/* * 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) 1999-2000 Image Power, Inc. * Copyright (c) 1999-2000 The University of British Columbia * Copyright (c) 2001-2003 Michael David Adams *  * 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__ *//* * Fixed-Point Number Class * * $Id$ */#ifndef JAS_FIX_H#define JAS_FIX_H/******************************************************************************\* Includes.\******************************************************************************/#include <stdio.h>#include <stdlib.h>#include <math.h>#include <jasper/jas_config.h>#include <jasper/jas_types.h>#ifdef __cplusplusextern "C" {#endif/******************************************************************************\* Constants.\******************************************************************************//* The representation of the value zero. */#define	JAS_FIX_ZERO(fix_t, fracbits) \	JAS_CAST(fix_t, 0)/* The representation of the value one. */#define	JAS_FIX_ONE(fix_t, fracbits) \	(JAS_CAST(fix_t, 1) << (fracbits))/* 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_CAST(fix_t, 1) << (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_CAST(fix_t, 1) << (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_CAST(fix_t, 1) << (fracbits)) - 1)))/* Round a fixed-point number to the nearest integer in the direction  of zero. */#define JAS_FIX_TRUNC(fix_t, fracbits, x) \	(((x) >= 0) ? JAS_FIX_FLOOR(fix_t, fracbits, x) : \	  JAS_FIX_CEIL(fix_t, fracbits, x))/******************************************************************************\* The below macros are for internal library use only.  Do not invoke them* directly in application code.\******************************************************************************//* Handle overflow. */#define	JAS_FIX_OFLOW() \	fprintf(stderr, "overflow error: file %s, line %d\n", __FILE__, __LINE__)/* Handle underflow. */#define	JAS_FIX_UFLOW() \	fprintf(stderr, "underflow error: file %s, line %d\n", __FILE__, __LINE__)#ifdef __cplusplus}#endif#endif