b else b
*/
static INLINE OPJ_UINT32 opj_uint_min(OPJ_UINT32 a, OPJ_UINT32 b) {
	return a < b ? a : b;
}

/**
Get the maximum of two integers
@return Returns a if a > b else b
*/
static INLINE OPJ_INT32 opj_int_max(OPJ_INT32 a, OPJ_INT32 b) {
	return (a > b) ? a : b;
}

/**
Get the maximum of two integers
@return Returns a if a > b else b
*/
static INLINE OPJ_UINT32 opj_uint_max(OPJ_UINT32  a, OPJ_UINT32  b) {
	return (a > b) ? a : b;
}

/**
Clamp an integer inside an interval
@return
<ul>
<li>Returns a if (min < a < max)
<li>Returns max if (a > max)
<li>Returns min if (a < min) 
</ul>
*/
static INLINE OPJ_INT32 opj_int_clamp(OPJ_INT32 a, OPJ_INT32 min, OPJ_INT32 max) {
	if (a < min)
		return min;
	if (a > max)
		return max;
	return a;
}
/**
@return Get absolute value of integer
*/
static INLINE OPJ_INT32 opj_int_abs(OPJ_INT32 a) {
	return a < 0 ? -a : a;
}
/**
Divide an integer and round upwards
@return Returns a divided by b
*/
static INLINE OPJ_INT32 opj_int_ceildiv(OPJ_INT32 a, OPJ_INT32 b) {
	return (a + b - 1) / b;
}

/**
Divide an integer and round upwards
@return Returns a divided by b
*/
static INLINE OPJ_UINT32  opj_uint_ceildiv(OPJ_UINT32  a, OPJ_UINT32  b) {
	return (a + b - 1) / b;
}

/**
Divide an integer by a power of 2 and round upwards
@return Returns a divided by 2^b
*/
static INLINE OPJ_INT32 opj_int_ceildivpow2(OPJ_INT32 a, OPJ_INT32 b) {
	return (a + (1 << b) - 1) >> b;
}
/**
Divide an integer by a power of 2 and round downwards
@return Returns a divided by 2^b
*/
static INLINE OPJ_INT32 opj_int_floordivpow2(OPJ_INT32 a, OPJ_INT32 b) {
	return a >> b;
}
/**
Get logarithm of an integer and round downwards
@return Returns log2(a)
*/
static INLINE OPJ_INT32 opj_int_floorlog2(OPJ_INT32 a) {
	OPJ_INT32 l;
	for (l = 0; a > 1; l++) {
		a >>= 1;
	}
	return l;
}
/**
Get logarithm of an integer and round downwards
@return Returns log2(a)
*/
static INLINE OPJ_UINT32  opj_uint_floorlog2(OPJ_UINT32  a) {
	OPJ_UINT32  l;
	for (l = 0; a > 1; ++l)
	{
		a >>= 1;
	}
	return l;
}

/**
Multiply two fixed-precision rational numbers.
@param a
@param b
@return Returns a * b
*/
static INLINE OPJ_INT32 opj_int_fix_mul(OPJ_INT32 a, OPJ_INT32 b) {
    OPJ_INT64 temp = (OPJ_INT64) a * (OPJ_INT64) b ;
    temp += temp & 4096;
    return (OPJ_INT32) (temp >> 13) ;
}

/* ----------------------------------------------------------------------- */
/*@}*/

/*@}*/

#endif