Help for a SamplerVoice based sample reader VST plugin

Audio Plugins
5

What you want to do in general shouldn't be too hard and using JUCE Synthesizer class is definitely the right direction. My suggestion would be to derive a child-class from JUCE's SamplerVoice and simply override the startNote method and multiply the velocity with the note's gain. I haven't tested the code below but it should give you an idea of what I am talking about:

class CustomGainSamplerVoice  : public SamplerVoice
{
public:
    CustomGainSamplerVoice(JuceDemoPluginAudioProcessor& myPluginProcessor)
        : parent (myPluginProcessor)
    {
    }


    void startNote (int midiNoteNumber, float velocity, SynthesiserSound* snd, int pitchWheel) override
    {
        if (midiNoteNumber == 36)
            velocity = velocity * parent.gainOne;
        else if (midiNoteNumber == 37)
            velocity = velocity * parent.gainTwo;

        // call the base class' method
        SamplerVoice::startNote(midiNoteNumber, velocity, snd, pitchWheel);
    }


private:
    JuceDemoPluginAudioProcessor& parent;

};