ComposerDesktopProject/dev/extend/drunk.c

/*
 * Copyright (c) 1983-2023 Trevor Wishart and Composers Desktop Project Ltd
 * http://www.trevorwishart.co.uk
 * http://www.composersdesktop.com
 *
 This file is part of the CDP System.

    The CDP System is free software; you can redistribute it
    and/or modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    The CDP System is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with the CDP System; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA
 *
 */



#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <structures.h>
#include <tkglobals.h>
#include <globcon.h>
#include <processno.h>
#include <modeno.h>
#include <arrays.h>
#include <extend.h>
#include <cdpmain.h>
#include <sfsys.h>
#include <osbind.h>

 //#ifdef unix
#define round(x) lround((x))
//#endif

int  drunk(int here,int *obufpos,int *thisbuf,int thisdur,double pregain,int *endwrite,int outbufspace,dataptr dz);
int  do_pause(int here,int *obufpos,int *endwrite,int *thisbuf,int thisdur,double pregain,int outbufspace,dataptr dz);
int  get_thisdur(int *thisdur,int *goalpcnt,int *pcnt,dataptr dz);
int  get_pos_and_dur_for_pause(int *here,int *thisdur,int *thisbuf,int *ibufpos,double pregain,dataptr dz);
int  get_pos(int *here,int thisdur,dataptr dz);
void do_pregain(double pregain,dataptr dz);
int  is_paus(int *goalpcnt,int *pcnt,dataptr dz);
int  convert_time_to_samplecnts(int paramno,dataptr dz);
int  convert_sec_steps_to_grain_steps(dataptr dz);
int  adjust_bufs(int here,int *ibufpos,int *thisbuf,double pregain,dataptr dz);
int  do_intermediate_write(int *endwrite,int *obufpos,dataptr dz);
int  make_drnk_splicetab(dataptr dz);
void setup_paus_params(dataptr dz);
int  get_maxvalue(int paramno,double *maxval,dataptr dz);
double get_pregain(dataptr dz);
int  do_start_splice(int chans,float *obuf,int *obufpos,float *ibuf,int *ibufpos,int *thisbuf,double pregain,
        int *endwrite,int outbufspace,dataptr dz);
int  do_end_splice(int chans,float *obuf,int *obufpos,float *ibuf,int *ibufpos,int *thisbuf,double pregain,dataptr dz);
int  bounce_off_file_end_if_necessary(int *here,int thisdur,int chans,int splicelen,dataptr dz);
int  get_pausdur(int *here,int splicelen,int chans,int *thisdur,dataptr dz);
int get_step(int chans,dataptr dz);
int get_new_pos(int here,int ambitus,int locus,int step);
int get_new_locus_pos(int here,int ambitus,int locus,int step);

/*************************** DO_DRUNKEN_WALK *************************/

int do_drunken_walk(dataptr dz)
{
    int exit_status;
    int here = 0, ibufpos, obufpos = 0, samps_processed = 0;
    double outsamptime;
    double  pregain = 1.0;
    int thisdur, endwrite = 0;
    int thisbuf;
    int is_a_pause;
    int goalpcnt = -1;  /* total events needed before pause: initialisation value -1 */
    int pcnt = 0;       /* count of events since last pause: initial val 0 > -1 */
    int chans = dz->infile->channels;
    int finished = FALSE;
    int outbufspace = dz->sampbuf[3] - dz->sampbuf[1];

