JUCE/modules/juce_audio_formats/sampler/juce_Sampler.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
{

//==============================================================================
/**
    A subclass of SynthesiserSound that represents a sampled audio clip.

    This is a pretty basic sampler, and just attempts to load the whole audio stream
    into memory.

    To use it, create a Synthesiser, add some SamplerVoice objects to it, then
    give it some SampledSound objects to play.

    @see SamplerVoice, Synthesiser, SynthesiserSound

    @tags{Audio}
*/
class JUCE_API  SamplerSound    : public SynthesiserSound
{
public:
    //==============================================================================
    /** Creates a sampled sound from an audio reader.

        This will attempt to load the audio from the source into memory and store
        it in this object.

        @param name         a name for the sample
        @param source       the audio to load. This object can be safely deleted by the
                            caller after this constructor returns
        @param midiNotes    the set of midi keys that this sound should be played on. This
                            is used by the SynthesiserSound::appliesToNote() method
        @param midiNoteForNormalPitch   the midi note at which the sample should be played
                                        with its natural rate. All other notes will be pitched
                                        up or down relative to this one
        @param attackTimeSecs   the attack (fade-in) time, in seconds
        @param releaseTimeSecs  the decay (fade-out) time, in seconds
        @param maxSampleLengthSeconds   a maximum length of audio to read from the audio
                                        source, in seconds
    */
    SamplerSound (const String& name,
                  AudioFormatReader& source,
                  const BigInteger& midiNotes,
                  int midiNoteForNormalPitch,
                  double attackTimeSecs,
                  double releaseTimeSecs,
                  double maxSampleLengthSeconds);

    /** Destructor. */
    ~SamplerSound() override;

    //==============================================================================
    /** Returns the sample's name */
    const String& getName() const noexcept                  { return name; }

    /** Returns the audio sample data.
        This could return nullptr if there was a problem loading the data.
    */
    AudioBuffer<float>* getAudioData() const noexcept       { return data.get(); }

    //==============================================================================
    /** Changes the parameters of the ADSR envelope which will be applied to the sample. */
    void setEnvelopeParameters (ADSR::Parameters parametersToUse)    { params = parametersToUse; }

    //==============================================================================
    bool appliesToNote (int midiNoteNumber) override;
    bool appliesToChannel (int midiChannel) override;

private:
    //==============================================================================
    friend class SamplerVoice;

    String name;
    std::unique_ptr<AudioBuffer<float>> data;
    double sourceSampleRate;
    BigInteger midiNotes;
    int length = 0, midiRootNote = 0;

    ADSR::Parameters params;

    JUCE_LEAK_DETECTOR (SamplerSound)
};


//==============================================================================
/**
    A subclass of SynthesiserVoice that can play a SamplerSound.

    To use it, create a Synthesiser, add some SamplerVoice objects to it, then
    give it some SampledSound objects to play.

    @see SamplerSound, Synthesiser, SynthesiserVoice

    @tags{Audio}
*/
class JUCE_API  SamplerVoice    : public SynthesiserVoice
{
public:
    //==============================================================================
    /** Creates a SamplerVoice. */
    SamplerVoice();

    /** Destructor. */
    ~SamplerVoice() override;

    //==============================================================================
    bool canPlaySound (SynthesiserSound*) override;

    void startNote (int midiNoteNumber, float velocity, SynthesiserSound*, int pitchWheel) override;
    void stopNote (float velocity, bool allowTailOff) override;

    void pitchWheelMoved (int newValue) override;
    void controllerMoved (int controllerNumber, int newValue) override;

    void renderNextBlock (AudioBuffer<float>&, int startSample, int numSamples) override;
    using SynthesiserVoice::renderNextBlock;

private:
    //==============================================================================
    double pitchRatio = 0;
    double sourceSamplePosition = 0;
    float lgain = 0, rgain = 0;

    ADSR adsr;

    JUCE_LEAK_DETECTOR (SamplerVoice)
};

} // namespace juce