util.h

大师写的二代小波经典之作

/*
 *  -*- Mode: ANSI C -*-
 *  $Id: util.h,v 1.5 1996/08/16 17:23:30 fernande Exp $
 *  $Source: /sgi.acct/sweldens/cvs/liftpack/include/util.h,v $
 *  Author: Fernandez, Gabriel
 *
 *  Contains common math functions and useful comparison functions.
 */
/* do not edit anything above this line */

#ifndef	__UTIL_H__
#define	__UTIL_H__

#include "flwtdef.h"

extern Flt min3 ( Flt __a, Flt __b, Flt __c );
extern Flt max3 ( Flt __a, Flt __b, Flt __c );
extern Flt min4 ( Flt __a, Flt __b, Flt __c, Flt __d );
extern Flt max4 ( Flt __a, Flt __b, Flt __c, Flt __d );
extern int zeroEps ( const Flt __x, const Flt __eps );
extern int zero ( const Flt __x );
extern Flt logBaseN ( const Flt __x, const Flt __n );
/* should be called only for positive powers of two */
extern int logbasetwo ( int __x );
/* called for nonnegative integers */
extern int ispoweroftwo ( int __x );
/* returns next n >= x such that n = 2^integer */
extern int nextpoweroftwo( int __x );

/* Useful macros */
#define ABS(x) ((x) < (Flt)0 ? -(x) : (x))
#define CEIL(num,den) ( ((num)+(den)-1)/(den) )
#define EVEN(x) (!ODD(x))
#define ODD(x)  ((x) & 0x01)
#define SIGN(x) ( (x) < 0 ? (-1) : ( (x) > 0 ? (1) ) : 0 )
#define SQR(x) ( (x) * (x) )
#define CUBE(x) ( (x) * (x) * (x) )
#define ROUND(x,min,max) ( (x) > (Flt)(max) ? (Flt)(max) : (x) < (Flt)(min) ? (Flt)(min) : (x) + (Flt)0.5 )
/* LUMA returns total intensity of r,g,b triple (i = .299R + .587G + .114B) */
#define LUMA(rd,gn,bl) ( (int)((Flt)(rd)*(Flt)0.299 + (Flt)(gn)*(Flt)0.587 + (Flt)(bl)*(Flt)0.114) )

#ifndef MAX
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#endif
#ifndef MIN
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#endif

#endif	/* __UTIL_H__ */