    display_virtual_time(0,dz);
    if((exit_status = read_samps(dz->sampbuf[0],dz))<0)
        return(exit_status);
    if(dz->vflag[IS_DRNK_OVERLAP]) {
        pregain = get_pregain(dz);
        do_pregain(pregain,dz);
    }
    while(samps_processed < dz->iparam[DRNK_TOTALDUR]) {
        outsamptime  = (double)((obufpos + dz->total_samps_written)/chans);
        if((exit_status = read_values_from_all_existing_brktables(outsamptime,dz))<0)
            return(exit_status);
        while((is_a_pause = get_thisdur(&thisdur,&goalpcnt,&pcnt,dz))==TRUE) {
            setup_paus_params(dz);
            if((exit_status = get_pos_and_dur_for_pause(&here,&thisdur,&thisbuf,&ibufpos,pregain,dz))<0)
                return(exit_status);
            if((exit_status = do_pause(ibufpos,&obufpos,&endwrite,&thisbuf,thisdur,pregain,outbufspace,dz))<0)
                return(exit_status);
            if((samps_processed = dz->total_samps_written + endwrite) >= dz->iparam[DRNK_TOTALDUR]) {
                finished = TRUE;
                break;
            }
            outsamptime  = (double)((obufpos + dz->total_samps_written)/chans);
            if((exit_status = read_values_from_all_existing_brktables(outsamptime,dz))<0)
                return(exit_status);
        }
        if(finished)
            break;
        if((exit_status = get_pos(&here,thisdur,dz))<0)
            return(exit_status);
        if((exit_status = adjust_bufs(here,&ibufpos,&thisbuf,pregain,dz))<0)
            return(exit_status);
        if((exit_status = drunk(ibufpos,&obufpos,&thisbuf,thisdur,pregain,&endwrite,outbufspace,dz))<0)
            return(exit_status);
        if(obufpos >= dz->buflen) {
            if((exit_status = do_intermediate_write(&endwrite,&obufpos,dz))<0)
                return(exit_status);
        }
        samps_processed = dz->total_samps_written + endwrite;
    }
    if(endwrite > 0) {
        if((exit_status = write_samps(dz->sampbuf[1],endwrite,dz))<0)
            return(exit_status);
    }
    display_virtual_time(dz->total_samps_written,dz);
    return(FINISHED);
}

/**************************** DRUNK **************************/

int drunk(int ibufpos,int *obufpos,int *thisbuf,int thisdur,double pregain,int *endwrite,int outbufspace,dataptr dz)
{
    int exit_status;
    int n, overlap, copyblk;
    int  chans = dz->infile->channels;
    int splicelen = dz->iparam[DRNK_SPLICELEN] * chans;
    int outbpos;
    float *ibuf = dz->sampbuf[0], *thisin;
    float *obuf = dz->sampbuf[1];
    int available_insamps;
    if((exit_status = do_start_splice(chans,obuf,obufpos,ibuf,&ibufpos,thisbuf,pregain,endwrite,outbufspace,dz))<0)
        return(exit_status);
    outbpos = *obufpos;
    copyblk = thisdur - splicelen;
    available_insamps  = dz->ssampsread - ibufpos;
    while(available_insamps < copyblk) {
        thisin  = ibuf+ibufpos;
        for(n=0;n<available_insamps;n++) {
            if(outbpos >= outbufspace) {
                *endwrite = outbpos;
                if((exit_status = do_intermediate_write(endwrite,&outbpos,dz))<0)
                    return(exit_status);
            }
            obuf[outbpos++] += thisin[n];
        }
        if((exit_status = read_samps(dz->sampbuf[0],dz))<0)
            return(exit_status);
        if(dz->vflag[IS_DRNK_OVERLAP])
            do_pregain(pregain,dz);          
        (*thisbuf)++;
        ibufpos  = 0;
        copyblk -= available_insamps;
        available_insamps = dz->ssampsread;
    }           
    if(copyblk > 0) {
        thisin  = ibuf+ibufpos;
        for(n=0;n<copyblk;n++) {
            if(outbpos >= outbufspace) {
                *endwrite = outbpos;
                if((exit_status = do_intermediate_write(endwrite,&outbpos,dz))<0)
                    return(exit_status);
            }
            obuf[outbpos++] += thisin[n];   
        }
        ibufpos += copyblk;
    }
    if((exit_status = do_end_splice(chans,obuf,&outbpos,ibuf,&ibufpos,thisbuf,pregain,dz))<0)
        return(exit_status);
    *endwrite = outbpos;
    outbpos -= splicelen;
    if(dz->vflag[IS_DRNK_OVERLAP]) {
        overlap = round((double)(thisdur/chans) * dz->param[DRNK_OVERLAP]) * chans; 
        outbpos  -= overlap;
    }
    *obufpos = outbpos;
    return(FINISHED);
} 

