klang::Filters::Biquad::Filter

Abstract filter class. More...

#include <klang.h>

Inheritance diagram for klang::Filters::Biquad::Filter:

Public Member Functions
virtual	~Filter ()
void	reset ()
	Reset filter state.
void	set (param f, param Q=root2.inv)
	Set the filter cutoff (and Q)
virtual void	init ()=0
void	process () noexcept
	Apply the biquad filter (Transposed Direct Form II)
	operator const signal & () override
	operator const signal & () const override
Modifier< signal > &	operator() (params... p)
virtual const signal &	input () const
virtual void	input (const signal &source)
virtual void	operator<< (const signal &source)
virtual const signal &	output () const
TYPE &	operator>> (TYPE &destination)
signal	operator+ (TYPE &other)
signal	operator* (TYPE &other)
signal	operator- (TYPE &other)
signal	operator/ (TYPE &other)

Public Attributes
float	f = 0
float	Q = 0
float	a1 = 0
float	a2 = 0
float	b0 = 1
float	b1 = 0
float	b2 = 0
float	a = 0
float	cos0 = 1
float	sin0 = 0
float	z [2] = { 0 }
signal	in
signal	out

Detailed Description

Definition at line 4225 of file klang.h.

Constructor & Destructor Documentation

~Filter()

virtual klang::Filters::Biquad::Filter::~Filter ( )

inlinevirtual

Definition at line 4227 of file klang.h.

{ }

Member Function Documentation

init()

virtual void klang::Filters::Biquad::Filter::init ( )

pure virtual

Implemented in klang::Filters::Biquad::APF, klang::Filters::Biquad::BPF, klang::Filters::Biquad::BRF, klang::Filters::Biquad::HPF, and klang::Filters::Biquad::LPF.

Referenced by set().

input() [1/3]

virtual void klang::Generic::Input< signal >::input ( )

inlineprotectedvirtualinherited

Reimplemented in klang::Debug, klang::Delay< SIZE >, klang::Generic::Function< signal, Args... >, and klang::Generic::Graph< SIZE >::Series.

Definition at line 1351 of file klang.h.

{ }

input() [2/3]

virtual const signal & klang::Generic::Input< signal >::input ( ) const

inlinevirtualinherited

Reimplemented in klang::Generic::Graph< SIZE >::Series.

Definition at line 1343 of file klang.h.

{ return in; }

input() [3/3]

virtual void klang::Generic::Input< signal >::input ( const signal & source )

inlinevirtualinherited

Definition at line 1347 of file klang.h.

{ in = source; input(); }

operator const signal &() [1/2]

klang::Generic::Modifier< signal >::operator const signal & ( ) const

inlineoverridevirtualinherited

Reimplemented from klang::Generic::Output< signal >.

Definition at line 1450 of file klang.h.

{ return out; } // return last output

operator const signal &() [2/2]

klang::Generic::Modifier< signal >::operator const signal & ( )

inlineoverridevirtualinherited

Reimplemented from klang::Generic::Output< signal >.

Definition at line 1449 of file klang.h.

{ process(); return out; } // return processed output

operator()()

Modifier< signal > & klang::Generic::Modifier< signal >::operator() ( params... p )

inlineinherited

Definition at line 1457 of file klang.h.

                                                {
        set(p...); return *this;
      }

operator*()

signal klang::Generic::Output< signal >::operator* ( TYPE & other )

inlineinherited

Definition at line 1372 of file klang.h.

{ process(); return out * (other); }

operator+()

signal klang::Generic::Output< signal >::operator+ ( TYPE & other )

inlineinherited

Definition at line 1371 of file klang.h.

{ process(); return out + (other); }

operator-()

signal klang::Generic::Output< signal >::operator- ( TYPE & other )

inlineinherited

Definition at line 1373 of file klang.h.

{ process(); return out - (other); }

operator/()

signal klang::Generic::Output< signal >::operator/ ( TYPE & other )

inlineinherited

Definition at line 1374 of file klang.h.

{ process(); return out / (other); }

operator<<()

virtual void klang::Generic::Input< signal >::operator<< ( const signal & source )

inlinevirtualinherited

Definition at line 1346 of file klang.h.

{ in = source; input(); }

operator>>()

TYPE & klang::Generic::Output< signal >::operator>> ( TYPE & destination )

inlineinherited

Definition at line 1364 of file klang.h.

{ process(); return destination = out; }

output()

virtual const signal & klang::Generic::Output< signal >::output ( ) const

inlinevirtualinherited

Definition at line 1360 of file klang.h.

{ return out; }

process()

void klang::Filters::Biquad::Filter::process ( )

inlinevirtualnoexcept

Reimplemented from klang::Generic::Modifier< signal >.

Definition at line 4268 of file klang.h.

                                  {
            const float z0 = z[0];
            const float z1 = z[1];
            const float y = b0 * in + z0;
            z[0] = b1 * in - a1 * y + z1;
            z[1] = b2 * in - a2 * y;
            out = y;
          }

References a1, a2, b0, b1, b2, and z.

reset()

void klang::Filters::Biquad::Filter::reset ( )

inline

Definition at line 4240 of file klang.h.

