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/*
==============================================================================
This file is part of the JUCE library.
Copyright (c) 2015 - ROLI Ltd.
Permission is granted to use this software under the terms of either:
a) the GPL v2 (or any later version)
b) the Affero GPL v3
Details of these licenses can be found at: www.gnu.org/licenses
JUCE is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE. See the GNU General Public License for more details.
------------------------------------------------------------------------------
To release a closed-source product which uses JUCE, commercial licenses are
available: visit www.juce.com for more information.
==============================================================================
*/
#include "../JuceLibraryCode/JuceHeader.h"
#include "../../GenericEditor.h"
class NoiseGate : public AudioProcessor
{
public:
//==============================================================================
//==============================================================================
NoiseGate()
: AudioProcessor (BusesProperties().withInput ("Input", AudioChannelSet::stereo())
.withOutput ("Output", AudioChannelSet::stereo())
.withInput ("Sidechain", AudioChannelSet::mono()))
{
addParameter (threshold = new AudioParameterFloat ("threshold", "Threshold", 0.0f, 1.0f, 0.5f));
addParameter (alpha = new AudioParameterFloat ("alpha", "Alpha", 0.0f, 1.0f, 0.8f));
}
~NoiseGate() {}
//==============================================================================
bool isBusesLayoutSupported (const BusesLayout& layouts) const override
{
// the sidechain can take any layout, the main bus needs to be the same on the input and output
return (layouts.getMainInputChannelSet() == layouts.getMainOutputChannelSet() &&
(! layouts.getMainInputChannelSet().isDisabled()));
}
//==============================================================================
void prepareToPlay (double /*sampleRate*/, int /*maxBlockSize*/) override { lowPassCoeff = 0.0f; sampleCountDown = 0; }
void releaseResources() override {}
void processBlock (AudioSampleBuffer& buffer, MidiBuffer&) override
{
AudioSampleBuffer mainInputOutput = getBusBuffer(buffer, true, 0);
AudioSampleBuffer sideChainInput = getBusBuffer(buffer, true, 1);
float alphaCopy = *alpha;
float thresholdCopy = *threshold;
for (int j = 0; j < buffer.getNumSamples(); ++j)
{
float mixedSamples = 0.0f;
for (int i = 0; i < sideChainInput.getNumChannels(); ++i)
mixedSamples += sideChainInput.getReadPointer (i) [j];
mixedSamples /= static_cast<float> (sideChainInput.getNumChannels());
lowPassCoeff = (alphaCopy * lowPassCoeff) + ((1.0f - alphaCopy) * mixedSamples);
if (lowPassCoeff >= thresholdCopy)
sampleCountDown = (int) getSampleRate();
// very in-effective way of doing this
for (int i = 0; i < mainInputOutput.getNumChannels(); ++i)
*mainInputOutput.getWritePointer (i, j) = sampleCountDown > 0 ? *mainInputOutput.getReadPointer (i, j) : 0.0f;
if (sampleCountDown > 0)
--sampleCountDown;
}
}
//==============================================================================
AudioProcessorEditor* createEditor() override { return new GenericEditor (*this); }
bool hasEditor() const override { return true; }
const String getName() const override { return "NoiseGate"; }
bool acceptsMidi() const override { return false; }
bool producesMidi() const override { return false; }
double getTailLengthSeconds() const override { return 0.0; }
int getNumPrograms() override { return 1; }
int getCurrentProgram() override { return 0; }
void setCurrentProgram (int) override {}
const String getProgramName (int) override { return ""; }
void changeProgramName (int, const String&) override {}
bool isVST2() const noexcept { return (wrapperType == wrapperType_VST); }
//==============================================================================
void getStateInformation (MemoryBlock& destData) override
{
MemoryOutputStream stream (destData, true);
stream.writeFloat (*threshold);
stream.writeFloat (*alpha);
}
void setStateInformation (const void* data, int sizeInBytes) override
{
MemoryInputStream stream (data, static_cast<size_t> (sizeInBytes), false);
threshold->setValueNotifyingHost (stream.readFloat());
alpha->setValueNotifyingHost (stream.readFloat());
}
enum
{
kVST2MaxChannels = 8
};
private:
//==============================================================================
AudioParameterFloat* threshold;
AudioParameterFloat* alpha;
int sampleCountDown;
float lowPassCoeff;
//==============================================================================
JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (NoiseGate)
};
//==============================================================================
// This creates new instances of the plugin..
AudioProcessor* JUCE_CALLTYPE createPluginFilter()
{
return new NoiseGate();
}
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