Implement slider tick animation on BPM calculator

include/tools/beatutils.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <vector>
+#include "mathutils.h"
+
+namespace beat_utils
+{
+    struct BeatInfo
+    {
+        long double rate_per_microsecond = 0.;
+        microsec average_interval = 0;
+    };
+
+    BeatInfo calculateBeatRateInfo(const std::vector<microsec>& approximate_deltas);
+}

include/tools/bpmcalculator.h

@@ -1,8 +1,8 @@
 #pragma once
 
 #include "tools/music.h"
+#include "tools/beatutils.h"
 #include <memory>
-#include <vector>
 
 class BPMCalculator
 {
@@ -15,15 +15,14 @@ public:
     void start();
     void stop();
     void click();
-    float fetchCurrentBPMApproximation();
+
+    const beat_utils::BeatInfo& fetchApproximatedInfo();
+    microsec fetchTimeUntilNextBeat();
 
     microsec getStartingOffset() const;
     void setStartingOffset(microsec offset);
     void moveStartingOffsetBy(microsec shift);
 
-    microsec fetchTimeUntilNextBeat();
-    microsec fetchBeatInterval();
-
 private:
     bool _need_recalculate;
     bool _calculating;
@@ -33,8 +32,7 @@ private:
     microsec _previous_click_offset;
     microsec _first_click_offset;
 
-    int _approximated_bpm;
+    beat_utils::BeatInfo _approximated_info;
 
-    inline float calculateBPM(microsec all_microseconds, std::size_t beats_amount) const;
     inline void reset();
 };

src/gui/editor.cpp

@@ -34,7 +34,7 @@ void Editor::enter()
 {
     auto& group = _group;
     auto& music = _music;
-    _music->openFromFile("40mp.ogg");
+    _music->openFromFile("Uta-test.flac");
     _music->setVolume(5);
 
     _bpm_calculator = std::make_shared<BPMCalculator>(_music);

src/gui/widgets/bpmcalculatorwidget.cpp

@@ -1,15 +1,21 @@
 #include "bpmcalculatorwidget.h"
 #include "tools/bpmcalculator.h"
 
+#include <iostream>
+
 BPMCalculatorWidget::BPMCalculatorWidget(const std::shared_ptr<BPMCalculator>& bpm_calculator, const std::shared_ptr<sf::Font>& font) :
     Window("BPM Calculation", font),
     _bpm_calculator(bpm_calculator),
-    _slider(std::make_shared<BPMSlider>())
+    _slider(std::make_shared<BPMSlider>()),
+    _ticked(false)
 {
     _bpm_value.setFont(*_font);
     _bpm_value.setCharacterSize(40);
     _bpm_value.setFillColor(sf::Color::Black);
     _bpm_value.setString("--");
+    _slap_buffer.loadFromFile("Tick.ogg");
+    _slap.setBuffer(_slap_buffer);
+    _slap.setVolume(30.);
 }
 
 void BPMCalculatorWidget::input(const sf::Event& event)
@@ -34,16 +40,22 @@ void BPMCalculatorWidget::update(const sf::Time& dt)
 {
     Window::update(dt);
 
-    const auto approximation = _bpm_calculator->fetchCurrentBPMApproximation();
-    if (approximation != 0)
+    const auto beat_info = _bpm_calculator->fetchApproximatedInfo();
+    if (beat_info.rate_per_microsecond != 0)
     {
-        _bpm_value.setString(std::to_string(approximation));
+        _bpm_value.setString(std::to_string(static_cast<int>(beat_info.rate_per_microsecond)));
 
         const microsec until_beat = _bpm_calculator->fetchTimeUntilNextBeat();
-        const microsec beat_interval = _bpm_calculator->fetchBeatInterval();
-
-        const auto time_relation = beat_interval / until_beat;
-        const auto slider_path_left = Window::rect().width / time_relation;
+        const auto time_relation = static_cast<long double>(beat_info.average_interval) / static_cast<long double>(until_beat);
+        const auto slider_path_left = _slider->rect().width / time_relation;
+        if (slider_path_left < 50)
+        {
+            if (!_ticked)
+                _slap.play();
+            _ticked = true;
+        }
+        else
+            _ticked = false;
 
