* fixed bug: MIDI region did not sound if its position was less than its start offset

git-svn-id: svn://localhost/ardour2/branches/3.0@3239 d708f5d6-7413-0410-9779-e7cbd77b26cf

7 files changed, 28 insertions, 14 deletions

diff --git a/libs/ardour/ardour/midi_model.h b/libs/ardour/ardour/midi_model.h
index 0852108077..f99855d238 100644
--- a/libs/ardour/ardour/midi_model.h
+++ b/libs/ardour/ardour/midi_model.h
@@ -72,7 +72,7 @@ public:
 	bool writing() const { return _writing; }
 	void end_write(bool delete_stuck=false);
 
-	size_t read (MidiRingBuffer& dst, nframes_t start, nframes_t nframes, nframes_t stamp_offset) const;
+	size_t read (MidiRingBuffer& dst, nframes_t start, nframes_t nframes, nframes_t stamp_offset, nframes_t negative_stamp_offset) const;
 
 	/** Resizes vector if necessary (NOT realtime safe) */
 	void append(const MIDI::Event& ev);
diff --git a/libs/ardour/ardour/midi_source.h b/libs/ardour/ardour/midi_source.h
index d465506819..997f3f9d69 100644
--- a/libs/ardour/ardour/midi_source.h
+++ b/libs/ardour/ardour/midi_source.h
@@ -55,7 +55,7 @@ class MidiSource : public Source
 	virtual uint32_t    n_channels () const { return 1; }
 	
 	// FIXME: integrate this with the Readable::read interface somehow
-	virtual nframes_t midi_read (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset) const;
+	virtual nframes_t midi_read (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset, nframes_t negative_stamp_offset) const;
 	virtual nframes_t midi_write (MidiRingBuffer& src, nframes_t cnt);
 
 	virtual void append_event_unlocked(EventTimeUnit unit, const MIDI::Event& ev) = 0;
@@ -98,7 +98,7 @@ class MidiSource : public Source
 	virtual int flush_header() = 0;
 	virtual int flush_footer() = 0;
 	
-	virtual nframes_t read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset) const = 0;
+	virtual nframes_t read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset, nframes_t negative_stamp_offset) const = 0;
 	virtual nframes_t write_unlocked (MidiRingBuffer& dst, nframes_t cnt) = 0;
 	
 	mutable Glib::Mutex _lock;
diff --git a/libs/ardour/ardour/smf_source.h b/libs/ardour/ardour/smf_source.h
index 626aa64def..7c729b10f3 100644
--- a/libs/ardour/ardour/smf_source.h
+++ b/libs/ardour/ardour/smf_source.h
@@ -102,7 +102,7 @@ class SMFSource : public MidiSource {
 
 	int init (string idstr, bool must_exist);
 
-	nframes_t read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cn, nframes_t stamp_offset) const;
+	nframes_t read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cn, nframes_t stamp_offset, nframes_t negative_stamp_offset) const;
 	nframes_t write_unlocked (MidiRingBuffer& dst, nframes_t cnt);
 
 	bool find (std::string path, bool must_exist, bool& is_new);
diff --git a/libs/ardour/midi_model.cc b/libs/ardour/midi_model.cc
index 4aa229b450..43ac4b0f96 100644
--- a/libs/ardour/midi_model.cc
+++ b/libs/ardour/midi_model.cc
@@ -292,9 +292,9 @@ MidiModel::MidiModel(Session& s, size_t size)
  * \return number of events written to \a dst
  */
 size_t
-MidiModel::read(MidiRingBuffer& dst, nframes_t start, nframes_t nframes, nframes_t stamp_offset) const
+MidiModel::read(MidiRingBuffer& dst, nframes_t start, nframes_t nframes, nframes_t stamp_offset, nframes_t negative_stamp_offset) const
 {
-	cerr << this << " MM::read @ " << start << " * " << nframes << " + " << stamp_offset << endl;
+	cerr << this << " MM::read @ " << start << " frames: " << nframes << " -> " << stamp_offset << endl;
 	cerr << this << " MM # notes: " << n_notes() << endl;
 
 	size_t read_events = 0;
@@ -310,7 +310,7 @@ MidiModel::read(MidiRingBuffer& dst, nframes_t start, nframes_t nframes, nframes
 
