/*
 * Copyright (c) 1983-2013 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 <structures.h>
#include <cdpmain.h>
#include <tkglobals.h>
#include <pnames.h>
#include <distort.h>
#include <processno.h>
#include <modeno.h>
#include <globcon.h>
#include <logic.h>
#include <filetype.h>
#include <mixxcon.h>
#include <distort1.h>
#include <flags.h>
#include <speccon.h>
#include <arrays.h>
#include <special.h>
#include <formants.h>
#include <sfsys.h>
#include <osbind.h>
#include <string.h>
#include <arrays.h>
#include <math.h>
#include <ctype.h>

/*

  PRESCALE PULSE-ENVELOPE FILE BETWEEN 0 and 1 in time and copy into parray[PULSENV]
  PRESCALE PULSE-TRANSPOS FILE BETWEEN 0 and 1 in time and copy into parray[PULSTRN]

  NB randomisation pulse-transposition only works if it's a brktable

  HAS TO BE MONO SNDFILE;

*/

static int      write_pulse_to_output(int *pbufpos,int *obufpos,dataptr dz);
static void     randomise_pulse_transposition(dataptr dz);
static int      randomise_pulse_envelope(int obufpos,dataptr dz);
static double   gen_sndtabindex(int obufpos,double *sndtabindex,double *pulsenvindex,double *envstep,
                                int insertsmps,double tablen,int randomise_transpos,dataptr dz);
static int      extract_waveform(int *waveset_start,dataptr dz);
static int      get_wavesetstart(int ibufpos,dataptr dz);
/* in ap_distort */
static int      prescale_pulse_transpos(dataptr dz);
static int      read_impulse_amp_val(double thistime,double *amp,dataptr dz);

/************************************* PREPROCESS_PULSE *************************************/

int preprocess_pulse(dataptr dz)
{
    double k;
    int exit_status;
    if(dz->iparam[PULSE_ENVSIZE] > 0) {
        if((dz->parray[PULSENV] = (double *)malloc((dz->iparam[PULSE_ENVSIZE] * 2) * sizeof(double)))==NULL) {
            sprintf(errstr,"Out of memory for storing backup of original pulse envelope.\n");
            return(MEMORY_ERROR);
        }
        memcpy((char *)dz->parray[PULSENV],(char *)dz->parray[ORIG_PULSENV],(dz->iparam[PULSE_ENVSIZE] * 2) * sizeof(double));
        /* copy original envelope into parray */
        if((dz->iparray[0] = (int *)malloc(dz->iparam[PULSE_ENVSIZE] * sizeof(int)))==NULL) {
            sprintf(errstr,"Out of memory for storing markers for envelope warping.\n");
            return(MEMORY_ERROR);
        }
    }
    if(dz->brksize[PULSE_TRANSPOS] > 0) {
        if((exit_status = prescale_pulse_transpos(dz))<0)
            return(exit_status);
    } else {
        k = dz->param[PULSE_TRANSPOS] / 12.0;
        dz->param[PULSE_TRANSPOS] = pow(2.0,k); /* convert semitones to frq-ratio */
    }
    return(FINISHED);
}

/*********************************** PRESCALE_PULSE_TRANSPOS *************************************/

int prescale_pulse_transpos(dataptr dz)
{
    int brklen = dz->brksize[PULSE_TRANSPOS] * 2;
    int maxtimindx = brklen  - 2;
    int n,m;
    double maxtime = dz->brk[PULSE_TRANSPOS][maxtimindx], scaler;
    scaler = 1.0/maxtime;
    for(n=0,m=1;n<brklen;n+=2,m+=2)
        dz->brk[PULSE_TRANSPOS][n] *= scaler;                   /* scale to 0 to 1 time range */
    dz->brk[PULSE_TRANSPOS][maxtimindx] = 1.0;
    if((dz->parray[PULSTRN] = (double *)malloc(brklen * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of memory for storing backup of original pulse transposition envelope\n");
        return(MEMORY_ERROR);
    }
    memcpy((char *)dz->parray[PULSTRN],(char *)dz->brk[PULSE_TRANSPOS],brklen * sizeof(double));
    return(FINISHED);
}

