FretBend supports alter (interval), prebend, and release

music21/articulations.py

@@ -76,7 +76,6 @@
 '''
 from __future__ import annotations
 
-import typing as t
 import unittest
 
 from music21 import base
@@ -596,27 +595,37 @@ class FretBend(FretIndication):
     Release is the quarterLength value from the start
     of the note for releasing the bend, if Any. Defaults to None.
 
-    WithBar indicates if the bend is done using a whammy bar movement. Defaults to False.
+    WithBar indicates what whammy bar movement is used, if any.
+    MusicXML supports 'scoop' or 'dip'. Defaults to None.
 
-    >>> fb = articulations.FretBend(bendAlter=interval.ChromaticInterval(-2), release=0.5)
+    >>> fb = articulations.FretBend(1,bendAlter=interval.ChromaticInterval(-2),release=0.5)
     >>> fb
-    <music21.articulations.FretBend 0>
+    <music21.articulations.FretBend 1>
     >>> fb.preBend
     False
     >>> fb.withBar
-    False
+
     >>> fb.bendAlter
     <music21.interval.ChromaticInterval -2>
     >>> fb.release 
     0.5
     '''
-    bendAlter: interval.IntervalBase | None
+    bendAlter: interval.Interval | interval.ChromaticInterval | None
     preBend: bool
-    release: float | None
-    withBar: bool 
-
-    def __init__(self, number=0, bendAlter=None, preBend=False, release=None, withBar=False, **keywords):
-        super().__init__(**keywords)
+    release: OffsetQL | None
+    withBar: str | None
+
+    def __init__(
+        self,
+        number: int = 0,
+        *,
+        bendAlter: interval.Interval | interval.ChromaticInterval | None = None,
+        preBend: bool = False,
+        release: OffsetQL | None = None,
+        withBar: str | None = None,
+        **keywords
+        ):
+        super().__init__(number=number, **keywords)
         self.bendAlter = bendAlter
         self.preBend = preBend
         self.release = release

music21/musicxml/m21ToXml.py

@@ -65,7 +65,7 @@
 from music21.musicxml import helpers
 from music21.musicxml.partStaffExporter import PartStaffExporterMixin
 from music21.musicxml import xmlObjects
-from music21.musicxml.xmlObjects import MusicXMLExportException, booleanToYesNo
+from music21.musicxml.xmlObjects import MusicXMLExportException
 from music21.musicxml.xmlObjects import MusicXMLWarning
 
 environLocal = environment.Environment('musicxml.m21ToXml')
@@ -5557,31 +5557,48 @@ def setBend(mxh: Element, bend: articulations.FretBend) -> None:
 
         >>> MEXClass = musicxml.m21ToXml.MeasureExporter
 
-        >>> a = articulations.FretBend()
+        >>> a = articulations.FretBend(bendAlter=interval.Interval(2))
 
         >>> from xml.etree.ElementTree import Element
         >>> mxh = Element('bend')
 
-        >>> MEXClass.setBend(mxh, a)
-        >>> MEXClass.dump(mxh)
+        >>> MEXclass.setbend(mxh, a)
+        >>> MEXclass.dump(mxh)
+        <bend>
+          <bend-alter>2</bend-alter>
+        </bend>
+        >>> a.pre-bend = True
+        >>> MEXclass.setbend(mxh, a)
+        >>> MEXclass.dump(mxh)
+        <bend>
+          <bend-alter>2</bend-alter>
+          <pre-bend/>
+        </bend>
+        >>> a = articulations.FretBend(bendAlter=interval.Interval(-2), release=OffsetQL(1, 10080))
+        >>> MEXclass.setbend(mxh, a)
+        >>> MEXclass.dump(mxh)
+        <bend>
+          <bend-alter>-2</bend-alter>
+          <release offset='1'>
+        </bend>
+        >>> a = articulations.FretBend(bendAlter=interval.Interval(-2), withBar='scoop')
+        >>> MEXclass.setbend(mxh, a)
+        >>> MEXclass.dump(mxh)
         <bend>
-          <bend-alter></bend-alter>
+          <bend-alter>1</bend-alter>
+          <with-bar>scoop</with-bar>
         </bend>
         '''
         bendAlterSubElement = SubElement(mxh, 'bend-alter')
         alter = bend.bendAlter
         if alter is not None:
-            # musicxml expects a number of semitones but not sure how to get it
-            # from a GeneralInterval
-            pass
+            bendAlterSubElement.text = str(alter.semitones)
         if bend.preBend:
             SubElement(mxh, 'pre-bend')
         if bend.release is not None:
-            # Specifies where the release starts in terms of 
-            # divisions relative to the current note.
             releaseSubElement = SubElement(mxh, 'release')
             quarterLengthValue = bend.release
-            divisionsValue = defaults.divisionsPerQuarter * quarterLengthValue
+            divisionsValue = int(defaults.divisionsPerQuarter * quarterLengthValue)
             releaseSubElement.set('offset', str(divisionsValue))
         if bend.withBar is not None:
             withBarSubElement = SubElement(mxh, 'with-bar')

