/*
SYNTHESIS.C
Oscar Pablo Di Liscia / Juan Pampin

Extracted from atsh synth-funcs.c, with slight modifications (by jpmeuret@free.fr) :
- change from random() to rand() random number generator (gcc 4 compatibility)
- do_synthesis no longer writes to a sound file, but simply allocates and returns
  a sample array => now independant from any sound IO library.
*/

#include <stdlib.h>
#include <stdio.h>
#include <math.h>

#include "atsa.h"

//CONSTANTS
#define TWO_PI (2*3.141592653589793)

#define TABLE_LENGTH 16384

#define SYNTH_RES  1
#define SYNTH_DET  2
#define SYNTH_BOTH 3


//MACROS
/*
;;; In these macros pha_1 and frq_1 refers to the instantaneous phase
;;; and frequency of the previous frame while pha and frq refer
;;; to the phase and frequency of the present frame.
*/
#define COMPUTE_M(pha_1, frq_1, pha, frq, dt) ((pha_1 + (frq_1 * dt) - pha) + ((frq - frq_1) * .5 * dt)) / TWO_PI   
#define COMPUTE_AUX(pha_1, pha, frq_1, dt, M) (pha + (TWO_PI * M)) - (pha_1 + (frq_1 * dt))
#define COMPUTE_ALPHA(aux, frq_1, frq, dt) ((3. / (dt * dt)) * aux ) - ((frq - frq_1) / dt)
#define COMPUTE_BETA(aux, frq_1, frq, dt) ((-2. / (dt * dt * dt)) * aux) + ((frq - frq_1) / (dt * dt))
/*
;;; note that for this macro the values of i should go
;;; from 0 to dt. So in the case of having 220 samples
;;; within a frame the increment for i will be dt/200
*/
#define INTERP_PHASE(pha_1, frq_1, alpha, beta, i) (beta * i * i * i) + (alpha * i * i)+ (frq_1 * i) + pha_1

#define ENG_RMS(val, ws) sqrt((double)val/(ws * (double)ATSA_NOISE_VARIANCE))

//STRUCTURES
typedef struct { //the time data for each time breakpoint of the time function
  int from; //from frame
  int to;   //to frame
  int size; //the size of the segment in frames
  double tfac; //stretching factor 1=invariant
} TIME_DATA;

typedef struct { //the data for the randi UG
  int   size; //size of the frame in samples this should be sr/freq.
  double a1;   //first amplitude value
  double a2;   //next  amplitude value
  int   cnt;  //sample position counter
} RANDI;


//GLOBAL VARIABLES
static double *sine_table = 0;

///////////////////////////////////////////////////////////////////
//randi output random numbers in the range of 1,-1
//getting a new number at frequency freq and interpolating
//the intermediate values.
static void randi_setup(double sr, double freq, RANDI *radat)
{
  radat->size= (int) (sr / freq) - 1;
  radat->a1  = rand();
  radat->a2  = rand();
  radat->cnt = 0;
}
///////////////////////////////////////////////////////////////////
static double randi(RANDI *radat)
{
  double output;

  if(radat->cnt == radat->size) { //get a new random value
    radat->a1  = radat->a2; 
    radat->a2  = rand();
    radat->cnt = 0;
  }

  output=(double)(((radat->a2 - radat->a1)/ radat->size) * radat->cnt)+ radat->a1;
  radat->cnt++;
  return(1. - ((double)(output /(long int)RAND_MAX) * 2.));
}
///////////////////////////////////////////////////////////////////
static double randif(RANDI *radat, double freq, double sr)
{
  double output;

  if(radat->cnt == radat->size) { //get a new random value
    radat->a1  = radat->a2; 
    radat->a2  = rand();
    radat->cnt = 0;
    radat->size= (int) (sr / freq) - 1;
  }

  output=(double)(((radat->a2 - radat->a1)/ radat->size) * radat->cnt)+ radat->a1;
  radat->cnt++;
  
  return(1. - ((double)(output /(long int)RAND_MAX) * 2.));
}
///////////////////////////////////////////////////////////////////
static void make_sine_table() 
{
int i;
double theta=0.;
double incr = TWO_PI / (double)TABLE_LENGTH;

sine_table= (double*) malloc(TABLE_LENGTH * sizeof(double));

 for(i=0; i < TABLE_LENGTH; i++) {
    sine_table[i] = sin(theta);
    theta +=incr;

