/*
 * 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
 *
 */



/* floatsam version */
#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 <extend.h>

int     reverse_it(int incnt,dataptr dz);
void    do_down_splice(dataptr dz);
int     add_to_splicebuf(float *iptr,dataptr dz);
int     find_zzchunk(int **thisstart,int **lastend, int *ziglistend, int *minsamp, dataptr dz);
int     adjust_buffer(int minsamp, int *oldminsec, int init, dataptr dz);
int     zig_or_zag(int direction,int *here,int *next,int is_startsplice,int is_endsplice,
                int *outbuf_space,int obufno,int splbufno, dataptr dz);
int     do_zigzags(int *thisstart,int *lastend,int *outbuf_space,int obufno,int splbufno,dataptr dz);
int     memcpy_with_check(char *bufptr,char *bufend,char *fromptr,int bytecnt);
int     setup_splices(int *base,int *last,int *here,int *next,int *after,int *end,
                int *is_startsplice,int *is_endsplice,dataptr dz);
static void do_end_splice(int samps_left,int obufno,dataptr dz);

#define ZIG     (1)
#define UNKNOWN (0)
#define ZAG     (-1)

#define NORMAL  (0)
#define REVERSE (1)

#define SECMARGIN  (256) 


/***************************** ZIGZAG **********************************/

int zigzag(dataptr dz)
{
    int exit_status;
    int *thisstart, *lastend = dz->lparray[ZIGZAG_TIMES], minsamp;
    int oldminsec = 0;
    int init = 1;
    int *ziglistend = dz->lparray[ZIGZAG_TIMES] + dz->itemcnt;
    int outbuf_space = dz->buflen, samps_left;
    int obufno, splbufno;
    switch(dz->process) {
    case(ZIGZAG):   obufno = 2; splbufno = 3; break;
    case(LOOP):
    case(SCRAMBLE): obufno = 1; splbufno = 2; break;
    default:
        sprintf(errstr,"Unknown case in zigzag()\n");
        return(PROGRAM_ERROR);
    }
    if((exit_status = find_zzchunk(&thisstart,&lastend,ziglistend,&minsamp,dz))!=CONTINUE) {
        if(exit_status == FINISHED)
            exit_status = GOAL_FAILED;
        switch(dz->process) {
        case(ZIGZAG):   sprintf(errstr,"WARNING: No valid zigzag found\n");     break;
        case(LOOP):     sprintf(errstr,"WARNING: No valid loop found\n");       break;
        case(SCRAMBLE): sprintf(errstr,"WARNING: No valid scramble found\n");   break;
        }
        return(exit_status);
    }
    if((exit_status = adjust_buffer(minsamp,&oldminsec,init,dz))<0)
        return(exit_status);
    init = 0;
    while(lastend < ziglistend) {
        if((exit_status = do_zigzags(thisstart,lastend,&outbuf_space,obufno,splbufno,dz))<0)
            return(exit_status);
        if((exit_status = find_zzchunk(&thisstart,&lastend,ziglistend,&minsamp,dz))!=CONTINUE) {
            if(exit_status==FINISHED)
                break;
            else
                return(exit_status);
        }
        if((exit_status = adjust_buffer(minsamp,&oldminsec,init,dz))<0)
            return(exit_status);
    }
    samps_left = dz->sbufptr[obufno] - dz->sampbuf[obufno];
    do_end_splice(samps_left,obufno,dz);
    if(samps_left > 0)
        return write_samps(dz->sampbuf[obufno],samps_left,dz);
    return FINISHED;
}

