def add_key_signatures(nodes: List[Node]) -> List[Node]:
"""Heuristic for deciding which accidentals are inline,
and which should be interpreted as components of a key signature.
Assumes staffline relationships have already been inferred.
The heuristic is defined for each staff S as the following:
* Take the leftmost clef C.
* Take the leftmost notehead (incl. grace notes) N.
* Take all accidentals A_S that overlap the space between C and N
horizontally (including C, not including N), and overlap the staff.
* Order A_S left-to-right
* Set m = C
* Initialize key signature K_S = {}
* For each a_S in A_S:
* if it is closer to m than to N, then:
* add a_S to K_S,
* set m = a_S
* else:
* break
Note that this modifies the accidentals and staffs in-place: they get inlinks
from their respective key signatures.
"""
graph = NotationGraph(nodes)
new_node_id = max([m.id for m in nodes]) + 1
key_signatures = []
staffs = [m for m in nodes if m.class_name == _CONST.STAFF]
for s in staffs:
# Take the leftmost clef C.
clefs = graph.parents(s.id, class_filter=_CONST.CLEF_CLASS_NAMES)
if len(clefs) == 0:
continue
leftmost_clef = min(clefs, key=lambda x: x.left)
# Take the leftmost notehead (incl. grace notes) N.
noteheads = graph.parents(s.id,
class_filter=_CONST.NOTEHEAD_CLASS_NAMES)
if len(noteheads) == 0:
continue
leftmost_notehead = min(noteheads, key=lambda x: x.left)
# Take all accidentals A_S that fall between C and N
# horizontally, and overlap the staff.
all_accidentals = [
m for m in nodes if m.class_name in _CONST.ACCIDENTAL_CLASS_NAMES
]
relevant_acc_bbox = s.top, leftmost_clef.left, s.bottom, leftmost_notehead.left
relevant_accidentals = [
m for m in all_accidentals if bounding_box_intersection(
m.bounding_box, relevant_acc_bbox) is not None
]
# Order A_S left-to-right.
ordered_accidentals = sorted(relevant_accidentals,
key=lambda x: x.left)
# Set m = C
current_lstop = leftmost_clef.right
key_signature_accidentals = []
# Iterate over accidentals; check if they are closer to lstop
# than to the first notehead
for a in ordered_accidentals:
if (a.left - current_lstop) < (leftmost_notehead.left - a.right):
key_signature_accidentals.append(a)
current_lstop = a.right
else:
break
# Build key signature and connect it to staff
if len(key_signature_accidentals) > 0:
key_signature_class_names = list(_CONST.KEY_SIGNATURE)[0]
# Note: there might be spurious links from the accidentals
# to notheads, if they were mis-interpreted during parsing.
# This actually might not matter; needs testing.
key_signature = merge_multiple_nodes(
key_signature_accidentals,
class_name=key_signature_class_names,
id_=new_node_id)
new_node_id += 1
link_nodes(key_signature, s)
for a in key_signature_accidentals:
link_nodes(key_signature, a)
key_signatures.append(key_signature)
logging.info('Adding {} key signatures'.format(len(key_signatures)))
return nodes + key_signatures
def add_staff_relationships(nodes: List[Node],
notehead_staffspace_threshold: float = 0.2) -> List[Node]:
id_to_node_mapping = {node.id: node for node in nodes}
ON_STAFFLINE_RATIO_THRESHOLD = notehead_staffspace_threshold
##########################################################################
logging.info('Find the staff-related symbols')
staffs = [c for c in nodes if c.class_name == _CONST.STAFF]
staff_related_symbols = defaultdict(list) # type: defaultdict[str, List[Node]]
notehead_symbols = defaultdict(list) # type: defaultdict[str, List[Node]]
rest_symbols = defaultdict(list) # type: defaultdict[str, List[Node]]
for node in nodes:
if node.class_name in _CONST.STAFF_RELATED_CLASS_NAMES:
staff_related_symbols[node.class_name].append(node)
if node.class_name in _CONST.NOTEHEAD_CLASS_NAMES:
notehead_symbols[node.class_name].append(node)
if node.class_name in _CONST.REST_CLASS_NAMES:
rest_symbols[node.class_name].append(node)
##########################################################################
logging.info('Adding staff relationships')
