Updates MidiExport to use Note Types

	- Now MidiExport is updated to use note types instead of relying
on negative length notes.
	- For that change it was necessary to find a way of letting
MidiExport know how long step notes should be. The solution found was to
add an attribute to the Instrument XML called "beatlen", which would
hold the number of frames of the instrument's beat. That would be
converted to ticks, so we could calculate how long the MIDI notes would
have to be to play the whole step note. If the attribute was not found,
the default value of 16 ticks would be used as a length of step notes,
as a fallback.

plugins/MidiExport/MidiExport.cpp

@@ -27,6 +27,7 @@
 
 #include "MidiExport.h"
 
+#include "Engine.h"
 #include "TrackContainer.h"
 #include "DataFile.h"
 #include "InstrumentTrack.h"
@@ -113,6 +114,7 @@ bool MidiExport::tryExport(const TrackContainer::TrackList &tracks,
 			int base_pitch = 0;
 			double base_volume = 1.0;
 			int base_time = 0;
+			int base_beatLen = 16;
 
 			MidiNoteVector midiClip;
 
@@ -128,6 +130,17 @@ bool MidiExport::tryExport(const TrackContainer::TrackList &tracks,
 						base_pitch += masterPitch;
 					}
 					base_volume = LocaleHelper::toDouble(it.attribute("volume", "100"))/100.0;
+					// From the PR 5902 forward (Note Types), the instrument XML includes the beat length
+					// in frames. We try to fetch it and convert to the length in ticks. If there's no beat
+					// length in XML, the default beat length of 16 ticks will be used.
+					QDomNode iNode = it.elementsByTagName("instrument").at(0);
+					if(!iNode.isNull()){
+						QDomElement i = iNode.toElement();
+						if(i.hasAttribute("beatlen"))
+						{
+							base_beatLen = i.attribute("beatlen", "0").toInt() / Engine::framesPerTick();
+						}
+					}
 				}
 
 				if (n.nodeName() == "midiclip")
@@ -137,7 +150,7 @@ bool MidiExport::tryExport(const TrackContainer::TrackList &tracks,
 				}
 
 			}
-			processPatternNotes(midiClip, INT_MAX);
+			processPatternNotes(midiClip, base_beatLen, INT_MAX);
 			writeMidiClipToTrack(mtrack, midiClip);
 			size = mtrack.writeToBuffer(buffer.data());
 			midiout.writeRawData((char *)buffer.data(), size);
@@ -188,6 +201,7 @@ bool MidiExport::tryExport(const TrackContainer::TrackList &tracks,
 
 		int base_pitch = 0;
 		double base_volume = 1.0;
+		int base_beatLen = 16;
 
 		// for each pattern in the pattern editor
 		for (QDomNode n = element.firstChild(); !n.isNull(); n = n.nextSibling())
@@ -201,6 +215,13 @@ bool MidiExport::tryExport(const TrackContainer::TrackList &tracks,
 					base_pitch += masterPitch;
 				}
 				base_volume = LocaleHelper::toDouble(it.attribute("volume", "100")) / 100.0;
+				QDomNode iNode = it.elementsByTagName("instrument").at(0);
+				if(!iNode.isNull()){
+					QDomElement i = iNode.toElement();
+					if(i.hasAttribute("beatlen")){
+						base_beatLen = i.attribute("beatlen", "0").toInt()/Engine::framesPerTick();
+					}
+				}
 			}
 
 			if (n.nodeName() == "midiclip")
@@ -247,7 +268,7 @@ bool MidiExport::tryExport(const TrackContainer::TrackList &tracks,
 					st.pop_back();
 				}
 
-				processPatternNotes(nv, pos);
+				processPatternNotes(nv, base_beatLen, pos);
 				writeMidiClipToTrack(mtrack, nv);
 
 				// next pattern track
@@ -279,6 +300,7 @@ void MidiExport::writeMidiClip(MidiNoteVector &midiClip, const QDomNode& n,
 		mnote.volume = qMin(qRound(base_volume * LocaleHelper::toDouble(note.attribute("vol", "100")) * (127.0 / 200.0)), 127);
 		mnote.time = base_time + note.attribute("pos", "0").toInt();
 		mnote.duration = note.attribute("len", "0").toInt();
+		mnote.type = static_cast<Note::Type>(note.attribute("type", "0").toInt());
 		midiClip.push_back(mnote);
 	}
 }
@@ -311,14 +333,15 @@ void MidiExport::writePatternClip(MidiNoteVector& src, MidiNoteVector& dst,
 			note.pitch = srcNote.pitch;
 			note.time = base + time;
 			note.volume = srcNote.volume;
+			note.type = srcNote.type;
 			dst.push_back(note);
 		}
 	}
 }
 
 
 
-void MidiExport::processPatternNotes(MidiNoteVector& nv, int cutPos)
+void MidiExport::processPatternNotes(MidiNoteVector& nv, int beatLen, int cutPos)
 {
 	std::sort(nv.begin(), nv.end());
 	int cur = INT_MAX, next = INT_MAX;
@@ -329,9 +352,9 @@ void MidiExport::processPatternNotes(MidiNoteVector& nv, int cutPos)
 			next = cur;
 			cur = it->time;
 		}
-		if (it->duration < 0)
+		if (it->type == Note::Type::Step)
 		{
-			it->duration = qMin(qMin(-it->duration, next - cur), cutPos - it->time);
+			it->duration = qMin(qMin(beatLen, next - cur), cutPos - it->time);
 		}
 	}
 }

plugins/MidiExport/MidiExport.h

@@ -30,6 +30,7 @@
 
 #include "ExportFilter.h"
 #include "MidiFile.hpp"
+#include "Note.h"
 
 class QDomNode;
 
@@ -46,6 +47,7 @@ struct MidiNote
 	uint8_t pitch;
 	int duration;
 	uint8_t volume;
+	Note::Type type;
 
 	inline bool operator<(const MidiNote &b) const
 	{
@@ -78,7 +80,7 @@ class MidiExport: public ExportFilter
 	void writeMidiClipToTrack(MTrack &mtrack, MidiNoteVector &nv);
 	void writePatternClip(MidiNoteVector &src, MidiNoteVector &dst,
 				int len, int base, int start, int end);
-	void processPatternNotes(MidiNoteVector &nv, int cutPos);
+	void processPatternNotes(MidiNoteVector &nv, int beatLen, int cutPos);
 
 	void error();
 

src/tracks/InstrumentTrack.cpp

@@ -831,6 +831,7 @@ void InstrumentTrack::saveTrackSpecificSettings( QDomDocument& doc, QDomElement
 	{
 		QDomElement i = doc.createElement( "instrument" );
 		i.setAttribute( "name", m_instrument->descriptor()->name );
+		i.setAttribute("beatlen", static_cast<int>(beatLen(nullptr)));
 		QDomElement ins = m_instrument->saveState( doc, i );
 		if(m_instrument->key().isValid()) {
 			ins.appendChild( m_instrument->key().saveXML( doc ) );