/************************* DO_ZIGZAGS ************************************/

int do_zigzags(int *thisstart,int *lastend,int *outbuf_space,int obufno,int splbufno,dataptr dz)
{
    int exit_status;
    int direction;
    int is_startsplice;
    int is_endsplice;
    int *last  = thisstart - 1;
    int *here  = thisstart;
    int *next  = thisstart + 1;
    int *after = thisstart + 2;
    int *base = dz->lparray[ZIGZAG_TIMES];
    int *end  = dz->lparray[ZIGZAG_TIMES] + dz->itemcnt;
    while(next <= lastend) {
        direction = setup_splices(base,last,here,next,after,end,&is_startsplice,&is_endsplice,dz);
        switch(dz->process) {
        case(ZIGZAG):
            break;               /* both ZIGS (forward) and ZAGS (backwards) are played */
        case(LOOP):
        case(SCRAMBLE):          
            if(dz->iparray[ZIGZAG_PLAY][here - base]==TRUE)
                direction = ZIG; /* FLAGS A (forward) PLAYED MOVE IN INFILE */
            else
                direction = ZAG; /* FLAGS A NON-PLAYED MOVE IN INFILE: which might be forward as well as backward */
            break;
        }
        if((exit_status = zig_or_zag(direction,here,next,is_startsplice,is_endsplice,outbuf_space,obufno,splbufno,dz))<0)
            return(exit_status);
        last++;
        here++;
        next++;
        after++;
    }
    return(FINISHED);
}

/****************************** ZIG_OR_ZAG ***********************************/

int zig_or_zag
(int direction,int *here,int *next,int is_startsplice,int is_endsplice,
int *outbuf_space,int obufno, int splbufno, dataptr dz)
{
    int  exit_status;
    int  bufno;
    int incnt  = abs(*next - *here), advance;
    int orig_incnt = incnt;
    int samps_remain;
    float *sbufend = dz->sampbuf[NORMAL] + dz->buflen;

    switch(direction) {
    case(ZIG):
        bufno = NORMAL;
        break;
    case(ZAG):
        switch(dz->process) {
        case(ZIGZAG):
            if((exit_status = reverse_it(incnt,dz))<0)
                return(exit_status);
            bufno = REVERSE;
            break;
        case(LOOP):
        case(SCRAMBLE):
            incnt  = *next - *here;
            if((dz->sbufptr[NORMAL] += incnt) < dz->sampbuf[NORMAL] || dz->sbufptr[NORMAL] >= sbufend) {
                sprintf(errstr,"Error in buffer accounting: zig_or_zag()\n");
                return(PROGRAM_ERROR);
            }
            return(FINISHED);
        default:
            sprintf(errstr,"Unknown case in zig_or_zag()\n");
            return(PROGRAM_ERROR);
        }
        break;
    default:
        sprintf(errstr,"Unknown case in zig_or_zag\n");
        return(PROGRAM_ERROR);
    }
    if(is_startsplice) {
        if((exit_status = add_to_splicebuf(dz->sbufptr[bufno],dz))<0)
            return(exit_status);
    }
    if(*outbuf_space >= incnt) {    /* ENOUGH SPACE IN OUTBUFFER To DO EVERYTHING */
        if(is_startsplice) {
            if((exit_status = memcpy_with_check
            ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],
                   (char *)dz->extrabuf[ZIGZAG_SPLBUF],dz->iparam[ZIG_SPLSAMPS]* sizeof(float)))<0)
                return(exit_status);
            dz->sbufptr[bufno]  += dz->iparam[ZIG_SPLSAMPS];
            dz->sbufptr[obufno] += dz->iparam[ZIG_SPLSAMPS];
            *outbuf_space       -= dz->iparam[ZIG_SPLSAMPS];
            advance = incnt-(2*dz->iparam[ZIG_SPLSAMPS]);
        } else
            advance = incnt - dz->iparam[ZIG_SPLSAMPS];
        if(!is_endsplice)
            advance += dz->iparam[ZIG_SPLSAMPS];
        if((exit_status = memcpy_with_check
        ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],(char *)dz->sbufptr[bufno],advance * sizeof(float)))<0)
            return(exit_status);
        dz->sbufptr[obufno] += advance;
        dz->sbufptr[bufno]  += advance;
        *outbuf_space       -= advance;
        if(is_endsplice) {
            memmove((char *)dz->extrabuf[ZIGZAG_SPLBUF],
                (char *)dz->sbufptr[bufno],dz->iparam[ZIG_SPLSAMPS]* sizeof(float));
            do_down_splice(dz);
            dz->sbufptr[bufno] += dz->iparam[ZIG_SPLSAMPS];
        }
        if(*outbuf_space <= 0) {
            if((exit_status = write_samps(dz->sampbuf[obufno],dz->buflen,dz))<0)
                return(exit_status);                                                                    
            dz->sbufptr[obufno] = dz->sampbuf[obufno];                                                          
            *outbuf_space = dz->buflen;
        }
    } else if(is_startsplice && (*outbuf_space <= dz->iparam[ZIG_SPLSAMPS])) {
                    /* OUTBUFFER SPACE LESS THAN (START)SPLICELEN */
        samps_remain = dz->iparam[ZIG_SPLSAMPS];
        dz->extrabufptr[ZIGZAG_SPLBUF] = dz->extrabuf[ZIGZAG_SPLBUF];

