#include "cs.h"			/*						UGENS1.C	*/
#include "ugens1.h"
#include <math.h>

static float	fzero = 0., fone = 1.;

linset(p)
 register LINE *p;
{
register float	dur;

	if ((dur = *p->idur) > fzero) {
		p->incr = (*p->ib - *p->ia) / dur / ekr;
		p->val = *p->ia;
	}
}

kline(p)
 register LINE *p;
{
	*p->xr = p->val;		/* rslt = val	*/
	p->val += p->incr;		/* val += incr	*/
}

aline(p)
 register LINE *p;
{
register float	val, inc, *ar;
register int	nsmps = ksmps;

	val = p->val;
	inc = p->incr;
	p->val += inc;		/* nxtval = val + inc */
	inc /= ensmps;
	ar = p->xr;
	do {	*ar++ = val;
		val += inc;	/* interp val for ksmps */
	}
	while (--nsmps);
}

expset(p)
 register EXPON *p;
{
register float	dur, a, b;

	if ((dur = *p->idur) > fzero ) {
		a = *p->ia;
		b = *p->ib;
		if ((a * b) > fzero) {
			p->mlt = pow((b / a),(1./dur/ekr));
			p->val = a;
		}
		else if (a == fzero)
			initerror("arg1 is zero");
		else if (b == fzero)
			initerror("arg2 is zero");
		else initerror("unlike signs");
	}
}

kexpon(p)
 register EXPON *p;
{
	*p->xr = p->val;		/* rslt = val	*/
	p->val *= p->mlt;		/* val *= mlt  */
}

expon(p)
 register EXPON *p;
{
register float	val, mlt, inc, *ar,nxtval;
register int	nsmps = ksmps;

	val = p->val;
	mlt = p->mlt;
	nxtval = val * mlt;	
	inc = nxtval - val;
	inc /= ensmps;		/* increment per sample */
	ar = p->xr;
	do {
		*ar++ = val;
		val += inc;	/* interp val for ksmps */
	}
	while (--nsmps);
	p->val = nxtval;	/*store next value */
}

#define	DUR(k) (*p->argums[2*k-1])
#define	IVAL(k) (*p->argums[2*(k-1)])

lsgset(p)
 register LINSEG *p;
{
register int	i, nsegs;
register float	d;

	if (DUR(1) > fzero) {			/* if idur1 <= 0, skip init */
		nsegs = p->INCOUNT >> 1;
		for (i = 1 ; i <= nsegs ; i++) {	/* init each seg ..  */
			if (DUR(i) > fzero) {
				d = DUR(i) * ekr;
				p->inc[i] = (IVAL(i+1) - IVAL(i)) / d;
				p->cnt[i] = (long) (d + .5); 
				p->val[i] = IVAL(i);
			}
			else {				/* til 0 dur or done */
				i++;
				break;
			}
		}
		p->cnt[i-1] = (1 << 30);	/* & set last cntr to infin */
		p->segno = 1;
	}
}

klnseg(p)
 register LINSEG *p;
{
register int	seg;

	seg = p->segno;
	while (--p->cnt[seg] < 0)
		p->segno = seg += 1;
	*p->rslt = p->val[seg];
	p->val[seg] += p->inc[seg];
}

linseg(p)
 register LINSEG *p;
{
register int	seg, nsmps = ksmps;
register float	li, val, *rs;

	seg = p->segno;
	while (--p->cnt[seg] < 0)
		p->segno = seg += 1;
	val = p->val[seg];
	li = p->inc[seg] / ensmps;
	rs = p->rslt;
	do {
		*rs++ = val;
		val += li;
	}
	while (--nsmps);
	p->val[seg] += p->inc[seg];
}

xsgset(p)
 register EXPSEG *p;
{
register int	i, nsegs;
register float	d;

	if (DUR(1) > fzero) {			/* if idur1 <= 0, skip init */
		nsegs = p->INCOUNT >> 1;
		for (i = 1 ; i <= nsegs ; i++) {	/* for each seg of   */
			if (DUR(i) > fzero) {		/*  pos dur, & valid */
				if (IVAL(i) * IVAL(i+1) <= fzero)    /* args */
					goto experr;
				d = DUR(i) * ekr;	/* init the seg vals */
				p->mlt[i] = pow((IVAL(i+1) / IVAL(i)), (1./d));
				p->cnt[i] = (long) (d + .5); 
				p->val[i] = IVAL(i);
			}
			else {
				i++;
				break;
			}
		}
		p->cnt[i-1] = (1 << 30); 	/* set last cntr to infin */
		p->segno = 1;
	}
	return;

