JUCE/modules/juce_dsp/maths/juce_Phase.h

/*
  ==============================================================================

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2020 - Raw Material Software Limited

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

namespace juce
{
namespace dsp
{

/**
    Represents an increasing phase value between 0 and 2*pi.

    This represents a value which can be incremented, and which wraps back to 0 when it
    goes past 2 * pi.

    @tags{DSP}
*/
template <typename Type>
struct Phase
{
    /** Resets the phase to 0. */
    void reset() noexcept               { phase = 0; }

    /** Returns the current value, and increments the phase by the given increment.
        The increment must be a positive value, it can't go backwards!
        The new value of the phase after calling this function will be (phase + increment) % (2 * pi).
    */
    Type advance (Type increment) noexcept
    {
        jassert (increment >= 0); // cannot run this value backwards!

        auto last = phase;
        auto next = last + increment;

        while (next >= MathConstants<Type>::twoPi)
            next -= MathConstants<Type>::twoPi;

        phase = next;
        return last;
    }

    Type phase = 0;
};

} // namespace dsp
} // namespace juce