MultichannelVolume.h

/*******************************************************************************
 The block below describes the properties of this PIP. A PIP is a short snippet
 of code that can be read by the Projucer and used to generate a JUCE project.

 BEGIN_JUCE_PIP_METADATA

  name:             MultichannelVolume

  dependencies:     juce_audio_basics, juce_audio_devices, juce_audio_formats, juce_audio_plugin_client, 
                    juce_audio_processors, juce_audio_utils, juce_core, juce_data_structures, juce_events, 
                    juce_graphics, juce_gui_basics, juce_gui_extra
  exporters:        xcode_mac

  type:             AudioProcessor
  mainClass:        MyPlugin

 END_JUCE_PIP_METADATA

*******************************************************************************/

#pragma once


//==============================================================================
class MyPlugin  : public AudioProcessor
{
public:
    //==============================================================================
    MyPlugin()
        : AudioProcessor (BusesProperties().withInput  ("Input",  AudioChannelSet::discreteChannels(64))
                                           .withOutput ("Output", AudioChannelSet::discreteChannels(64)))
		
    {
		addParameter(new AudioParameterFloat("mainvolume", "Master volume", -96.0, 12.0, 0.0));
		for (int i=0;i<64;++i)
			addParameter(new AudioParameterFloat("chanvolume"+String(i), "Channel "+String(i+1)+" volume", -96.0, 12.0, 0.0));
    }

    ~MyPlugin()
    {
    }

    void prepareToPlay (double, int) override {}
	void releaseResources() override {}
	inline float getFloatParameter(int index)
	{
		const auto& pars = getParameters();
		return *(dynamic_cast<AudioParameterFloat*>(pars[index]));
	}
	inline void setFloatParameter(int index, float val)
	{
		const auto& pars = getParameters();
		*(dynamic_cast<AudioParameterFloat*>(pars[index])) = val;
	}
    void processBlock (AudioBuffer<float>& buffer, MidiBuffer&) override
    {
        ScopedNoDenormals noDenormals;
        auto totalNumInputChannels  = getTotalNumInputChannels();
        auto totalNumOutputChannels = getTotalNumOutputChannels();
		for (auto i = totalNumInputChannels; i < totalNumOutputChannels; ++i)
            buffer.clear (i, 0, buffer.getNumSamples());

        float maingain = Decibels::decibelsToGain(getFloatParameter(0));
		for (int channel = 0; channel < totalNumInputChannels; ++channel)
        {
            auto* channelData = buffer.getWritePointer (channel);
			float changain = Decibels::decibelsToGain(getFloatParameter(channel + 1));
			for (int i = 0; i < buffer.getNumSamples(); ++i)
				channelData[i] *= changain*maingain;
        }
    }

    //==============================================================================
    AudioProcessorEditor* createEditor() override          
	{ 
		return new GenericAudioProcessorEditor(this);
	}
    bool hasEditor() const override                        
	{ 
		return true;   
	}

    //==============================================================================
    const String getName() const override                  { return "MultichannelVolume"; }
    bool acceptsMidi() const override                      { return false; }
    bool producesMidi() const override                     { return false; }
    double getTailLengthSeconds() const override           { return 0; }

    //==============================================================================
    int getNumPrograms() override                          { return 1; }
    int getCurrentProgram() override                       { return 0; }
    void setCurrentProgram (int) override                  {}
    const String getProgramName (int) override             { return {}; }
    void changeProgramName (int, const String&) override   {}

    //==============================================================================
    void getStateInformation (MemoryBlock& destData) override
    {
		ValueTree state("multichanvolumestate");
		auto& pars = getParameters();
		for (int i = 0; i < pars.size(); ++i)
			state.setProperty("par"+String(i), getFloatParameter(i), nullptr);
		MemoryOutputStream stream(destData, true);
		state.writeToStream(stream);
    }

    void setStateInformation (const void* data, int sizeInBytes) override
    {
		ValueTree state = ValueTree::readFromData(data, sizeInBytes);
		if (state.isValid() == true)
		{
			auto& pars = getParameters();
			for (int i = 0; i < pars.size(); ++i)
			{
				setFloatParameter(i, state.getProperty("par"+String(i), 0.0));
			}
		}
    }

    //==============================================================================
    bool isBusesLayoutSupported (const BusesLayout& layouts) const override
    {
        if (layouts.getMainOutputChannelSet() != AudioChannelSet::mono()
            && layouts.getMainOutputChannelSet() != AudioChannelSet::stereo())
            return false;
		if (layouts.getMainOutputChannelSet() != layouts.getMainInputChannelSet())
            return false;
		return true;
    }

private:
    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MyPlugin)
};