/**************************** DO_PAUSE **************************/

int do_pause(int ibufpos,int *obufpos,int *endwrite,int *thisbuf,int thisdur,double pregain,
    int outbufspace,dataptr dz)
{
    int exit_status;
    int n, copyblk, write_block;
    int outbpos;
    int  chans = dz->infile->channels;
    int splicelen = dz->iparam[DRNK_SPLICELEN] * chans;
    float *ibuf = dz->sampbuf[0], *thisin;
    float *obuf = dz->sampbuf[1], *thisout;
    int available_insamps, available_outspace;
/* ?? */
    if((exit_status = do_start_splice(chans,obuf,obufpos,ibuf,&ibufpos,thisbuf,pregain,endwrite,outbufspace,dz))<0)
        return(exit_status);
    outbpos = *obufpos;
    copyblk = thisdur - splicelen;
    write_block = dz->sampbuf[3] - dz->sampbuf[1]; /* writeable block = outbuf + overflow */
    available_outspace = write_block - outbpos;
    available_insamps  = dz->ssampsread - ibufpos;
    while(copyblk >= available_outspace) {
        while(available_insamps <= available_outspace) {
            thisout = obuf+outbpos;
            thisin  = ibuf+ibufpos;
            for(n=0;n<available_insamps;n++)
                thisout[n] += thisin[n];    
            if((exit_status = read_samps(dz->sampbuf[0],dz))<0)
                return(exit_status);
            if(dz->vflag[IS_DRNK_OVERLAP])
                do_pregain(pregain,dz);
            (*thisbuf)++;
            ibufpos             = 0;
            outbpos            += available_insamps;
            copyblk            -= available_insamps;
            available_outspace -= available_insamps;
            available_insamps   = dz->ssampsread;           
        }
        if(available_outspace > 0) {
            thisout = obuf+outbpos;
            thisin  = ibuf+ibufpos;
            for(n=0;n<available_outspace;n++)
                thisout[n] += thisin[n];    
            ibufpos           += available_outspace;
            outbpos           += available_outspace;
            copyblk           -= available_outspace;
            available_insamps  = dz->ssampsread - ibufpos;          
        }
        if(write_block > 0) {
            if((exit_status = write_samps(dz->sampbuf[1],write_block,dz))<0)
                return(exit_status);
        }
        display_virtual_time(dz->total_samps_written,dz);
        memset((char *)dz->sampbuf[1],0,write_block * sizeof(float));
        write_block = dz->sampbuf[2] - dz->sampbuf[1];  /* change writeable block to outbuf only */
        outbpos = 0;
        available_outspace = dz->buflen;
    }
    while(available_insamps < copyblk) {
        thisout = obuf+outbpos;
        thisin  = ibuf+ibufpos;
        for(n=0;n<available_insamps;n++)
            thisout[n] += thisin[n];    
        if((exit_status = read_samps(dz->sampbuf[0],dz))<0)
            return(exit_status);
        if(dz->vflag[IS_DRNK_OVERLAP])
            do_pregain(pregain,dz);
        (*thisbuf)++;
        ibufpos  = 0;
        outbpos += available_insamps;
        copyblk -= available_insamps;
        available_insamps = dz->ssampsread;         
    }
    if(copyblk > 0) {
        thisout = obuf+outbpos;
        thisin  = ibuf+ibufpos;
        for(n=0;n<copyblk;n++)
            thisout[n] += thisin[n];    
        ibufpos += copyblk;
        outbpos += copyblk;
    }
    if((exit_status = do_end_splice(chans,obuf,&outbpos,ibuf,&ibufpos,thisbuf,pregain,dz))<0)
        return(exit_status);
    *endwrite = outbpos;
    outbpos -= splicelen;
    if(outbpos >= dz->buflen) { /* if we're now beyond outbuf end: do bufwrite & copyback */
        if((exit_status = do_intermediate_write(endwrite,&outbpos,dz))<0)
            return(exit_status);
    }
    *obufpos = outbpos;
    return FINISHED;
} 

/***************************** GET_THISDUR *******************************/

int get_thisdur(int *thisdur,int *goalpcnt,int *pcnt,dataptr dz)
{
    double randv;
    if(dz->mode==HAS_SOBER_MOMENTS && is_paus(goalpcnt,pcnt,dz))
        return TRUE;
    randv  = drand48() * dz->param[DRNK_CLOKRND];
    if((*thisdur = round((double)dz->iparam[DRNK_CLOKTIK] * (1.0 + randv)))<dz->iparam[DRNK_SPLICELEN])
        *thisdur = round((double)dz->iparam[DRNK_CLOKTIK] * (1.0 - randv));
    *thisdur *= dz->infile->channels;
    return FALSE;
}

