private void CreateSlideNotes(Song s, Dictionary<Pattern, RowFxData[,]> patternFxData)
{
var processedPatterns = new HashSet<Pattern>();
// Convert slide notes + portamento to our format.
foreach (var c in s.Channels)
{
if (!c.SupportsSlideNotes)
continue;
var songSpeed = s.FamitrackerSpeed;
var lastNoteInstrument = (Instrument)null;
var lastNoteArpeggio = (Arpeggio)null;
var lastNoteValue = (byte)Note.NoteInvalid;
var portamentoSpeed = 0;
var slideSpeed = 0;
var slideShift = c.IsN163WaveChannel ? 2 : 0;
var slideSign = c.IsN163WaveChannel || c.IsFdsWaveChannel || c.IsVrc7FmChannel ? -1 : 1; // Inverted channels.
for (int p = 0; p < s.Length; p++)
{
var pattern = c.PatternInstances[p];
if (pattern == null)
continue;
var patternLen = s.GetPatternLength(p);
for (var it = pattern.GetDenseNoteIterator(0, patternLen); !it.Done; it.Next())
{
var location = new NoteLocation(p, it.CurrentTime);
var note = it.CurrentNote;
// Look for speed changes.
s.ApplySpeedEffectAt(location, ref songSpeed);
if (!patternFxData.ContainsKey(pattern) || processedPatterns.Contains(pattern))
continue;
var fxData = patternFxData[pattern];
var slideTarget = 0;
for (int i = 0; i < fxData.GetLength(1); i++)
{
var fx = fxData[location.NoteIndex, i];
if (fx.param != 0)
{
// When the effect it turned on, we need to add a note.
if ((fx.fx == Effect_PortaUp ||
fx.fx == Effect_PortaDown ||
fx.fx == Effect_SlideUp ||
fx.fx == Effect_SlideDown) &&
lastNoteValue >= Note.MusicalNoteMin &&
lastNoteValue <= Note.MusicalNoteMax && (note == null || !note.IsValid))
{
if (note == null)
{
note = pattern.GetOrCreateNoteAt(location.NoteIndex);
it.Resync();
}
note.Value = lastNoteValue;
note.Instrument = lastNoteInstrument;
note.Arpeggio = lastNoteArpeggio;
note.HasAttack = false;
}
}
if (fx.fx == Effect_PortaUp)
{
// If we have a Qxx/Rxx on the same row as a 1xx/2xx, things get weird.
if (slideTarget == 0)
slideSpeed = (-fx.param * slideSign) << slideShift;
}
if (fx.fx == Effect_PortaDown)
{
// If we have a Qxx/Rxx on the same row as a 1xx/2xx, things get weird.
if (slideTarget == 0)
slideSpeed = ( fx.param * slideSign) << slideShift;
}
if (fx.fx == Effect_Portamento)
{
portamentoSpeed = fx.param;
}
if (fx.fx == Effect_SlideUp && note != null && note.IsMusical)
{
slideTarget = Utils.Clamp(note.Value + (fx.param & 0xf), Note.MusicalNoteMin, Note.MusicalNoteMax);
slideSpeed = (-((fx.param >> 4) * 2 + 1)) << slideShift;
}
if (fx.fx == Effect_SlideDown && note != null && note.IsMusical)
{
slideTarget = Utils.Clamp(note.Value - (fx.param & 0xf), Note.MusicalNoteMin, Note.MusicalNoteMax);
slideSpeed = (((fx.param >> 4) * 2 + 1)) << slideShift;
}
}
// Create a slide note.
if (note != null && !note.IsSlideNote)
{
if (note.IsMusical)
{
var slideSource = note.Value;
var noteTable = NesApu.GetNoteTableForChannelType(c.Type, s.Project.PalMode, s.Project.ExpansionNumChannels);
var pitchLimit = NesApu.GetPitchLimitForChannelType(c.Type);
// If we have a new note with auto-portamento enabled, we need to
// swap the notes since our slide notes work backward compared to
// FamiTracker.
if (portamentoSpeed != 0)
{
// Ignore notes with no attack since we created them to handle a previous slide.
if (note.HasAttack && lastNoteValue >= Note.MusicalNoteMin && lastNoteValue <= Note.MusicalNoteMax)
{
slideSpeed = portamentoSpeed;
slideTarget = note.Value;
slideSource = lastNoteValue;
note.Value = lastNoteValue;
}
}
// Our implementation of VRC7 pitches is quite different from FamiTracker.