/************************************* DO_PULSETRAIN *************************************/

int do_pulsetrain(dataptr dz)
{
    int exit_status;
    float *ibuf = dz->sampbuf[0];   /* stores input  */
    float *obuf = dz->sampbuf[1];   /* stores output */
    float *sbuf = dz->sampbuf[2];   /* stores waveset cycoes, for SYN option  */
    float *pbuf = dz->sampbuf[3];   /* stores pulse, before writing to output */
    int srate = dz->infile->srate;
    float *spliceptr, *obufend = obuf + dz->buflen;
    int startsamp = round(dz->param[PULSE_STARTTIME] * srate);
    int insertdur = round(dz->param[PULSE_DUR] * srate);
    int last_total_ssampsread, total_ssampsread = 0, ssampsread = 0, insertsmps = 0;
    int  smpsecsize = F_SECSIZE, secsleft, edit_todo = (int)round(ENDBIT_SPLICE);
    int ibufpos = 0, ibufleft, obufpos = 0, pbufpos = 0, obufleft;
    double amp, frq, sndtabindex, pulsenvindex;
    int waveset_len = 0;
    double envstep;
    int randomise_transpos = 0, firsttime = 1;
    int smps_pretime, waveset_start;
    double interp, valdiff, k;
    float val, upval;
    int here, n, m;

    if(dz->mode == PULSE_SYNI)
        startsamp = dz->iparam[PULSE_STARTTIME];
    else
        startsamp = round(dz->param[PULSE_STARTTIME] * srate);

    /* PROCESS FILE PRIOR TO PULSE-TRAIN'S START, IF NESS */

    if(dz->mode == PULSE_IMP) {
        k = dz->duration;
        if(!dz->vflag[PULSE_KEEPSTART]) {
            k -= dz->param[PULSE_STARTTIME];
            if(!dz->vflag[PULSE_KEEPEND])
                k = min(dz->param[PULSE_DUR],k);
        } else if(!dz->vflag[PULSE_KEEPEND]) {
            k = dz->param[PULSE_STARTTIME] + dz->param[PULSE_DUR];
            k = min(dz->duration,k);
        }
    } else {
        k = dz->param[PULSE_DUR];
        if(dz->vflag[PULSE_KEEPEND]) {
            k += dz->duration;
            if(!dz->vflag[PULSE_KEEPSTART])
                k -= dz->param[PULSE_STARTTIME];
        } else if(dz->vflag[PULSE_KEEPSTART])
            k += dz->param[PULSE_STARTTIME];
    }
    dz->tempsize = (int)round(k * (dz->infile->srate));

    while(total_ssampsread + dz->buflen < startsamp) {
        if(( exit_status = read_samps(ibuf,dz)) < 0) {
            sprintf(errstr, "Can't read samps from input soundfile\n");
            return(SYSTEM_ERROR);
        }
        ssampsread = dz->ssampsread;
        last_total_ssampsread = total_ssampsread;
        total_ssampsread += ssampsread;
        if(dz->vflag[PULSE_KEEPSTART]) {
            if(ssampsread > 0) {
                if((exit_status = write_samps(ibuf,ssampsread,dz))<0)
                    return(exit_status);
            }
        }
    }
    if((secsleft = (startsamp - total_ssampsread)/smpsecsize)> 0) {
        if(( ssampsread = fgetfbufEx(ibuf,secsleft * F_SECSIZE, dz->ifd[0],0)) < 0) {
            sprintf(errstr, "Can't read samps from input soundfile\n");
            return(SYSTEM_ERROR);
        }
        last_total_ssampsread = total_ssampsread;
        total_ssampsread += ssampsread;
        if(dz->vflag[PULSE_KEEPSTART]) {
            if(ssampsread > 0) {
                if((exit_status = write_samps(ibuf,ssampsread,dz))<0)
                    return(exit_status);
            }
        }
    }
    smps_pretime = startsamp - total_ssampsread;    /* no of samples before param-specified time */

    if(( ssampsread = fgetfbufEx(ibuf, dz->buflen + F_SECSIZE, dz->ifd[0],0)) < 0) {
        sprintf(errstr, "Can't read samples from input soundfile\n");   /* To get wraparound points */
        return(SYSTEM_ERROR);
    }
    last_total_ssampsread = total_ssampsread;
    if(ssampsread > dz->buflen) {
        sndseekEx(dz->ifd[0],last_total_ssampsread + dz->buflen,0);
        total_ssampsread = last_total_ssampsread + dz->buflen;
    } else {        /* We'RE AT END oF FILE... */
        total_ssampsread = last_total_ssampsread + ssampsread;
        ibuf[ssampsread] = 0.0; /* CREATE zero-val wraparound points */

