Interpolate music sample rate

include/note.h

@@ -16,7 +16,7 @@ public:
 
     virtual void putToGame(const microsec &offset) = 0;
     virtual bool isInGame() const = 0;
-    virtual bool isExpired() const = 0;
+    virtual bool shouldRemove() const = 0;
 
     microsec offset() const
     {

src/classicgame/classicmapcreator.cpp

@@ -9,11 +9,12 @@ Beatmap ClassicMapCreator::createBeatmap(const std::string& filepath) const
 {
     (void) filepath;
 
-    microsec starting_beat_offset = 352162;
+    microsec starting_beat_offset = 362162;
     int amount_of_beats = 209;
     microsec interval = 1412162;
-    microsec tempo_interval = interval / 4;
-    microsec note_input_offset = 412162 / 3;
+    microsec tempo_interval = interval / 2;
+    microsec note_input_offset = 412162 / 2;
+    microsec note_input_offset_fast = 412162 / 6;
     microsec bpm_iterator = starting_beat_offset;
     microsec bpm_end = starting_beat_offset + (interval * amount_of_beats);
 
@@ -30,7 +31,7 @@ Beatmap ClassicMapCreator::createBeatmap(const std::string& filepath) const
     while (bpm_iterator < bpm_end)
     {
         ClassicNote::ClassicNoteInitializer init;
-        ClassicNote::ClassicNoteInitializer::Element element, element2;
+        ClassicNote::ClassicNoteInitializer::Element element;
         init.intervals = input_intervals;
         init.perfect_offset = bpm_iterator;
 
@@ -39,22 +40,29 @@ Beatmap ClassicMapCreator::createBeatmap(const std::string& filepath) const
         element.keys = {sf::Keyboard::W, sf::Keyboard::Up};
         element.type = Type::UP;
 
+        init.elements = {element};
+
+        notes.emplace_back(new ClassicNote(std::move(init), _graphics_manager));
+
         if (counter == 0)
         {
-            counter = 3;
-            element2.coordinates = {x, 300.};
+            ClassicNote::ClassicNoteInitializer init2;
+            ClassicNote::ClassicNoteInitializer::Element element2;
+            init2.intervals = input_intervals;
+            init2.perfect_offset = bpm_iterator + note_input_offset_fast;
+
+            element2.coordinates = {x + 35, 390. + 50.};
             element2.falling_curve_interpolation = {};
-            element2.keys = {sf::Keyboard::A, sf::Keyboard::Left};
-            element2.type = Type::LEFT;
+            element2.keys = {sf::Keyboard::D, sf::Keyboard::Right};
+            element2.type = Type::RIGHT;
 
-            init.elements = {element, element2};
+            init2.elements = {element2};
+            notes.emplace_back(new ClassicNote(std::move(init2), _graphics_manager));
+            counter = 3;
         }
-        else
-            init.elements = {element};
 
         --counter;
 
-        notes.emplace_back(new ClassicNote(std::move(init), _graphics_manager));
         bpm_iterator += tempo_interval;
         x += 70;
 

src/classicgame/classicnote.cpp

@@ -1,8 +1,11 @@
 #include "classicnote.h"
 #include "classicsprite.h"
 #include "classicgraphicsmanager.h"
+
+// Replace with interface by dependency injection
 #include "classicflyinganimationscenario.h"
 #include "classicdyinganimationscenario.h"
+//
 
 ClassicNote::ClassicNote(ClassicNoteInitializer &&init, const std::unique_ptr<ClassicGraphicsManager> &manager) :
     Note(init.perfect_offset),
@@ -17,6 +20,7 @@ ClassicNote::ClassicNote(ClassicNoteInitializer &&init, const std::unique_ptr<Cl
         _elements[i].coordinates = init.elements[i].coordinates;
         _elements[i].type = init.elements[i].type;
 
+        // Animations will be injected into note.
         _elements[i].animations[State::NONE] = nullptr;
         _elements[i].animations[State::FLYING] = std::make_shared<ClassicFlyingAnimationScenario>();
         _elements[i].animations[State::ACTIVE] = _elements[i].animations[State::FLYING];
@@ -49,7 +53,7 @@ bool ClassicNote::isInGame() const
         || _state == State::DYING;
 }
 
