Fractional Ring Buffer

Overview

Fractional ring buffer allows sub-sample indexing using interpolation. fractional_ring_buffer is a subclass of ring_buffer that overloads the index operator to provide sub-sample indexing.

Include

#include <q/utility/fractional_ring_buffer.hpp>

Declaration

template <
   typename T
 , typename Storage = std::vector<T>
 , typename Index = float
 , typename Interpolation = sample_interpolation::linear>
class fractional_ring_buffer : public ring_buffer<T, Storage>
{
public:

   using value_type = T;
   using storage_type = Storage;
   using index_type = Index;
   using interpolation_type = Interpolation;

   using ring_buffer<T, Storage>::ring_buffer;

   // get data (index can be fractional)
   T const operator[](Index index) const;
};

Expressions

As a subclass of ring_buffer, fractional_ring_buffer inherits all the publicly accessible member functions, member variables, and types of its base class.

In addition to valid expressions for ring_buffer, fractional_ring_buffer allows these expressions.

Notation

T

Element type, e.g. float.

S

Storage type, e.g. std::vector<T>.

I

Index type, e.g. float.

X

Interpolation type, e.g. sample_interpolation::linear.

rb_type

A fractional_ring_buffer<T, S, I, X> type.

rb

Object of type fractional_ring_buffer<T, S, I, X>.

i

Object of type I.

a [, b, c, d]

Required a, optional b, c, d.

Type Construction

Expression Semantics 
fractional_ring_buffer<
   T [, S, I, X]>

Instantiate a fractional_ring_buffer type given:

  1. Element type T

  2. Storage type S (optional)

  3. Index type I (optional)

  4. Interpolation type, X (optional)

Examples:

using rb_type1 = fractional_ring_buffer<double>
using rb_type2 = fractional_ring_buffer<float, std::vector<float>>
using rb_type3 = fractional_ring_buffer<float, std::array<float, 64>, float>
using rb_type4 = fractional_ring_buffer<int, std::vector<float, float, sample_interpolation::linear>

Type Accessors

Expression Semantics

rb_type::value_type

Get the underlying element type.

rb_type::storage_type

Get the underlying storage type.

rb_type::index_type

Get the underlying index type.

rb_type::interpolation_type

Get the underlying interpolation type.

Accessors

Expression Semantics Return Type

rb[i]

Get the element at index i. rb[0] refers to the latest element. rb[rb.size()-1] refers to the oldest element. Index can be fractional (e.g. rb[2.5]).

T& or T const& if rb is const.
i < 0 || i > rb.size()-1 is undefined behavior.