    }

    /* FIND START OF WAVESETS */

    if((waveset_start = get_wavesetstart(smps_pretime,dz)) < 0) {
        sprintf(errstr,"Can't find the required waveset start within a single buffer.\n");
        return(GOAL_FAILED);
    }
    if((waveset_start > 0) && dz->vflag[PULSE_KEEPSTART]) {
        memcpy((char *)obuf,(char *)ibuf,waveset_start * sizeof(float));
        obufpos = waveset_start;        /* copy any inbuf remnant prior to pulsing, to outbuf */
    }
    ibufpos = waveset_start;

    if(dz->mode!=PULSE_IMP) {
        if((waveset_len = extract_waveform(&waveset_start,dz))<0) {     /* NB copy rounding sample[s] at end */
            sprintf(errstr,"Can't find the required wavesets within a single buffer.\n");
            return(GOAL_FAILED);
        }
        sndtabindex = 0.0;                                                      /* position in storage buffer */
    } else
        sndtabindex = (double)waveset_start;            /* position in input buffer */

    /* INITIALISE SHAPE AND LENGTH OF FIRST IMPULSE */

    if(dz->iparam[PULSE_ENVSIZE] > 0)
        randomise_pulse_envelope(obufpos,dz);   /* randomise shape of pulse, and copy reshaped pulse to read-env-table */
    /* +insert edit shoulders at start and end */
    if(!flteq(dz->param[PULSE_PITCHRAND],0.0)) {
        randomise_transpos = 1;
        if(dz->brksize[PULSE_TRANSPOS] <= 0) {
            fprintf(stdout,"WARNING: Randomisation of transposition only applies to a transposition TABLE\n");
            fflush(stdout);
            randomise_transpos = 0;
        } else
            randomise_pulse_transposition(dz);
    } else if (dz->brksize[PULSE_TRANSPOS] > 0) {           /* if NOT randomised, convert to frqratio NOW */
        for(n=0,m=1;n<dz->brksize[PULSE_TRANSPOS];n++,m+=2) {
            k = dz->parray[PULSTRN][m]/SEMITONES_PER_OCTAVE;
            dz->brk[PULSE_TRANSPOS][m] = pow(2.0,k);
        }
    }
    pulsenvindex = 0.0;
    if(dz->iparam[PULSE_ENVSIZE] <= 0)
        amp = 1.0;
    else
        amp = dz->parray[PULSENV][0];
    if(dz->brksize[PULSE_FRQ] > 0) {
        if((exit_status = read_value_from_brktable(0.0,PULSE_FRQ,dz))<0)
            return exit_status;
    }
    frq = dz->param[PULSE_FRQ];
    if(dz->param[PULSE_FRQRAND] > 0.0) {
        k = ((drand48() * 2.0) - 1.0) * dz->param[PULSE_FRQRAND];
        k /= SEMITONES_PER_OCTAVE;
        k = pow(2.0,k);
        frq *= k;
    }
    envstep = frq/srate;

