/*
    crossfm.c:

    Copyright (C) 2005 Francois Pinot

    This file is part of Csound.

    The Csound Library 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.

    Csound 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 Csound; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA
*/

#include "csdl.h"
#include "crossfm.h"
#include <math.h>

int xfmset(CSOUND *csound, CROSSFM *p)
{
  FUNC *ftp1 = csound->FTFind(csound, p->ifn1);
  FUNC *ftp2 = csound->FTFind(csound, p->ifn2);
  if (ftp1 == NULL  ||  ftp2 == NULL) {
    return csound->InitError(csound, Str("crossfm: ftable not found"));
  }
  p->siz1 = (MYFLT)ftp1->flen;
  p->siz2 = (MYFLT)ftp2->flen;
  p->ftp1 = ftp1;
  p->ftp2 = ftp2;
  if (*p->iphs1 >= FL(0.0)) {
    p->phase1 = *p->iphs1;
    p->sig1 = FL(0.0);
  }
  if (*p->iphs2 >= FL(0.0)) {
    p->phase2 = *p->iphs2;
    p->sig2 = FL(0.0);
  }
  p->frq1adv = (XINARG1) ? 1 : 0;
  p->frq2adv = (XINARG2) ? 1 : 0;
  p->ndx1adv = (XINARG3) ? 1 : 0;
  p->ndx2adv = (XINARG4) ? 1 : 0;
  return OK;
}

int xfm(CSOUND *csound, CROSSFM *p)
{
  MYFLT *out1, *out2;
  MYFLT *xfrq1, *xfrq2, *xndx1, *xndx2;
  MYFLT k, cps;
  MYFLT frq1, frq2, si1, si2;
  MYFLT siz1, siz2;
  MYFLT *tbl1, *tbl2;
  MYFLT phase1, phase2;
  MYFLT sig1, sig2;
  int i, n1, n2;
  
  out1 = p->aout1;
  out2 = p->aout2;
  xfrq1 = p->xfrq1;
  xfrq2 = p->xfrq2;
  xndx1 = p->xndx1;
  xndx2 = p->xndx2;
  siz1 = p->siz1;
  siz2 = p->siz2;
  tbl1 = p->ftp1->ftable;
  tbl2 = p->ftp2->ftable;
  cps = *p->kcps;
  k = FL(1.0) / csound->esr;
  
  phase1 = p->phase1;
  phase2 = p->phase2;
  sig1 = p->sig1;
  sig2 = p->sig2;
  
  for (i = 0; i < csound->ksmps; i++) {
    frq1 = *xfrq1 * cps;
    frq2 = *xfrq2 * cps;
    si1 = (frq1 + *xndx2 * frq2 * sig2) * k;
    si2 = (frq2 + *xndx1 * frq1 * sig1) * k;
    *out1++ = sig1;
    *out2++ = sig2;
    phase1 += si1;
    phase1 -= (MYFLT)floor(phase1);
    phase2 += si2;
    phase2 -= (MYFLT)floor(phase2);
    n1 = (int)(phase1 * siz1);
    n2 = (int)(phase2 * siz2);
    sig1 = tbl1[n1];
    sig2 = tbl2[n2];
    xfrq1 += p->frq1adv;
    xfrq2 += p->frq2adv;
    xndx1 += p->ndx1adv;
    xndx2 += p->ndx2adv;
  }
  
  p->phase1 = phase1;
  p->phase2 = phase2;
  p->sig1 = sig1;
  p->sig2 = sig2;
  return OK;
}

int xfmi(CSOUND *csound, CROSSFM *p)
{
  MYFLT *out1, *out2;
  MYFLT *xfrq1, *xfrq2, *xndx1, *xndx2;
  MYFLT k, cps;
  MYFLT frq1, frq2, si1, si2;
  MYFLT siz1, siz2;
  MYFLT *tbl1, *tbl2;
  MYFLT phase1, phase2;
  MYFLT sig1, sig2;
  MYFLT x, y1, y2;
  int i, n1, n2;
  
  out1 = p->aout1;
  out2 = p->aout2;
  xfrq1 = p->xfrq1;
  xfrq2 = p->xfrq2;
  xndx1 = p->xndx1;
  xndx2 = p->xndx2;
  siz1 = p->siz1;
  siz2 = p->siz2;
  tbl1 = p->ftp1->ftable;
  tbl2 = p->ftp2->ftable;
  cps = *p->kcps;
  k = FL(1.0) / csound->esr;
  
  phase1 = p->phase1;
  phase2 = p->phase2;
  sig1 = p->sig1;
  sig2 = p->sig2;
  
  for (i = 0; i < csound->ksmps; i++) {
    frq1 = *xfrq1 * cps;
    frq2 = *xfrq2 * cps;
    si1 = (frq1 + *xndx2 * frq2 * sig2) * k;
    si2 = (frq2 + *xndx1 * frq1 * sig1) * k;
    *out1++ = sig1;
    *out2++ = sig2;
    phase1 += si1;
    phase1 -= (MYFLT)floor(phase1);
    phase2 += si2;
    phase2 -= (MYFLT)floor(phase2);
    x = phase1 * siz1;
    n1 = (int)x;
    y1 = tbl1[n1];
    sig1 = (tbl1[n1+1]-y1) * (x - (MYFLT)floor(x)) + y1;
    x = phase2 * siz2;
    n2 = (int)x;
    y2 = tbl2[n2];
    sig2 = (tbl2[n2+1]-y2) * (x - (MYFLT)floor(x)) + y2;
    xfrq1 += p->frq1adv;
    xfrq2 += p->frq2adv;
    xndx1 += p->ndx1adv;
    xndx2 += p->ndx2adv;
  }
  
  p->phase1 = phase1;
  p->phase2 = phase2;
  p->sig1 = sig1;
  p->sig2 = sig2;
  return OK;
}

#define S sizeof

static OENTRY localops[] = {
  { "crossfm", S(CROSSFM), 5, "aa", "xxxxkiioo", (SUBR)xfmset, NULL, (SUBR)xfm },
  { "crossfmi", S(CROSSFM), 5, "aa", "xxxxkiioo", (SUBR)xfmset, NULL, (SUBR)xfmi }
};

LINKAGE