}
return;
}
////////////////////////////////////////////////////////////////////
static double ioscilator(double amp,double frec,int op, double sr, double *oscpt)
{
  double output;
  double incr = frec * (double)TABLE_LENGTH / sr; 
  int   v2=0;

  if (!sine_table)
    make_sine_table();

  //LINEAR INTERPOLATION
  //v2=((int)(oscpt[op] + 1.)) % TABLE_LENGTH;
  v2=(int)(oscpt[op] + 1.);
  while ( v2 >= TABLE_LENGTH )
    v2 -=TABLE_LENGTH;

  output=amp * (sine_table[(int)oscpt[op]] + 	
	 ((sine_table[(int)v2] - sine_table[(int)oscpt[op]]) * ( oscpt[op] - (int)oscpt[op] )));

  //  oscpt[op] = remainder(oscpt[op] + incr, (double)TABLE_LENGTH);
  oscpt[op]  += incr;
  while ( oscpt[op] >= (double)TABLE_LENGTH )
    oscpt[op] -=(double)TABLE_LENGTH;
  while ( oscpt[op] < 0. )
    oscpt[op] +=(double)TABLE_LENGTH;

  return output;
}
///////////////////////////////////////////////////////////////
static double locate_frame(ATS_SOUND *ats_sound, double from_frame, double time, double dif)
{
//Assuming that the duration of each frame may be different, we
//do not have any other method to locate the frame for a given time

 int i=(int)floor(from_frame), frame=0;

  //These two cases are obvious
  if(time <= ats_sound->time[0][1]){
    return 0;
  }
  if(time >= ats_sound->time[0][ats_sound->frames-1]){
    return ats_sound->frames - 1;
  }

  //not obvious cases...
  if(dif >= 0.)

    do {
      if(ats_sound->time[0][i] >= time) {
        frame = i;
        break;
      }
      ++i;
    } while(i < ats_sound->frames);

  else

    do {
      if(ats_sound->time[0][i] <= time) {
        frame = i;
        break;
      }
      --i;
    } while(i > 0);

  if(frame < 0)
    frame = 0;
  else if(frame > ats_sound->frames-1)
    frame = ats_sound->frames - 1;

  return frame;
}
////////////////////////////////////////////////////////////////////
//Synthesizes a Buffer using phase interpolation (not used for the moment)
/*
static void synth_buffer_phint(double a1, double a2, double f1, double f2, double p1, double p2, double dt, double frame_samps, double* frbuf)
{
  double t_inc, a_inc, M, aux, alpha, beta, time, amp, scale, new_phase;
  int k, index;
  double out=0., phase=0.;

  if (!sine_table)
    make_sine_table();

  f1  *=TWO_PI;
  f2  *=TWO_PI;
  t_inc= dt  / frame_samps;
  a_inc= (a2 - a1) / frame_samps;
  M    = COMPUTE_M(p1, f1, p2, f2,dt);
  aux  = COMPUTE_AUX(p1, p2, f1, dt, M);
  alpha= COMPUTE_ALPHA(aux,f1,f2,dt);
  beta = COMPUTE_BETA(aux,f1,f2,dt);
  time = 0.;
  amp  = a1;
  scale = TWO_PI / ((double)TABLE_LENGTH - 1.); //must take it out from here...

  for(k = 0; k < (int)frame_samps; k++) { 
 
    phase = INTERP_PHASE(p1,f1,alpha,beta,time);
    new_phase = (phase >= TWO_PI  ? phase - TWO_PI : phase);
    index=(int)((new_phase / TWO_PI)*(double)TABLE_LENGTH - 1.);
    while ( index >= TABLE_LENGTH ) {
      index -=TABLE_LENGTH;
    }
     while ( index < 0 ) {
      index +=TABLE_LENGTH;
    }
    out = sine_table[index] * amp;