    /* DO IMPULSE TRAIN */

    while(insertsmps < insertdur) {
        if(!firsttime && flteq(pulsenvindex,0.0)) {     /* if at start of new pulse */
            if((exit_status = write_pulse_to_output(&pbufpos,&obufpos,dz))<0)
                return(exit_status);
        }
        firsttime = 0;
        if(dz->mode!=PULSE_IMP) {
            interp = fmod(sndtabindex,1.0);
            here = (int)floor(sndtabindex);
            val    = sbuf[here++];
            upval  = sbuf[here];
            valdiff = (upval - val) * interp;
            pbuf[pbufpos++] = (float)((val + valdiff) * amp);
            if(pbufpos >= dz->buflen) {
                sprintf(errstr,"Pulse length exceeds length of internal buffer : cannot proceed.\n");
                return(GOAL_FAILED);
            }
        } else {
            interp = fmod(sndtabindex,1.0);
            ibufpos = (int)floor(sndtabindex);
            while(ibufpos  >= ssampsread) {
                /* read extra sector, for wraparound vals for interpolation */
                if(( ssampsread = fgetfbufEx(ibuf, dz->buflen + F_SECSIZE, dz->ifd[0],0)) < 0) {
                    sprintf(errstr, "Can't read samps from input soundfile\n");     /* read failed */
                    return(SYSTEM_ERROR);
                }
                if(ssampsread <= 0) {   /* read zero bytes = EOF */
                    if(obufpos > 0) {
                        if((exit_status = write_samps(obuf,obufpos,dz))<0)
                            return(exit_status);
                    }
                    return(FINISHED);
                }
                if(ssampsread <= dz->buflen) {  /* generate zero-val wraparound points if buffer+wrap not full */
                    ibuf[ssampsread] = 0.0;
                    total_ssampsread += ssampsread;
                } else {
                    last_total_ssampsread = total_ssampsread;
                    ssampsread = dz->buflen;        /* effective read is a buffer-full */
                    total_ssampsread += ssampsread;
                    sndseekEx(dz->ifd[0],last_total_ssampsread + dz->buflen,0);
                }
                ibufpos -= dz->buflen; /* as current read succeeded, last input buffer was full: so this val is >= 0 */
                sndtabindex -= (double)dz->buflen;
            }
            val    = ibuf[ibufpos++];
            upval  = ibuf[ibufpos];
            valdiff = (upval - val) * interp;
            pbuf[pbufpos++] = (float)((val + valdiff) * amp);
            if(pbufpos >= dz->buflen) {
                sprintf(errstr,"Pulse length exceeds length of internal buffer : cannot proceed\n");
                return(GOAL_FAILED);
            }
        }
        amp = gen_sndtabindex(obufpos,&sndtabindex,&pulsenvindex,&envstep,insertsmps,(double)waveset_len,randomise_transpos,dz);
        insertsmps++;
    }
    if(pbufpos > 0) {
        if((exit_status = write_pulse_to_output(&pbufpos,&obufpos,dz))<0)
            return(exit_status);
    }

    /* DO REST OF INPUT FILE AFTER PULSETRAIN, IF NESS */

    if(dz->vflag[PULSE_KEEPEND]) {
        for(;;) {
            ibufleft = ssampsread - ibufpos;
            obufleft = dz->buflen - obufpos;
            spliceptr = obuf+obufpos;
            if(ibufleft >= obufleft) {
                memcpy((char *)(obuf+obufpos),(char *)(ibuf+ibufpos),obufleft * sizeof(float));
                while(edit_todo > 0) {
                    k = *spliceptr * ((ENDBIT_SPLICE - (double)edit_todo)/ENDBIT_SPLICE);
                    *spliceptr++ = (float)k;
                    edit_todo--;
                    if(spliceptr >= obufend)
                        break;
                }
                ibufpos += obufleft;
                if((exit_status = write_samps(obuf,dz->buflen,dz))<0)
                    return(exit_status);
                obufpos = 0;
            } else {
                memcpy((char *)(obuf+obufpos),(char *)(ibuf+ibufpos),ibufleft * sizeof(float));
                while(edit_todo > 0) {
                    k = *spliceptr * ((ENDBIT_SPLICE - (double)edit_todo)/ENDBIT_SPLICE);
                    *spliceptr++ = (float)k;
                    edit_todo--;
                    if(spliceptr >= obufend)
                        break;
                }
                obufpos += ibufleft;
                if(( exit_status = read_samps(ibuf, dz)) < 0) {
                    sprintf(errstr, "Can't read samps from input soundfile\n");
                    return(SYSTEM_ERROR);
                }
                ssampsread = dz->ssampsread;
                if(ssampsread <= 0)
                    break;
                ibufpos = 0;
            }
        }
    }
    if(obufpos > 0) {
        if((exit_status = write_samps(obuf,obufpos,dz))<0)
            return(exit_status);
    }
    return(FINISHED);
}