         _slider->setTickPosition(slider_path_left);
     }

src/gui/widgets/bpmcalculatorwidget.h

@@ -6,6 +6,8 @@
 #include <functional>
 #include <SFML/Graphics/RectangleShape.hpp>
 #include <SFML/Graphics/Text.hpp>
+#include <SFML/Audio/Sound.hpp>
+#include <SFML/Audio/SoundBuffer.hpp>
 
 class BPMCalculator;
 
@@ -28,6 +30,10 @@ private:
     std::shared_ptr<BPMCalculator> _bpm_calculator;
     std::shared_ptr<BPMSlider> _slider;
 
+    sf::SoundBuffer _slap_buffer;
+    sf::Sound _slap;
+    bool _ticked;
+
     sf::Text _bpm_value;
 };
 

src/tools/beatutils.cpp

@@ -0,0 +1,23 @@
+#include "tools/beatutils.h"
+#include <numeric>
+#include <iostream>
+
+auto beat_utils::calculateBeatRateInfo(const std::vector<microsec>& approximate_deltas) -> BeatInfo
+{
+    if (approximate_deltas.empty())
+        return {};
+
+    const microsec sum = std::accumulate(approximate_deltas.begin(), approximate_deltas.end(), 0);
+    const std::size_t amount = approximate_deltas.size();
+
+    long double average = static_cast<long double>(sum)
+                        / static_cast<long double>(amount);
+
+
+
+    return BeatInfo
+    {
+        60000000. / average,
+        static_cast<microsec>(average)
+    };
+}

src/tools/bpmcalculator.cpp

@@ -3,8 +3,6 @@
 #include <numeric>
 #include <iostream>
 
-constexpr float MICROSECONDS_IN_MINUTE_f = 60000000.;
-
 BPMCalculator::BPMCalculator(const std::shared_ptr<Music>& music) :
     _music(music)
 {
@@ -16,7 +14,7 @@ void BPMCalculator::reset()
     _calculating = false;
     _deltas.clear();
     _previous_click_offset = 0;
-    _approximated_bpm = 0;
+    _first_click_offset = 0;
     _need_recalculate = true;
 }
 
@@ -54,6 +52,7 @@ void BPMCalculator::click()
     if (_previous_click_offset == 0)
     {
         _previous_click_offset = click_offset;
+        _first_click_offset = click_offset;
         return;
     }
 
@@ -63,32 +62,20 @@ void BPMCalculator::click()
     _previous_click_offset = click_offset;
 }
 
-float BPMCalculator::fetchCurrentBPMApproximation()
+const beat_utils::BeatInfo& BPMCalculator::fetchApproximatedInfo()
 {
-    if (!_need_recalculate)
-        return _approximated_bpm;
+    //if (!_need_recalculate)
+        //return _approximated_info;
 
-    _need_recalculate = false;
+    //_need_recalculate = false;
 
-    const microsec sum = std::accumulate(_deltas.begin(), _deltas.end(), 0);
     bool hasEnoughDeltas = _deltas.size() >= 8;
 
-    _approximated_bpm = (!hasEnoughDeltas)
-                      ?  0.
-                      :  calculateBPM(sum, _deltas.size());
+    _approximated_info = (!hasEnoughDeltas)
+                       ?  beat_utils::BeatInfo{}
+                       :  beat_utils::calculateBeatRateInfo(_deltas);
 
-    return _approximated_bpm;
-}
-
-float BPMCalculator::calculateBPM(microsec all_microseconds, std::size_t beats_amount) const
-{
-    if (beats_amount == 0)
-        return 0;
-
-    float relation = static_cast<float>(all_microseconds)
-                   / static_cast<float>(beats_amount);
-
-    return static_cast<float>(1. / relation);
+    return _approximated_info;
 }
 
 microsec BPMCalculator::getStartingOffset() const
@@ -110,10 +97,5 @@ microsec BPMCalculator::fetchTimeUntilNextBeat()
 {
     const microsec actual_offset = _music->fetchOffset() - _first_click_offset;
 
-    return fetchBeatInterval() % actual_offset;
-}
-
-microsec BPMCalculator::fetchBeatInterval()
-{
-    return static_cast<microsec>(1. / fetchCurrentBPMApproximation());
+    return actual_offset % fetchApproximatedInfo().average_interval;
 }