JUCE/modules/juce_audio_basics/mpe/juce_MPENote.cpp

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

   This file is part of the JUCE library.
   Copyright (c) 2016 - ROLI Ltd.

   Permission is granted to use this software under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license/

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
   OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
   USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   OF THIS SOFTWARE.

   -----------------------------------------------------------------------------

   To release a closed-source product which uses other parts of JUCE not
   licensed under the ISC terms, commercial licenses are available: visit
   www.juce.com for more information.

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

namespace
{
    uint16 generateNoteID (int midiChannel, int midiNoteNumber) noexcept
    {
        jassert (midiChannel > 0 && midiChannel <= 16);
        jassert (midiNoteNumber >= 0 && midiNoteNumber < 128);

        return uint16 ((midiChannel << 7) + midiNoteNumber);
    }
}

//==============================================================================
MPENote::MPENote (int midiChannel_,
                  int initialNote_,
                  MPEValue noteOnVelocity_,
                  MPEValue pitchbend_,
                  MPEValue pressure_,
                  MPEValue timbre_,
                  KeyState keyState_) noexcept
    : noteID (generateNoteID (midiChannel_, initialNote_)),
      midiChannel (uint8 (midiChannel_)),
      initialNote (uint8 (initialNote_)),
      noteOnVelocity (noteOnVelocity_),
      pitchbend (pitchbend_),
      pressure (pressure_),
      timbre (timbre_),
      noteOffVelocity (MPEValue::minValue()),
      keyState (keyState_)
{
    jassert (keyState != MPENote::off);
    jassert (isValid());
}

MPENote::MPENote() noexcept
    : noteID (0),
      midiChannel (0),
      initialNote (0),
      noteOnVelocity (MPEValue::minValue()),
      pitchbend (MPEValue::centreValue()),
      pressure (MPEValue::centreValue()),
      timbre (MPEValue::centreValue()),
      noteOffVelocity (MPEValue::minValue()),
      keyState (MPENote::off)
{
}

//==============================================================================
bool MPENote::isValid() const noexcept
{
    return midiChannel > 0 && midiChannel <= 16 && initialNote < 128;
}

//==============================================================================
double MPENote::getFrequencyInHertz (double frequencyOfA) const noexcept
{
    double pitchInSemitones = double (initialNote) + totalPitchbendInSemitones;
    return frequencyOfA * std::pow (2.0, (pitchInSemitones - 69.0) / 12.0);
}

//==============================================================================
bool MPENote::operator== (const MPENote& other) const noexcept
{
    jassert (isValid() && other.isValid());
    return noteID == other.noteID;
}

bool MPENote::operator!= (const MPENote& other) const noexcept
{
    jassert (isValid() && other.isValid());
    return noteID != other.noteID;
}

//==============================================================================
//==============================================================================
#if JUCE_UNIT_TESTS

class MPENoteTests : public UnitTest
{
public:
    MPENoteTests() : UnitTest ("MPENote class") {}

    //==============================================================================
    void runTest() override
    {
        beginTest ("getFrequencyInHertz");
        {
            MPENote note;
            note.initialNote = 60;
            note.totalPitchbendInSemitones = -0.5;
            expectEqualsWithinOneCent (note.getFrequencyInHertz(), 254.178);
        }
    }

private:
    //==============================================================================
    void expectEqualsWithinOneCent (double frequencyInHertzActual,
                                    double frequencyInHertzExpected)
    {
        double ratio = frequencyInHertzActual / frequencyInHertzExpected;
        double oneCent = 1.0005946;
        expect (ratio < oneCent);
        expect (ratio > 1.0 / oneCent);
    }
};

static MPENoteTests MPENoteUnitTests;

#endif // JUCE_UNIT_TESTS