/************************************* GET_WAVESETSTART *************************************/

int get_wavesetstart(int ibufpos,dataptr dz)
{
    float *ibuf = dz->sampbuf[0];

    if(ibuf[ibufpos] > 0.0) {
        while(ibuf[ibufpos] > 0.0) {
            if(++ibufpos >= dz->buflen)
                return(-1);
        }
    } else if(ibuf[ibufpos] < 0.0) {
        while(ibuf[ibufpos] < 0.0) {
            if(++ibufpos >= dz->buflen)
                return(-1);
        }
    } else {
        while(smpflteq(ibuf[ibufpos],0.0)) {
            if(++ibufpos >= dz->buflen)
                return(-1);
        }
    }
    return(ibufpos);
}

/************************************* EXTRACT_WAVEFORM *************************************/

// NOV 2002 MAXSAMP -> F_MAXSAMP as well as short -> float
int extract_waveform(int *waveset_start,dataptr dz)
{
    int ibufpos = *waveset_start, waveform_len = 0;
    float *ibuf = dz->sampbuf[0];
    float *sbuf = dz->sampbuf[2];
    double frqlimit = dz->infile->srate/PULSE_FRQLIM;
    double amplimit = dbtogain((double)PULSE_DBLIM) * F_MAXSAMP;
    int capture_samps = 0, capture_wavesets = 0;
    int last_waveform_len = 0;
    double maxval, last_maxval = 0.0, wcntr = 0;

    if(dz->mode == PULSE_SYN)
        capture_samps = (int)round(dz->param[PULSE_WAVETIME] * dz->infile->srate);
    else
        capture_wavesets = dz->iparam[PULSE_WAVETIME];
    while(smpflteq(ibuf[ibufpos],0.0)) {
        if(++ibufpos >= dz->buflen)
            return(-1);
    }
    *waveset_start = ibufpos;
    maxval = fabs(ibuf[ibufpos]);

    switch(dz->mode) {
    case(PULSE_SYN):
        for(;;) {
            if(ibuf[ibufpos] > 0.0) {
                while(ibuf[ibufpos] > 0.0) {
                    if(++ibufpos >= dz->buflen)
                        return(-1);
                    maxval = max(maxval,fabs(ibuf[ibufpos]));
                }
                while(ibuf[ibufpos] <= 0.0) {
                    if(++ibufpos >= dz->buflen)
                        return(-1);
                    maxval = max(maxval,fabs(ibuf[ibufpos]));
                }
            } else if(ibuf[ibufpos] < 0.0) {
                while(ibuf[ibufpos] < 0.0) {
                    if(++ibufpos >= dz->buflen)
                        return(-1);
                    maxval = max(maxval,fabs(ibuf[ibufpos]));
                }
                while(ibuf[ibufpos] >= 0.0) {
                    if(++ibufpos >= dz->buflen)
                        return(-1);
                    maxval = max(maxval,fabs(ibuf[ibufpos]));
                }
            }
            if((waveform_len = ibufpos - *waveset_start) >= capture_samps)
                break;
            else {
                last_waveform_len = waveform_len;
                last_maxval = maxval;
            }
        }
        if(capture_samps - last_waveform_len < waveform_len - capture_samps) {
            waveform_len = last_waveform_len;
            maxval = last_maxval;
        }
        break;
    case(PULSE_SYNI):
        while(wcntr < capture_wavesets) {
            if(ibuf[ibufpos] > 0.0) {
                while(ibuf[ibufpos] > 0.0) {
                    if(++ibufpos >= dz->buflen)
                        return(-1);
                    maxval = max(maxval,fabs(ibuf[ibufpos]));
                }
                while(ibuf[ibufpos] <= 0.0) {
                    if(++ibufpos >= dz->buflen)
                        return(-1);
                    maxval = max(maxval,fabs(ibuf[ibufpos]));
                }
            } else if(ibuf[ibufpos] < 0.0) {
                while(ibuf[ibufpos] < 0.0) {
                    if(++ibufpos >= dz->buflen)
                        return(-1);
                    maxval = max(maxval,fabs(ibuf[ibufpos]));
                }
                while(ibuf[ibufpos] >= 0.0) {
                    if(++ibufpos >= dz->buflen)
                        return(-1);
                    maxval = max(maxval,fabs(ibuf[ibufpos]));
                }
            }
            wcntr++;
        }
        waveform_len = ibufpos - *waveset_start;
        break;
    }
    if(waveform_len <= 0) {
        sprintf(errstr,"Failed to establish a viable sound to loop\n");
        return(GOAL_FAILED);
    } else if((double)waveform_len <= frqlimit) {
        frqlimit = (double)dz->infile->srate/(double)waveform_len;
        fprintf(stdout,"WARNING: Waveset length is only %d samples, corresponding to frq >= %.1lf hz\n",waveform_len,frqlimit);
        fflush(stdout);
    }
    if((double)maxval <= amplimit) {
        fprintf(stdout,"WARNING: Waveset amplitude is <= %lf dB\n",(double)PULSE_DBLIM);
        fflush(stdout);
    }
    memcpy((char *)sbuf,(char *)(ibuf + *waveset_start),waveform_len * sizeof(float));
    return(waveform_len);
}