        if((exit_status = memcpy_with_check
        ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],(char *)dz->extrabufptr[ZIGZAG_SPLBUF],(*outbuf_space) * sizeof(float)))<0)
            return(exit_status);
        if((exit_status = write_samps(dz->sampbuf[obufno],dz->buflen,dz))<0)
            return(exit_status);                                                                    
        dz->extrabufptr[ZIGZAG_SPLBUF] += *outbuf_space;
        dz->sbufptr[obufno] = dz->sampbuf[obufno];                                                          
        samps_remain  -= *outbuf_space;                             
        *outbuf_space  = dz->buflen;
        if(samps_remain > 0) {
            if((exit_status = memcpy_with_check
            ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],(char *)(dz->extrabufptr[ZIGZAG_SPLBUF]),samps_remain * sizeof(float)))<0)
                return(exit_status);
            dz->sbufptr[obufno] += samps_remain;                                                            
            *outbuf_space  -= samps_remain;                                 
        }
        dz->sbufptr[bufno] += dz->iparam[ZIG_SPLSAMPS];
        advance = incnt - (2 *dz->iparam[ZIG_SPLSAMPS]);
        if(!is_endsplice)
            advance += dz->iparam[ZIG_SPLSAMPS];
        if((exit_status = memcpy_with_check
        ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],(char *)dz->sbufptr[bufno],advance * sizeof(float)))<0)
            return(exit_status);
        dz->sbufptr[obufno]     += advance;
        dz->sbufptr[bufno] += advance;
        *outbuf_space      -= advance;  
        if(is_endsplice) {
            memmove((char *)dz->extrabuf[ZIGZAG_SPLBUF],
                 (char *)dz->sbufptr[bufno],(size_t)dz->iparam[ZIG_SPLSAMPS]* sizeof(float));
            do_down_splice(dz);
            dz->sbufptr[bufno] += dz->iparam[ZIG_SPLSAMPS];
        }
    } else if(*outbuf_space <= incnt - dz->iparam[ZIG_SPLSAMPS]) {
                    /* OUTBUFFER SPACE DOESN'T REACH UP INTO ENDSPLICE */
        if(is_startsplice) {
            if((exit_status = memcpy_with_check
            ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],(char *)dz->extrabuf[ZIGZAG_SPLBUF],
                   (int)dz->iparam[ZIG_SPLSAMPS]* sizeof(float)))<0)
                return(exit_status);
            dz->sbufptr[bufno]  += dz->iparam[ZIG_SPLSAMPS];
            dz->sbufptr[obufno] += dz->iparam[ZIG_SPLSAMPS];
            advance = *outbuf_space - dz->iparam[ZIG_SPLSAMPS];
        } else 
            advance = *outbuf_space;
        if((exit_status = memcpy_with_check
        ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],(char *)dz->sbufptr[bufno],advance * sizeof(float)))<0)
            return(exit_status);
        if((exit_status = write_samps(dz->sampbuf[obufno],dz->buflen,dz))<0)
            return(exit_status);
        dz->sbufptr[bufno] += advance;
        dz->sbufptr[obufno]      = dz->sampbuf[obufno];
        incnt         -= *outbuf_space;
        *outbuf_space  = dz->buflen;
        advance = incnt - dz->iparam[ZIG_SPLSAMPS];  
        if(!is_endsplice)
            advance += dz->iparam[ZIG_SPLSAMPS];
        if(advance > 0) {
            if((exit_status = memcpy_with_check
            ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],(char *)dz->sbufptr[bufno],advance * sizeof(float)))<0)
                return(exit_status);
            dz->sbufptr[obufno]     += advance;
            dz->sbufptr[bufno] += advance;
            *outbuf_space      -= advance;
        }
        if(is_endsplice) {
            memmove((char *)dz->extrabuf[ZIGZAG_SPLBUF],(char *)dz->sbufptr[bufno],
                (size_t)dz->iparam[ZIG_SPLSAMPS]* sizeof(float));
            do_down_splice(dz);
            dz->sbufptr[bufno] += dz->iparam[ZIG_SPLSAMPS];
        }
    } else {        /* OUTBUFFER SPACE REACHES INTO MIDDLE OF ENDSPLICE */
        if(is_startsplice) {
            if((exit_status = memcpy_with_check
            ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],
                  (char *)dz->extrabuf[ZIGZAG_SPLBUF],dz->iparam[ZIG_SPLSAMPS]* sizeof(float)))<0)
                return(exit_status);
            dz->sbufptr[bufno]  += dz->iparam[ZIG_SPLSAMPS];
            dz->sbufptr[obufno] += dz->iparam[ZIG_SPLSAMPS];
            *outbuf_space       -= dz->iparam[ZIG_SPLSAMPS];
            advance = incnt - (2*dz->iparam[ZIG_SPLSAMPS]);
        } else
            advance = incnt - dz->iparam[ZIG_SPLSAMPS];
        if(!is_endsplice) {
            advance += dz->iparam[ZIG_SPLSAMPS];
            if((exit_status = memcpy_with_check
            ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],(char *)dz->sbufptr[bufno],(*outbuf_space) * sizeof(float)))<0)
                return(exit_status);
            if((exit_status = write_samps(dz->sampbuf[obufno],dz->buflen,dz))<0)
                return(exit_status);
            dz->sbufptr[bufno] += *outbuf_space;
            dz->sbufptr[obufno] = dz->sampbuf[obufno];
            advance -= *outbuf_space;
            *outbuf_space = dz->buflen;
            if((exit_status = memcpy_with_check
            ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],(char *)dz->sbufptr[bufno],advance * sizeof(float)))<0)
                return(exit_status);
            dz->sbufptr[bufno]  += advance;
            dz->sbufptr[obufno] += advance;
            *outbuf_space       -= advance;
        } else {
            if((exit_status = memcpy_with_check
            ((char *)dz->sbufptr[obufno],(char *)dz->sampbuf[splbufno],(char *)dz->sbufptr[bufno],advance * sizeof(float)))<0)
                return(exit_status);
            dz->sbufptr[obufno] += advance;
            dz->sbufptr[bufno]  += advance;
            memmove((char *)dz->extrabuf[ZIGZAG_SPLBUF],
                 (char *)dz->sbufptr[bufno],dz->iparam[ZIG_SPLSAMPS]* sizeof(float));
            do_down_splice(dz);
            dz->sbufptr[bufno] += dz->iparam[ZIG_SPLSAMPS];
            *outbuf_space = dz->sampbuf[splbufno] - dz->sbufptr[obufno];
            if(*outbuf_space > dz->iparam[ZIG_SPLSAMPS]) {
                sprintf(errstr,"Error in counting logic: zig_or_zag()\n");
                return(PROGRAM_ERROR);
            }
            if(*outbuf_space <= 0) {
                sprintf(errstr,"Error 2 in counting logic: zig_or_zag()\n");
                return(PROGRAM_ERROR);
            }
        }
    }
    if(direction ==ZAG) {
        dz->sbufptr[0] -= orig_incnt;
        dz->sbufptr[1]  = dz->sampbuf[1];
    }
    return(FINISHED);
}