# - Which direction do the relationships lead in?
# Need to define this.
#
# Staff -> symbol?
# Symbol -> staff?
# It does not really matter, but it's more intuitive to attach symbols
# onto a pre-existing staff. So, symbol -> staff.
for class_name, nodes in list(staff_related_symbols.items()):
for node in nodes: # type: Node
# Find the related staff. Relatedness is measured by row overlap.
# That means we have to modify the staff bounding box to lead
# from the leftmost to the rightmost column. This holds
# especially for the staff_grouping symbols.
for staff in staffs:
top, left, bottom, right = staff.bounding_box
left = 0
right = max(right, node.right)
if node.overlaps((top, left, bottom, right)):
link_nodes(node, staff)
##########################################################################
logging.info('Adding rest --> staff relationships.')
for class_name, nodes in list(rest_symbols.items()):
for node in nodes: # type: Node
closest_staff = min([s for s in staffs],
key=lambda x: ((x.bottom + x.top) / 2. - (node.bottom + node.top) / 2.) ** 2)
link_nodes(node, closest_staff)
##########################################################################
logging.info('Adding notehead relationships.')
# NOTE:
# This part should NOT rely on staffspace masks in any way!
# They are highly unreliable.
# Sort the staff objects top-down. Assumes stafflines do not cross,
# and that there are no crazy curves at the end that would make the lower
# stafflines stick out over the ones above them...
stafflines = [c for c in nodes if c.class_name == _CONST.STAFFLINE]
stafflines = sorted(stafflines, key=lambda c: c.top)
staffspaces = [c for c in nodes if c.class_name == _CONST.STAFFSPACE]
staffspaces = sorted(staffspaces, key=lambda c: c.top)
staves = [c for c in nodes if c.class_name == _CONST.STAFF]
staves = sorted(staves, key=lambda c: c.top)
# Indexing data structures.
#
# We need to know:
# - per staffline and staffspace: its containing staff
_staff_per_ss_sl = {}
# - per staffline and staffspace: its index (top to bottom) within the staff
_ss_sl_idx_wrt_staff = {}
# Reverse indexes:
# If I know which staff (by id) and which index of staffline/staffspace,
# I want to retrieve the given staffline/staffspace Node:
_staff_and_idx2ss = defaultdict(dict)
_staff_and_idx2sl = defaultdict(dict)
# Build the indexes
for _staff in staves:
# Keep the top-down ordering from above:
_s_stafflines = [_staffline for _staffline in stafflines
if _staff.id in _staffline.inlinks]
_s_staffspaces = [_staffspace for _staffspace in staffspaces
if _staff.id in _staffspace.inlinks]
for i, _sl in enumerate(_s_stafflines):
_staff_per_ss_sl[_sl.id] = _staff
_ss_sl_idx_wrt_staff[_sl.id] = i
_staff_and_idx2sl[_staff.id][i] = _sl
logging.debug('Staff {0}: stafflines {1}'.format(_staff.id,
_staff_and_idx2sl[_staff.id]))
for i, _ss in enumerate(_s_staffspaces):
_staff_per_ss_sl[_ss.id] = _staff
_ss_sl_idx_wrt_staff[_ss.id] = i
_staff_and_idx2ss[_staff.id][i] = _ss
logging.debug(pprint.pformat(dict(_staff_and_idx2ss)))
for class_name, nodes in list(notehead_symbols.items()):
for node in nodes:
ct, cl, cb, cr = node.bounding_box
################
# Add relationship to given staffline or staffspace.
# If notehead has leger lines, skip it for now.
has_leger_line = False
for o in node.outlinks:
if id_to_node_mapping[o].class_name == _CONST.LEGER_LINE:
has_leger_line = True
break
if has_leger_line:
# Attach to the appropriate staff:
# meaning, staff closest to the innermost leger line.
lls = [id_to_node_mapping[o] for o in node.outlinks
if id_to_node_mapping[o].class_name == _CONST.LEGER_LINE]
