juce_ProcessorDuplicator.h

/*
  ==============================================================================
 
   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited
 
   JUCE is an open source library subject to commercial or open-source
   licensing.
 
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   Agreement and JUCE Privacy Policy.
 
   End User License Agreement: www.juce.com/juce-7-licence
   Privacy Policy: www.juce.com/juce-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.
 
  ==============================================================================
*/
 
namespace juce::dsp
{
 
template <typename MonoProcessorType, typename StateType>
struct ProcessorDuplicator
{
    ProcessorDuplicator() : state (new StateType()) {}
    ProcessorDuplicator (StateType* stateToUse) : state (stateToUse) {}
    ProcessorDuplicator (typename StateType::Ptr stateToUse) : state (std::move (stateToUse)) {}
    ProcessorDuplicator (const ProcessorDuplicator&) = default;
    ProcessorDuplicator (ProcessorDuplicator&&) = default;
 
    void prepare (const ProcessSpec& spec)
    {
        processors.removeRange ((int) spec.numChannels, processors.size());
 
        while (static_cast<size_t> (processors.size()) < spec.numChannels)
            processors.add (new MonoProcessorType (state));
 
        auto monoSpec = spec;
        monoSpec.numChannels = 1;
 
        for (auto* p : processors)
            p->prepare (monoSpec);
    }
 
    void reset() noexcept      { for (auto* p : processors) p->reset(); }
 
    template <typename ProcessContext>
    void process (const ProcessContext& context) noexcept
    {
        jassert ((int) context.getInputBlock().getNumChannels()  <= processors.size());
        jassert ((int) context.getOutputBlock().getNumChannels() <= processors.size());
 
        auto numChannels = static_cast<size_t> (jmin (context.getInputBlock().getNumChannels(),
                                                      context.getOutputBlock().getNumChannels()));
 
        for (size_t chan = 0; chan < numChannels; ++chan)
            processors[(int) chan]->process (MonoProcessContext<ProcessContext> (context, chan));
    }
 
    typename StateType::Ptr state;
 
private:
    template <typename ProcessContext>
    struct MonoProcessContext : public ProcessContext
    {
        MonoProcessContext (const ProcessContext& multiChannelContext, size_t channelToUse)
            : ProcessContext (multiChannelContext), channel (channelToUse)
        {}
 
        size_t channel;
 
        typename ProcessContext::ConstAudioBlockType getInputBlock()  const noexcept       { return ProcessContext::getInputBlock() .getSingleChannelBlock (channel); }
        typename ProcessContext::AudioBlockType      getOutputBlock() const noexcept       { return ProcessContext::getOutputBlock().getSingleChannelBlock (channel); }
    };
 
    juce::OwnedArray<MonoProcessorType> processors;
};
 
} // namespace juce::dsp