main.cpp

#include <JuceHeader.h>

class Noise : public juce::AudioSource
{
public:
    void prepareToPlay(int samplesPerBlockExpected, double sampleRate) override
    {
        // nothing to do here, we can generate the noise without preparing anything
    }
    void releaseResources() override
    {
        // nothing to do here, we didn't use anything to release
    }
    void getNextAudioBlock(const juce::AudioSourceChannelInfo& bufferToFill) override
    {
        bufferToFill.clearActiveBufferRegion();
        auto bufferPointers = bufferToFill.buffer->getArrayOfWritePointers();
        for (int i = 0; i < bufferToFill.numSamples; ++i)
        {
            float out = juce::jmap(rgen.nextFloat(),0.0f,1.0f,-1.0f,1.0f) * 0.1f; // generate output sample
            // copy to all output channels
            for (int j=0;j<bufferToFill.buffer->getNumChannels();++j)
            {
                bufferPointers[j][i+bufferToFill.startSample] = out;
            }
        }
    }
private:
    juce::Random rgen;
};

//==============================================================================
int main (int argc, char* argv[])
{
    juce::ScopedJuceInitialiser_GUI gui_init; // even if this isn't a GUI app, the Juce message manager needs to be running
    juce::AudioDeviceManager aman;
    aman.initialiseWithDefaultDevices(0, 2); // 0 inputs, 2 outputs for the audio
    juce::AudioSourcePlayer player;
    Noise noiseSource;
    player.setSource(&noiseSource);
    aman.addAudioCallback(&player);
    juce::Thread::sleep(1000); // keep the audio playing for 1 second (1000 milliseconds)
    return 0;
}