/* RWD got as far as here...ARRRRGGGGHHHHH!!!!!!!! */

/****************************** ADJUST_BUFFER ******************************/
/* is all this simply to seek to minsamp? */
int adjust_buffer(int minsamp, int *oldminsec, int init, dataptr dz)
{
    int minsec, secchange, sampchange = 0, samp_at_sector_start = 0;
    minsec    = minsamp/SECMARGIN;      /* minimum sector in file that we need, for next read */
    secchange = minsec - *oldminsec;    /* number of sectors we need to move buffer along */
    *oldminsec = minsec;                        

    if(init) {              /* On first read */                 
        if(secchange<0) {   /* secchange must be >= 0 from start of file */
            sprintf(errstr,"Anomaly in first pass of adjust_buffer()\n");
            return(PROGRAM_ERROR);
        }
        if(secchange) {     /* seek to 1st buffer needed */
            sampchange = secchange * SECMARGIN;
            if(sndseekEx(dz->ifd[0],sampchange,0)<0) {      
                sprintf(errstr,"sndseek: Failed in adjust_buffer()\n");
                return(SYSTEM_ERROR);
            }               /* find sample-number (in file) of first sample in buffer */
            samp_at_sector_start = sampchange;
        }                   /* read 1st buffer */
        if(fgetfbufEx(dz->sampbuf[0],dz->buflen,dz->ifd[0],0)<0) {  
            sprintf(errstr,"read() 0 Failed in adjust_buffer()\n");
            return(SYSTEM_ERROR);
        }
        dz->sbufptr[0] = dz->sampbuf[0] + (dz->lparray[ZIGZAG_TIMES][0] - samp_at_sector_start);    
        return(FINISHED);           
    }                       /* IF NOT in first read */

//TW UPDATE (Removed below) 
//  if(!secchange) {        /* Data should have been checked to avoid zero zigs or zags */
//      sprintf(errstr,"Search anomaly in adjust_buffer()\n");
//      return(PROGRAM_ERROR);
//  }                   
 
/* sampchange = Change in samp position in file from current buffer start to next buffer start.
 * NB, it should be impossible for this to exceed buffer_size
 * because initial point must be within current buffer,
 * & total length of any segment must be less than buffer_size (controlled by param range-setting) !!
 */

    if(abs(sampchange = secchange * SECMARGIN) > dz->buflen) {
        sprintf(errstr,"Anomaly in sampseek arithmetic: adjust_buffer()\n");
        return(PROGRAM_ERROR);
    }
                            /* Seek first to start of current buff */
                            /* and then, by the calculated offset, to start of new buf */

    if(sndseekEx(dz->ifd[0],minsec * SECMARGIN,0)<0) {
        sprintf(errstr,"sndseek() 1 Failed in adjust_buffer()\n");
        return(SYSTEM_ERROR);
    }
                    /* read the new buffer */
    if(fgetfbufEx(dz->sampbuf[0],dz->buflen,dz->ifd[0],0)<0) {
        sprintf(errstr,"fgetfbufEx() Anomaly in adjust_buffer()\n");
        return(SYSTEM_ERROR);
    }       
    
    /* reposition buffer pointer within NEW buffer */
    dz->sbufptr[0] -= sampchange;
    if(dz->sbufptr[0] < dz->sampbuf[0]) {
        sprintf(errstr,"adjust_buffer(): Input buffer anomaly - pointer off start of buffer.\n");
        return(PROGRAM_ERROR);
    }
    if(dz->sbufptr[0] >= dz->sampbuf[1]) {
        sprintf(errstr,"adjust_buffer(): Input buffer anomaly - pointer off end of buffer.\n");
        return(PROGRAM_ERROR);
    }
    return(FINISHED);
}