/************************************* GEN_TABINDEX *************************************/

double gen_sndtabindex(int obufpos,double *sndtabindex,double *pulsenvindex,double *envstep,
                       int insertsmps,double tablen,int randomise_transpos,dataptr dz)
{
    int exit_status;
    double thistime, amp, frq, k;
    *pulsenvindex += *envstep;
    if(*pulsenvindex >= 1.0) {
        if(dz->iparam[PULSE_ENVSIZE] <= 0) {                    /* no impulse: must continue to end of sndtable (zero-cross) to avoid glitch */
            *sndtabindex += dz->param[PULSE_TRANSPOS];      /* transpos sticks at previous value as table end has been reached */
            if(*sndtabindex >= tablen) {
                *pulsenvindex = 0.0;                            /* reset to start of envelope */
                *sndtabindex = 0.0;
                thistime = (double)insertsmps/(double)dz->infile->srate;
                if(dz->brksize[PULSE_FRQ] > 0) {
                    if((exit_status = read_value_from_brktable(thistime,PULSE_FRQ,dz))<0)
                        return exit_status;
                }
                frq = dz->param[PULSE_FRQ];
                if(dz->param[PULSE_FRQRAND] > 0.0) {
                    k = ((drand48() * 2.0) - 1.0) * dz->param[PULSE_FRQRAND];
                    k /= SEMITONES_PER_OCTAVE;
                    k = pow(2.0,k);
                    frq *= k;
                }
                *envstep = frq/dz->infile->srate;
                if(randomise_transpos && (dz->param[PULSE_PITCHRAND] > 0.0))
                    randomise_pulse_transposition(dz);
            }
            return(1.0);                                                    /* no impulse: amplitude is always 1.0 */
        }
        /* GET NEW VALUE OF PULSE FRQ, AND HENCE OF STEP IN ENVEL TABLE */
        thistime = (double)insertsmps/(double)dz->infile->srate;
        if(dz->brksize[PULSE_FRQ] > 0) {
            if((exit_status = read_value_from_brktable(thistime,PULSE_FRQ,dz))<0)
                return exit_status;
        }
        frq = dz->param[PULSE_FRQ];
        if(dz->param[PULSE_FRQRAND] > 0.0) {
            k = ((drand48() * 2.0) - 1.0) * dz->param[PULSE_FRQRAND];
            k /= SEMITONES_PER_OCTAVE;
            k = pow(2.0,k);
            frq *= k;
        }
        *envstep = frq/dz->infile->srate;
        if(dz->iparam[PULSE_ENVSIZE] > 0)
            randomise_pulse_envelope(obufpos,dz);   /* randomise shape of pulse, and copy reshaped pulse to read-env-table */
        /* insert edit shoulders at start and end */
        /* orig envelope has been copied to parray[PULSENV], variant copied back to brk[] */

        if(randomise_transpos && (dz->param[PULSE_PITCHRAND] > 0.0))
            randomise_pulse_transposition(dz);

