Added multi-bus support for audio plug-in clients

examples/PlugInSamples/MultiOutSynth/Source/MultiOutSynth.cpp

@@ -0,0 +1,162 @@
+/*
+ ==============================================================================
+
+ MultiOutSynth.cpp
+ Created: 23 Nov 2015 3:08:33pm
+ Author:  Fabian Renn
+
+ ==============================================================================
+ */
+
+#include "../JuceLibraryCode/JuceHeader.h"
+#include "../../GenericEditor.h"
+
+//==============================================================================
+/**
+ */
+class MultiOutSynth  : public AudioProcessor
+{
+public:
+    enum
+    {
+        maxMidiChannel = 16,
+        maxNumberOfVoices = 5
+    };
+
+    //==============================================================================
+    MultiOutSynth()
+    {
+        // The base class constructor will already add a main stereo output bus
+        // If you want to add your own main channel then simply call clear the
+        // output buses (busArrangement.outputBuses.clear()) and then add your own
+
+        // Add additional output buses but disable these by default
+        for (int busNr = 1; busNr < maxMidiChannel; ++busNr)
+            busArrangement.outputBuses.add (AudioProcessorBus (String ("Output #") += String (busNr + 1), AudioChannelSet::disabled()));
+
+
+        // initialize other stuff (not related to buses)
+        formatManager.registerBasicFormats();
+
+        for (int midiChannel = 0; midiChannel < maxMidiChannel; ++midiChannel)
+        {
+            synth.add (new Synthesiser());
+
+            for (int i = 0; i < maxNumberOfVoices; ++i)
+                synth[midiChannel]->addVoice (new SamplerVoice());
+        }
+
+        loadNewSample (BinaryData::singing_ogg, BinaryData::singing_oggSize);
+    }
+
+    ~MultiOutSynth() {}
+
+    //==============================================================================
+    bool setPreferredBusArrangement (bool isInputBus, int busIndex,
+                                     const AudioChannelSet& preferred) override
+    {
+        const int numChannels = preferred.size();
+        const bool isMainBus = (busIndex == 0);
+
+        // do not allow disabling the main output bus
+        if (isMainBus && preferred.isDisabled()) return false;
+
+        // only support mono or stereo (or disabling) buses
+        if (numChannels > 2) return false;
+
+
+        // pass the call on to the base class
+        return AudioProcessor::setPreferredBusArrangement (isInputBus, busIndex, preferred);
+    }
+
+    //==============================================================================
+    void prepareToPlay (double newSampleRate, int samplesPerBlock) override
+    {
+        ignoreUnused (samplesPerBlock);
+
+        for (int midiChannel = 0; midiChannel < maxMidiChannel; ++midiChannel)
+            synth[midiChannel]->setCurrentPlaybackSampleRate (newSampleRate);
+    }
+
+    void releaseResources() override {}
+
+    void processBlock (AudioSampleBuffer& buffer, MidiBuffer& midiBuffer) override
+    {
+        buffer.clear();
+
+        for (int busNr = 0; busNr < maxMidiChannel; ++busNr)
+        {
+            MidiBuffer midiChannelBuffer = filterMidiMessagesForChannel (midiBuffer, busNr + 1);
+            AudioSampleBuffer audioBusBuffer = busArrangement.getBusBuffer (buffer, false, busNr);
+
+            synth [busNr]->renderNextBlock (audioBusBuffer, midiChannelBuffer, 0, audioBusBuffer.getNumSamples());
+        }
+    }
+
+    //==============================================================================
+    AudioProcessorEditor* createEditor() override { return new GenericEditor (*this); }
+    bool hasEditor() const override               { return true;   }
+
+    //==============================================================================
+    const String getName() const override               { return "Gain PlugIn"; }
+    bool acceptsMidi() const override                   { return false; }
+    bool producesMidi() const override                  { return false; }
+    bool silenceInProducesSilenceOut() const override   { return true; }
+    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 String(); }
+    void changeProgramName (int , const String& ) override { }
+
+    //==============================================================================
+    void getStateInformation (MemoryBlock&) override {}
+    void setStateInformation (const void*, int) override {}
+
+private:
+    //==============================================================================
+    static MidiBuffer filterMidiMessagesForChannel (const MidiBuffer& input, int channel)
+    {
+        MidiMessage msg;
+        int samplePosition;
+        MidiBuffer output;
+
+        for (MidiBuffer::Iterator it (input); it.getNextEvent (msg, samplePosition);)
+            if (msg.getChannel() == channel) output.addEvent (msg, samplePosition);
+
+        return output;
+    }
+
+    void loadNewSample (const void* data, int dataSize)
+    {
+        MemoryInputStream* soundBuffer = new MemoryInputStream (data, static_cast<std::size_t> (dataSize), false);
+        ScopedPointer<AudioFormatReader> formatReader (formatManager.findFormatForFileExtension ("ogg")->createReaderFor (soundBuffer, true));
+
+        BigInteger midiNotes;
+        midiNotes.setRange (0, 126, true);
+        SynthesiserSound::Ptr newSound = new SamplerSound ("Voice", *formatReader, midiNotes, 0x40, 0.0, 0.0, 10.0);
+
+        for (int channel = 0; channel < maxMidiChannel; ++channel)
+            synth[channel]->removeSound (0);
+
+        sound = newSound;
+
+        for (int channel = 0; channel < maxMidiChannel; ++channel)
+            synth[channel]->addSound (sound);
+    }
+
+    //==============================================================================
+    AudioFormatManager formatManager;
+    OwnedArray<Synthesiser> synth;
+    SynthesiserSound::Ptr sound;
+
+    //==============================================================================
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MultiOutSynth)
+};
+
+//==============================================================================
+// This creates new instances of the plugin..
+AudioProcessor* JUCE_CALLTYPE createPluginFilter()
+{
+    return new MultiOutSynth();
+}