make octave tracking implementation match spkr(4) better

mmllib/mml.py

@@ -206,7 +206,8 @@ def mml(macro, _nplay=None, _barline=None, _mmltrk=None):
     bpm = 120
     octave = 4
     octave_tracking = False
-    octave_tracking_last_note = None
+    octave_tracking_onhold = True
+    octave_tracking_last_note = 12 * octave
     timevalue = 4
     # result normalised MML
     normml = ["O4L4T120MN "]
@@ -231,14 +232,22 @@ def mml(macro, _nplay=None, _barline=None, _mmltrk=None):
 
         if char in _MML_NAME2STEP.keys():
             # base note
-            if octave_tracking and octave_tracking_last_note:
-                if note - octave_tracking_last_note > 6:
-                    octave -= 1
-                    normml[0] += "<"
-                elif note - octave_tracking_last_note < -6:
-                    octave += 1
-                    normml[0] += ">"
             note = 12 * octave + _MML_NAME2STEP[char]
+            # octave tracking implementation
+            if octave_tracking and not octave_tracking_onhold:
+                if abs(note - octave_tracking_last_note) > \
+                  abs(note + 12 - octave_tracking_last_note):
+                    normml[0] += ">"
+                    octave += 1
+                    note += 12
+                if abs(note - octave_tracking_last_note) > \
+                  abs(note - 12 - octave_tracking_last_note):
+                    normml[0] += "<"
+                    octave -= 1
+                    note -= 12
+            octave_tracking_onhold = False
+            octave_tracking_last_note = note
+            # base note information
             extra = (octave, char, u'♮')
             bnote = char
 
@@ -256,6 +265,7 @@ def mml(macro, _nplay=None, _barline=None, _mmltrk=None):
                     bnote = _MML_STEP2NAME_ES[note % 12]
                 macro.pop(0)
 
+            # base note and accidental
             normml[0] += bnote
 
             # length
@@ -267,9 +277,6 @@ def mml(macro, _nplay=None, _barline=None, _mmltrk=None):
 
             # sustain dots, and play the note
             _play(macro, normml, res, bpm, art, note, _length, extra)
-
-            # remember last note for octave tracking
-            octave_tracking_last_note = note
         elif char == "L":
             timevalue = _getint(macro, 1, 64, 4)
             normml[0] += "L" + str(timevalue)
@@ -290,12 +297,14 @@ def mml(macro, _nplay=None, _barline=None, _mmltrk=None):
             if macro[0].isdigit():
                 octave = _getint(macro, 0, 6, 4)
                 normml[0] += "O" + str(octave)
+                octave_tracking_onhold = True
             else:
                 char = macro.pop(0)
                 if char == "L":
                     octave_tracking = True
                 elif char == "N":
                     octave_tracking = False
+                    octave_tracking_onhold = False
 
         elif char == "P":
             _length = _getint(macro, 1, 64, timevalue)
@@ -310,11 +319,13 @@ def mml(macro, _nplay=None, _barline=None, _mmltrk=None):
             if octave > 0:
                 octave -= 1
                 normml[0] += char
+            octave_tracking_onhold = True
 
         elif char == ">":
             if octave < 6:
                 octave += 1
                 normml[0] += char
+            octave_tracking_onhold = True
 
         elif char == "|":
             normml[0] += " "