JUCE/examples/BLOCKS/BlocksSynth/Source/Audio.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 "Oscillators.h"

/**
    Class to handle the Audio functionality
*/
class Audio : public AudioIODeviceCallback
{
public:
    Audio()
    {
        // Set up the audio device manager
        audioDeviceManager.initialiseWithDefaultDevices (0, 2);
        audioDeviceManager.addAudioCallback (this);

        // Set up the synthesiser and add each of the waveshapes
        synthesiser.clearVoices();
        synthesiser.clearSounds();

        synthesiser.addVoice (new SineVoice());
        synthesiser.addVoice (new SquareVoice());
        synthesiser.addVoice (new SawVoice());
        synthesiser.addVoice (new TriangleVoice());

        synthesiser.addSound (new SineSound());
        synthesiser.addSound (new SquareSound());
        synthesiser.addSound (new SawSound());
        synthesiser.addSound (new TriangleSound());
    }

    ~Audio()
    {
        audioDeviceManager.removeAudioCallback (this);
    }

    /** Audio callback */
    void audioDeviceIOCallback (const float **/*inputChannelData*/, int /*numInputChannels*/,
                                float **outputChannelData, int numOutputChannels, int numSamples) override
    {
        AudioSampleBuffer sampleBuffer = AudioSampleBuffer (outputChannelData, numOutputChannels, numSamples);
        sampleBuffer.clear();

        synthesiser.renderNextBlock (sampleBuffer, MidiBuffer(), 0, numSamples);
    }

    void audioDeviceAboutToStart (AudioIODevice* device) override
    {
        synthesiser.setCurrentPlaybackSampleRate (device->getCurrentSampleRate());
    }

    void audioDeviceStopped() override {}

    /** Called to turn a synthesiser note on */
    void noteOn (int channel, int noteNum, float velocity)
    {
        synthesiser.noteOn (channel, noteNum, velocity);
    }

    /** Called to turn a synthesiser note off */
    void noteOff (int channel, int noteNum, float velocity)
    {
        synthesiser.noteOff (channel, noteNum, velocity, false);
    }

    /** Called to turn all synthesiser notes off */
    void allNotesOff()
    {
        for (auto i = 1; i < 5; ++i)
            synthesiser.allNotesOff (i, false);
    }

    /** Send pressure change message to synthesiser */
    void pressureChange (int channel, float newPressure)
    {
        synthesiser.handleChannelPressure (channel, static_cast<int> (newPressure * 127));
    }

    /** Send pitch change message to synthesiser */
    void pitchChange (int channel, float pitchChange)
    {
        synthesiser.handlePitchWheel (channel, static_cast<int> (pitchChange * 127));
    }

private:
    AudioDeviceManager audioDeviceManager;
    Synthesiser synthesiser;

    //==============================================================================
    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (Audio)
};