MainComponent.h

#pragma once

#include <random>
#include "../JuceLibraryCode/JuceHeader.h"

class NoiseGenerator
{
public:
	NoiseGenerator() {}
	void toggleSound(bool isOn, int chan, double sampleRate, double gain)
	{
		if (isOn)
		{
			m_outchan = chan;
			m_gain = gain;
			m_env.setSampleRate(sampleRate);
			m_env.setParameters({ 0.1f,0.5f,0.1f,5.0f });
			m_env.noteOn();
		}
		else
		{
			m_env.noteOff();
		}
	}
	void processAudio(AudioBuffer<float>& buf, int startSample, int numSamples)
	{
		if (m_gain == 0.0)
			return;
		for (int i = 0; i < numSamples; ++i)
		{
			float sample = m_gain * m_dist(m_rng) * m_env.getNextSample();
			buf.addSample(m_outchan, i+startSample, sample);
		}
		if (m_env.isActive() == false)
			m_gain = 0.0;
	}
private:
	ADSR m_env;
	std::mt19937 m_rng;
	std::uniform_real_distribution<float> m_dist{ -1.0f,1.0f };
	int m_outchan = 0;
	double m_gain = 0.0;
};

class MainComponent   : public AudioAppComponent
{
public:
    //==============================================================================
    MainComponent()
    {
		addAndMakeVisible(leftNoiseButton);
		addAndMakeVisible(rightNoiseButton);
		leftNoiseButton.setButtonText("Left noise");
		rightNoiseButton.setButtonText("Right noise");
		leftNoiseButton.onClick = [this]() 
		{ m_leftGenerator.toggleSound(leftNoiseButton.getToggleState(), 0, getSamplerate(),0.2); };
		rightNoiseButton.onClick = [this]() 
		{ m_rightGenerator.toggleSound(rightNoiseButton.getToggleState(), 1, getSamplerate(),0.2); };
        // Some platforms require permissions to open input channels so request that here
        if (RuntimePermissions::isRequired (RuntimePermissions::recordAudio)
            && ! RuntimePermissions::isGranted (RuntimePermissions::recordAudio))
        {
            RuntimePermissions::request (RuntimePermissions::recordAudio,
                                         [&] (bool granted) { if (granted)  setAudioChannels (2, 2); });
        }
        else
        {
            // Specify the number of input and output channels that we want to open
            setAudioChannels (0, 2);
        }
		setSize(800, 100);
    }
	double getSamplerate()
	{
		if (deviceManager.getCurrentAudioDevice())
			return deviceManager.getCurrentAudioDevice()->getCurrentSampleRate();
		return 1.0;
	}
    ~MainComponent()
    {
		shutdownAudio();
    }

    void prepareToPlay (int samplesPerBlockExpected, double sampleRate) override
    {
        
    }

    void getNextAudioBlock (const AudioSourceChannelInfo& bufferToFill) override
    {
        bufferToFill.clearActiveBufferRegion();
		m_leftGenerator.processAudio(*bufferToFill.buffer, bufferToFill.startSample, bufferToFill.numSamples);
		m_rightGenerator.processAudio(*bufferToFill.buffer, bufferToFill.startSample, bufferToFill.numSamples);
	}

    void releaseResources() override
    {
    }

    void paint (Graphics& g) override
    {
        g.fillAll (getLookAndFeel().findColour (ResizableWindow::backgroundColourId));
	}

    void resized() override
    {
		leftNoiseButton.setBounds(0, 0, getWidth() / 2 -2 , 30);
		rightNoiseButton.setBounds(getWidth()/2, 0, getWidth() / 2 - 2, 30);
    }


private:
    ToggleButton leftNoiseButton, rightNoiseButton;
	NoiseGenerator m_leftGenerator, m_rightGenerator;
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MainComponent)
};