JUCE/examples/Demo/Source/Demos/AudioLiveScrollingDisplay.h

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2017 - ROLI Ltd.

   JUCE is an open source library subject to commercial or open-source
   licensing.

   By using JUCE, you agree to the terms of both the JUCE 5 End-User License
   Agreement and JUCE 5 Privacy Policy (both updated and effective as of the
   27th April 2017).

   End User License Agreement: www.juce.com/juce-5-licence
   Privacy Policy: www.juce.com/juce-5-privacy-policy

   Or: You may also use this code under the terms of the GPL v3 (see
   www.gnu.org/licenses).

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

#pragma once

#include "../JuceDemoHeader.h"


//==============================================================================
/* This component scrolls a continuous waveform showing the audio that's
   coming into whatever audio inputs this object is connected to.
*/
class LiveScrollingAudioDisplay  : public AudioVisualiserComponent,
                                   public AudioIODeviceCallback
{
public:
    LiveScrollingAudioDisplay()  : AudioVisualiserComponent (1)
    {
        setSamplesPerBlock (256);
        setBufferSize (1024);
    }

    //==============================================================================
    void audioDeviceAboutToStart (AudioIODevice*) override
    {
        clear();
    }

    void audioDeviceStopped() override
    {
        clear();
    }

    void audioDeviceIOCallback (const float** inputChannelData, int numInputChannels,
                                float** outputChannelData, int numOutputChannels,
                                int numberOfSamples) override
    {
        for (int i = 0; i < numberOfSamples; ++i)
        {
            float inputSample = 0;

            for (int chan = 0; chan < numInputChannels; ++chan)
                if (const float* inputChannel = inputChannelData[chan])
                    inputSample += inputChannel[i];  // find the sum of all the channels

            inputSample *= 10.0f; // boost the level to make it more easily visible.

            pushSample (&inputSample, 1);
        }

        // We need to clear the output buffers before returning, in case they're full of junk..
        for (int j = 0; j < numOutputChannels; ++j)
            if (float* outputChannel = outputChannelData[j])
                zeromem (outputChannel, sizeof (float) * (size_t) numberOfSamples);
    }

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (LiveScrollingAudioDisplay)
};