/**********************************************************************
* Demonstration of a bandpass numerical filter using Module filter_r  *
* ------------------------------------------------------------------- *
* SAMPLE RUN:                                                         *
* Input file 'input.txt' contains:                                    *
*                                                                     *
* Input Signal                                                        *
* 200                                                                 *
* 0.00000000000000E+0000   0.00000000000000E+0000                     *
* 2.51256700736135E-0003   1.40504705905914E+0000                     *
* 5.02513401472271E-0003   1.39680230617523E+0000                     *
* 7.53770102208762E-0003   3.99903088808060E-0001                     *
* 1.00502680294454E-0002   0.00000000000000E+0000                     *
* 1.25628350368032E-0002   7.07106769084930E-0001                     *
* 1.50754020441752E-0002   1.26007354259491E+0000                     *
* 1.75879690515330E-0002   4.31350797414780E-0001                     *
* 2.01005360588908E-0002  -1.17557048797607E+0000                     *
* --/--                                                               *
* 4.77387731398721E-0001   1.00000000000000E+0000                     *
* 4.79900298405937E-0001   1.84206306934357E+0000                     *
* 4.82412865413608E-0001   1.17557048797607E+0000                     *
* 4.84925432420823E-0001  -4.31350797414780E-0001                     *
* 4.87437999428039E-0001  -1.26007354259491E+0000                     *
* 4.89950566435709E-0001  -7.07106769084930E-0001                     *
* 4.92463133442925E-0001   1.78893358460108E-0018                     *
* 4.94975700450141E-0001  -3.99903088808060E-0001                     *
* 4.97488267457811E-0001  -1.39680230617523E+0000                     *
* 5.00000834465027E-0001  -1.40504705905914E+0000                     *
*                                                                     *
* Output file 'output.txt' contains (lowpass - Fc=60):                *
*                                                                     *
* Filtered Signal (lowpass)                                           *
* 200                                                                 *
* 0.000000  0.000000                                                  *
* 0.002513  0.123316                                                  *
* 0.005025  0.430956                                                  *
* 0.007538  0.637626                                                  *
* 0.010050  0.575908                                                  *
* 0.012563  0.480040                                                  *
* --/--                                                               *
* 0.487439  0.387428                                                  *
* 0.489952  -0.018459                                                 *
* 0.492464  -0.186481                                                 *
* 0.494977  -0.193248                                                 *
* 0.497489  -0.317190                                                 *
* 0.500002  -0.591049                                                 *
*                                                                     *
* Output file 'output1.txt' contains (highpass - Fc=60):              *
*                                                                     *
* Filtered Signal (highpass)                                          *
* 200                                                                 *
* 0.000000  0.134854                                                  *
* 0.002513  -0.020172                                                 *
* 0.005025  -0.467873                                                 *
* 0.007538  -0.571431                                                 *
* 0.010050  -0.153637                                                 * 
* 0.012563  0.212561                                                  *
* --/--                                                               *
* 0.489952  0.367969                                                  *
* 0.487439  -0.048799                                                 *
* 0.492464  0.229072                                                  *
* 0.494977  -0.204981                                                 *
* 0.497489  -0.270452                                                 *
* 0.500002  0.168433                                                  *
* ------------------------------------------------------------------- *
* References:                                                         *
*                                                                     *
*  http://en.wikipedia.org/wiki/Digital_biquad_filter                 *  
*  http://www.musicdsp.org/archive.php?classid=3#225                  *  
*  http://www.musicdsp.org/showone.php?id=197                         *
*  http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt                *
*  http://www.musicdsp.org/archive.php?classid=3#225                  *
*  http://www.musicdsp.org/showArchiveComment.php?ArchiveID=225       *
*                                                                     *
*                            Visual C++ Release By J-P Moreau, Paris. *
*                                       (www.jpmoreau.fr)             *
***********************************************************************
Note: Here, only the lowpass and highpass options are demonstrated.
------------------------------------------------------------------ */
// *** To link with files basis_r.cpp, vmblock.cpp and filter_r.cpp.

#include "filter_r.h"

  FILE *fp1, *fp2;
  TRbjEqFilter lRGJFilter;  // see module filter_r.cpp
  int i;
  
  float *lIn;               // input table of float

  char title[80];           // caption

  int kSamples;             // number of points
  float kSamplesPerSec;     // sample rate

  float t,ti,tf,dt;         // t = current time, ti = starting time  
                            // tf = ending time, dt = time increment 
  float Fc;                 // cut-off frequency

  void *vmblock;            // see file vmblock.h


void main() {

  fp1 = fopen("input.txt","read");
  fscanf(fp1,"%s", title);
  fscanf(fp1,"%d", &kSamples);

// Allocate memory for vectors lIn and lOut
  vmblock = vminit();
  lIn  = (float *) vmalloc(vmblock, VEKTOR, kSamples, 0);  

  fscanf(fp1,"%f %f", &ti, &lIn[0]); 
  for (i=1; i<kSamples-1; i++)
    fscanf(fp1,"%f %f", &t, &lIn[i]); 
  fscanf(fp1,"%f %f", &tf, &lIn[kSamples-1]);
  fclose(fp1);

  Fc = 60.0;  

  dt = (tf-ti)/(kSamples-1);            // time increment
  kSamplesPerSec = 1*kSamples/(tf-ti);  // points/sec

// apply filter and save results
  lRGJFilter.InitFilter(kSamplesPerSec, 0);

  lRGJFilter.CalcFilterCoeffs(kLowPass,Fc,0.3,0.0, false);

  fp2 = fopen("output.txt","write");  
  fprintf(fp2,"Filtered Signal (lowpass)\n");
  fprintf(fp2,"%d\n", kSamples);

  t=ti;
  for (i=0; i<kSamples; i++) {
    fprintf(fp2, " %f  %f\n", t, lRGJFilter.Process1(lIn[i]));
    t += dt;
  }

  fclose(fp2);
  printf("\n Lowpass results in file output.txt...\n\n");

  lRGJFilter.CalcFilterCoeffs(kHighPass,Fc,0.3,0.0, false);

  fp2 = fopen("output1.txt","write");  
  fprintf(fp2,"Filtered Signal (highpass)\n");
  fprintf(fp2,"%d\n", kSamples);

  t=ti;
  for (i=0; i<kSamples; i++) {
    fprintf(fp2, " %f  %f\n", t, lRGJFilter.Process1(lIn[i]));
    t += dt;
  }

  fclose(fp2);
  printf("\n Highpass results in file output1.txt...\n");

  getchar();
  vmfree(vmblock);  // free memory

}

// end of file test_fil.cpp