/*************************** FIND_ZZCHUNK ************************************/

int find_zzchunk(int **thisstart,int **lastend, int *ziglistend, int *minsamp, dataptr dz)
{
    int *p, min_samp, max_samp, lastmin_samp = 0, lastmax_samp = 0;
    int check;
    int max_smpsize = dz->buflen - SECMARGIN;   
                                                /*  Max zig-segment permitted, taking into a/c */
                                                /*  need to round up to a whole sector AT THE ENDS!! */
    *thisstart  = *lastend;                     /* Set start of current segment to end of last segment */
    p = *thisstart;
                        /* WE'RE SEARCHING FOR THE earliest and latest times among successive zigtimes */
    min_samp = *p;                              /* so preset both of these to the current first zigtime */
    max_samp = *p;
    p++;
    while(p < ziglistend) {                         /* search forward through the zigtimes list */
        check = 0;
        if(*p < min_samp) {                     /* if this zigtime earlier than any encountered so far */
            lastmin_samp = min_samp;            /* store last earliest elsewhere, and keep new one */
            min_samp = *p;
            check = 1;                          /* flag that a new earliest-time has been registered */
        } else if(*p > max_samp) {              /* if this zigtime later than any encountered so far */
            lastmax_samp = max_samp;            /* store last latest elsewhere, and keep new one */ 
            max_samp = *p;
            check = 2;                          /* flag that a new latest-time has been registered */
        }
        if(check) {                                 /* If a new earliest or latest time has been found */
            if(max_samp - min_samp > max_smpsize) { /* If the span between earliest and latest is TOO LARGE */
                if(check==2)                        /* restore the previous earliest(or latest) time */
                    max_samp = lastmax_samp;
                else    
                    min_samp = lastmin_samp;
                break;                              /* and break from the loop */
            }                                       /* (Otherwise next zigtime would be beyond a bufferlength) */
        }
        p++;
    }
    if(max_samp - min_samp < 0) {
        sprintf(errstr,"Anomaly in find_zzchunk()\n");
        return(PROGRAM_ERROR);
    }
    if(max_samp - min_samp == 0)
        return(FINISHED);           
    *minsamp = min_samp;                            /* flag position of earliest time, as a samp-count in file */
                /*  NB... 
                 *  if we reached end of ziglist (p = ziglistend), lastend = end of list = ziglistend - 1
                 *  if we dropped out of loop, because last found time was unacceptable, 
                 * we must baktrak in the the ziglist by 1. Hence...
                 */
    *lastend = p - 1;

    return(CONTINUE);
}

/********************** ADD_TO_SPLICEBUF *************************/

int add_to_splicebuf(float *iptr,dataptr dz)
{
//TW CHANGED
//  /*int*/float val;
    double val;
    float *sptr = dz->extrabuf[ZIGZAG_SPLBUF];
    int n, m;
    for(n=0;n<dz->iparam[ZIG_SPLICECNT];n++) {
        for(m=0;m<dz->infile->channels;m++) {
            val = *sptr + /*round*/(float)(*iptr * dz->parray[ZIGZAG_SPLICE][n]);
            *sptr  = (float)val;
            sptr++;
            iptr++;
        }
    }
    return(FINISHED);
}

/********************** DO_DOWN_SPLICE *************************/

void do_down_splice(dataptr dz)
{
    /*int*/double val;
    float *sptr = dz->extrabuf[ZIGZAG_SPLBUF];
    int n, m;
    for(n=dz->iparam[ZIG_SPLICECNT]-1;n>=0;n--) {
        for(m = 0;m<dz->infile->channels;m++) {
            val = /*round*/(*sptr * dz->parray[ZIGZAG_SPLICE][n]);
            *sptr = (float)val;
            sptr++;
        }
    }
}

