ComposerDesktopProject/dev/distort/distort.c

/*
 * 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
 *
 */



/* floatsam version*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <structures.h>
#include <tkglobals.h>
#include <globcon.h>
#include <modeno.h>
#include <arrays.h>
#include <distort.h>
#include <cdpmain.h>

#include <sfsys.h>
#include <osbind.h>

#if defined unix || defined __GNUC__
#define round lround
#endif

//TW COMMENT : phase as used here, with vals >1 or <-1 (meaning above zero or below zero) in intrinsically 'int'
//             phase is also not 'float' elsewhere,
//                         To avoid the construction "switch((int)phase)", I've made phase 'int' everywhere, casting in situ where ness.

//static int    distort_func(float *b,int tthis,int i,float phase,int lastzero,float cyclemax,dataptr dz);
static int      distort_func(float *b,int tthis,int i,int phase,int lastzero,float cyclemax,dataptr dz);
//static int    distort_func_crosbuf(int tthis,int i,float phase,int lastzero,float cyclemax,int oldbufcnt,dataptr dz);
static int      distort_func_crosbuf(int tthis,int i,int phase,int lastzero,float cyclemax,int oldbufcnt,dataptr dz);
static int      sinusoid(int tthis,int lastzero,float cyclemax,int endcycle,dataptr dz);
static int      end_sinusoid(int tthis,int lastzero,float cyclemax,int newbufcnt,int oldbufcnt,dataptr dz);
static int      genpulse(int step,float maxamp,float *bufptr,float *bufend);
static int      triangle(float *b,int lastzero,float cyclemax,int endcycle);
static int      end_triangle(int tthis,int lastzero,float cyclemax,int newbufcnt,int oldbufcnt,dataptr dz);
//static int    exaggerate(int lastzero,int thiszero,float phase,float *b,double powfac);
static int      exaggerate(int lastzero,int thiszero,int phase,float *b,double powfac);
static int      do_exagg
                        (double lastmax,int lastpos,double thismax,int thispos,double powfac,float *b);
//static int    do_exagg2(float phase,int lastpos,int thispos,double powfac,float *b);
static int      do_exagg2(int phase,int lastpos,int thispos,double powfac,float *b);
//static int    end_exagg(int tthis,int lastzero,int newbufcnt,int oldbufcnt,double powfac,float phase,dataptr dz);
static int      end_exagg(int tthis,int lastzero,int newbufcnt,int oldbufcnt,double powfac,int phase,dataptr dz);
static int      get_powfac(int lastzero,int thiszero,dataptr dz);

/************************* DO_DISTORT ***********************************
 *
 * Works on SINGLE HALF wavecycles.
 *
 * This looks for single half-wavecycles, and does not change there
 * number (or their phase) in the output. It therefore resets the
 * input & output phase on each entry.
 */

int do_distort(int tthis,int is_last,int *lastzero,float *cyclemax,dataptr dz)
{
        int exit_status;
        register int i = *lastzero;
        int     oldbufcnt, lastmarker;
        int     phase = 1;
        float   *b          = dz->sampbuf[tthis];
        int     samples = dz->buflen;
        if(is_last)
                samples  = dz->ssampsread;
//TW CHANGED
        while(smpflteq(b[i],0.0) && i<samples)
                i++;
        lastmarker = i;
        if(b[i]<0)
                phase  = -1;
        while(i < samples)  {
                switch(phase) {
                case(1):
                        if(b[i] > 0) {
                                if(b[i]>*cyclemax)
                                        *cyclemax=b[i];
                                i++;
                        } else {
                                if((exit_status = distort_func(b,tthis,i,phase,*lastzero,*cyclemax,dz))<0)
                                        return(exit_status);
                                i = lastmarker = reset(i,samples,b,lastzero,cyclemax);
                                if(b[i]<0)
                                        phase=-1;
                        }
                        break;
                case(-1):
                        if(b[i] < 0) {
                                if(b[i]<*cyclemax)
                                        *cyclemax=b[i];
                                i++;
                        } else {
                                if((exit_status = distort_func(b,tthis,i,phase,*lastzero,*cyclemax,dz))<0)
                                        return(exit_status);
                                i = lastmarker = reset(i,samples,b,lastzero,cyclemax);
                                if(b[i]>0)
                                        phase=1;
                        }
                        break;
                }
        }
        if(!is_last) {
                oldbufcnt = dz->buflen - *lastzero;
                b = dz->sampbuf[!tthis];
                samples = dz->ssampsread;
                i = 0;
                switch(phase) {
                case(1):
                        while(i < samples)  {
                                if(b[i]>0) {
                                        if(b[i]>*cyclemax)
                                                *cyclemax = b[i];
                                        i++;
                                } else
                                        break;
                        }
                        break;
                case(-1):
                        while(i < samples)  {
                                if(b[i]<0) {
                                        if(b[i]<*cyclemax)
                                                *cyclemax = b[i];
                                        i++;
                                } else
                                        break;
                        }
                        break;
                }
                if((exit_status = distort_func_crosbuf(tthis,i,phase,*lastzero,*cyclemax,oldbufcnt,dz))<0)
                        return(exit_status);
                i = lastmarker = reset(i,samples,dz->sampbuf[!tthis],lastzero,cyclemax);
        }
        return(FINISHED);
}

