Mozzi  version v2.0
sound synthesis library for Arduino
Smooth< T > Class Template Reference

A simple infinite impulse response low pass filter for smoothing control or audio signals. More...

#include <Smooth.h>

Detailed Description

template<class T>
class Smooth< T >

A simple infinite impulse response low pass filter for smoothing control or audio signals.

This algorithm comes from http://en.wikipedia.org/wiki/Low-pass_filter: y[i] := y[i-1] + α * (x[i] - y[i-1]), translated as out = last_out + a * (in - last_out). It's not calibrated to any real-world update rate, so if you use it at MOZZI_CONTROL_RATE and you change MOZZI_CONTROL_RATE, you'll need to adjust the smoothness value to suit.

Template Parameters
Tthe type of numbers being smoothed. Watch out for numbers overflowing the internal calculations. Some experimentation is recommended.
Note
Timing: ~5us for 16 bit types, ~1us for 8 bit types.

Definition at line 35 of file Smooth.h.

Public Member Functions

 Smooth (float smoothness)
 Constructor. More...
 
 Smooth ()
 Constructor. More...
 
next (T in)
 Filters the input and returns the filtered value. More...
 
operator() (T n)
 Filters the input and returns the filtered value. More...
 
void setSmoothness (float smoothness)
 Sets how much smoothing the filter will apply to its input. More...
 

Constructor & Destructor Documentation

◆ Smooth() [1/2]

template<class T >
Smooth< T >::Smooth ( float  smoothness)
inline

Constructor.

Parameters
smoothnesssets how much smoothing the filter will apply to its input. Use a float in the range 0~1, where 0 is not very smooth and 0.99 is very smooth.

Definition at line 47 of file Smooth.h.

◆ Smooth() [2/2]

template<class T >
Smooth< T >::Smooth ( )
inline

Constructor.

This constructor which doesn't take a smoothness parameter is useful when you incorporate Smooth into another class definition. You need to call setSmoothness(float) for your object before using Smooth.

Note
there's probably a better way to do this...

Definition at line 57 of file Smooth.h.

Member Function Documentation

◆ next()

template<class T >
T Smooth< T >::next ( in)
inline

Filters the input and returns the filtered value.

You can also use the operator() function, eg. something like mySmoother(input-value).

Parameters
inthe signal to be smoothed.
Returns
the filtered signal.

Definition at line 66 of file Smooth.h.

◆ operator()()

template<class T >
T Smooth< T >::operator() ( n)
inline

Filters the input and returns the filtered value.

Same as next(input-value).

Parameters
inthe signal to be smoothed.
Returns
the filtered signal.

Definition at line 79 of file Smooth.h.

◆ setSmoothness()

template<class T >
void Smooth< T >::setSmoothness ( float  smoothness)
inline

Sets how much smoothing the filter will apply to its input.

Parameters
smoothnesssets how much smoothing the filter will apply to its input. Use a float in the range 0~1, where 0 is not very smooth and 0.99 is very smooth.

Definition at line 90 of file Smooth.h.