// Compensate for larger pitches in higher octaves by shifting. We cant shift by
// a large amount because the period is 9-bit and FamiTracker is restricted to
// this for slides (octave never changes).
var octaveSlideShift = c.IsVrc7FmChannel && note.Value >= 12 ? 1 : 0;
// 3xx/Qxy/Rxy : We know which note we are sliding to and the speed, but we
// don't know how many frames it will take to get there.
if (slideTarget != 0)
{
// Advance in the song until we have the correct number of frames.
var numFrames = Math.Max(1, Math.Abs((noteTable[slideSource] - noteTable[slideTarget]) / (slideSpeed << octaveSlideShift)));
note.SlideNoteTarget = (byte)slideTarget;
// TODO: Here we consider if the start note has a delay, but ignore the end note. It might have one too.
var nextLocation = location;
s.AdvanceNumberOfFrames(ref nextLocation, numFrames, note.HasNoteDelay ? -note.NoteDelay : 0, songSpeed, s.Project.PalMode);
// Still to see if there is a note between the current one and the
// next note, this could append if you add a note before the slide
// is supposed to finish.
if (FindNextSlideEffect(c, location, out var nextLocation2, patternFxData))
{
nextLocation = NoteLocation.Min(nextLocation, nextLocation2);
// If the slide is interrupted by another slide effect, we will not reach
// the final target, but rather some intermediate note. Let's do our best
// to interpolate and figure out the best note.
var numFramesUntilNextSlide = s.CountFramesBetween(location, nextLocation, songSpeed, s.Project.PalMode);
var ratio = Utils.Clamp(numFramesUntilNextSlide / numFrames, 0.0f, 1.0f);
var intermediatePitch = (int)Math.Round(Utils.Lerp(noteTable[slideSource], noteTable[slideTarget], ratio));
slideTarget = FindBestMatchingNote(noteTable, intermediatePitch, Math.Sign(slideSpeed));
note.SlideNoteTarget = (byte)slideTarget;
}
if (nextLocation.PatternIndex < s.Length)
{
// Add an extra note with no attack to stop the slide.
var nextPattern = c.PatternInstances[nextLocation.PatternIndex];
if (!nextPattern.Notes.TryGetValue(nextLocation.NoteIndex, out var nextNote) || !nextNote.IsValid)
{
nextNote = nextPattern.GetOrCreateNoteAt(nextLocation.NoteIndex);
nextNote.Instrument = note.Instrument;
nextNote.Value = (byte)slideTarget;
nextNote.HasAttack = false;
it.Resync();
}
else if (nextNote != null && nextNote.IsRelease)
{
Log.LogMessage(LogSeverity.Warning, $"A slide note ends on a release note. This is currently unsupported and will require manual correction. {GetPatternString(nextPattern, nextLocation.NoteIndex)}");
}
}
// 3xx, Qxx and Rxx stops when its done.
slideSpeed = 0;
}
// 1xx/2xy : We know the speed at which we are sliding, but need to figure out what makes it stop.
else if (slideSpeed != 0 && FindNextSlideEffect(c, location, out var nextLocation, patternFxData))
{
// See how many frames until the slide stops.
var numFrames = (int)Math.Round(s.CountFramesBetween(location, nextLocation, songSpeed, s.Project.PalMode));
// TODO: Here we consider if the start note has a delay, but ignore the end note. It might have one too.
numFrames = Math.Max(1, numFrames - (note.HasNoteDelay ? note.NoteDelay : 0));
// Compute the pitch delta and find the closest target note.
var newNotePitch = Utils.Clamp(noteTable[slideSource] + numFrames * (slideSpeed << octaveSlideShift), 0, pitchLimit);
var newNote = FindBestMatchingNote(noteTable, newNotePitch, Math.Sign(slideSpeed));
note.SlideNoteTarget = (byte)newNote;
// If the FX was turned off, we need to add an extra note.
var nextPattern = c.PatternInstances[nextLocation.PatternIndex];
if (!nextPattern.Notes.TryGetValue(nextLocation.NoteIndex, out var nextNote) || !nextNote.IsValid)
{
nextNote = nextPattern.GetOrCreateNoteAt(nextLocation.NoteIndex);
nextNote.Instrument = note.Instrument;
nextNote.Value = (byte)newNote;
nextNote.HasAttack = false;
it.Resync();
}
else if (nextNote != null && nextNote.IsRelease)
{
Log.LogMessage(LogSeverity.Warning, $"A slide note ends on a release note. This is currently unsupported and will require manual correction. {GetPatternString(nextPattern, nextLocation.NoteIndex)}");
}
}
}
}
if (note != null && (note.IsMusical || note.IsStop))
{
lastNoteValue = note.IsSlideNote ? note.SlideNoteTarget : note.Value;
lastNoteInstrument = note.Instrument;
lastNoteArpeggio = note.Arpeggio;
}
}
processedPatterns.Add(pattern);
}
}
}
