project-kyoku/timeline.cpp

#include "timeline.h"
#include "note.h"

Timeline::Timeline()
{
    // BPM of METEOR is 170.
    // Length is 1:14
    // I calculated that the time between beats is about 1412162 microseconds

    microsec starting_beat_offset = 372162;
    int amount_of_beats = 209;
    microsec time_between_beats = 1412162;
    microsec note_input_offset = 412162;
    microsec interval = starting_beat_offset + (time_between_beats * amount_of_beats);

    Note::resetPrecisionQualifier(note_input_offset / 2);

    while (interval > 0)
    {
        _timeline.emplace_back(new Note(interval, note_input_offset));
        interval -= time_between_beats;
    }

    _active_note = nullptr;
    _top_note = _timeline.begin();
}

Timeline::~Timeline()
{
    for (auto note : _timeline)
        delete note;

    _timeline.clear();
    _top_note = _timeline.end();
    _active_note = nullptr;

    Note::resetPrecisionQualifier();
}

void Timeline::update(const microsec &microseconds)
{
    checkCurrentActiveNote(microseconds);
    checkForNextActiveNote(microseconds);
}

void Timeline::checkCurrentActiveNote(const microsec &microseconds)
{
    if (_active_note && !_active_note->isActive(microseconds))
    {
        _active_note = nullptr;
        ++_top_note;
    }
}

void Timeline::checkForNextActiveNote(const microsec &microseconds)
{
    if (!_active_note && (*_top_note)->isActive(microseconds))
    {
        _active_note = *_top_note;
    }
}

const Note* Timeline::fetchActiveNote(const microsec &microseconds) noexcept
{
    update(microseconds);
    return _active_note;
}