source: flair-src/trunk/lib/FlairFilter/src/LowPassFilter_impl.cpp@ 147

// %flair:license{
// This file is part of the Flair framework distributed under the
// CECILL-C License, Version 1.0.
// %flair:license}
//  created:    2011/05/01
//  filename:   LowPassFilter_impl.cpp
//
//  author:     Guillaume Sanahuja
//              Copyright Heudiasyc UMR UTC/CNRS 7253
//
//  version:    $Id: $
//
//  purpose:    objet permettant le calcul d'un filtre passe bas
//
//
/*********************************************************************/

#include "LowPassFilter_impl.h"
#include "LowPassFilter.h"
#include <cvmatrix.h>
#include <Layout.h>
#include <GroupBox.h>
#include <SpinBox.h>
#include <DoubleSpinBox.h>

#define PI ((float)3.14159265358979323846)

using std::string;
using namespace flair::core;
using namespace flair::gui;
using namespace flair::filter;

LowPassFilter_impl::LowPassFilter_impl(const LowPassFilter *self,
                                       const LayoutPosition *position,
                                       string name,
                                       const cvmatrix *init_value) {

  if (init_value != NULL) {
    // init output matrix of same size as init
    cvmatrix_descriptor *desc =new cvmatrix_descriptor(init_value->Rows(), init_value->Cols());

    for (int i = 0; i < init_value->Rows(); i++) {
      for (int j = 0; j < init_value->Cols(); j++) {
        desc->SetElementName(i, j, init_value->Name(i, j));
      }
    }
    output = new cvmatrix(self, desc,init_value->GetDataType().GetElementDataType(), name);
    for (int i = 0; i < init_value->Rows(); i++) {
      for (int j = 0; j < init_value->Cols(); j++) {
        output->SetValue(i, j, init_value->Value(i,j));
      }
    }
  } else {
    // if NULL, assume dimension 1, and init=0
    cvmatrix_descriptor *desc = new cvmatrix_descriptor(1, 1);
    desc->SetElementName(0, 0, "output");
    output = new cvmatrix(self, desc, floatType, name);
    output->SetValue(0, 0, 0);
  }

  // init UI
  GroupBox *reglages_groupbox = new GroupBox(position, name);
  T = new DoubleSpinBox(reglages_groupbox->NewRow(), "period, 0 for auto", " s",
                        0, 10, 0.01);
  freq = new DoubleSpinBox(reglages_groupbox->NewRow(), "cutoff frequency",
                           " Hz", 0, 10000, 0.1, 2, 1);
                           
  previous_time=GetTime();
}

LowPassFilter_impl::~LowPassFilter_impl() {}

void LowPassFilter_impl::UpdateFrom(const io_data *data) {
  float delta_t;
  cvmatrix *input = (cvmatrix *)data;

  // on prend une fois pour toute les mutex et on fait des accès directs
  output->GetMutex();
  input->GetMutex();

  if (T->Value() == 0) {
    delta_t = (float)(data->DataTime() - previous_time) / 1000000000.;
  } else {
    delta_t = T->Value();
  }
  for (int i = 0; i < input->Rows(); i++) {
    for (int j = 0; j < input->Cols(); j++) {
      float cutoff=freq->Value();
      if (cutoff == 0 || freq->ValueChanged()) {
        output->SetValueNoMutex(i, j, input->ValueNoMutex(i, j));
      } else {
        output->SetValueNoMutex(i, j, (1 - 2 * PI * cutoff * delta_t) *
                                              output->ValueNoMutex(i, j) +
                                          2 * PI * cutoff * delta_t *
                                              input->ValueNoMutex(i, j));
      }
    }
  }
 
  input->ReleaseMutex();
  output->ReleaseMutex();

  output->SetDataTime(data->DataTime());
  previous_time = data->DataTime();
}