JUCE/modules/juce_audio_processors/utilities/juce_AudioParameterFloat.cpp

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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

   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
{

AudioParameterFloat::AudioParameterFloat (const String& idToUse, const String& nameToUse,
                                          NormalisableRange<float> r, float def,
                                          const String& labelToUse, Category categoryToUse,
                                          std::function<String(float, int)> stringFromValue,
                                          std::function<float(const String&)> valueFromString)
   : RangedAudioParameter (idToUse, nameToUse, labelToUse, categoryToUse),
     range (r), value (def), defaultValue (def),
     stringFromValueFunction (stringFromValue),
     valueFromStringFunction (valueFromString)
{
    if (stringFromValueFunction == nullptr)
    {
        auto numDecimalPlacesToDisplay = [this]
        {
            int numDecimalPlaces = 7;

            if (range.interval != 0.0f)
            {
                if (approximatelyEqual (std::abs (range.interval - (int) range.interval), 0.0f))
                    return 0;

                auto v = std::abs (roundToInt (range.interval * pow (10, numDecimalPlaces)));

                while ((v % 10) == 0 && numDecimalPlaces > 0)
                {
                    --numDecimalPlaces;
                    v /= 10;
                }
            }

            return numDecimalPlaces;
        }();

        stringFromValueFunction = [numDecimalPlacesToDisplay] (float v, int length)
        {
            String asText (v, numDecimalPlacesToDisplay);
            return length > 0 ? asText.substring (0, length) : asText;
        };
    }

    if (valueFromStringFunction == nullptr)
        valueFromStringFunction = [] (const String& text) { return text.getFloatValue(); };
}

AudioParameterFloat::AudioParameterFloat (String pid, String nm, float minValue, float maxValue, float def)
   : AudioParameterFloat (pid, nm, { minValue, maxValue, 0.01f }, def)
{
}

AudioParameterFloat::~AudioParameterFloat()
{
    #if __cpp_lib_atomic_is_always_lock_free
     static_assert (std::atomic<float>::is_always_lock_free,
                    "AudioParameterFloat requires a lock-free std::atomic<float>");
    #endif
}

float AudioParameterFloat::getValue() const                              { return convertTo0to1 (value); }
void AudioParameterFloat::setValue (float newValue)                      { value = convertFrom0to1 (newValue); valueChanged (get()); }
float AudioParameterFloat::getDefaultValue() const                       { return convertTo0to1 (defaultValue); }
int AudioParameterFloat::getNumSteps() const                             { return AudioProcessorParameterWithID::getNumSteps(); }
String AudioParameterFloat::getText (float v, int length) const          { return stringFromValueFunction (convertFrom0to1 (v), length); }
float AudioParameterFloat::getValueForText (const String& text) const    { return convertTo0to1 (valueFromStringFunction (text)); }
void AudioParameterFloat::valueChanged (float)                           {}

AudioParameterFloat& AudioParameterFloat::operator= (float newValue)
{
    if (value != newValue)
        setValueNotifyingHost (convertTo0to1 (newValue));

    return *this;
}

} // namespace juce