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Diffstat (limited to 'src/libjasper/jpc/jpc_math.c')
| -rw-r--r-- | src/libjasper/jpc/jpc_math.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/src/libjasper/jpc/jpc_math.c b/src/libjasper/jpc/jpc_math.c new file mode 100644 index 0000000..f268554 --- /dev/null +++ b/src/libjasper/jpc/jpc_math.c @@ -0,0 +1,121 @@ +/* + * 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__ + */ + +/* + * Math Library + * + * $Id: jpc_math.c,v 1.1 2008/10/17 06:15:00 scuri Exp $ + */ + +/******************************************************************************\ +* Includes +\******************************************************************************/ + +#include <assert.h> +#include <stdio.h> +#include <string.h> +#include <math.h> +#include <stdlib.h> +#include <stdarg.h> + +#include "jpc_math.h" + +/******************************************************************************\ +* Miscellaneous Functions +\******************************************************************************/ + +/* Calculate the integer quantity floor(log2(x)), where x is a positive + integer. */ +int jpc_floorlog2(int x) +{ + int y; + + /* The argument must be positive. */ + assert(x > 0); + + y = 0; + while (x > 1) { + x >>= 1; + ++y; + } + return y; +} + +/* Calculate the bit position of the first leading one in a nonnegative + integer. */ +/* This function is the basically the same as ceillog2(x), except that the + allowable range for x is slightly different. */ +int jpc_firstone(int x) +{ + int n; + + /* The argument must be nonnegative. */ + assert(x >= 0); + + n = -1; + while (x > 0) { + x >>= 1; + ++n; + } + return n; +} |