/***************************** GET_POS_AND_DUR_FOR_PAUSE *******************************/

int get_pos_and_dur_for_pause(int *here,int *thisdur,int *thisbuf,int *ibufpos,double pregain,dataptr dz)
{                                          
    int exit_status;
    int step;
    int chans = dz->infile->channels;
    int ambitus   = dz->iparam[DRNK_AMBITUS]   * chans;
    int locus     = dz->iparam[DRNK_LOCUS]  * chans;
    int splicelen = dz->iparam[DRNK_SPLICELEN] * chans;

    if(ambitus>0 && (step = get_step(chans,dz))!=0)
        *here = get_new_pos(*here,ambitus,locus,step);

    if((exit_status = get_pausdur(here,splicelen,chans,thisdur,dz))<0)
        return(exit_status);
    
    return adjust_bufs(*here,ibufpos,thisbuf,pregain,dz);
}

/***************************** GET_POS *******************************/

int get_pos(int *here,int thisdur,dataptr dz)
{                                          
    int step = 0;
    int  chans = dz->infile->channels;
    int ambitus   = dz->iparam[DRNK_AMBITUS]   * chans;
    int locus      = dz->iparam[DRNK_LOCUS]     * chans;
    int splicelen = dz->iparam[DRNK_SPLICELEN] * chans;

    if(ambitus > 0 && (step = get_step(chans,dz))!=0)
        *here = get_new_pos(*here,ambitus,locus,step);
    else if(dz->iparam[DRNK_LAST_LOCUS] != dz->iparam[DRNK_LOCUS])
        *here = get_new_locus_pos(*here,ambitus,locus,step);
    dz->iparam[DRNK_LAST_LOCUS] = dz->iparam[DRNK_LOCUS];
    return bounce_off_file_end_if_necessary(here,thisdur,chans,splicelen,dz);
}

/*************************** PREGAIN ****************************
 *
 * Allows for effect of overlapping segments.
 */

void do_pregain(double pregain,dataptr dz)
{
    int i;
    double j;
    float *iptr = dz->sampbuf[0];
    for(i=0;i<dz->ssampsread;i++) {
        j = (*iptr) * pregain;
        *iptr++ = (float) /*round*/j; 
    }
}

/******************************* IS_PAUS *******************************/

int is_paus(int *goalpcnt,int *pcnt,dataptr dz)
{
    if(*goalpcnt < 0) {                             /* if 1st time */
        setup_paus_params(dz);
        *goalpcnt  = round(drand48() * (double)dz->iparam[DRNK_DRNKTIK_RANG]);
        *goalpcnt += dz->iparam[DRNK_MIN_DRNKTIK];
    } else if((*pcnt)++ >= *goalpcnt) {             /* if counted enough events to insert pause  */
        setup_paus_params(dz);
        *goalpcnt  = round(drand48() * (double)dz->iparam[DRNK_DRNKTIK_RANG]);
        *goalpcnt += dz->iparam[DRNK_MIN_DRNKTIK];
        *pcnt = 0;                                  /* Reset event counter to zero    */
        return TRUE;                                /* Flag that pz has been returned */
    }
    return FALSE;                                   /* ELSE Flag no pz on this occasion */
}

/************************* ADJUST_BUFS *********************/

int adjust_bufs(int here,int *ibufpos,int *thisbuf,double pregain,dataptr dz)
{
    int exit_status;
    int nextbuf = here/dz->buflen;
    if(nextbuf != *thisbuf) {
        if((sndseekEx(dz->ifd[0],nextbuf * dz->buflen,0))<0) {
            sprintf(errstr,"seek error in adjust_bufs()\n");
            return(SYSTEM_ERROR);
        }
        if((exit_status = read_samps(dz->sampbuf[0],dz))<0)
            return(exit_status);
        if(dz->vflag[IS_DRNK_OVERLAP])
            do_pregain(pregain,dz);
    }           
    *ibufpos = here % dz->buflen;
    if(*ibufpos >= dz->ssampsread) {
        sprintf(errstr,"Buffer accounting problem: adjust_bufs()\n"); 
        return(PROGRAM_ERROR);
    }
    *thisbuf = nextbuf;
    return FINISHED;
}

/************************* DO_INTERMEDIATE_WRITE *********************/

int do_intermediate_write(int *endwrite,int *obufpos,dataptr dz)
{
    int exit_status;
    int samps_to_move   = *endwrite - dz->buflen;
    int samps_available = dz->sampbuf[3] - dz->sampbuf[1];
    if((exit_status = write_samps(dz->sampbuf[1],dz->buflen,dz))<0)
        return(exit_status);
    display_virtual_time(dz->total_samps_written,dz);
    memmove((char *)dz->sampbuf[1],(char *)dz->sampbuf[2],(size_t)(samps_to_move* sizeof(float)));
    memset((char *)(dz->sampbuf[1] + samps_to_move),0,(size_t)((samps_available - samps_to_move)*sizeof(float)));
    *endwrite -= dz->buflen;
    *obufpos -= dz->buflen;
    return(FINISHED);
}

