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

[ardour.git] / libs / ardour / midi_region.cc

diff --git a/libs/ardour/midi_region.cc b/libs/ardour/midi_region.cc
index 26eb0e5054b0e9226220df4629a7f6f773423143..c3ce6db327c97ad912fa267403b425ee8d03db5d 100644 (file)
--- 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" */
        }