/********************** REVERSE_IT ***************************/

int reverse_it(int incnt,dataptr dz)
{
    int n;
    int k, chans = dz->infile->channels;
    float *s1ptr = dz->sbufptr[0];
    float *s2ptr;
    dz->sbufptr[1] = dz->sampbuf[1];  /* point to stsrt of reversed-segment buffer */
    s2ptr = dz->sbufptr[1];
    incnt /= chans;
    s1ptr -= chans;
    for(n=0;n<incnt;n++) {
        for(k=0;k<chans;k++)
            *s2ptr++ = *s1ptr++;
        s1ptr -= 2 * chans;
    }
    return(FINISHED);
}

/********************** MEMCPY_WITH_CHECK ***************************/

int memcpy_with_check(char *bufptr,char *bufend,char *fromptr,int bytecnt)
{
    if(bufend - bufptr < bytecnt) {
        sprintf(errstr,"Attempted to copy too many bytes to buffer: memcpy_with_check()\n");
        return(PROGRAM_ERROR);
    }
    if(bytecnt < 0) {
        sprintf(errstr,"Attempted to copy -ve number of bytes: memcpy_with_check()\n");
        return(PROGRAM_ERROR);
    }

    memmove(bufptr,fromptr,(size_t)bytecnt);
    return(FINISHED);
}

/********************** SETUP_SPLICES ***************************/

int setup_splices
(int *base,int *last,int *here,int *next,int *after,int *end,int *is_startsplice,int *is_endsplice,dataptr dz)
{
    int predirection   = UNKNOWN;
    int postdirection  = UNKNOWN;
    int direction;
    int place = here - base;
    *is_startsplice = TRUE;
    *is_endsplice   = TRUE;
    if(here > base) {
        if(*last < *here)
            predirection = ZIG;
        else            
            predirection = ZAG;
    }
    if(after < end) {
        if(*next < *after)
            postdirection = ZIG;
        else            
            postdirection = ZAG;
    }
    if(*here < *next)
        direction = ZIG;
    else
        direction = ZAG;
    if(direction == predirection)
        *is_startsplice = FALSE;
    if(direction == postdirection)
        *is_endsplice   = FALSE;
    switch(dz->process) {
    case(LOOP):
    case(SCRAMBLE):
        if(here > base 
        && dz->iparray[ZIGZAG_PLAY][place]==TRUE && dz->iparray[ZIGZAG_PLAY][place-1]==FALSE)
            *is_startsplice = TRUE;
        if(after < end
        && dz->iparray[ZIGZAG_PLAY][place]==TRUE && dz->iparray[ZIGZAG_PLAY][place+1]==FALSE)
            *is_endsplice = TRUE;
        break;
    }
    if(after==end && dz->iparam[ZIG_RUNSTOEND])
        *is_endsplice   = FALSE;
    if(here==base && *here == 0)
        *is_startsplice = FALSE;
    return(direction);
}

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

void do_end_splice(int samps_left,int obufno,dataptr dz)
{
//TW CHANGED
//  float *sptr, val;
    float *sptr;
    double val;
    int  n/*, val*/;
    int   m;
    int  splicelen = dz->iparam[ZIG_SPLICECNT] * dz->infile->channels;
    if(samps_left < splicelen) {
        fprintf(stdout,"WARNING: No buffer space to do end splice. Possible click at end.\n");
        fflush(stdout);
    } else {
        sptr = dz->sbufptr[obufno] - splicelen;
        for(n=dz->iparam[ZIG_SPLICECNT]-1;n>=0;n--) {
            for(m = 0;m<dz->infile->channels;m++) {
                val = /*round*/(*sptr * dz->parray[ZIGZAG_SPLICE][n]);
                *sptr = (float)val;
                sptr++;
            }
        }       
    }
}

