55 lines
1.2 KiB
C++
55 lines
1.2 KiB
C++
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#include "tools/bpmcalculator.h"
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#include <cmath>
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#include <numeric>
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#include <iostream>
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constexpr microsec MICROSECONDS_IN_MINUTE = 60000000;
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BPMCalculator::BPMCalculator(const std::shared_ptr<Music>& music) :
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_music(music),
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_previous_click_offset(0)
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{}
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void BPMCalculator::setMusic(const std::shared_ptr<Music>& music)
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{
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_music = music;
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}
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void BPMCalculator::startListening(const microsec &offset)
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{
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_deltas.clear();
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_previous_click_offset = 0;
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_music->setOffset(offset);
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_music->play();
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}
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void BPMCalculator::stopListening()
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{
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_music->stop();
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}
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void BPMCalculator::click()
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{
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const microsec click_offset = _music->fetchOffset();
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if (_previous_click_offset == 0)
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{
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_previous_click_offset = click_offset;
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return;
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}
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const microsec delta = click_offset - _previous_click_offset;
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_deltas.emplace_back(delta);
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_previous_click_offset = click_offset;
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}
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int BPMCalculator::getCurrentApproximation() const
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{
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const microsec sum = std::accumulate(_deltas.begin(), _deltas.end(), 0);
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return (sum == 0)
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? 0.
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: static_cast<int>(static_cast<float>(MICROSECONDS_IN_MINUTE) / (static_cast<float>(sum) / static_cast<float>(_deltas.size())));
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}
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