/*************************** DISTORT_FUNC ******************************/

int distort_func(float *b,int tthis,int i,int phase,int lastzero,float cyclemax,dataptr dz)
{
        int exit_status;
        register int j;
        int halfcycle, step;
        float    clipmax;
        switch(dz->mode) {
        case(DISTORT_SQUARE_FIXED):
                clipmax = FCLIPMAX * (float)phase;
                for(j=lastzero;j<i;j++)
                        b[j]=clipmax;                   /* 4 */
                break;
        case(DISTORT_SQUARE):
                for(j=lastzero;j<i;j++)
                        b[j]=cyclemax;
                break;
        case(DISTORT_TRIANGLE_FIXED):
                clipmax = FCLIPMAX * (float)phase;
                if(i - lastzero > 3) {
                        if((exit_status = triangle(b,lastzero,clipmax,i))<0)
                                return(exit_status);
                }
                break;
        case(DISTORT_TRIANGLE):
                if(i - lastzero > 3) {
                        if((exit_status = triangle(b,lastzero,cyclemax,i))<0)
                                return(exit_status);
                }
                break;
        case(DISTORT_INVERT_HALFCYCLE):
                for(j=lastzero;j<i;j++)
                        b[j]=cyclemax - b[j];
                break;
        case(DISTORT_CLICK):
                halfcycle = i - lastzero;
                step = min((int)dz->iparam[DISTORT_PULSE],halfcycle);
                if((exit_status = genpulse(step,cyclemax,b+lastzero,b+i))<0)
                        return(exit_status);
                break;
        case(DISTORT_SINE):
                if(i - lastzero > 5) {
                        if((exit_status = sinusoid(tthis,lastzero,cyclemax,i,dz))<0)
                                return(exit_status);
                }
                break;
        case(DISTORT_EXAGG):
                if(dz->brksize[DISTORT_POWFAC] && (exit_status = get_powfac(lastzero,i,dz))<0)
                        return(exit_status);
                if((exit_status = exaggerate(lastzero,i,phase,dz->sampbuf[tthis],dz->param[DISTORT_POWFAC]))<0)
                        return(exit_status);
                break;
        default:
                sprintf(errstr,"Unknown case in distort_func()\n");
                return(PROGRAM_ERROR);
        }
        return(FINISHED);
}

