ref: de5fb20b98c830cf38e08058c4df874c9ab6f816
dir: /jasper/jas_fix.h/
/*
* Copyright (c) 1999-2000 Image Power, Inc. and the University of
* British Columbia.
* Copyright (c) 2001-2002 Michael David Adams.
* All rights reserved.
*/
/* __START_OF_JASPER_LICENSE__
*
* JasPer License Version 2.0
*
* Copyright (c) 2001-2006 Michael David Adams
* Copyright (c) 1999-2000 Image Power, Inc.
* Copyright (c) 1999-2000 The University of British Columbia
*
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person (the
* "User") 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, 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:
*
* 1. The above copyright notices and this permission notice (which
* includes the disclaimer below) shall be included in all copies or
* substantial portions of the Software.
*
* 2. The name of a copyright holder shall not be used to endorse or
* promote products derived from the Software without specific prior
* written permission.
*
* THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS
* LICENSE. NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER
* THIS DISCLAIMER. THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS
* "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 OF THIRD PARTY RIGHTS. IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
* INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. NO ASSURANCES ARE
* PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE
* THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.
* EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS
* BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL
* PROPERTY RIGHTS OR OTHERWISE. AS A CONDITION TO EXERCISING THE RIGHTS
* GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE
* ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY. THE SOFTWARE
* IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL
* SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,
* AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL
* SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH
* THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,
* PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH
* RISK ACTIVITIES"). THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY
* EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.
*
* __END_OF_JASPER_LICENSE__
*/
/*!
* @file jas_fix.h
* @brief JasPer Fixed-Point Number Class
*/
#ifndef JAS_FIX_H
#define JAS_FIX_H
/******************************************************************************\
* Includes.
\******************************************************************************/
/* The configuration header file should be included first. */
#include <jasper/jas_config.h> /* IWYU pragma: keep */
#include <jasper/jas_types.h>
#ifdef __cplusplus
extern "C" {
#endif
/******************************************************************************\
* Constants.
\******************************************************************************/
/* The representation of the value zero. */
#define JAS_FIX_ZERO(fix_t, fracbits) \
JAS_INTTOFIX(fix_t, fracbits, 0)
/* The representation of the value one. */
#define JAS_FIX_ONE(fix_t, fracbits) \
JAS_INTTOFIX(fix_t, fracbits, 1)
/* The representation of the value one half. */
#define JAS_FIX_HALF(fix_t, fracbits) \
(JAS_CAST(fix_t, 1) << ((fracbits) - 1))
/******************************************************************************\
* Conversion operations.
\******************************************************************************/
/* Convert an int to a fixed-point number. */
#define JAS_INTTOFIX(fix_t, fracbits, x) \
(JAS_CAST(fix_t, x) << (fracbits))
/* Convert a fixed-point number to an int. */
#define JAS_FIXTOINT(fix_t, fracbits, x) \
JAS_CAST(int, (x) >> (fracbits))
/* Convert a fixed-point number to a double. */
#define JAS_FIXTODBL(fix_t, fracbits, x) \
(JAS_CAST(double, x) / JAS_FIX_ONE(fix_t, fracbits))
/* Convert a double to a fixed-point number. */
#define JAS_DBLTOFIX(fix_t, fracbits, x) \
JAS_CAST(fix_t, ((x) * JAS_CAST(double, JAS_FIX_ONE(fix_t, fracbits))))
/******************************************************************************\
* Basic arithmetic operations.
* All other arithmetic operations are synthesized from these basic operations.
* There are three macros for each type of arithmetic operation.
* One macro always performs overflow/underflow checking, one never performs
* overflow/underflow checking, and one is generic with its behavior
* depending on compile-time flags.
* Only the generic macros should be invoked directly by application code.