experr:	if (IVAL(i) == 0)
		sprintf(errmsg,"ival%d is zero",i);
	else if (IVAL(i+1) == 0)
		sprintf(errmsg,"ival%d is zero",i+1);
	else sprintf(errmsg,"ival%d sign conflict",i+1);
	initerror(errmsg);
}

kxpseg(p)
  register EXPSEG *p;
{
register int	seg;

	seg = p->segno;
	while (--p->cnt[seg] < 0)
		p->segno = seg += 1;
	*p->rslt = p->val[seg];
	p->val[seg] *= p->mlt[seg];
}

expseg(p)
  register EXPSEG *p;
{
register int	seg, nsmps = ksmps;
register float	li, val, *rs;
	float	nxtval;

	seg = p->segno;
	while (--p->cnt[seg] < 0)
		p->segno = seg += 1;
	val = p->val[seg];
	nxtval = val * p->mlt[seg];
	li = (nxtval - val) / ensmps;
	rs = p->rslt;
	do {
		*rs++ = val;
		val += li;
	}
	while (--nsmps);
	p->val[seg] = nxtval ;
}

lnnset(p)
  register LINEN *p;
{
register float a,b,dur;

	if ((dur = *p->idur) > fzero) {
		p->cnt1 = (long)(*p->iris * ekr + .5);
		if (p->cnt1 > 0L) {
			p->inc1 = fone / (float) p->cnt1;
			p->val = fzero;
		}
		else p->inc1 = p->val = fone;
		a = dur * ekr + .5;
		b = *p->idec * ekr + .5;
		if ((long) b > 0L) {
			p->cnt2 = (long) (a - b);
			p->inc2 = fone /  b;
		}
		else {
			p->inc2 = fone;
			p->cnt2 = (long) a;
		}
		p->lin1 = fzero;
		p->lin2 = fone;
	}
}

klinen(p)
 register LINEN *p;
{
register float fact = fone;

	if (p->cnt1 > 0L) {
		fact = p->lin1;
		p->lin1 += p->inc1;
		p->cnt1--;
	}
	if (p->cnt2)
		p->cnt2--;
	else {
		fact *= p->lin2;
		p->lin2 -= p->inc2;
	}
	*p->rslt = *p->sig * fact;
}

linen(p)
 register LINEN *p;
{
register int flag=0, nsmps=ksmps;
register float *rs,*sg,li,val,nxtval=1;
	
	val = p->val;
	rs = p->rslt;
	sg = p->sig;
	if (p->cnt1 > 0L) {
		flag = 1;
		p->lin1 += p->inc1;
		p->cnt1--;
		nxtval = p->lin1;
	}
	if (p->cnt2 <= 0L) {
		flag = 1;
		p->lin2 -= p->inc2;
		nxtval *= p->lin2;
	}
	else p->cnt2--;
	p->val = nxtval;
	if (flag) {
		li = (nxtval - val)/ensmps;
		if (p->XINCODE) {
			do {
				*rs++ = *sg++ * val;
				val += li;
			}
			while(--nsmps);
		}	
		else {
			do {
				*rs++ = *sg * val;
				val += li;
			}
			while(--nsmps);
		}
	}
	else {
	        if (p->XINCODE) {
		  do *rs++ = *sg++;
		  while(--nsmps);
		}
		else {
		  do *rs++ = *sg;
		  while(--nsmps);
		}
	}
}

evxset(p)
  register ENVLPX *p;
{
register FUNC	*ftp;
register float	ixmod, iatss, idur, prod, diff, asym, nk, denom, irise;
static	float	f100 = 100.;
	long	cnt1;