music21/musicxml/xmlObjects.py

@@ -67,7 +67,6 @@
                                ('stopped', articulations.Stopped),
                                ('snap-pizzicato', articulations.SnapPizzicato),
                                ('string', articulations.StringIndication),
-                               ('bend', articulations.FretBend),
                                # hammer-on and pull-off not implemented because handled
                                # in method objectAttachedSpannersToTechnicals of m21ToXml.py
                                # ('hammer-on', articulations.HammerOn),

music21/musicxml/xmlToM21.py

@@ -3877,18 +3877,63 @@ def xmlTechnicalToArticulation(self, mxObj):
             environLocal.printDebug(f'Cannot translate {tag} in {mxObj}.')
             return None
 
-    @staticmethod
-    def setBend(mxh, bend):
+    def setBend(self, mxh, bend):
+        '''
+        Gets the bend amplitude from the bend-alter tag,
+        then optional pre-bend and with-bar tags are processed,
+        as well as release which is converted from divisions to music21 time.
+
+        Called from xmlTechnicalToArticulation
+
+        >>> from xml.etree.ElementTree import fromstring as EL
+        >>> MP = musicxml.xmlToM21.MeasureParser()
+
+        >>> mxTech = EL('<bend><bend-alter>2</bend-alter></bend>')
+        >>> a = MP.xmlTechnicalToArticulation(mxTech)
+        >>> a
+        <music21.articulations.FretBend 0>
+        >>> a.bendAlter.semitones
+        2
+        >>> a.release
+
+        >>> a.withBar
+
+        >>> a.preBend
+        False
+
+        >>> mxTech = EL('<bend><bend-alter>-2</bend-alter><pre-bend/></bend>')
+        >>> a = MP.xmlTechnicalToArticulation(mxTech)
+        >>> a.bendAlter.semitones
+        -2
+        >>> a.preBend
+        True
+
+        >>> mxTech = EL('<bend><bend-alter>-2</bend-alter><release offset="1"/></bend>')
+        >>> a = MP.xmlTechnicalToArticulation(mxTech)
+        >>> a.bendAlter.semitones
+        -2
+        >>> a.release
+        Fraction(1, 10080)
+
+        >>> mxTech = EL('<bend><bend-alter>-1</bend-alter><with-bar>dip</with-bar></bend>')
+        >>> a = MP.xmlTechnicalToArticulation(mxTech)
+        >>> a.bendAlter.semitones
+        -1
+        >>> a.withBar
+        'dip'
+        '''
         alter = mxh.find('bend-alter')
         if alter is not None:
             if alter.text is not None:
-                bend.bendAlter = interval.Interval(int(alter.text))
+                bend.bendAlter = interval.Interval(float(alter.text))
         if mxh.find('pre-bend') is not None:
             bend.preBend = True
+        if mxh.find('with-bar') is not None:
+            bend.withBar = mxh.find('with-bar').text
         if mxh.find('release') is not None:
             try:
                 divisions = float(mxh.find('release').get('offset'))
-                bend.release = divisions / defaults.divisionsPerQuarter
+                bend.release = opFrac(divisions / self.divisions)
             except (ValueError, TypeError) as unused_err:
                 bend.release = 0.0