    /////////////////////////////////////////////////////////
    time +=t_inc;
    amp  +=a_inc;
    frbuf[k] +=out; //buffer adds each partial at each pass
  }

  return;
}
*/
////////////////////////////////////////////////////////////////////
//Synthesizes a Buffer NOT using phase interpolation
static void synth_deterministic_only(double a1, double a2, double f1, double f2, double frame_samps, 
                              int op, double *oscpt, SPARAMS* sparams, int *selected,
			      double* frbuf)
{
  int k;
  double  a_inc, f_inc, amp, frec;

  amp  =  a1;
  frec =  f1;
  a_inc= (a2 - a1) / frame_samps;
  f_inc= (f2 - f1) / frame_samps;
  
  if(a1==0. && a2==0.) 
      return; //no synthesis if no amplitude

  //we should do this conditional on the main loop... 
  if (!sparams->allorsel || !selected || selected[op]) {
    for(k = 0; k < frame_samps; k++) {
      //buffer adds each partial at each pass
      frbuf[k] += ioscilator(amp,frec,op,sparams->sr,oscpt) * sparams->amp;  
      amp  +=a_inc;
      frec +=f_inc;
    }
  }
  return;
}
////////////////////////////////////////////////////////////////////
static void synth_residual_only(double a1, double a2,double freq,double frame_samps,int op,double *oscpt, RANDI* rdata, SPARAMS* sparams, double* frbuf)
{
  int k;
  double  a_inc, amp;
  
  amp  =  a1;
  a_inc= (a2 - a1) / frame_samps;
  
  if(a1==0. && a2==0.) return; //no synthesis if no amplitude
  
  for(k = 0; k < (int)frame_samps; k++) { 
    frbuf[k] += ioscilator(amp,freq,op,sparams->sr,oscpt) * sparams->ramp * randi(rdata);  
    amp += a_inc;
  }
 
  return;  
}
////////////////////////////////////////////////////////////////////
static void synth_both(double a1, double a2, double f1, double f2, double frame_samps,int op, double *oscpt,double r1, double r2, RANDI* rdata, SPARAMS* sparams, int *selected, double* frbuf)
{
  int k;
  double  a_inc, f_inc, amp, frec;
  double  r_inc, res;
  double  out=0., rsig;
  double  rf1, rf2, rf_inc, rfreq;
  
  rf1   =(f1< 500.? 50. : f1 * .05);
  rf2   =(f2< 500.? 50. : f2 * .05);
  rf_inc=(rf2 - rf1) / frame_samps;
  rfreq = rf1;
  amp   =  a1;
  frec  =  f1;
  res   =  r1;
  a_inc = (a2 - a1) / frame_samps;
  f_inc = (f2 - f1) / frame_samps;
  r_inc = (r2 - r1) / frame_samps;
   

  if(a1==0. && a2==0.) return; //no synthesis if no amplitude
  
  //we should do this conditional on the main loop... 
  if (!sparams->allorsel || !selected || selected[op]) {
    
    for(k = 0; k < (int)frame_samps; k++) { 
      out = ioscilator(1.0,frec,op,sparams->sr,oscpt);  
      rsig = res*randif(rdata,rfreq,sparams->sr);
      frbuf[k] += out * (amp * sparams->amp + rsig * sparams->ramp);
      amp   +=  a_inc;
      frec  +=  f_inc;
      res   +=  r_inc;
      rfreq += rf_inc;
    }
  }
  return;
}

static double compute_max_frame_dur(ATS_SOUND *ats_sound)
{
  int i;
  double dt,maxtim=0.;

  for(i=0; i<ats_sound->frames - 1; ++i) {
    dt=ats_sound->time[0][1+i] - ats_sound->time[0][i];
    if(dt > maxtim) 
      maxtim=dt; //find out max. dt.
  }

  return maxtim;
}

////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////
/////////THIS IS THE MAIN SYNTHESIS LOOP////////////////////////////
////////////////////////////////////////////////////////////////////
void do_atsh_synthesis(ATS_SOUND *ats_sound, SPARAMS* sparams, CURVE* timenv, int *selected,
		       double** out_samps, int* n_out_samps)
{
  int i,x,z,j,maxlen, curr, next, sflag;
  double dt=0., rfreq;
  double frame_samps, bw=.1;
  int bframe, eframe;
  double dur, dy, cxval, cyval, nxval, nyval, difx, dify;
  TIME_DATA *tdata;
  int nbp;
  double *dospt=0, *rospt=0;
  RANDI *rarray=0;
  double* res_band_edges=ATSA_CRITICAL_BAND_EDGES;
  double res_band_centers[ATSA_CRITICAL_BANDS];
  double maxtim, todo;
  double* frbuf;
  int n_samps;
  //double done=0;