/************************ DISTORT_FUNC_CROSBUF **********************/

int distort_func_crosbuf(int tthis,int i,int phase,int lastzero,float cyclemax,int oldbufcnt,dataptr dz)
{
        int exit_status;
        register int j;
        int end_bit, halfcycle, step;
        float *buf = dz->sampbuf[tthis];
        /*int*/float clipmax;
        switch(dz->mode) {
        case(DISTORT_SQUARE_FIXED):
                clipmax = (float)(FCLIPMAX * (float)phase);
                for(j=lastzero;j<dz->buflen; j++)
                        buf[j] = clipmax;
                buf = dz->sampbuf[!tthis];
                for(j=0;j<i;j++)
                        buf[j] = clipmax;
                break;
        case(DISTORT_SQUARE):
                for(j=lastzero;j<dz->buflen; j++)
                        buf[j] = cyclemax;
                buf = dz->sampbuf[!tthis];
                for(j=0;j<i;j++)
                        buf[j] = cyclemax;
                break;
        case(DISTORT_TRIANGLE_FIXED):
                clipmax = (float)(FCLIPMAX * (float)phase);
                if(oldbufcnt + i > 3) {
                        if((exit_status = end_triangle(tthis,lastzero,clipmax,i,oldbufcnt,dz))<0)
                                return(exit_status);
                }
                break;
        case(DISTORT_TRIANGLE):
                if(oldbufcnt + i > 3) {
                        if((exit_status = end_triangle(tthis,lastzero,cyclemax,i,oldbufcnt,dz))<0)
                                return(exit_status);
                }
                break;
        case(DISTORT_INVERT_HALFCYCLE):
                for(j=lastzero;j<dz->buflen; j++)
                        buf[j] = cyclemax - buf[j];
                buf = dz->sampbuf[!tthis];
                for(j=0;j<i;j++)
                        buf[j] = cyclemax - buf[j];
                break;
        case(DISTORT_CLICK):
                end_bit = dz->buflen - lastzero;
                halfcycle = i + end_bit;
                step = min((int)dz->iparam[DISTORT_PULSE],halfcycle);
                if(step > end_bit) {
                        if((exit_status = genpulse(end_bit,cyclemax,buf+lastzero,buf+dz->buflen))<0)
                                return(exit_status);
                        buf = dz->sampbuf[!tthis];
                        if((exit_status = genpulse(step - end_bit,cyclemax,buf,buf+i))<0)
                                return(exit_status);
                } else {
                        if((exit_status = genpulse(end_bit,cyclemax,buf + lastzero,buf + dz->buflen))<0)
                                return(exit_status);
                        buf = dz->sampbuf[!tthis];
                        if((exit_status = genpulse(0,cyclemax,buf,buf+i))<0)
                                return(exit_status);
                }
                break;
        case(DISTORT_SINE):
                if(oldbufcnt + i > 5) {
                        if((exit_status = end_sinusoid(tthis,lastzero,cyclemax,i,oldbufcnt,dz))<0)
                                return(exit_status);
                }
                break;
        case(DISTORT_EXAGG):
                if(dz->brksize[DISTORT_POWFAC] && (exit_status = get_powfac(lastzero,dz->buflen+i,dz))<0)
                        return(exit_status);
                if((exit_status = end_exagg(tthis,lastzero,i,oldbufcnt,dz->param[DISTORT_POWFAC],phase,dz))<0)
                        return(exit_status);
                break;
        default:
                sprintf(errstr,"Unknown case in distort_func_crosbuf()\n");
                return(PROGRAM_ERROR);
        }
        return(FINISHED);
}

/***************************** SINUSOID ******************************
 *
 * Create sinusoidal half-wave, over half-cycle.
 */

int sinusoid(int tthis,int lastzero,float cyclemax,int endcycle,dataptr dz)
{
        float *bb          = dz->sampbuf[tthis];
        int i, j, start   = lastzero;                                   /* 1 */
        int half_cyclecnt = endcycle - lastzero;                /* 2 */
        double index_factor = (double)SINETABLEN/(double)half_cyclecnt;
        for(j=start, i=0; j<endcycle; j++, i++)
                bb[j] = /*round*/(float) (dz->parray[DISTORT_SIN][round(i * index_factor)] * cyclemax);
        return(FINISHED);
}

/*********************** END_SINUSOID ***************************/

int end_sinusoid(int tthis,int lastzero,float cyclemax,int newbufcnt,int oldbufcnt,dataptr dz)
{
        float *bb           = dz->sampbuf[tthis];
        int i, j, start    = lastzero;
        int half_cyclecnt  = oldbufcnt + newbufcnt;
        double index_factor = (double)SINETABLEN/(double)half_cyclecnt;
        for(j=start, i=0; j<dz->buflen; j++,i++)
                bb[j] = /*round*/(float)(dz->parray[DISTORT_SIN][round(i * index_factor)] * cyclemax);
        bb = dz->sampbuf[!tthis];
        for(j=0; j<newbufcnt; j++, i++)
                bb[j] = /*round*/(float)(dz->parray[DISTORT_SIN][round(i * index_factor)] * cyclemax);
        return(FINISHED);
}