\******************************************************************************/
/* Calculate the sum of two fixed-point numbers. */
#if !defined(DEBUG_OVERFLOW)
#define JAS_FIX_ADD JAS_FIX_ADD_FAST
#else
#define JAS_FIX_ADD JAS_FIX_ADD_OFLOW
#endif
/* Calculate the sum of two fixed-point numbers without overflow checking. */
#define JAS_FIX_ADD_FAST(fix_t, fracbits, x, y) ((x) + (y))
/* Calculate the sum of two fixed-point numbers with overflow checking. */
#define JAS_FIX_ADD_OFLOW(fix_t, fracbits, x, y) \
((x) >= 0) ? \
(((y) >= 0) ? ((x) + (y) >= 0 || JAS_FIX_OFLOW(), (x) + (y)) : \
((x) + (y))) : \
(((y) >= 0) ? ((x) + (y)) : ((x) + (y) < 0 || JAS_FIX_OFLOW(), \
(x) + (y)))
/* Calculate the product of two fixed-point numbers. */
#if !defined(DEBUG_OVERFLOW)
#define JAS_FIX_MUL JAS_FIX_MUL_FAST
#else
#define JAS_FIX_MUL JAS_FIX_MUL_OFLOW
#endif
/* Calculate the product of two fixed-point numbers without overflow
checking. */
#define JAS_FIX_MUL_FAST(fix_t, fracbits, bigfix_t, x, y) \
JAS_CAST(fix_t, (JAS_CAST(bigfix_t, x) * JAS_CAST(bigfix_t, y)) >> \
(fracbits))
/* Calculate the product of two fixed-point numbers with overflow
checking. */
#define JAS_FIX_MUL_OFLOW(fix_t, fracbits, bigfix_t, x, y) \
((JAS_CAST(bigfix_t, x) * JAS_CAST(bigfix_t, y) >> (fracbits)) == \
JAS_CAST(fix_t, (JAS_CAST(bigfix_t, x) * JAS_CAST(bigfix_t, y) >> \
(fracbits))) ? \
JAS_CAST(fix_t, (JAS_CAST(bigfix_t, x) * JAS_CAST(bigfix_t, y) >> \
(fracbits))) : JAS_FIX_OFLOW())
/* Calculate the product of a fixed-point number and an int. */
#if !defined(DEBUG_OVERFLOW)
#define JAS_FIX_MULBYINT JAS_FIX_MULBYINT_FAST
#else
#define JAS_FIX_MULBYINT JAS_FIX_MULBYINT_OFLOW
#endif
/* Calculate the product of a fixed-point number and an int without overflow
checking. */
#define JAS_FIX_MULBYINT_FAST(fix_t, fracbits, x, y) \
JAS_CAST(fix_t, ((x) * (y)))
/* Calculate the product of a fixed-point number and an int with overflow
checking. */
#define JAS_FIX_MULBYINT_OFLOW(fix_t, fracbits, x, y) \
JAS_FIX_MULBYINT_FAST(fix_t, fracbits, x, y)
/* Calculate the quotient of two fixed-point numbers. */
#if !defined(DEBUG_OVERFLOW)
#define JAS_FIX_DIV JAS_FIX_DIV_FAST
#else
#define JAS_FIX_DIV JAS_FIX_DIV_UFLOW
#endif
/* Calculate the quotient of two fixed-point numbers without underflow
checking. */
#define JAS_FIX_DIV_FAST(fix_t, fracbits, bigfix_t, x, y) \
JAS_CAST(fix_t, (JAS_CAST(bigfix_t, x) << (fracbits)) / (y))
/* Calculate the quotient of two fixed-point numbers with underflow
checking. */
#define JAS_FIX_DIV_UFLOW(fix_t, fracbits, bigfix_t, x, y) \
JAS_FIX_DIV_FAST(fix_t, fracbits, bigfix_t, x, y)
/* Negate a fixed-point number. */
#if !defined(DEBUG_OVERFLOW)
#define JAS_FIX_NEG JAS_FIX_NEG_FAST
#else
#define JAS_FIX_NEG JAS_FIX_NEG_OFLOW
#endif
/* Negate a fixed-point number without overflow checking. */
#define JAS_FIX_NEG_FAST(fix_t, fracbits, x) \
(-(x))
/* Negate a fixed-point number with overflow checking. */
/* Yes, overflow is actually possible for two's complement representations,
although highly unlikely to occur. */
#define JAS_FIX_NEG_OFLOW(fix_t, fracbits, x) \
(((x) < 0) ? (-(x) > 0 || JAS_FIX_OFLOW(), -(x)) : (-(x)))
/* Perform an arithmetic shift left of a fixed-point number. */
#if !defined(DEBUG_OVERFLOW)
#define JAS_FIX_ASL JAS_FIX_ASL_FAST
#else
#define JAS_FIX_ASL JAS_FIX_ASL_OFLOW
#endif
/* Perform an arithmetic shift left of a fixed-point number without overflow
checking. */
#define JAS_FIX_ASL_FAST(fix_t, fracbits, x, n) \
((x) << (n))
/* Perform an arithmetic shift left of a fixed-point number with overflow
checking. */
#define JAS_FIX_ASL_OFLOW(fix_t, fracbits, x, n) \
((((x) << (n)) >> (n)) == (x) || JAS_FIX_OFLOW(), (x) << (n))
/* Perform an arithmetic shift right of a fixed-point number. */
#if !defined(DEBUG_OVERFLOW)
#define JAS_FIX_ASR JAS_FIX_ASR_FAST
#else
#define JAS_FIX_ASR JAS_FIX_ASR_UFLOW
#endif
/* Perform an arithmetic shift right of a fixed-point number without underflow
checking. */
#define JAS_FIX_ASR_FAST(fix_t, fracbits, x, n) \
((x) >> (n))
/* Perform an arithmetic shift right of a fixed-point number with underflow
checking. */
#define JAS_FIX_ASR_UFLOW(fix_t, fracbits, x, n) \
JAS_FIX_ASR_FAST(fix_t, fracbits, x, n)
/******************************************************************************\
* Other basic arithmetic operations.
