sfizz/src/sfizz/Smoothers.cpp
2020-07-27 21:01:07 +02:00

52 lines
1.3 KiB
C++

// SPDX-License-Identifier: BSD-2-Clause
// This code is part of the sfizz library and is licensed under a BSD 2-clause
// license. You should have receive a LICENSE.md file along with the code.
// If not, contact the sfizz maintainers at https://github.com/sfztools/sfizz
#include "Smoothers.h"
namespace sfz {
Smoother::Smoother()
{
}
void Smoother::setSmoothing(uint8_t smoothValue, float sampleRate)
{
smoothing = (smoothValue > 0);
if (smoothing) {
filter.setGain(std::tan(1.0f / (2 * Default::smoothTauPerStep * smoothValue * sampleRate)));
}
}
void Smoother::reset(float value)
{
filter.reset(value);
}
void Smoother::process(absl::Span<const float> input, absl::Span<float> output, bool canShortcut)
{
CHECK_SPAN_SIZES(input, output);
if (input.size() == 0)
return;
if (canShortcut) {
float in = input.front();
float rel = std::abs(in - current()) / (std::abs(in) + config::virtuallyZero);
canShortcut = rel < config::smoothingShortcutThreshold;
}
if (canShortcut) {
if (input.data() != output.data())
copy<float>(input, output);
filter.reset(input.back());
} else if (smoothing) {
filter.processLowpass(input, output);
} else if (input.data() != output.data()) {
copy<float>(input, output);
}
}
}