  //fix special params values
  if (sparams->end <= sparams->beg)
      sparams->end = ats_sound->dur - sparams->beg;

  //do residual data transfer if noise data is present
  if (ats_sound->band_energy) {
    for(i=0; i<ats_sound->frames; ++i) {
      band_energy_to_res(ats_sound, i);
    }
  }
  //NOW CHECK WHAT TO DO...
  if(sparams->ramp == 0.) { //deterministic synthesis only
    sflag=SYNTH_DET;
  }
  else {
    if(sparams->amp == 0.) { //residual synthesis only
      sflag=SYNTH_RES;
    }
    else { //residual and deterministic synthesis
      sflag=SYNTH_BOTH;
    }
  }
  
  //precompute some useful data.
  nbp   = get_nbp(timenv);
  dur   = sparams->end - sparams->beg;
  dy    = get_maxy_value(timenv) - get_miny_value(timenv);
  tdata = (TIME_DATA*)malloc(nbp * sizeof(TIME_DATA));

  sparams->max_stretch=0.;  
  todo=0;

  //We first must calculate data of each control point
  bframe = 0;
  for(i=0; i < nbp - 1; ++i){
    //get the data from the time envelope and convert it to time
    cxval= dur * get_x_value(timenv, i); // We assume xmin=0, xmax=1
    cyval= dur * get_y_value(timenv, i) * dy; // We assume ymin=0
    nxval= dur * get_x_value(timenv, i+1); // We assume xmin=0, xmax=1
    nyval= dur * get_y_value(timenv, i+1) * dy; // We assume ymin=0
    
    //diff=0. is a special case we must take in account
    //here all we do is to set it to one millisecond (arbitrarly)
    difx= nxval - cxval;
    if(difx == 0.) difx=.001; 
    dify= nyval - cyval;
    if(dify == 0.) dify=.001; 

    //find out the max. stretching factor(needed to allocate the I/O buffer)
    if(fabs(difx) / fabs(dify) >= sparams->max_stretch) {
      sparams->max_stretch=fabs(difx) / fabs(dify);
    }
    
    //locate the frame for the begining and end of segments
    if(i == 0){
      if(dify < 0.)
	  bframe = (int)locate_frame(ats_sound, ats_sound->frames, cyval, dify);
      else {
	bframe = (int)locate_frame(ats_sound, 0, cyval, dify);
      }	
    }
    eframe= (int)locate_frame(ats_sound, bframe, nyval, dify);

    //collect the data to be used
    tdata[i].from= bframe;
    tdata[i].to  = eframe;
    tdata[i].size= (int)fabs(eframe - bframe) + 1;
    tdata[i].tfac= fabs(difx/dify);

    // update the number of samples to synthesise
    if (eframe >= ats_sound->frames - 1)
      dt=fabs(ats_sound->dur - ats_sound->time[0][bframe]);
    else
      dt=fabs(ats_sound->time[0][eframe+1] - ats_sound->time[0][bframe]);
    todo+=dt * sparams->sr * tdata[i].tfac;

    fprintf(stderr, "do_synthesis(atsh): seg %d : from=%d, to=%d, size=%d, tfac=%f, dt=%f\n", 
	    i, tdata[i].from, tdata[i].to, tdata[i].size, tdata[i].tfac, dt);
          
    bframe=eframe;
  }
  
  //ALLOCATE OUTPUT SAMPLE ARRAY
  *out_samps = (double*)malloc((int)todo*sizeof(double));
  fprintf(stderr, "do_synthesis(atsh): %d samples to be generated\n", (int)todo);

  //ALLOCATE AND CLEAN AUDIO BUFFER
  maxtim = compute_max_frame_dur(ats_sound);
  maxlen= (int)ceil(maxtim * sparams->sr * sparams->max_stretch); 
  frbuf = (double *) malloc(maxlen * sizeof(double));
  for(z = 0; z < maxlen; ++z) {
    frbuf[z]=0.;
  }

