Not Exact an issue- Get note time near to song time

[FabioZumbi12]

Hi,

Me again and now with my game come to be ready soon using your source <3
Take a look: https://www.youtube.com/watch?v=fqLiBD0p2cI

But i am not here only to show you the game, but to ask about notes.

As you can see on some notes in this video, some notes next to other one have different distances, where on midi the distance is equals.

I think the way i using to get notes is not the best, but the song time is not the exat time of note, then, i cant get the note form midi only quering the song time, i need to get next nearest note based on last note time and new time in a interval.

Is there a best way to get the exat note using the song time?

I have created a Dictionary to cache the notes for difficulties based on note time. The way i get the note is:

tempNotes.Where(pairs => pairs.Key == actualTime || pairs.Key > lastTime && pairs.Key < position).ToList().ForEach(pairs =>
{
  ...
  lastTime = actualTime;
}

Where the key is the note time.
And i run this loop on every frame.

If you know a better way to get and put the note time on my Disctionay or a better way to get the next note, ill glad if you can help.

Thank you!

Edit: This is only with too near notes, with other notes theres no problems.

[melanchall]

Hi,

Welcome back! Watched the video, looks really nice! Great job :)

As for you problem, can you say what are actualTime and position variables? Please clarify your issue. As far as I understand the problem is you can miss some notes because their times don't equal times of notes in audio file, and so you should remember what note was played last and take next one. Is it correct?

Max

[melanchall]

@FabioZumbi12 Is your question still actual?

[FabioZumbi12]

Oh sorry,
Because a lot of notifications on my github i didnt have seen this :x

Still... but only for too near notes.

The position and actual time is in TotalMicroseconds.
I not exact missing notes but some notes is near to next mutch than other, where on midi is the same time.

Edit.: A print to show what i mean: http://prntscr.com/i83jk4

[melanchall]

So your task is to get nearest note to the current position in audio file, yes?

For example:

Audio file |    1  2      3  4
MIDI file  |    a    b    c    d

When current song pointer stays on note 1 in audio file the a note in MIDI file should be played and b for 2, c for 3 and d for 4? The problem is how to find nearest note to the specified time?

[FabioZumbi12]

The initial task its to get the exact time from song to note.

But i have a music playing in runtime, then i need to get the note using the song time. On my trys, using something like track.GetNotes().Where(note => note.TimeAs<MetricTimeSpan>(tempo).TotalMicroseconds == position) but never is equals, then, i need to find the next or previous note near and too short than position, whitout repeat this note again.

The task need to get the nearest, if is not equals.
U know what i mean with this explanation?

Thanks for your time and sorry for the delayed aswers.

[melanchall]

Now I got it, thanks! :)

What about this code:

var notes = midiFile.GetNotes().ToArray();
var usedNotes = new List<Note>();

// ...

// Find the note nearest to the current position (this should be done every frame)

Note nearestNote = null;
var distance = long.MaxValue;

foreach (var note in notes.Where(n => !usedNotes.Contains(n)))
{
    var newDistance = Math.Abs(position - note.TimeAs<MetricTimeSpan>(tempo).TotalMicroseconds);
    
    // Notes are returned by GetNotes in order of ascending times so we can stop the loop
    // when current distance between position and note's time is not decreased
    if (newDistance >= distance)
        break;

    distance = newDistance;
    nearestNote = note;
}

if (nearestNote != null)
    usedNotes.Add(nearestNote);

Can you test it and say whether it is faster than your solution or not?

[melanchall]

@FabioZumbi12 Is your problem solved?

[FabioZumbi12]

Sorry for the delay. I think yes changing the music speed. Thanks for help <3