/************************* SETUP_PAUS_PARAMS *********************/

void setup_paus_params(dataptr dz)
{
    int tempval;

    if(dz->iparam[DRNK_MIN_DRNKTIK] > dz->iparam[DRNK_MAX_DRNKTIK]) {
        tempval                      = dz->iparam[DRNK_MIN_DRNKTIK];
        dz->iparam[DRNK_MIN_DRNKTIK] = dz->iparam[DRNK_MAX_DRNKTIK];
        dz->iparam[DRNK_MAX_DRNKTIK] = tempval;
    }
    dz->iparam[DRNK_DRNKTIK_RANG] = (int)(dz->iparam[DRNK_MAX_DRNKTIK] - dz->iparam[DRNK_MIN_DRNKTIK]);

    if(dz->param[DRNK_MIN_PAUS] >= dz->insams[0])
        dz->iparam[DRNK_MAXHOLD] = TRUE;
    else {
        dz->iparam[DRNK_MAXHOLD] = FALSE;
        if(dz->iparam[DRNK_MIN_PAUS] > dz->iparam[DRNK_MAX_PAUS]) {
            tempval                   = dz->iparam[DRNK_MIN_PAUS];
            dz->iparam[DRNK_MIN_PAUS] = dz->iparam[DRNK_MAX_PAUS];
            dz->iparam[DRNK_MAX_PAUS] = tempval;
        }
        dz->iparam[DRNK_PAUS_RANG] = (int)(dz->iparam[DRNK_MAX_PAUS] - dz->iparam[DRNK_MIN_PAUS]);
    }
}

/************************* GET_PREGAIN *********************/
             
double get_pregain(dataptr dz)
{
    double val;
    val = 1.0 - dz->param[DRNK_MAX_OVLAP];      /* e.g. 3/4+ -> 1/4 || .76 -> .24 */
    val = 1.0/val;                              /* i.e  1/4  -> 4   || .24 -> 4+  */
    val += 1.0;                                 /* i.e. 4    -> 5   || 4+  -> 5+  */    
//TW UPDATE
//  return val;
    return 1.0/val;
}

/*************************** DO_START_SPLICE **************************/

int do_start_splice(int chans,float *obuf,int *obufpos,float *ibuf,int *ibufpos,int *thisbuf,
    double pregain,int *endwrite,int outbufspace,dataptr dz) 
{
    int exit_status;
    int n;
    int m;
    int outbpos = *obufpos;
    int inbpos  = *ibufpos;
    for(n=0;n<dz->iparam[DRNK_SPLICELEN];n++) {
        for(m=0;m<chans;m++) {          
            if(outbpos >= outbufspace) {
                *endwrite = outbpos;
                if((exit_status = do_intermediate_write(endwrite,&outbpos,dz))<0)
                    return(exit_status);
            }
            obuf[outbpos++] += (float)/*round*/((double)ibuf[inbpos++] * dz->parray[DRNK_SPLICETAB][n]); 
        }
        if(inbpos >= dz->ssampsread) {
            if((exit_status = read_samps(dz->sampbuf[0],dz))<0)
                return(exit_status);
            if(dz->vflag[IS_DRNK_OVERLAP])
                do_pregain(pregain,dz);
            inbpos = 0;
            (*thisbuf)++;
        }
    }
    *obufpos = outbpos;
    *ibufpos = inbpos;
    return(FINISHED);
}


/*************************** DO_END_SPLICE **************************/

int do_end_splice(int chans,float *obuf,int *obufpos,float *ibuf,int *ibufpos,int *thisbuf,double pregain,dataptr dz) 
{
    int exit_status;
    int n;
    int m;
    int outbpos = *obufpos;
    int inbpos  = *ibufpos;
    for(n=dz->iparam[DRNK_SPLICELEN]-1;n>=0;n--) {
        for(m=0;m<chans;m++)            
            obuf[outbpos++] += (float)/*round*/((double)ibuf[inbpos++] * dz->parray[DRNK_SPLICETAB][n]); 
        if(inbpos >= dz->ssampsread) {
            if((exit_status = read_samps(dz->sampbuf[0],dz))<0)
                return(exit_status);
            if(dz->vflag[IS_DRNK_OVERLAP])
                do_pregain(pregain,dz);
            inbpos = 0;
            (*thisbuf)++;           
        }
    }
    *obufpos = outbpos;
    *ibufpos = inbpos;
    return(FINISHED);
}