        *pulsenvindex = 0.0;                            /* reset to start of envelope */
        if((exit_status = read_impulse_amp_val(*pulsenvindex,&amp,dz))<0)
            return exit_status;
        if(dz->mode!=PULSE_IMP)
            *sndtabindex = 0.0;
        else
            *sndtabindex = floor(*sndtabindex + 1.0);       /* sync table pointer with actual samples in input stream */
    } else {
        if(dz->iparam[PULSE_ENVSIZE] <= 0) {                    /* no impulse */
            if(dz->brksize[PULSE_TRANSPOS]) {
                if((exit_status = read_value_from_brktable(*pulsenvindex,PULSE_TRANSPOS,dz))<0)
                    return exit_status;
            }
            *sndtabindex += dz->param[PULSE_TRANSPOS];
            *sndtabindex = fmod(*sndtabindex,tablen);       /* cycle around soundtable */
            return(1.0);                                                            /* no impulse: amplitude is always 1.0 */
        }
        if((exit_status = read_impulse_amp_val(*pulsenvindex,&amp,dz))<0)
            return exit_status;
        if(dz->brksize[PULSE_TRANSPOS]) {
            if((exit_status = read_value_from_brktable(*pulsenvindex,PULSE_TRANSPOS,dz))<0)
                return exit_status;
        }
        *sndtabindex += dz->param[PULSE_TRANSPOS];
        if(dz->mode!=PULSE_IMP)
            *sndtabindex = fmod(*sndtabindex,tablen);
    }
    return amp;
}

/************************************* RANDOMISE_PULSE_ENVELOPE *************************************/

int randomise_pulse_envelope(int obufpos,dataptr dz)
{
    int n, m, kk, maxpos, maxmark;
    int *mark = dz->iparray[0];
    double ratio, above, below, randmove, k, maxi, timearound;
    double convertor = (dz->param[PULSE_FRQ] * ENDBIT_SPLICE)/(double)dz->infile->srate;
    double abovestep, belowstep, minbelowtime, minabovetime;
    int not_above, not_below;

    dz->parray[PULSENV][0] = dz->parray[ORIG_PULSENV][0];
    for(n=3;n<dz->iparam[PULSE_ENVSIZE]*2;n+=2) {
        if(dz->parray[ORIG_PULSENV][n] < dz->parray[ORIG_PULSENV][n-2]) {
            ratio = dz->parray[PULSENV][n-2]/dz->parray[ORIG_PULSENV][n-2]; /* ratio of previous val's new height to it's old height */
            above = (dz->parray[ORIG_PULSENV][n-2] - dz->parray[ORIG_PULSENV][n]) * ratio; /* vert distance twixt preceding point & this, scaled */
            below = (dz->parray[ORIG_PULSENV][n]) * ratio;                                                  /* vert distance twixt 0 & this, scaled */
            k = ((drand48() * 2.0) - 1.0) * dz->param[PULSE_SHAPERAND];
            if(k >= 0.0)
                randmove = above * k;
            else
                randmove = below * k;
            dz->parray[PULSENV][n] = below + randmove;
        } else if(dz->parray[ORIG_PULSENV][n] > dz->parray[ORIG_PULSENV][n-2]) {
            ratio = (1.0 - dz->parray[PULSENV][n-2])/(1.0 - dz->parray[ORIG_PULSENV][n-2]); /* simil ratio of dist from top [1.0] */
            above = (1.0 - dz->parray[ORIG_PULSENV][n]) * ratio; /* vert distance twixt top [1.0] & this point, scaled */
            below = (dz->parray[ORIG_PULSENV][n] - dz->parray[ORIG_PULSENV][n-2]) * ratio; /* vert distance preceeding pnt & this, scaled */
            k = ((drand48() * 2.0) - 1.0) * dz->param[PULSE_SHAPERAND];
            if(k >= 0.0)
                randmove = above * k;
            else
                randmove = below * k;
            dz->parray[PULSENV][n] = dz->parray[PULSENV][n-2] + below + randmove;
        } else {
            dz->parray[PULSENV][n] = dz->parray[PULSENV][n-2];
        }
    }
    /* randomise pulse-env timings */
    for(m=1;m < dz->iparam[PULSE_ENVSIZE]-1; m++)
        mark[m] = 0;
    kk = dz->iparam[PULSE_ENVSIZE] - 2;
    while(kk>0) {
        maxi = 0.0;
        maxpos = 0;
        maxmark = 0;
        not_above = 0;
        not_below = 0;
        for(m=1,n=2;n < (dz->iparam[PULSE_ENVSIZE]-1) * 2; n+=2,m++) {
            if(mark[m]==0) {
                timearound = dz->parray[PULSENV][n+2] - dz->parray[PULSENV][n-2];
                if(timearound > maxi) {
                    maxi = timearound;
                    maxpos = n;
                    maxmark = m;
                }
            }
        }
        abovestep = dz->parray[PULSENV][maxpos+3] - dz->parray[PULSENV][maxpos+1];
        belowstep = dz->parray[PULSENV][maxpos+1] - dz->parray[PULSENV][maxpos-1];
        minbelowtime = fabs(convertor * belowstep);
        minabovetime = fabs(convertor * abovestep);
        if((above = dz->parray[PULSENV][maxpos+2] - dz->parray[PULSENV][maxpos]) < minabovetime)
            not_above = 1;
        if((below = dz->parray[PULSENV][maxpos] - dz->parray[PULSENV][maxpos-2]) < minbelowtime)
            not_below = 1;
        if(not_above) {
            if(not_below) {
                sprintf(errstr,"WARNING: possible glitch, due to sudden envelope change, after %lf secs\n",
                        (dz->total_samps_written + obufpos)/(double)dz->infile->srate);
                fflush(stdout);
                k = 0.0;
            } else
                k = drand48() * -1.0 * dz->param[PULSE_TIMERAND];
        } else if(not_below)
            k = drand48() * dz->param[PULSE_TIMERAND];
        else
            k = ((drand48() * 2.0) - 1.0) * dz->param[PULSE_TIMERAND];
        /* KLUDGE --> */
        k *= 0.5;
        /* <-- KLUDGE */
        if(k >= 0.0)
            randmove = above * k;
        else
            randmove = below * k;
        dz->parray[PULSENV][maxpos] += randmove;
        mark[maxmark] = 1;
        kk--;
    }
    return(FINISHED);
}