# Furthest from notehead's top is innermost.
# (If notehead is below staff and crosses a ll., one
# of these numbers will be negative. But that doesn't matter.)
ll_max_dist = max(lls, key=lambda ll: ll.top - node.top)
# Find closest staff to max-dist leger ine
staff_min_dist = min(staves,
key=lambda ss: min((ll_max_dist.bottom - ss.top) ** 2,
(ll_max_dist.top - ss.bottom) ** 2))
link_nodes(node, staff_min_dist)
continue
# - Find the related staffline.
# - Because of curved stafflines, this has to be done w.r.t.
# the horizontal position of the notehead.
# - Also, because stafflines are NOT filled in (they do not have
# intersections annotated), it is necessary to use a wider
# window than just the notehead.
# - We will assume that STAFFLINES DO NOT CROSS.
# (That is a reasonable assumption.)
#
# - For now, we only work with more or less straight stafflines.
overlapped_stafflines = []
overlapped_staffline_idxs = []
for i, staff in enumerate(stafflines):
# This is the assumption of straight stafflines!
if (ct <= staff.top <= cb) or (ct <= staff.bottom <= cb):
overlapped_stafflines.append(staff)
overlapped_staffline_idxs.append(i)
if node.id < 10:
logging.debug('Notehead {0} ({1}): overlaps {2} stafflines'.format(node.id,
node.bounding_box,
len(overlapped_stafflines), ))
if len(overlapped_stafflines) == 1:
staff = overlapped_stafflines[0]
dtop = staff.top - ct
dbottom = cb - staff.bottom
if min(dtop, dbottom) / max(dtop, dbottom) < ON_STAFFLINE_RATIO_THRESHOLD:
logging.info('Notehead {0}, staffline {1}: very small ratio {2:.2f}'
''.format(node.id, staff.id,
min(dtop, dbottom) / max(dtop, dbottom)))
# Staffspace?
#
# To get staffspace:
# - Get orientation (below? above?)
_is_staffspace_above = False
if dtop > dbottom:
_is_staffspace_above = True
# - Find staffspaces adjacent to the overlapped staffline.
# NOTE: this will fail with single-staffline staves, because
# they do NOT have the surrounding staffspaces defined...
_staffline_idx_wrt_staff = _ss_sl_idx_wrt_staff[staff.id]
if _is_staffspace_above:
_staffspace_idx_wrt_staff = _staffline_idx_wrt_staff
else:
_staffspace_idx_wrt_staff = _staffline_idx_wrt_staff + 1
# Retrieve the given staffsapce
_staff = _staff_per_ss_sl[staff.id]
tgt_staffspace = _staff_and_idx2ss[_staff.id][_staffspace_idx_wrt_staff]
# Link to staffspace
link_nodes(node, tgt_staffspace)
# And link to staff
_c_staff = _staff_per_ss_sl[tgt_staffspace.id]
link_nodes(node, _c_staff)
else:
# Staffline!
link_nodes(node, staff)
# And staff:
_c_staff = _staff_per_ss_sl[staff.id]
link_nodes(node, _c_staff)
elif len(overlapped_stafflines) == 0:
# Staffspace!
# Link to the staffspace with which the notehead has
# greatest vertical overlap.
#
# Interesting corner case:
# Sometimes noteheads "hang out" of the upper/lower
# staffspace, so they are not entirely covered.
overlapped_staffspaces = {}
for _ss_i, staff in enumerate(staffspaces):
if staff.top <= node.top <= staff.bottom:
overlapped_staffspaces[_ss_i] = min(staff.bottom, node.bottom) - node.top
elif node.top <= staff.top <= node.bottom:
overlapped_staffspaces[_ss_i] = staff.bottom - max(node.top, staff.top)
if len(overlapped_staffspaces) == 0:
logging.warning('Notehead {0}: no overlapped staffline object, no leger line!'