/*************************** GET_NEW_POS **************************/

int get_new_pos(int here,int ambitus,int locus,int step)
{
    int current_stray = here - locus;                   /* distance frm start available seg (locus) to current pos*/
    int new_stray = current_stray + step;               /* new_stray = distance from locus */
    int otherstray, newstep;
    if(new_stray > ambitus || new_stray < -ambitus ) {  /* if new_stray greater than ambitus */
        otherstray = current_stray - step;
        if(otherstray >= 0 && otherstray <= ambitus)
            here = locus + otherstray;                  /* try reversing step */
        else if(otherstray <0 && otherstray >= -ambitus)
            here = locus + otherstray;                      
        else {                                              
            newstep = abs(new_stray) % ambitus;         /* otherwise take modulus */
            if(step >= 0)
                here = locus + newstep;
            else
                here = locus - newstep;
        }
    } else
        here += step;
    if(here<0)                                          /* Bounce off start of buffer if ness */
        here = -here;
    return(here);
}

/*************************** GET_NEW_LOCUS_POS **************************/

int get_new_locus_pos(int here,int ambitus,int locus,int step)
{
    int current_stray = here - locus;                   /* distance frm start available seg (locus) to current pos*/
    int new_stray = current_stray + step;               /* new_stray = distance from locus */
    if(new_stray > ambitus || new_stray < -ambitus)     /* if new_stray greater than ambitus */
        here = locus + step;
    else
        here += step;
    if(here<0)                                          /* Bounce off start of buffer if ness */
        here = -here;
    return(here);
}

/*************************** GET_STEP **************************/

int get_step(int chans,dataptr dz)
{
    int step;
    double dstep  = (drand48() * 2.0) - 1.0;    /* range +1 to -1 */
    dstep *= dz->param[DRNK_GSTEP];     /* range +gstep to -gstep */
    step   = round(dstep);              /* Current stepsize in mintime-grains */                
    step  *= dz->iparam[DRNK_LGRAIN];   /* Current stepsize in samples        */
    step  *= chans;
    return step;
}

/*************************** GET_PAUSDUR **************************/

int get_pausdur(int *here,int splicelen,int chans,int *thisdur,dataptr dz)
{
    int this_pause;
    int max_pause = dz->insams[0] - *here - splicelen;
    if(EVEN(chans) && ODD(max_pause)) {
        sprintf(errstr,"Stereo anomaly at file end: get_pausdur()\n");
        return(PROGRAM_ERROR);
    }
    if(max_pause < 0) {
        sprintf(errstr,"Negative pause duration: get_pausdur()\n");
        return(PROGRAM_ERROR);
    }
    if(dz->iparam[DRNK_MAXHOLD])
        *thisdur = max_pause;
    else {
        this_pause  = round(drand48() * dz->iparam[DRNK_PAUS_RANG]); /* gen pause dur between */
        this_pause += dz->iparam[DRNK_MIN_PAUS];                     /* given limits */
        this_pause *= chans;
        *thisdur  = min(this_pause,max_pause);                       /* but not >endoffile */
    }                                                         
    return(FINISHED);
}

/*************************** BOUNCE_OFF_FILE_END_IF_NECESSARY **************************/
//TW MY CURRENT CODE AGREES WITH THIS, so removed #ifdef
int bounce_off_file_end_if_necessary(int *here,int thisdur,int chans,int splicelen,dataptr dz)
{
    int diff, initial_diff, needed;
    initial_diff = abs(dz->insams[0] - *here);  /* Ensure enough room to read final segment and splice */
    if(EVEN(chans) && ODD(initial_diff)) {
        sprintf(errstr,"Stereo anomaly at file end: bounce_off_file_end_if_necessary()\n");
        return(PROGRAM_ERROR);
    }
    if((needed = thisdur + splicelen) > dz->insams[0]) {
        sprintf(errstr,"Segment duration exceeds size of sound\n");
        return(DATA_ERROR);
    }
    while((diff = dz->insams[0] - *here) < needed) {
        *here -= initial_diff;                  /* Bounce off end of buffer if ness */
        if(*here < 0 || initial_diff == 0) {    /* But, if it bounces off BOTH ends !! */
            *here = (dz->insams[0] - needed)/dz->infile->channels;
            *here = (int)round(*here * drand48()) * dz->infile->channels;
        }
    }
    return(FINISHED);
}