/***************************** GENPULSE ****************************/

int genpulse(int step,float maxamp,float *bufptr,float *bufend)
{
        int n, m, z, sum = 0;
        float ampval =  maxamp;
        while(sum < step) {
                n = round(drand48() * MAXWIDTH);          /* TRUNCATE */
                n++;
                sum += n;
                z = min(n,step-sum);
                for(m=0;m<z;m++)
                        *bufptr++ = ampval;
                ampval = -ampval;
        }
        while(bufptr<bufend)
                *bufptr++ = 0;
        return(FINISHED);
}

/***************************** TRIANGLE ******************************
 *
 * Create triangular half-wave, over half-cycle.
 *
 * (0)  Samples values calculated as reals, then approxd to integers.
 * (1)  establish start of loop after initial sample (set to zero).
 * (2)  'half_cyclecnt' is number of samples in the half_cycle.
 *      'halfcnt' is count to mid-point of triangle form.
 * (3)  establish midpoint of half_cycle.
 * (4)  Set initial sample to zero.
 * (5)  Calculate real increment(decrement) to create triangular form.
 * (6)  Create triangle from start to middle.
 * (7)  For even number of samples in half-cycle, add extra peak sample.
 * (8)  Create middle sample of triangle.
 * (9)  Create triangle from middle to end.
 */

int triangle(float *b,int lastzero,float cyclemax,int endcycle)
{
        double realval = 0.0, step;                                             /* 0 */
        int start     = lastzero+1;                                     /* 1 */
        int half_cyclecnt = endcycle - lastzero;                /* 2 */
        int halfcnt   = (half_cyclecnt+1)/2;
        int middle    = lastzero + halfcnt;                     /* 3 */
        int j;
        b[lastzero] = 0;                                                                /* 4 */
        step = (double)cyclemax/(double)halfcnt;                /* 5 */
        for(j=start; j<middle; j++) {
                realval += step;                                                        /* 6 */
                b[j]    = (float)realval;
        }
        if(EVEN(half_cyclecnt))
                realval += step;                                                        /* 7 */
        b[middle] = (float)/*round*/(realval);                          /* 8 */
        for(j=middle+1; j<endcycle; j++) {
                realval -= step;                                                        /* 9 */
                b[j]     = (float)realval;
        }
        return(FINISHED);
}

/*********************** END_TRIANGLE ***************************
 *
 * (0)  Sample values calculated as reals, then approximated to integers.
 * (1)  half_cycle is now that counted in original buffer, plus the part
 *      counted into the next buffer (newbufcnt).
 * (1a) The count as far as middle of half-cycle.
 * (1b) middle = actual sample index of midpoint of half-cycle.
 * (1c) Set inital sample of half-cycle to a zero.
 * (1d) calculate the increment (=decrement) to create triangle wave.
 * (2)  If midpoint of triangle is in ORIGINAL buffer...
 * (3)  ..create values from start to middle,
 * (A)  ..if half_cycle has even number of samples, get extra peak value.
 * (5)  ..put in middle value.
 * (6)  ..create values from middle to end of buf.
 * (7)  ..switch to other buf.
 * (8)  ..create values from start of new buf, to end of triangle.
 * (9)  Else, midpoint of triangle is in OTHER buffer...
 * (10) ..create values from start to end of buffer.
 * (11) ..decrement location of middle by size of original buffer.
 * (12) ..switch to other buf.
 * (13) ..create values from start of new buf, to middle of triangle.
 * (14) ..if half_cycle has even number of samples, get extra peak value.
 * (15) ..put in middle value.
 * (16) ..create values from middle to end of triangle.
 */

