/* Copyright (c) 1999 Miller Puckette.  The
contents of this file are free for any use, but BOTH THE AUTHOR AND UCSD
DISCLAIM ALL WARRANTIES related to it.  Although not written in Java, this
still should not be used to control any machinery containing a sharp blade or
combustible materiel, or as part of any life support system or weapon. */

#include "m_pd.h"
#include <math.h>
#include <stdio.h>
#ifdef _MSC_VER /* this is only needed with Microsoft's compiler */
#pragma warning( disable : 4244 )
#pragma warning( disable : 4305 )
#endif

static t_class *pique_class;

typedef struct _pique
{
    t_object x_obj;
    int x_n;
    float x_errthresh;
    float *x_freq;
    float *x_amp;
    float *x_ampre;
    float *x_ampim;
} t_pique;

static void *pique_new(t_floatarg f)
{
    int n = f;
    t_pique *x = (t_pique *)pd_new(pique_class);
    if (n < 1) n = 100;
    x->x_n = n;
    x->x_errthresh = 0;
    x->x_freq = t_getbytes(n * sizeof(*x->x_freq));
    x->x_amp = t_getbytes(n * sizeof(*x->x_amp));
    x->x_ampre = t_getbytes(n * sizeof(*x->x_ampre));
    x->x_ampim = t_getbytes(n * sizeof(*x->x_ampim));
    outlet_new(&x->x_obj, &s_list);
    return (x);
}

static float hanning(float pidetune, float sinpidetune)
{
    float pi = 3.14159;
    if (pidetune < 0.01 && pidetune > -0.01) return (1);
    else if (pidetune > 3.14 && pidetune < 3.143) return (0.5);
    else if (pidetune < -3.14 && pidetune > -3.143) return (0.5);
    else return (sinpidetune/pidetune - 0.5 *
        (sinpidetune/(pidetune+pi) + sinpidetune/(pidetune-pi)));
}

static float peakerror(float *fpreal, float *fpimag, float pidetune,
    float norm, float peakreal, float peakimag)
{
    float sinpidetune = sin(pidetune);
    float cospidetune = cos(pidetune);
    float windowshould = hanning(pidetune, sinpidetune);
    float realshould = windowshould * (
        peakreal * cospidetune + peakimag * sinpidetune);
    float imagshould =  windowshould * (
        peakimag * cospidetune - peakreal * sinpidetune);
    float realgot = norm * (fpreal[0] - 0.5 * (fpreal[1] + fpreal[-1]));
    float imaggot = norm * (fpimag[0] - 0.5 * (fpimag[1] + fpimag[-1]));
    float realdev = realshould - realgot, imagdev = imagshould - imaggot;
    
    /* post("real %f->%f; imag %f->%f", realshould, realgot,
        imagshould, imaggot); */
    return (realdev * realdev + imagdev * imagdev);
}

static void pique_doit(int npts, t_float *fpreal, t_float *fpimag,
    int npeak, int *nfound, t_float *fpfreq, t_float *fpamp,
        t_float *fpampre, t_float *fpampim, float errthresh)
{
    float srate = sys_getsr();      /* not sure how to get this correctly */
    float oneovern = 1.0/ (float)npts;
    float fperbin = srate * oneovern;
    float pow1, pow2 = 0, pow3 = 0, pow4 = 0, pow5 = 0;
    float re1, re2 = 0, re3 = *fpreal;
    float im1, im2 = 0, im3 = 0, powthresh, relativeerror;
    int count, peakcount = 0, n2 = (npts >> 1);
    float *fp1, *fp2;
    for (count = n2, fp1 = fpreal, fp2 = fpimag, powthresh = 0;
        count--; fp1++, fp2++)
            powthresh += (*fp1) * (*fp1) + (*fp2) * (*fp2) ; 
    powthresh *= 0.00001;
    for (count = 1; count < n2; count++)
    {
        float windreal, windimag, pi = 3.14159;
        float detune, pidetune, sinpidetune, cospidetune,
            ampcorrect, freqout, ampout, ampoutreal, ampoutimag;
        float rpeak, rpeaknext, rpeakprev;
        float ipeak, ipeaknext, ipeakprev;
        float errleft, errright;
        fpreal++;
        fpimag++;
        re1 = re2;
        re2 = re3;
        re3 = *fpreal;
        im1 = im2;
        im2 = im3;
        im3 = *fpimag;
        if (count < 2) continue;
        pow1 = pow2;
        pow2 = pow3;
        pow3 = pow4;
        pow4 = pow5;
            /* get Hanning-windowed spectrum by convolution */
        windreal = re2 - 0.5 * (re1 + re3);
        windimag = im2 - 0.5 * (im1 + im3);
        pow5 = windreal * windreal + windimag * windimag;
        /* if (count < 30) post("power %f", pow5); */
        if (count < 5) continue;
            /* check for a peak.  The actual bin is count-3. */
        if (pow3 <= pow2 || pow3 <= pow4 || pow3 <= pow1 || pow3 <= pow5
            || pow3 < powthresh)
                continue;
            /* go back for the raw FFT values around the peak. */
        rpeak = fpreal[-3];
        rpeaknext = fpreal[-2];
        rpeakprev = fpreal[-4];
        ipeak = fpimag[-3];
        ipeaknext = fpimag[-2];
        ipeakprev = fpimag[-4];
            /* recalculate Hanning-windowed spectrum by convolution */
        windreal = rpeak - 0.5 * (rpeaknext + rpeakprev);
        windimag = ipeak - 0.5 * (ipeaknext + ipeakprev);
        
