/* quantize the start time */
private static void QuantizeStartTime(
int StartTime,
int QuarterNoteLen,
NoteFlags QuantizedDuration,
double QuantizedDurationAdjust,
out FractionRec StartTimeOut,
out double StartTimeAdjustOut,
out double WholeNoteStartTimeAdjust)
{
uint Denominator;
double QuantizedStartTime;
double OrigDuration;
FractionRec OrigDurationFractional;
/* start times must be a multiple of the 64th note. see rationale */
/* in comment at top of this file. */
Denominator = 64;
NoteNoteObjectRec.ConvertDurationFrac(QuantizedDuration, out OrigDurationFractional);
OrigDuration = (4 * QuarterNoteLen) * QuantizedDurationAdjust
* FractionRec.Fraction2Double(OrigDurationFractional);
/* compute start time to nearest division they allow */
FractionRec.Double2Fraction(StartTime / (double)(QuarterNoteLen * 4), Denominator, out StartTimeOut);
/* set start time adjust (relative to duration) */
QuantizedStartTime = FractionRec.Fraction2Double(StartTimeOut) * (4 * QuarterNoteLen);
StartTimeAdjustOut = (QuantizedStartTime - StartTime) / OrigDuration;
WholeNoteStartTimeAdjust = (QuantizedStartTime - StartTime) / (4 * QuarterNoteLen);
}
/* convert interval track into quantized track. */
public static bool ConvertIntervalToQuantized(
IntervalTrackRec IntervalTrack,
QuantizedTrackRec QuantizedTrack,
int MidiQuarterNote)
{
int Scan;
int Limit;
TimeMatchRec[] MatchingTable = new TimeMatchRec[4 /*divisions*/ * 2 /*dot*/ * 9 /*notetypes*/];
int MatchingTableLength;
/* build duration matching table */
MatchingTableLength = 0;
for (Scan = 0; Scan < 4 /*divisions*/ * 2 /*dot*/ * 9 /*notetypes*/; Scan += 1)
{
double MIDIClocks;
NoteFlags Descriptor;
FractionRec DurationFraction;
/* determine root duration and descriptor */
switch (Scan % 9)
{
default:
Debug.Assert(false);
throw new InvalidOperationException();
case 0:
Descriptor = NoteFlags.e64thNote;
break;
case 1:
Descriptor = NoteFlags.e32ndNote;
break;
case 2:
Descriptor = NoteFlags.e16thNote;
break;
case 3:
Descriptor = NoteFlags.e8thNote;
break;
case 4:
Descriptor = NoteFlags.e4thNote;
break;
case 5:
Descriptor = NoteFlags.e2ndNote;
break;
case 6:
Descriptor = NoteFlags.eWholeNote;
break;
case 7:
Descriptor = NoteFlags.eDoubleNote;
break;
case 8:
Descriptor = NoteFlags.eQuadNote;
break;
}
/* determine if dot is needed */
if (((Scan / 9) % 2) != 0)
{
/* dot needed */
Descriptor |= NoteFlags.eDotModifier;
}
/* determine what division is needed */
switch (((Scan / 9) / 2) % 4)
{
default:
Debug.Assert(false);
throw new InvalidOperationException();
case 0:
break;
case 1:
Descriptor |= NoteFlags.eDiv3Modifier;
break;
case 2:
Descriptor |= NoteFlags.eDiv5Modifier;
break;
case 3:
Descriptor |= NoteFlags.eDiv7Modifier;
break;
}
/* how int is this note */
NoteNoteObjectRec.ConvertDurationFrac(Descriptor, out DurationFraction); /* units of whole notes */
MIDIClocks = MidiQuarterNote * (4 * FractionRec.Fraction2Double(DurationFraction));
/* add to table if note can be represented in the timing scheme */
/* AND only if note is an integer multiple of the 64th div3 (see */
/* comment at the top of this file for the rationale) */
if ((MIDIClocks == Math.Floor(MIDIClocks)) && (MIDIClocks >= 1) && IntMultOf64thDiv3(Descriptor))
{