int end_triangle(int tthis,int lastzero,float cyclemax,int newbufcnt,int oldbufcnt,dataptr dz)
{
        double realval = 0.0, step;                                     /* 0 */
        int start     = lastzero+1;
        int half_cyclecnt  = oldbufcnt + newbufcnt;/* 1 */
        int halfcnt   = (half_cyclecnt+1)/2;            /* 1a */
        int middle    = lastzero + halfcnt;             /* 1b */
        int j;
        float *b = dz->sampbuf[tthis];
        b[lastzero] = 0.0;                                                      /* 1c */
        step = (double)cyclemax/(double)(halfcnt);
        if(middle < dz->buflen) {                                       /* 2 */
                for(j=start; j<middle; j++) {
                        realval += step;                                        /* 3 */
                        b[j]    = (float)realval;
                }
                if(EVEN(half_cyclecnt))                                 /* A */
                        realval += step;
                b[middle] = (float)realval;                             /* 5 */
                for(j=middle+1; j<dz->buflen; j++) {
                        realval -= step;                                        /* 6 */
                        b[j]    = (float)realval;
                }
                b = dz->sampbuf[!tthis];                                /* 7 */
                for(j=0; j<newbufcnt; j++) {
                        realval -= step;                                        /* 8 */
                        b[j]    = (float)realval;
                }
        } else {                                                                        /* 9 */
                for(j=start; j<dz->buflen; j++) {
                        realval += step;                                        /* 10 */
                        b[j]    = (float)realval;
                }
                middle -= dz->buflen;                                   /* 11 */
                b = dz->sampbuf[!tthis];                                /* 12 */
                for(j=0; j<middle; j++) {
                        realval += step;                                        /* 13 */
                        b[j]    = (float)realval;
                }
                if(EVEN(half_cyclecnt))                                 /* 14 */
                        realval += step;
                b[middle] = (float)realval;                             /* 15 */
                for(j=middle+1; j<newbufcnt; j++) {
                        realval -= step;                                        /* 16 */
                        b[j]     = (float)realval;
                }
        }
        return(FINISHED);
}

/************************** RESET ******************************
 *
 * (9)  Reset lastzero, marking state of new (half)wavecycle.
 * (10) Skip any zero samples : drop out if end of samples in buffer reached.
 * (11) Reset maximum sample in halfcycle to mimimum (zero).
 * (12) Return first NON-ZERO sample.
 */

int reset(int i,int samples,float *bbuf,int *lastzero,float *cyclemax)
{
        *lastzero = i;                                          /* 9 */
        while(bbuf[i]==0.0 && i < samples)      /* 10 */
                i++;
        *cyclemax=0.0;                                          /* 11 */
        return(i);                                                      /* 12 */
}

/****************************** EXAGGERATE *******************************/

int exaggerate(int lastzero,int thiszero,int phase,float *b,double powfac)
{
        int exit_status;
        int n = lastzero + 1;
        double lastmax, thismax; // thismin;
        int   lastpos, thispos; //, minpos;
        int OK = 1;
        switch(phase) {
        case(1):
                while(b[n] >= b[n-1])
                        n++;
                lastmax = (double)b[n-1];
                lastpos = n-1;
                if(powfac < 0.0)
                        exit_status = do_exagg2(phase,lastzero+1,lastpos,powfac,b);
                else
                        exit_status = do_exagg2(phase,lastzero,lastpos,powfac,b);
                if(exit_status < 0)
                        return(exit_status);
                while(n < thiszero) {
                        while(b[n] < b[n-1]) {
                                if(++n >= thiszero) {
                                        OK = 0;
                                        break;
                                }
                        }
                        if(OK) {
                            //thismin = (double)b[n-1];
                            //minpos  = n-1;
                                while(b[n] >= b[n-1])
                                        n++;
                                thismax = (double)b[n-1];
                                thispos = n-1;
                                if((exit_status = do_exagg(lastmax,lastpos,thismax,thispos,powfac,b))<0)
                                        return(exit_status);
                                lastmax = thismax;
                                lastpos = thispos;
                        } else
                                break;
                }
                if(powfac < 0.0)
                        exit_status = do_exagg2(phase,lastpos+1,n-1,powfac,b);
                else
                        exit_status = do_exagg2(phase,lastpos,n-1,powfac,b);
                if(exit_status < 0)
                        return(exit_status);
                break;
        case(-1):
                while(b[n] <= b[n-1])
                        n++;
                lastmax = (double)b[n-1];
                lastpos = n-1;
                if(powfac < 0.0)
                        exit_status = do_exagg2(phase,lastzero+1,lastpos,powfac,b);
                else
                        exit_status = do_exagg2(phase,lastzero,lastpos,powfac,b);
                if(exit_status < 0)
                        return(exit_status);
                while(n < thiszero) {
                        while(b[n] > b[n-1]) {
                                if(++n >= thiszero) {
                                        OK = 0;
                                        break;
                                }
                        }
                        if(OK) {
                          //thismin = (double)b[n-1];
                          //minpos  = n-1;
                                while(b[n] <= b[n-1])
                                        n++;
                                thismax = (double)b[n-1];
                                thispos = n-1;
                                if((exit_status = do_exagg(lastmax,lastpos,thismax,thispos,powfac,b))<0)
                                        return(exit_status);
                                lastmax = thismax;
                                lastpos = thispos;
                        } else
                                break;
                }
                if(powfac < 0.0)
                        exit_status = do_exagg2(phase,lastpos+1,n-1,powfac,b);
                else
                        exit_status = do_exagg2(phase,lastpos,n-1,powfac,b);
                if(exit_status < 0)
                        return(exit_status);
                break;
        }
        return(FINISHED);
}