\******************************************************************************/
/* Calculate the difference between two fixed-point numbers. */
#define JAS_FIX_SUB(fix_t, fracbits, x, y) \
JAS_FIX_ADD(fix_t, fracbits, x, JAS_FIX_NEG(fix_t, fracbits, y))
/* Add one fixed-point number to another. */
#define JAS_FIX_PLUSEQ(fix_t, fracbits, x, y) \
((x) = JAS_FIX_ADD(fix_t, fracbits, x, y))
/* Subtract one fixed-point number from another. */
#define JAS_FIX_MINUSEQ(fix_t, fracbits, x, y) \
((x) = JAS_FIX_SUB(fix_t, fracbits, x, y))
/* Multiply one fixed-point number by another. */
#define JAS_FIX_MULEQ(fix_t, fracbits, bigfix_t, x, y) \
((x) = JAS_FIX_MUL(fix_t, fracbits, bigfix_t, x, y))
/******************************************************************************\
* Miscellaneous operations.
\******************************************************************************/
/* Calculate the absolute value of a fixed-point number. */
#define JAS_FIX_ABS(fix_t, fracbits, x) \
(((x) >= 0) ? (x) : (JAS_FIX_NEG(fix_t, fracbits, x)))
/* Is a fixed-point number an integer? */
#define JAS_FIX_ISINT(fix_t, fracbits, x) \
(JAS_FIX_FLOOR(fix_t, fracbits, x) == (x))
/* Get the sign of a fixed-point number. */
#define JAS_FIX_SGN(fix_t, fracbits, x) \
((x) >= 0 ? 1 : (-1))
/******************************************************************************\
* Relational operations.
\******************************************************************************/
/* Compare two fixed-point numbers. */
#define JAS_FIX_CMP(fix_t, fracbits, x, y) \
((x) > (y) ? 1 : (((x) == (y)) ? 0 : (-1)))
/* Less than. */
#define JAS_FIX_LT(fix_t, fracbits, x, y) \
((x) < (y))
/* Less than or equal. */
#define JAS_FIX_LTE(fix_t, fracbits, x, y) \
((x) <= (y))
/* Greater than. */
#define JAS_FIX_GT(fix_t, fracbits, x, y) \
((x) > (y))
/* Greater than or equal. */
#define JAS_FIX_GTE(fix_t, fracbits, x, y) \
((x) >= (y))
/******************************************************************************\
* Rounding functions.
\******************************************************************************/
/* Round a fixed-point number to the nearest integer. */
#define JAS_FIX_ROUND(fix_t, fracbits, x) \
(((x) < 0) ? JAS_FIX_FLOOR(fix_t, fracbits, JAS_FIX_ADD(fix_t, fracbits, \
(x), JAS_FIX_HALF(fix_t, fracbits))) : \
JAS_FIX_NEG(fix_t, fracbits, JAS_FIX_FLOOR(fix_t, fracbits, \
JAS_FIX_ADD(fix_t, fracbits, (-(x)), JAS_FIX_HALF(fix_t, fracbits)))))
/* Round a fixed-point number to the nearest integer in the direction of
negative infinity (i.e., the floor function). */
#define JAS_FIX_FLOOR(fix_t, fracbits, x) \
((x) & (~(JAS_FIX_ONE(fix_t, fracbits) - 1)))
/******************************************************************************\
* The below macros are for internal library use only. Do not invoke them
* directly in application code.
\******************************************************************************/
/* Handle overflow. */
#define JAS_FIX_OFLOW() \
jas_eprintf("overflow error: file %s, line %d\n", __FILE__, __LINE__)
/* Handle underflow. */
#define JAS_FIX_UFLOW() \
jas_eprintf("underflow error: file %s, line %d\n", __FILE__, __LINE__)
#ifdef __cplusplus
}
#endif
#endif