	if ((ftp = ftfind(p->ifn)) == NULL)
		return;
	p->ftp = ftp;
	if ((idur = *p->idur) > fzero) {
		if ((iatss = fabs(*p->iatss)) == fzero) {
			initerror("iatss = 0");
			return;
		}
		if (iatss != fone && (ixmod = *p->ixmod) != fzero) {
			if (fabs(ixmod) > .95) {
				initerror("ixmod out of range.");
				return;
			}
			ixmod = -sin(sin(ixmod));
			prod = ixmod * iatss;
			diff = ixmod - iatss;
			denom = diff + prod + 1.;
			if (denom == fzero)
				asym = f100;
			else {
				asym = 2 * prod / denom;
				if(fabs(asym) > f100)
					asym = f100;
			}
			iatss = (iatss - asym) / (1. - asym);
			asym = asym* *(ftp->ftable + ftp->flen); /* +1 */
		}
		else asym = fzero;
		if ((irise = *p->irise) > fzero) {
			p->phs = fzero;
			p->ki = (long) (kicvt / irise);
			p->val = *ftp->ftable;
		}
		else {
			p->phs = -1.;
			p->val = *(ftp->ftable + ftp->flen)-asym;
			irise = fzero;	/* in case irise < 0 */
		}
		if (!(*(ftp->ftable + ftp->flen)))
			initerror("rise func ends with zero");
		cnt1 = (long) ((idur - irise - *p->idec) * ekr + .5);
		if (cnt1 < 0L) {
			cnt1 = 0L;
			nk = ekr;
		}
		else {
			if (*p->iatss < fzero || cnt1 <= 4L)
				nk = ekr;
			else nk = (float) cnt1;
		}
		p->mlt1 = pow(iatss, (fone/nk));
		if (*p->idec > fzero) {
			if (*p->iatdec <= fzero)
				initerror("non-positive iatdec.");
			else p->mlt2 = pow((double)*p->iatdec,
					   ((double)1./ *p->idec/ekr));
		}
		p->cnt1 = cnt1;
		p->asym = asym;
	}
}

knvlpx(p)
  register ENVLPX *p;
{
register FUNC 	*ftp;
register long	phs;
register float 	fact, v1, fract, *ftab;

	ftp = p->ftp;
	if ((phs = p->phs) >= 0) {
		fract = PFRAC(phs);
		ftab = ftp->ftable + (phs >> ftp->lobits);
		v1 = *ftab++;
		fact = (v1 + (*ftab - v1) * fract);
		phs += p->ki;
		if (phs >= MAXLEN) {  /* check that 2**N+1th pnt is good */
			p->val = *(ftp->ftable + ftp->flen );
			if (!p->val)
				perferror("envlpx rise func ends with zero");
			p->val -= p->asym;
			phs = -1L;
		}
		p->phs = phs;
	}
	else {
		fact = p->val;
		if (p->cnt1 > 0L) {
			p->val *= p->mlt1;
			fact += p->asym;
			p->cnt1--;
			if (p->cnt1 == 0L)
				p->val += p->asym;
		}
		else p->val *= p->mlt2;
	}
	*p->rslt = *p->xamp * fact;
}

envlpx(p)
  register ENVLPX *p;
{
register FUNC 	*ftp;
register long	phs;
register int	nsmps = ksmps;
register float 	*xamp, *rslt, val, nxtval, li, v1, fract, *ftab;

	xamp = p->xamp;
	rslt = p->rslt;
	val = p->val;
	if ((phs = p->phs) >= 0L) {
		ftp = p->ftp;
		fract = PFRAC(phs);
		ftab = ftp->ftable + (phs >> ftp->lobits);
		v1 = *ftab++;
		nxtval = (v1 + (*ftab - v1) * fract);
		phs += p->ki;
		if (phs >= MAXLEN) {  /* check that 2**N+1th pnt is good */
			nxtval = *(ftp->ftable + ftp->flen );
			if (!nxtval)
				perferror("envlpx rise func ends with zero");
			nxtval -= p->asym;
			phs = -1;
		}
		p->phs = phs;
	}
	else {
		nxtval = val;
		if (p->cnt1 > 0L) {
			nxtval *= p->mlt1;
			nxtval += p->asym;
			p->cnt1--;
		}
		else nxtval *= p->mlt2;
	}
	p->val = nxtval;
	li = (nxtval - val)/ensmps;	/* linear interpolation factor */
	if (p->XINCODE) {		/* for audio rate amplitude: */
		do {
			*rslt++ = *xamp++ * val;
			val += li;
		}
		while(--nsmps);
	}	
	else {
		do {
			*rslt++ = *xamp * val;
			val += li;
		}
		while(--nsmps);
	}
}