/****************************** DO_EXAGG ******************************/

int do_exagg
(double lastmax,int lastpos,double thismax,int thispos,double powfac,float *b)
{
        double maxdif = thismax - lastmax;
        double posdif = thispos - lastpos;
        double local_max, rati_o;
        int n, m;
        for(n = lastpos+1, m = 1; n<thispos; n++, m++) {
                local_max = lastmax + (maxdif * (double)m/posdif);
                rati_o    = min(((double)b[n]/local_max),1.0);
                rati_o    = pow(rati_o,powfac);
                b[n]      = (float)/*round*/((double)b[n] * rati_o);
        }
        return(FINISHED);
}

/*************************** DO_EXAGG2 *******************************/

int do_exagg2(int phase,int lastpos,int thispos,double powfac, float *b)
{
        int n;
        double val, valdiff = (double)max(fabs(b[lastpos]),fabs(b[thispos]));
        for(n = lastpos; n<=thispos; n++) {
                val  = (double)b[n]/valdiff;
                val *= (float)phase;
                val  = pow(val,powfac);
                val *= valdiff * (float)phase;
                b[n] = (float)/*round*/(val);
        }
        return(FINISHED);
}

/************************ END_EXAGG *******************************/

int end_exagg(int tthis,int lastzero,int newbufcnt,int oldbufcnt,double powfac,int phase,dataptr dz)
{
        float *bold  = dz->sampbuf[tthis] + lastzero;
    float *bnew  = dz->sampbuf[!tthis];
    float *btemp = dz->sampbuf[2];
    memmove((char *)btemp,(char *)bold,oldbufcnt * sizeof(float));
    btemp += oldbufcnt;
    memmove((char *)btemp,(char *)bnew,newbufcnt * sizeof(float));
    exaggerate(0,oldbufcnt+newbufcnt,phase,dz->sampbuf[2],powfac);

    btemp = dz->sampbuf[2];                     /* copy the transformed material back to where it came from */
    memmove((char *)bold,(char *)btemp,oldbufcnt * sizeof(float));
    btemp += oldbufcnt;
    memmove((char *)bnew,(char *)btemp,newbufcnt * sizeof(float));
        return(FINISHED);
}

/************************ GET_POWFAC *******************************/

int get_powfac(int lastzero,int thiszero,dataptr dz)
{
        double thistime;
        thistime  = (double)(dz->total_samps_read - dz->ssampsread - dz->buflen);       /* START OF BUF IN USE */
        thistime += ((double)(thiszero + lastzero)/2.0);                        /* MEAN OFFSET OF CYCLE IN CURRENT BUF */
        thistime /= (double)dz->infile->srate;
        return read_value_from_brktable(thistime,DISTORT_POWFAC,dz);
}

