/* Copyright (c) 1995 Entropic Research Laboratory, Inc. *//* @(#)Utils.h	1.2 9/26/95 ATT/ERL/ESI *//* * Utils.h == structure to hold methods for internal use within `waves'; *	      each `Signal' contains one of these. * * Not to be confused with `Methods' which coordinate the execution * of external commands (i.e. messages). */typedef struct {  int (*write_data)();		/* signal I/O routines */  int (*read_data)();  int (*free_data)();		/* special freeing methods (data specific) */  double (*sig_dur)();		/* signal duration of entire file */  double (*buf_start)();	/* start time of data in memory */  double (*buf_end)();		/* end time of data in memory */  double (*index_to_time)();    /* convert array index to time */  int (*time_to_index)();	/* convert time to buffer array index */} Utils;/* * These macros use the above utility methods to replace the old macros * START_TIME, END_TIME, and DURATION. */#define BUF_END_TIME(sig)	((sig)->utils->buf_end(sig))#define BUF_START_TIME(sig)	((sig)->utils->buf_start(sig))#define BUF_DURATION(sig)	(BUF_END_TIME(sig)-BUF_START_TIME(sig))#define SIG_DURATION(sig)	(((sig)->utils->sig_dur)? \				 (sig)->utils->sig_dur(sig) : \				 (double)(sig)->file_size/(sig)->freq)#define SIG_END_TIME(sig)       ((sig)->start_time + SIG_DURATION(sig))#define SIG_START_TIME(sig)     ((sig)->start_time)