 	while (_read_iter != end() && _read_iter->time() < start + nframes) {
 		assert(_read_iter->size() > 0);
-		dst.write(_read_iter->time() + stamp_offset, _read_iter->size(), _read_iter->buffer());
+		dst.write(_read_iter->time() + stamp_offset - negative_stamp_offset, _read_iter->size(), _read_iter->buffer());
 		cerr << this << " MM::read event @ " << _read_iter->time()  
 		     << " type: " << hex << int(_read_iter->type()) << dec 
 		     << " note: " << int(_read_iter->note()) 
diff --git a/libs/ardour/midi_region.cc b/libs/ardour/midi_region.cc
index 26eb0e5054..c3ce6db327 100644
--- a/libs/ardour/midi_region.cc
+++ b/libs/ardour/midi_region.cc
@@ -131,7 +131,8 @@ MidiRegion::master_read_at (MidiRingBuffer& out, nframes_t position, nframes_t d
 nframes_t
 MidiRegion::_read_at (const SourceList& srcs, MidiRingBuffer& dst, nframes_t position, nframes_t dur, uint32_t chan_n, NoteMode mode) const
 {
-	//cerr << _name << "._read_at(" << position << ") - " << _position << " duration: " << dur << endl;
+	cerr << "reading from region " << _name << " position: " << _position << " start: " << _start << endl;
+	cerr << _name << "._read_at(" << position << ") - " << position << " duration: " << dur << endl;
 
 	nframes_t internal_offset = 0;
 	nframes_t src_offset      = 0;
@@ -171,6 +172,17 @@ MidiRegion::_read_at (const SourceList& srcs, MidiRingBuffer& dst, nframes_t pos
 	boost::shared_ptr<MidiSource> src = midi_source(chan_n);
 	src->set_note_mode(mode);
 
+	nframes_t output_buffer_position = 0;
+	nframes_t negative_output_buffer_position = 0;
+	if(_position >= _start) {
+		// handle resizing of beginnings of regions correctly
+		output_buffer_position = _position - _start;
+	} else {
+		// when _start is greater than _position, we have to subtract
+		// _start from the note times in the midi source
+		negative_output_buffer_position = _start; 
+	}
+	
 	if (src->midi_read (
 			// the destination buffer
 			dst,  
@@ -179,7 +191,9 @@ MidiRegion::_read_at (const SourceList& srcs, MidiRingBuffer& dst, nframes_t pos
 			// how many bytes
 			to_read, 
 			// the offset in the output buffer
-			_position - _start
+			output_buffer_position,
+			// what to substract from note times written in the output buffer
+			negative_output_buffer_position
 		) != to_read) {
 		return 0; /* "read nothing" */
 	}
diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index eab87376eb..aeb898a31b 100644
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -101,15 +101,15 @@ MidiSource::set_state (const XMLNode& node)
 }
 
 nframes_t
-MidiSource::midi_read (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset) const
+MidiSource::midi_read (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset, nframes_t negative_stamp_offset) const
 {
 	Glib::Mutex::Lock lm (_lock);
 	if (_model) {
-		const size_t n_events = _model->read(dst, start, cnt, stamp_offset);
+		const size_t n_events = _model->read(dst, start, cnt, stamp_offset, negative_stamp_offset);
 		cout << "Read " << n_events << " events from model." << endl;
 		return cnt;
 	} else {
-		return read_unlocked (dst, start, cnt, stamp_offset);
+		return read_unlocked (dst, start, cnt, stamp_offset, negative_stamp_offset);
 	}
 }
 
diff --git a/libs/ardour/smf_source.cc b/libs/ardour/smf_source.cc
index 6df78f3b29..18d7e87d88 100644
--- a/libs/ardour/smf_source.cc
+++ b/libs/ardour/smf_source.cc
@@ -331,7 +331,7 @@ SMFSource::read_event(uint32_t* delta_t, uint32_t* size, Byte** buf) const
 
 /** All stamps in audio frames */
 nframes_t
-SMFSource::read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset) const
+SMFSource::read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset, nframes_t negative_stamp_offset) const
 {
 	cerr << "SMF read_unlocked " << name() << " read " << start << ", count=" << cnt << ", offset=" << stamp_offset << endl;
 
@@ -377,7 +377,7 @@ SMFSource::read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, n
 					((time / (double)_ppqn) * frames_per_beat)) + stamp_offset;
 
 			if (ev_frame_time <= start + cnt)
-				dst.write(ev_frame_time, ev_size, ev_buffer);
+				dst.write(ev_frame_time - negative_stamp_offset, ev_size, ev_buffer);
 			else
 				break;
 		}