fix macOS build (following Projucer changes made in Windows, which removed /Applications/JUCE/modules from its headers). move JUCE headers under source control, so that Windows and macOS can both build against same version of JUCE. remove AUv3 target (I think it's an iOS thing, so it will never work with this macOS fluidsynth dylib).

modules/juce_dsp/processors/juce_Bias.h

@@ -0,0 +1,158 @@
+/*
+  ==============================================================================
+
+   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.
+
+  ==============================================================================
+*/
+
+namespace juce
+{
+namespace dsp
+{
+
+/**
+    Adds a DC offset (voltage bias) to the audio samples.
+
+    This is a useful preprocessor for asymmetric waveshaping when a waveshaper is
+    bookended by a bias on input and a DC-offset removing high pass filter on output.
+
+    This is an extremely simple bias implementation that simply adds a value to a signal.
+    More complicated bias behaviours exist in real circuits - for your homework ;).
+
+    @tags{DSP}
+*/
+template <typename FloatType>
+class Bias
+{
+public:
+    Bias() noexcept {}
+
+    //==============================================================================
+    /** Sets the DC bias
+        @param newBias DC offset in range [-1, 1]
+    */
+    void setBias (FloatType newBias) noexcept
+    {
+        jassert (newBias >= static_cast<FloatType> (-1) && newBias <= static_cast<FloatType> (1));
+        bias.setValue(newBias);
+    }
+
+    //==============================================================================
+    /** Returns the DC bias
+        @return DC bias, which should be in the range [-1, 1]
+    */
+    FloatType getBias() const noexcept              { return bias.getTargetValue(); }
+
+    /** Sets the length of the ramp used for smoothing gain changes. */
+    void setRampDurationSeconds (double newDurationSeconds) noexcept
+    {
+        if (rampDurationSeconds != newDurationSeconds)
+        {
+            rampDurationSeconds = newDurationSeconds;
+            updateRamp();
+        }
+    }
+
+    double getRampDurationSeconds() const noexcept  { return rampDurationSeconds; }
+
+    //==============================================================================
+    /** Called before processing starts */
+    void prepare (const ProcessSpec& spec) noexcept
+    {
+        sampleRate = spec.sampleRate;
+        updateRamp();
+    }
+
+    void reset() noexcept
+    {
+        bias.reset (sampleRate, rampDurationSeconds);
+    }
+
+    //==============================================================================
+    /** Returns the result of processing a single sample. */
+    template <typename SampleType>
+    SampleType processSample (SampleType inputSample) const noexcept
+    {
+        return inputSample + bias.getNextValue();
+    }
+
+    //==============================================================================
+    /** Processes the input and output buffers supplied in the processing context. */
+    template<typename ProcessContext>
+    void process (const ProcessContext& context) noexcept
+    {
+        auto&& inBlock  = context.getInputBlock();
+        auto&& outBlock = context.getOutputBlock();
+
+        jassert (inBlock.getNumChannels() == outBlock.getNumChannels());
+        jassert (inBlock.getNumSamples() == outBlock.getNumSamples());
+
+        auto len         = inBlock.getNumSamples();
+        auto numChannels = inBlock.getNumChannels();
+
+        if (context.isBypassed)
+        {
+            bias.skip (static_cast<int> (len));
+
+            if (context.usesSeparateInputAndOutputBlocks())
+                outBlock.copy (inBlock);
+
+            return;
+        }
+
+        if (numChannels == 1)
+        {
+            auto* src = inBlock.getChannelPointer (0);
+            auto* dst = outBlock.getChannelPointer (0);
+
+            for (size_t i = 0; i < len; ++i)
+                dst[i] = src[i] + bias.getNextValue();
+        }
+        else
+        {
+            auto* biases = static_cast<FloatType*> (alloca (sizeof (FloatType) * len));
+
+            for (size_t i = 0; i < len; ++i)
+                biases[i] = bias.getNextValue();
+
+            for (size_t chan = 0; chan < numChannels; ++chan)
+                FloatVectorOperations::add (outBlock.getChannelPointer (chan),
+                                            inBlock.getChannelPointer (chan),
+                                            biases, static_cast<int> (len));
+        }
+    }
+
+
+private:
+    //==============================================================================
+    LinearSmoothedValue<FloatType> bias;
+    double sampleRate = 0, rampDurationSeconds = 0;
+
+    void updateRamp() noexcept
+    {
+        if (sampleRate > 0)
+            bias.reset (sampleRate, rampDurationSeconds);
+    }
+};
+
+} // namespace dsp
+} // namespace juce