//TW UPDATE : NEW FUNCTION
/************************ DISTORT_OVERLOAD *******************************/

// NOV 2002: NEED TO FIX buffers to float, MAXSAMP to F_MAXSAP, (short) to THINGY!!
int distort_overload(dataptr dz)
{
        int exit_status, n;
//      short *buf;
        float *buf;
        double *tab = NULL;
        double maxgate, mingate, inc_ratio, time = 0.0, timestep = 0.01, tabposd = 0.0, normaliser, k;
        int stepper, tabpos = 0, in_maxgate = 0, in_mingate = 0;

        buf = dz->sampbuf[0];
        if(dz->mode==OVER_SINE)
                tab = dz->parray[0];
        maxgate = dz->param[DISTORTER_MULT];
        mingate = -maxgate;
        inc_ratio = (double)DISTORTER_TABLEN/(double)dz->infile->srate;
        stepper = (int)round((double)dz->infile->srate * timestep);
        normaliser = ((double)F_MAXSAMP/(maxgate + 1.0)) /* TEST * 0.9 */;

//      while(dz->bytes_left > 0) {
        while(dz->samps_left > 0) {
//              if((exit_status = read_bytes((char *)dz->bigbuf,dz))<0)
                if((exit_status = read_samps(dz->bigbuf,dz))<0)
                        return(exit_status);
                switch(dz->mode) {
                case(OVER_NOISE):
                        for(n=0;n<dz->ssampsread;n++) {
                                if(!(n%stepper)) {
                                        if((exit_status = read_values_from_all_existing_brktables(time,dz))<0)
                                                return(exit_status);
                                        time += timestep;
                                }
                                if((double)buf[n] >= maxgate) {
                                        k = 1.0 - (drand48() * dz->param[DISTORTER_DEPTH]);
//                                      buf[n] = (short)round(k * maxgate);
                                        buf[n] = (float)(k * maxgate);
                                } else if((double)buf[n] <= mingate) {
                                        k = 1.0 - (drand48() * dz->param[DISTORTER_DEPTH]);
//                                      buf[n] = (short)round(k * mingate);
                                        buf[n] = (float)(k * mingate);
                                }
//                              buf[n] = (short)round(buf[n] * normaliser);
                                buf[n] = (float)(buf[n] * normaliser);
                        }
                        break;
                case(OVER_SINE):
                        for(n=0;n<dz->ssampsread;n++) {
                                if(!(n%stepper)) {
                                        if((exit_status = read_values_from_all_existing_brktables(time,dz))<0)
                                                return(exit_status);
                                        time += timestep;
                                }
                                if((double)buf[n] >= maxgate) {
                                        if(!in_maxgate) {
                                                tabpos = 0;
                                                tabposd = 0.0;
                                                in_mingate = 0;
                                                in_maxgate = 1;
                                        }
                                        k = 1.0 + (tab[tabpos] * dz->param[DISTORTER_DEPTH]);
//                                      buf[n] = (short)round(k * maxgate);
                                        buf[n] = (float)(k * maxgate);
                                } else if((double)buf[n] <= mingate) {
                                        if(!in_mingate) {
                                                tabpos = 0;
                                                tabposd = 0.0;
                                                in_maxgate = 0;
                                                in_mingate = 1;
                                        }
                                        k = 1.0 + (tab[tabpos] * dz->param[DISTORTER_DEPTH]);
//                                      buf[n] = (short)round(k * mingate);
                                        buf[n] = (float)(k * mingate);
                                } else {
                                        in_maxgate = 0;
                                        in_mingate = 0;
                                }
//                              buf[n] = (short)round(buf[n] * normaliser);
                                buf[n] = (float)(buf[n] * normaliser);
                                tabposd = fmod(tabposd + (dz->param[DISTORTER_FRQ] * inc_ratio),(double)DISTORTER_TABLEN);
                                tabpos = round(tabposd) % DISTORTER_TABLEN;
                        }
                        break;
                }
                if(dz->ssampsread > 0) {
                        if((exit_status = write_samps(dz->bigbuf,dz->ssampsread,dz))<0)
                                return(exit_status);
                }
        }
        return(FINISHED);
}