juicysfplugin/modules/juce_dsp/processors/juce_Gain.h

148 lines
5.0 KiB
C++

/*
==============================================================================
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
{
/**
Applies a gain to audio samples as single samples or AudioBlocks.
@tags{DSP}
*/
template <typename FloatType>
class Gain
{
public:
Gain() noexcept {}
//==============================================================================
/** Applies a new gain as a linear value. */
void setGainLinear (FloatType newGain) noexcept { gain.setValue (newGain); }
/** Applies a new gain as a decibel value. */
void setGainDecibels (FloatType newGainDecibels) noexcept { setGainLinear (Decibels::decibelsToGain<FloatType> (newGainDecibels)); }
/** Returns the current gain as a linear value. */
FloatType getGainLinear() const noexcept { return gain.getTargetValue(); }
/** Returns the current gain in decibels. */
FloatType getGainDecibels() const noexcept { return Decibels::gainToDecibels<FloatType> (getGainLinear()); }
/** Sets the length of the ramp used for smoothing gain changes. */
void setRampDurationSeconds (double newDurationSeconds) noexcept
{
if (rampDurationSeconds != newDurationSeconds)
{
rampDurationSeconds = newDurationSeconds;
reset();
}
}
/** Returns the ramp duration in seconds. */
double getRampDurationSeconds() const noexcept { return rampDurationSeconds; }
/** Returns true if the current value is currently being interpolated. */
bool isSmoothing() const noexcept { return gain.isSmoothing(); }
//==============================================================================
/** Called before processing starts. */
void prepare (const ProcessSpec& spec) noexcept
{
sampleRate = spec.sampleRate;
reset();
}
/** Resets the internal state of the gain */
void reset() noexcept
{
if (sampleRate > 0)
gain.reset (sampleRate, rampDurationSeconds);
}
//==============================================================================
/** Returns the result of processing a single sample. */
template <typename SampleType>
SampleType JUCE_VECTOR_CALLTYPE processSample (SampleType s) noexcept
{
return s * gain.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)
{
gain.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] * gain.getNextValue();
}
else
{
auto* gains = static_cast<FloatType*> (alloca (sizeof (FloatType) * len));
for (size_t i = 0; i < len; ++i)
gains[i] = gain.getNextValue();
for (size_t chan = 0; chan < numChannels; ++chan)
FloatVectorOperations::multiply (outBlock.getChannelPointer (chan),
inBlock.getChannelPointer (chan),
gains, static_cast<int> (len));
}
}
private:
//==============================================================================
LinearSmoothedValue<FloatType> gain;
double sampleRate = 0, rampDurationSeconds = 0;
};
} // namespace dsp
} // namespace juce