Carla/source/modules/juce_audio_basics/mpe/juce_MPEValue.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.

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

MPEValue::MPEValue() noexcept  : normalisedValue (8192)
{
}

MPEValue::MPEValue (int value)  : normalisedValue (value)
{
}

//==============================================================================
MPEValue MPEValue::from7BitInt (int value) noexcept
{
    jassert (value >= 0 && value <= 127);

    const int valueAs14Bit = value <= 64 ? value << 7 : int (jmap<float> (float (value - 64), 0.0f, 63.0f, 0.0f, 8191.0f)) + 8192;
    return MPEValue (valueAs14Bit);
}

MPEValue MPEValue::from14BitInt (int value) noexcept
{
    jassert (value >= 0 && value <= 16383);
    return MPEValue (value);
}

//==============================================================================
MPEValue MPEValue::minValue() noexcept      { return MPEValue::from7BitInt (0); }
MPEValue MPEValue::centreValue() noexcept   { return MPEValue::from7BitInt (64); }
MPEValue MPEValue::maxValue() noexcept      { return MPEValue::from7BitInt (127); }

int MPEValue::as7BitInt() const noexcept
{
    return normalisedValue >> 7;
}

int MPEValue::as14BitInt() const noexcept
{
    return normalisedValue;
}

//==============================================================================
float MPEValue::asSignedFloat() const noexcept
{
    return (normalisedValue < 8192)
           ? jmap<float> (float (normalisedValue), 0.0f, 8192.0f, -1.0f, 0.0f)
           : jmap<float> (float (normalisedValue), 8192.0f, 16383.0f, 0.0f, 1.0f);
}

float MPEValue::asUnsignedFloat() const noexcept
{
    return jmap<float> (float (normalisedValue), 0.0f, 16383.0f, 0.0f, 1.0f);
}

//==============================================================================
bool MPEValue::operator== (const MPEValue& other) const noexcept
{
    return normalisedValue == other.normalisedValue;
}

bool MPEValue::operator!= (const MPEValue& other) const noexcept
{
    return ! operator== (other);
}

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

class MPEValueTests  : public UnitTest
{
public:
    MPEValueTests() : UnitTest ("MPEValue class") {}

    void runTest() override
    {
        beginTest ("comparison operator");
        {
            MPEValue value1 = MPEValue::from7BitInt (7);
            MPEValue value2 = MPEValue::from7BitInt (7);
            MPEValue value3 = MPEValue::from7BitInt (8);

            expect (value1 == value1);
            expect (value1 == value2);
            expect (value1 != value3);
        }

        beginTest ("special values");
        {
            expectEquals (MPEValue::minValue().as7BitInt(), 0);
            expectEquals (MPEValue::minValue().as14BitInt(), 0);

            expectEquals (MPEValue::centreValue().as7BitInt(), 64);
            expectEquals (MPEValue::centreValue().as14BitInt(), 8192);

            expectEquals (MPEValue::maxValue().as7BitInt(), 127);
            expectEquals (MPEValue::maxValue().as14BitInt(), 16383);
        }

        beginTest ("zero/minimum value");
        {
            expectValuesConsistent (MPEValue::from7BitInt (0),  0, 0, -1.0f, 0.0f);
            expectValuesConsistent (MPEValue::from14BitInt (0), 0, 0, -1.0f, 0.0f);
        }

        beginTest ("maximum value");
        {
            expectValuesConsistent (MPEValue::from7BitInt (127),    127, 16383, 1.0f, 1.0f);
            expectValuesConsistent (MPEValue::from14BitInt (16383), 127, 16383, 1.0f, 1.0f);
        }

        beginTest ("centre value");
        {
            expectValuesConsistent (MPEValue::from7BitInt (64),    64, 8192, 0.0f, 0.5f);
            expectValuesConsistent (MPEValue::from14BitInt (8192), 64, 8192, 0.0f, 0.5f);
        }

        beginTest ("value halfway between min and centre");
        {
            expectValuesConsistent (MPEValue::from7BitInt (32),    32, 4096, -0.5f, 0.25f);
            expectValuesConsistent (MPEValue::from14BitInt (4096), 32, 4096, -0.5f, 0.25f);
        }
    }

private:
    //==============================================================================
    void expectValuesConsistent (MPEValue value,
                                 int expectedValueAs7BitInt,
                                 int expectedValueAs14BitInt,
                                 float expectedValueAsSignedFloat,
                                 float expectedValueAsUnsignedFloat)
    {
        expectEquals (value.as7BitInt(), expectedValueAs7BitInt);
        expectEquals (value.as14BitInt(), expectedValueAs14BitInt);
        expectFloatWithinRelativeError (value.asSignedFloat(), expectedValueAsSignedFloat, 0.0001f);
        expectFloatWithinRelativeError (value.asUnsignedFloat(), expectedValueAsUnsignedFloat, 0.0001f);
    }

    //==============================================================================
    void expectFloatWithinRelativeError (float actualValue, float expectedValue, float maxRelativeError)
    {
        const float maxAbsoluteError = jmax (1.0f, std::fabs (expectedValue)) * maxRelativeError;
        expect (std::fabs (expectedValue - actualValue) < maxAbsoluteError);
    }
};

static MPEValueTests MPEValueUnitTests;

#endif // JUCE_UNIT_TESTS