-bool ClassicNote::isExpired() const
+bool ClassicNote::shouldRemove() const
 {
     return _state == State::DEAD;
 }

src/classicgame/classicnote.h

@@ -56,7 +56,7 @@ public:
     virtual void input(PlayerInput&& inputdata) override;
     virtual void putToGame(const microsec &music_offset) override;
     virtual bool isInGame() const override;
-    virtual bool isExpired() const override;
+    virtual bool shouldRemove() const override;
     virtual void draw() const override;
 
 private:
@@ -67,11 +67,11 @@ private:
         std::array<std::shared_ptr<ClassicAnimationScenario>, 5> animations;
 
         std::array<sf::Keyboard::Key, 2> keys;
-        Coordinates coordinates;
-        Type type;
-
-        bool pressed = false;
-        sf::Keyboard::Key pressed_as;
+        Coordinates coordinates;                // Each note may consist of several buttons.
+        Type type;                              // For example, ↑ → or ↓ → ←
+                                                // Note Element represents this idea.
+        bool pressed = false;                   // Each ending button in such sequence
+        sf::Keyboard::Key pressed_as;           //                       is an element.
     };
 
     std::vector<NoteElement> _elements;

src/classicgame/classictimeline.cpp

@@ -2,7 +2,10 @@
 #include "classictimeline.h"
 #include <iostream>
 
-ClassicTimeline::ClassicTimeline()
+ClassicTimeline::ClassicTimeline() :
+    _sfml_music_offset(0),
+    _previous_frame_offset(0),
+    _absolute_offset(0)
 {
     // BPM of METEOR is 170.
     // Length is 1:14
@@ -12,7 +15,6 @@ ClassicTimeline::ClassicTimeline()
 
     _music.openFromFile(song_filename);
     _music.setVolume(10);
-    _last_timestamp = -1;
 }
 
 void ClassicTimeline::run(std::vector<Note*>&& notes, const microsec& visibility)
@@ -27,6 +29,8 @@ void ClassicTimeline::run(std::vector<Note*>&& notes, const microsec& visibility
 
     fetchVisibleNotes();
     _music.play();
+
+    _previous_frame_offset = _offset_interpolator.restart().asMicroseconds();
 }
 
 ClassicTimeline::~ClassicTimeline()
@@ -44,15 +48,20 @@ void ClassicTimeline::clear()
 
 void ClassicTimeline::update()
 {
-    const auto& music_offset = currentMusicOffset();
-    if (music_offset != _last_timestamp)
+    const auto interpolator_timestamp = _offset_interpolator.getElapsedTime().asMicroseconds();
+    const auto sfml_new_offset = currentMusicOffset();
+
+    _absolute_offset += (interpolator_timestamp - _previous_frame_offset);
+    _previous_frame_offset = interpolator_timestamp;
+    if (sfml_new_offset != _sfml_music_offset)
     {
-        checkCurrentActiveNote();
-        checkForNextActiveNote();
-        updateVisibleSprites(music_offset);
+        _absolute_offset = ((_absolute_offset + sfml_new_offset) / 2);
+        _sfml_music_offset = sfml_new_offset;
     }
 
-    _last_timestamp = music_offset;
+    checkCurrentActiveNote();
+    checkForNextActiveNote();
+    updateVisibleSprites(_absolute_offset);
 }
 
 void ClassicTimeline::checkCurrentActiveNote()
@@ -118,8 +127,7 @@ bool ClassicTimeline::isVisiblyClose(const Iterator& iterator, const microsec& m
 
 void ClassicTimeline::fetchVisibleNotes()
 {
-    const microsec music_offset = currentMusicOffset();
-    findLastVisibleNote(music_offset);
+    findLastVisibleNote(_absolute_offset);
     findFirstVisibleNote();
 }
 
@@ -151,7 +159,7 @@ void ClassicTimeline::findFirstVisibleNote()
     while (note_iterator != _last_visible_note)
     {
         auto note = *note_iterator;
-        if (note->isExpired())
+        if (note->shouldRemove())
             ++_first_visible_note;
 
         ++note_iterator;

src/classicgame/classictimeline.h

@@ -3,6 +3,7 @@
 #include "timeline.h"
 
 #include <SFML/Audio/Music.hpp>
+#include <SFML/System/Clock.hpp>
 #include <vector>
 #include <memory>
 
@@ -33,9 +34,12 @@ private:
     std::vector<microsec> _input_intervals;
     std::vector<Note*> _timeline;
     microsec _visibility_offset;
-    microsec _last_timestamp;
 
     sf::Music _music;
+    sf::Clock _offset_interpolator;
+    microsec _sfml_music_offset;
+    microsec _previous_frame_offset;
+    microsec _absolute_offset;
 
     void updateVisibleSprites(const microsec& music_offset);
     void checkCurrentActiveNote();