source: flair-src/trunk/lib/FlairFilter/src/unexported/ButterworthLowPass_impl.h@ 7

/*!
 * \file ButterworthLowPass_impl.h
 * \brief Classe permettant le calcul d'un filtre passe bas de Butterworth
 * \author Guillaume Sanahuja, Copyright Heudiasyc UMR UTC/CNRS 7253
 * \date 2011/05/01
 * \version 4.0
 */

#ifndef BUTTERWORTHLOWPASS_H_IMPL_H
#define BUTTERWORTHLOWPASS_H_IMPL_H

#include <IODevice.h>
#include <Butterworth.h>

namespace flair
{
    namespace core
    {
        class cvmatrix;
    }
    namespace gui
    {
        class LayoutPosition;
        class SpinBox;
        class DoubleSpinBox;
    }
    namespace filter
    {
        class ButterworthLowPass;
    }
}

// Storage for Layout
//de-templatized for pimpl idom
//comes from iir from Bernd Porr
class LayoutStorage
{
    public:
        LayoutStorage(int MaxPoles)
        {
            this->MaxPoles=MaxPoles;
            m_pairs=(Iir::PoleZeroPair*)malloc((MaxPoles+1)/2*sizeof(Iir::PoleZeroPair));
        }
        ~LayoutStorage()
        {
            free(m_pairs);
        }
        operator Iir::LayoutBase ()
        {
            return Iir::LayoutBase (MaxPoles, m_pairs);
        }

    private:
        Iir::PoleZeroPair *m_pairs;
        int MaxPoles;
};

// Storage for Cascade
//de-templatized for pimpl idom
//comes from iir from Bernd Porr
class CascadeStages
{
    public:
        CascadeStages(int MaxStages)
        {
            this->MaxStages=MaxStages;
            m_stages=(Iir::Cascade::Stage*)malloc(MaxStages*sizeof(Iir::Cascade::Stage));
            m_states=(Iir::DirectFormII*)malloc(MaxStages*sizeof(Iir::DirectFormII));
        }
        ~CascadeStages()
        {
            free(m_stages);
            free(m_states);
        }
        void reset ()
        {
            Iir::DirectFormII* state = m_states;
            for (int i = MaxStages; --i >= 0; ++state)
            state->reset();
        }

        template <typename Sample>
        inline Sample filter(const Sample in)
        {
            double out = in;
            Iir::DirectFormII* state = m_states;
            Iir::Biquad const* stage = m_stages;
            for (int i = MaxStages; --i >= 0; ++state, ++stage)
            out = state->process1 (out, *stage);
            return static_cast<Sample> (out);
        }

        Iir::Cascade::Storage getCascadeStorage()
        {
            return Iir::Cascade::Storage (MaxStages, m_stages);
        }

    private:
        int MaxStages;
        Iir::Cascade::Stage *m_stages;
        Iir::DirectFormII *m_states;
};

//de-templatized for pimpl idom
//comes from iir from Bernd Porr
class PoleFilter : Iir::Butterworth::LowPassBase,public CascadeStages
{
    public:
        PoleFilter (int MaxPoles):CascadeStages((MaxPoles + 1) / 2)
        {
            this->MaxPoles=MaxPoles;
            m_analogStorage=new LayoutStorage(MaxPoles);
            m_digitalStorage=new LayoutStorage(MaxPoles);
            // This glues together the factored base classes
            // with the templatized storage classes.
            Iir::Butterworth::LowPassBase::setCascadeStorage (this->getCascadeStorage());
            Iir::Butterworth::LowPassBase::setPrototypeStorage (*m_analogStorage,*m_digitalStorage);
        }
        ~PoleFilter()
        {
            delete m_analogStorage;
            delete m_digitalStorage;
        }
        void setup (double sampleRate,double cutoffFrequency)
        {
            Iir::Butterworth::LowPassBase::setup (MaxPoles, sampleRate,cutoffFrequency);
        }

    private:
        int MaxPoles;
        LayoutStorage* m_analogStorage;
        LayoutStorage* m_digitalStorage;
};


class ButterworthLowPass_impl
{
    public:
        ButterworthLowPass_impl(flair::filter::ButterworthLowPass* self,const flair::gui::LayoutPosition* position,std::string name,int order);
        ~ButterworthLowPass_impl();
        void UpdateFrom(const flair::core::io_data *data);
        flair::core::cvmatrix *output;

    private:
        flair::gui::DoubleSpinBox *cutoff,*T;
        PoleFilter* f;
        bool first_update;
        flair::core::Time previous_time;
};

#endif // BUTTERWORTHLOWPASS_H_IMPL_H