//TW NEW FUNCTION (converted to float)
/********************** DO_BTOB ***************************/

int do_btob(dataptr dz)
{
    int exit_status,  chans = dz->infile->channels;
    float *ibuf = dz->sampbuf[0], *obuf = dz->sampbuf[1], *sbuf = dz->sampbuf[2];
    int total_samps_got = 0, obufcnt = 0, splicecnt = 0, startsamp, k, n, m;
    double spliceval = 1.0, spliceincr = 1.0/(double)(dz->iparam[BTOB_SPLEN]/chans);
    int samps_to_work_on = dz->insams[0] - dz->iparam[BTOB_CUT] - (dz->iparam[BTOB_SPLEN]/2);
    int bufcnt = dz->insams[0]/dz->buflen;
    int finished = 0;

    if(bufcnt * dz->buflen < dz->insams[0])
        bufcnt++;
    for(k = bufcnt-1; k >=0; k--) {
        if((sndseekEx(dz->ifd[0],k * dz->buflen,0)) < 0) {
            sprintf(errstr,"sndseekEx() 1 Failed in do_btob()\n");
            return(SYSTEM_ERROR);
        }
        if((exit_status = read_samps(ibuf,dz))<0)
            return(exit_status);
        for(n = dz->ssampsread-chans; n>=0;n-=chans) {
            if(obuf==sbuf) {
                for(m=0;m<chans;m++)
                    sbuf[splicecnt++] = (float)(ibuf[n+m] * spliceval);
                spliceval -= spliceincr;            
                if(splicecnt >= dz->iparam[BTOB_SPLEN]) {
                    finished = 1;
                    break;
                }
            } else {            /* if NOT in splice, check whether going into splice */
                for(m=0;m<chans;m++)
                    obuf[obufcnt++] = ibuf[n+m];
                if(obufcnt >= dz->buflen) {
                    if((exit_status = write_samps(obuf,dz->buflen,dz))<0)
                        return(exit_status);
                    obufcnt = 0;
                }
                if((total_samps_got += chans) >= samps_to_work_on) {
                    obuf= sbuf;
                    spliceval -= spliceincr;            
                }
            }
        }
        if(finished)
            break;
    }
    startsamp = dz->iparam[BTOB_CUT] - (dz->iparam[BTOB_SPLEN]/2);
    k = startsamp/dz->buflen;
    if((sndseekEx(dz->ifd[0],k * dz->buflen,0)) < 0) {
        sprintf(errstr,"sndseekEx() 2 Failed in do_btob()\n");
        return(SYSTEM_ERROR);
    }
    startsamp -= k * dz->buflen;
    splicecnt = 0;
    spliceval = 0.0;
    if((exit_status = read_samps(ibuf,dz))<0)
        return(exit_status);
    do {
        for(n = startsamp; n <dz->ssampsread;n+=chans) {
            if(obuf==sbuf) {
                for(m=0;m<chans;m++)
                    sbuf[splicecnt+m] = (float)((ibuf[n+m] * spliceval) + sbuf[splicecnt+m]);
                spliceval += spliceincr;
                if((splicecnt += chans) >= dz->iparam[BTOB_SPLEN]) {
                    obuf = dz->sampbuf[1];
                    for(m=0;m<dz->iparam[BTOB_SPLEN];m++)
                        obuf[obufcnt++] = sbuf[m];
                    if(obufcnt >= dz->buflen) {
                        if((exit_status = write_samps(obuf,dz->buflen,dz))<0)
                            return(exit_status);
                        obufcnt = 0;
                    }
                }
            } else {
                for(m=0;m<chans;m++)
                    obuf[obufcnt++] = ibuf[n+m];
                if(obufcnt >= dz->buflen) {
                    if((exit_status = write_samps(obuf,dz->buflen,dz))<0)
                        return(exit_status);
                    obufcnt = 0;
                }
            }
        }
        startsamp = 0;
        if((exit_status = read_samps(ibuf,dz))<0)
            return(exit_status);
    } while(dz->ssampsread > 0);
    if(obufcnt > 0) {
        if((exit_status = write_samps(obuf,obufcnt,dz))<0)
            return(exit_status);
    }
    return(FINISHED);
}