MatchingTable[MatchingTableLength].Ticks = (int)MIDIClocks;
MatchingTable[MatchingTableLength].Descriptor = Descriptor;
MatchingTableLength += 1;
}
}
/* quantize note events */
Limit = GetIntervalTrackLength(IntervalTrack);
for (Scan = 0; Scan < Limit; Scan += 1)
{
IntEventRec Event;
Event = GetIntervalTrackIndexedEvent(IntervalTrack, Scan);
switch (IntervalEventGetType(Event))
{
default:
Debug.Assert(false);
throw new InvalidOperationException();
case IntEventType.eIntervalNoteEvent:
{
/* input values */
int StartTime;
int Duration;
short MIDIPitch;
short MIDIAttackVelocity;
short MIDIReleaseVelocity;
/* output values */
NoteFlags QuantizedDuration;
double QuantizedDurationAdjust;
int WholeNoteOverflow;
FractionRec QuantizedStartTime;
double QuantizedStartTimeAdjust;
double WholeNoteStartTimeAdjust; /* auxiliary value */
/* stuff */
QuantEventRec QuantEvent;
/* get the information */
GetIntervalNoteEventInfo(Event, out StartTime, out Duration, out MIDIPitch,
out MIDIAttackVelocity, out MIDIReleaseVelocity);
/* quantize duration */
QuantizeDuration(Duration, MidiQuarterNote, MatchingTable,
MatchingTableLength, out QuantizedDuration, out QuantizedDurationAdjust,
out WholeNoteOverflow);
Debug.Assert(IntMultOf64thDiv3(QuantizedDuration)); // non-64div3 duration quantization?
/* quantize start time */
QuantizeStartTime(StartTime, MidiQuarterNote, QuantizedDuration,
QuantizedDurationAdjust, out QuantizedStartTime, out QuantizedStartTimeAdjust,
out WholeNoteStartTimeAdjust);
Debug.Assert(FractionIntMultOf64thDiv3(QuantizedStartTime)); // non-64div3 start time quantization?
/* bump start time to end of whole note chain */
QuantizedStartTime.Integer += (uint)WholeNoteOverflow;
/* create new event & insert into track */
QuantEvent = NewQuantizedNoteEvent(QuantizedStartTime,
QuantizedStartTimeAdjust, QuantizedDuration, QuantizedDurationAdjust,
MIDIPitch, MIDIAttackVelocity, MIDIReleaseVelocity);
QuantizedTrackInsertEventSorted(QuantizedTrack, QuantEvent);
/* insert whole notes behind the last note in reverse order */
while (WholeNoteOverflow > 0)
{
QuantEventRec Predecessor;
/* create preceding whole note */
QuantizedStartTime.Integer -= 1;
Predecessor = NewQuantizedNoteEvent(QuantizedStartTime,
WholeNoteStartTimeAdjust, NoteFlags.eWholeNote, 1, MIDIPitch,
MIDIAttackVelocity, MIDIReleaseVelocity);
QuantizedTrackInsertEventSorted(QuantizedTrack, Predecessor);
/* set tie */
PutQuantizedEventTieTarget(Predecessor, QuantEvent);
QuantEvent = Predecessor;
/* step */
WholeNoteOverflow -= 1;
}
}
break;
case IntEventType.eIntervalCommentEvent:
{
QuantEventRec QuantEvent;
/* input values */
int StartTime;
string OriginalString;
/* output values */
FractionRec QuantizedStartTime;
/* get the information */
GetIntervalCommentEventInfo(Event, out StartTime, out OriginalString);
/* compute start time to nearest 64th div3 */
FractionRec.Double2Fraction(StartTime / (double)MidiQuarterNote,
64 * 3, out QuantizedStartTime);
Debug.Assert(FractionIntMultOf64thDiv3(QuantizedStartTime)); //non-64div3 start time quantization?
/* create new event & insert into track */
QuantEvent = NewQuantizedCommentEvent(QuantizedStartTime, 0, OriginalString);
QuantizedTrackInsertEventSorted(QuantizedTrack, QuantEvent);
}
break;
}
}
return(true);
}