/************************************* RANDOMISE_PULSE_TRANSPOSITION *************************************/

void randomise_pulse_transposition(dataptr dz)
{
    int n, m;
    double k;
    for(n=0,m=1;n<dz->brksize[PULSE_TRANSPOS];n++,m+=2) {
        if(flteq(dz->brk[PULSE_TRANSPOS][m],0.0))
            dz->brk[PULSE_TRANSPOS][m] = 1.0;
        else {
            k = ((drand48() * 2.0) - 1.0) * dz->param[PULSE_PITCHRAND];
            k *= dz->parray[PULSTRN][m]/SEMITONES_PER_OCTAVE;
            dz->brk[PULSE_TRANSPOS][m] = pow(2.0,k);
        }
    }
}

/************************************* WRITE_PULSE_TO_OUTPUT *************************************/

int write_pulse_to_output(int *pbufpos,int *obufpos,dataptr dz)
{
    int exit_status;
    float *obuf = dz->sampbuf[1];
    float *pbuf = dz->sampbuf[3];
    int n, m;
    if(dz->iparam[PULSE_ENVSIZE] > 0) {
        for(n=0;n<round(ENDBIT_SPLICE);n++)             /* WRITE PULSE-BUFFER TO OUTPUT, with relevant splices if there's an impulse envelope */
            pbuf[n] = (float)(pbuf[n] * (double)n/ENDBIT_SPLICE);
        for(m = *pbufpos-1,n=0;n<round(ENDBIT_SPLICE);n++,m--)
            pbuf[m] = (float)(pbuf[m] * (double)n/ENDBIT_SPLICE);
    }
    for(n=0;n<*pbufpos;n++) {
        obuf[(*obufpos)++] = pbuf[n];
        if(*obufpos >= dz->buflen) {
            if((exit_status = write_samps(obuf,dz->buflen,dz))<0)
                return(exit_status);
            *obufpos = 0;
        }
    }
    *pbufpos = 0;
    return(FINISHED);
}

/**************************** READ_IMPULSE_AMP_VAL *****************************/

int read_impulse_amp_val(double thistime,double *amp,dataptr dz)
{
    double *p, lotime, loval, hitime, hival, timediff, step, ratio;
    p = dz->parray[PULSENV];
    if(flteq(thistime,0.0)) {
        *amp = dz->parray[PULSENV][1];
        return(FINISHED);
    }
    while(*p < thistime)
        p += 2;
    p -= 2;
    lotime = *p++;
    loval  = *p++;
    hitime = *p++;
    hival  = *p++;
    timediff = thistime - lotime;
    step = hival - loval;
    ratio = timediff/(hitime-lotime);
    *amp = loval + (step * ratio);
    return(FINISHED);
}