  switch(sflag) { //see which memory resources do we need and allocate them
  case SYNTH_DET: {
    dospt = (double *) malloc(ats_sound->partials * sizeof(double));
    for(z=0; z<ats_sound->partials; ++z) {
      dospt[z]=0.;
    }
    break;
  }
  case SYNTH_RES: {
    rospt = (double *) malloc(ATSA_CRITICAL_BANDS * sizeof(double)); 
    rarray= (RANDI *) malloc(ATSA_CRITICAL_BANDS * sizeof(RANDI));
    for(z=0; z<ATSA_CRITICAL_BANDS; ++z) {
      res_band_centers[z]= res_band_edges[z]+((res_band_edges[z+1]-res_band_edges[z])*0.5); 
      randi_setup(sparams->sr,res_band_edges[z+1]-res_band_edges[z],&rarray[z]);
      rospt[z]=0.;
    }
    break;
  }
  case SYNTH_BOTH: {
    dospt = (double *) malloc(ats_sound->partials * sizeof(double));
    rarray= (RANDI *) malloc(ats_sound->partials * sizeof(RANDI));
    for(z=0; z<ats_sound->partials; ++z) {
	rfreq=bw * (ats_sound->frq[z][(int)floorf(tdata[0].from)] < 500. ? 
		    500. : ats_sound->frq[z][(int)floorf(tdata[0].from)]);
      randi_setup(sparams->sr,rfreq,&rarray[z]);
      dospt[z]=0.;
    }
    break;  
  }
  }

  //NOW DO IT...
  n_samps=0;
  for(i = 0; i < nbp - 1; i++) { 

    curr=tdata[i].from;
 
    for(j=0; j < tdata[i].size; j++) {

      next= tdata[i].from < tdata[i].to ? curr+1 : curr-1 ;	        
      if(next < 0 || next >= ats_sound->frames) 
	break;

      dt=fabs(ats_sound->time[0][next] - ats_sound->time[0][curr]);
      frame_samps=dt * sparams->sr * tdata[i].tfac ;      
      //done += frame_samps;
      //fprintf(stderr, "do_synthesis: i=%d, curr=%d, next=%d, dt=%g, samps=%f (%f/%f)\n", 
      //      i, curr, next, dt, frame_samps, done, todo);

      switch (sflag) {
      case SYNTH_DET: { //deterministic synthesis only
	for(x = 0; x < ats_sound->partials; x++) {                       
	  synth_deterministic_only(ats_sound->amp[x][curr], 
				   ats_sound->amp[x][next], 
				   ats_sound->frq[x][curr] * sparams->frec,
				   ats_sound->frq[x][next] * sparams->frec, 
				   frame_samps,x, dospt, sparams, selected, frbuf);
	}
	break;
      }	
      case SYNTH_RES: { //residual synthesis only
	for(x = 0; x < ATSA_CRITICAL_BANDS; x++) {
	  synth_residual_only(ENG_RMS(ats_sound->band_energy[x][curr], ats_sound->window_size), 
			      ENG_RMS(ats_sound->band_energy[x][next], ats_sound->window_size) ,
			      res_band_centers[x],frame_samps,x,rospt,
			      &rarray[x],sparams, frbuf);  
	}
	break;
      }
      case SYNTH_BOTH: { //residual and deterministic synthesis  
	for(x = 0; x < ats_sound->partials; x++) {
	  synth_both(ats_sound->amp[x][curr], 
		     ats_sound->amp[x][next], 
		     ats_sound->frq[x][curr] * sparams->frec,
		     ats_sound->frq[x][next] * sparams->frec, 
		     frame_samps,x, dospt,
		     ENG_RMS(ats_sound->res[x][curr] * sparams->ramp, ats_sound->window_size), 
		     ENG_RMS(ats_sound->res[x][next] * sparams->ramp, ats_sound->window_size),
		     &rarray[x], sparams, selected, frbuf);     	  	         
	}
	break;
	
      }
      }//end switch
      
      for(z=0; z< maxlen; ++z) {      //copy output buffer to out_samps and clean it
	if(z < (int)frame_samps) {      
	  (*out_samps)[n_samps++] = (double)frbuf[z];	  
	}
	frbuf[z]=0.;   
      }
      curr= next;

      fprintf(stderr, "    frame#%d, samps=%f (%d/%f)\n", j, frame_samps, n_samps, todo);
    }
    
  } //CHANGE CONTROL POINT
  
  *n_out_samps = n_samps;

  fprintf(stderr, "do_synthesis(atsh): %d samples generated\n", *n_out_samps);

  free(frbuf);
  if (dospt)
      free(dospt);
  if (rospt)
      free(rospt);
  if (rarray)
      free(rarray);
  free(tdata);

  return;
}