                       {
            f = 0;
            Q = 0;
            b0 = 1;
            a1 = a2 = b1 = b2 = 0;
            a = 0;
            z[0] = z[1] = 0;
          }

References a, a1, a2, b0, b1, b2, f, Q, and z.

set()

void klang::Filters::Biquad::Filter::set ( param f, param Q = root2.inv )

inline

Definition at line 4250 of file klang.h.

                                                 {
            if (Filter::f != f || Filter::Q != Q) {
              Filter::f = f;
              Filter::Q = Q;
 
              const float w = f * fs.w;
              cos0 = cosf(w);
              sin0 = sinf(w);
 
              if (Q < 0.5) Q = 0.5;
              a = sin0 / (2.f * Q);
              init();
            }
          }

References a, cos0, f, init(), klang::signal::operator*(), Q, sin0, and klang::SampleRate::w.

Member Data Documentation

a

float klang::Filters::Biquad::Filter::a = 0

Definition at line 4234 of file klang.h.

Referenced by klang::Filters::Biquad::APF::init(), klang::Filters::Biquad::BRF::init(), klang::Filters::Biquad::HPF::init(), klang::Filters::Biquad::LPF::init(), klang::Filters::Biquad::BPF::init_peak(), klang::Filters::Biquad::BPF::init_skirt(), reset(), and set().

a1

float klang::Filters::Biquad::Filter::a1 = 0

Definition at line 4232 of file klang.h.

Referenced by klang::Filters::Biquad::APF::init(), klang::Filters::Biquad::BRF::init(), klang::Filters::Biquad::HPF::init(), klang::Filters::Biquad::LPF::init(), klang::Filters::Biquad::BPF::init_peak(), klang::Filters::Biquad::BPF::init_skirt(), process(), and reset().

a2

float klang::Filters::Biquad::Filter::a2 = 0

Definition at line 4232 of file klang.h.

Referenced by klang::Filters::Biquad::APF::init(), klang::Filters::Biquad::BRF::init(), klang::Filters::Biquad::HPF::init(), klang::Filters::Biquad::LPF::init(), klang::Filters::Biquad::BPF::init_peak(), klang::Filters::Biquad::BPF::init_skirt(), process(), and reset().

b0

float klang::Filters::Biquad::Filter::b0 = 1

Definition at line 4232 of file klang.h.

Referenced by klang::Filters::Biquad::APF::init(), klang::Filters::Biquad::BRF::init(), klang::Filters::Biquad::HPF::init(), klang::Filters::Biquad::LPF::init(), klang::Filters::Biquad::BPF::init_peak(), klang::Filters::Biquad::BPF::init_skirt(), process(), and reset().

b1

float klang::Filters::Biquad::Filter::b1 = 0

Definition at line 4232 of file klang.h.

Referenced by klang::Filters::Biquad::APF::init(), klang::Filters::Biquad::BRF::init(), klang::Filters::Biquad::HPF::init(), klang::Filters::Biquad::LPF::init(), klang::Filters::Biquad::BPF::init_peak(), klang::Filters::Biquad::BPF::init_skirt(), process(), and reset().

b2

float klang::Filters::Biquad::Filter::b2 = 0

Definition at line 4232 of file klang.h.

Referenced by klang::Filters::Biquad::APF::init(), klang::Filters::Biquad::BRF::init(), klang::Filters::Biquad::HPF::init(), klang::Filters::Biquad::LPF::init(), klang::Filters::Biquad::BPF::init_peak(), klang::Filters::Biquad::BPF::init_skirt(), process(), and reset().

cos0

float klang::Filters::Biquad::Filter::cos0 = 1

Definition at line 4235 of file klang.h.

Referenced by klang::Filters::Biquad::APF::init(), klang::Filters::Biquad::BRF::init(), klang::Filters::Biquad::HPF::init(), klang::Filters::Biquad::LPF::init(), klang::Filters::Biquad::BPF::init_peak(), klang::Filters::Biquad::BPF::init_skirt(), and set().

f

float klang::Filters::Biquad::Filter::f = 0

Definition at line 4229 of file klang.h.

Referenced by reset(), and set().

in

signal klang::Generic::Input< signal >::in

inherited

Definition at line 1340 of file klang.h.

{ 0.f };

out

signal klang::Generic::Output< signal >::out

inherited

Definition at line 1357 of file klang.h.

{ 0.f };

Q

float klang::Filters::Biquad::Filter::Q = 0

Definition at line 4230 of file klang.h.

Referenced by reset(), and set().

sin0

float klang::Filters::Biquad::Filter::sin0 = 0

Definition at line 4236 of file klang.h.

Referenced by klang::Filters::Biquad::BPF::init_skirt(), and set().

z

float klang::Filters::Biquad::Filter::z[2] = { 0 }

Definition at line 4237 of file klang.h.

{ 0 };  // filter state

Referenced by process(), and reset().