        detune = ((rpeakprev - rpeaknext) *
            (2.0 * rpeak - rpeakprev - rpeaknext) +
                (ipeakprev - ipeaknext) *
                    (2.0 * ipeak - ipeakprev - ipeaknext)) /
                        (4.0 * pow3);
        /* if (count < 30) post("detune %f", detune); */
        if (detune > 0.7 || detune < -0.7) continue;
            /* the frequency is the sum of the bin frequency and detuning */ 
        freqout = fperbin * ((float)(count-3) + detune);
        pidetune = pi * detune;
        sinpidetune = sin(pidetune);
        cospidetune = cos(pidetune);
        ampcorrect = 1.0 / hanning(pidetune, sinpidetune);
                /* Multiply by 2 to get real-sinusoid peak amplitude 
                and divide by N to normalize FFT */
        ampcorrect *= 2. * oneovern;
            /* amplitude is peak height, corrected for Hanning window shape */

        ampout = ampcorrect * sqrt(pow3);
        ampoutreal = ampcorrect *
            (windreal * cospidetune - windimag * sinpidetune);
        ampoutimag = ampcorrect *
            (windreal * sinpidetune + windimag * cospidetune);
        if (errthresh > 0)
        {
            /* post("peak %f %f", freqout, ampout); */
            errleft = peakerror(fpreal-4, fpimag-4, pidetune+pi,
                2. * oneovern, ampoutreal, ampoutimag);
            errright = peakerror(fpreal-2, fpimag-2, pidetune-pi,
                2. * oneovern,  ampoutreal, ampoutimag);
            relativeerror = (errleft + errright)/(ampout * ampout);
            if (relativeerror > errthresh) continue;
        }
        /* post("power %f, error %f, relative %f",
            pow3, errleft + errright, relativeerror); */
        *fpfreq++ = freqout;
        *fpamp++ = ampout;
        *fpampre++ = ampoutreal;
        *fpampim++ = ampoutimag;
        if (++peakcount == npeak) break;
    }
    *nfound = peakcount;
}

static void pique_list(t_pique *x, t_symbol *s, int argc, t_atom *argv)
{
    int npts = atom_getintarg(0, argc, argv);
    t_symbol *symreal = atom_getsymbolarg(1, argc, argv);
    t_symbol *symimag = atom_getsymbolarg(2, argc, argv);
    int npeak = atom_getintarg(3, argc, argv);
    int n;
    t_garray *a;
    t_float *fpreal, *fpimag;
    if (npts < 8 || npeak < 1) error("pique: bad npoints or npeak");
    if (npeak > x->x_n) npeak = x->x_n;
    if (!(a = (t_garray *)pd_findbyclass(symreal, garray_class)) ||
        !garray_getfloatarray(a, &n, &fpreal) ||
            n < npts)
                error("%s: missing or bad array", symreal->s_name);
    else if (!(a = (t_garray *)pd_findbyclass(symimag, garray_class)) ||
        !garray_getfloatarray(a, &n, &fpimag) ||
            n < npts)
                error("%s: missing or bad array", symimag->s_name);
    else
    {
        int nfound, i;
        float *fpfreq = x->x_freq;
        float *fpamp = x->x_amp;
        float *fpampre = x->x_ampre;
        float *fpampim = x->x_ampim;
        pique_doit(npts, fpreal, fpimag, npeak,
            &nfound, fpfreq, fpamp, fpampre, fpampim, x->x_errthresh);
        for (i = 0; i < nfound; i++, fpamp++, fpfreq++, fpampre++, fpampim++)
        {
            t_atom at[5];
            SETFLOAT(at, (float)i);
            SETFLOAT(at+1, *fpfreq);
            SETFLOAT(at+2, *fpamp);
            SETFLOAT(at+3, *fpampre);
            SETFLOAT(at+4, *fpampim);
            outlet_list(x->x_obj.ob_outlet, &s_list, 5, at);   
        }
    }
}

static void pique_errthresh(t_pique *x, t_floatarg f)
{
    x->x_errthresh = f;
}

static void pique_free(t_pique *x)
{
    int n = x->x_n;
    t_freebytes(x->x_freq, n * sizeof(*x->x_freq));
    t_freebytes(x->x_amp, n * sizeof(*x->x_amp));
    t_freebytes(x->x_ampre, n * sizeof(*x->x_ampre));
    t_freebytes(x->x_ampim, n * sizeof(*x->x_ampim));
}

void pique_setup(void)
{
    pique_class = class_new(gensym("pique"), (t_newmethod)pique_new,
        (t_method)pique_free, sizeof(t_pique),0, A_DEFFLOAT, 0);
    class_addlist(pique_class, pique_list);
    class_addmethod(pique_class, (t_method)pique_errthresh,
        gensym("errthresh"), A_FLOAT, 0);
    post("pique 0.1 for PD version 23");
}