''.format(node.id))
_ss_i_max = max(list(overlapped_staffspaces.keys()),
key=lambda x: overlapped_staffspaces[x])
max_overlap_staffspace = staffspaces[_ss_i_max]
link_nodes(node, max_overlap_staffspace)
_c_staff = _staff_per_ss_sl[max_overlap_staffspace.id]
link_nodes(node, _c_staff)
elif len(overlapped_stafflines) == 2:
# Staffspace between those two lines.
s1 = overlapped_stafflines[0]
s2 = overlapped_stafflines[1]
_staff1 = _staff_per_ss_sl[s1.id]
_staff2 = _staff_per_ss_sl[s2.id]
if _staff1.id != _staff2.id:
raise ValueError('Really weird notehead overlapping two stafflines'
' from two different staves: {0}'.format(node.id))
_staffspace_idx = _ss_sl_idx_wrt_staff[s2.id]
staff = _staff_and_idx2ss[_staff2.id][_staffspace_idx]
link_nodes(node, staff)
# And link to staff:
_c_staff = _staff_per_ss_sl[staff.id]
link_nodes(node, _c_staff)
elif len(overlapped_stafflines) > 2:
raise ValueError('Really weird notehead overlapping more than 2 stafflines:'
' {0}'.format(node.id))
return nodes
def add_staff_relationships(nodes: List[Node],
notehead_staffspace_threshold: float = 0.2,
reprocess_noteheads_inside_staff_with_lls: bool = True):
"""Adds the relationships from various symbols to staff objects:
stafflines, staffspaces, and staffs.
:param nodes: The list of Nodes in the document. Must
include the staff objects.
:param notehead_staffspace_threshold: A notehead is considered to be
on a staffline if it intersects a staffline, and the ratio between
how far above the staffline and how far below the staffline it reaches
is at least this (default: 0.2). The ratio is computed both ways:
d_top / d_bottom and d_bottom / d_top, and the minimum is taken,
so the default in effect restricts d_top / d_bottom between 0.2 and 0.8:
in other words, the imbalance of the notehead's bounding box around
the staffline should be less than 1:4.
:param reprocess_noteheads_inside_staff_with_lls: If set to True, will check against noteheads
that are connected to leger lines, but intersect a staffline. If found,
will remove their edges before further processing, so that the noteheads
will seem properly unprocessed.
Note that this handling is a bit ad-hoc for now. However, we currently
do not have a better place to fit this in, since the Best Practices
currently call for first applying the syntactic parser and then
adding staff relationships.
:return: The list of Nodes corresponding to the new graph.
"""
graph = NotationGraph(nodes)
id_to_node_mapping = {node.id: node for node in nodes}
ON_STAFFLINE_RATIO_TRHESHOLD = notehead_staffspace_threshold
##########################################################################
if reprocess_noteheads_inside_staff_with_lls:
ll_noteheads_on_staff = find_noteheads_on_staff_linked_to_leger_line(nodes)
logging.info('Reprocessing noteheads that are inside a staff, but have links'
' to leger lines. Found {0} such noteheads.'
''.format(len(ll_noteheads_on_staff)))
for n in ll_noteheads_on_staff:
# Remove all links to leger lines.
leger_lines = graph.children(n, class_filter=[_CONST.LEGER_LINE_CLASS_NAME])
for ll in leger_lines:
graph.remove_edge(n.id, ll.id)
##########################################################################
logging.info('Find the staff-related symbols')
staffs = [c for c in nodes if c.class_name == _CONST.STAFF_CLASS_NAME]
staff_related_symbols = collections.defaultdict(list)
notehead_symbols = collections.defaultdict(list)
rest_symbols = collections.defaultdict(list)
for node in nodes:
if node.class_name in _CONST.STAFF_RELATED_CLASS_NAMES:
# Check if it already has a staff link
if not graph.has_children(node, [_CONST.STAFF_CLASS_NAME]):
staff_related_symbols[node.class_name].append(node)
if node.class_name in _CONST.NOTEHEAD_CLASS_NAMES:
if not graph.has_children(node, [_CONST.STAFF_CLASS_NAME]):
notehead_symbols[node.class_name].append(node)
if node.class_name in _CONST.REST_CLASS_NAMES:
if not graph.has_children(node, [_CONST.STAFF_CLASS_NAME]):
rest_symbols[node.class_name].append(node)
##########################################################################
logging.info('Adding staff relationships')
# - Which direction do the relationships lead in?
# Need to define this.
#
# Staff -> symbol?
# Symbol -> staff?
# It does not really matter, but it's more intuitive to attach symbols
# onto a pre-existing staff. So, symbol -> staff.
for class_name, cs in list(staff_related_symbols.items()):
for node in cs:
# Find the related staff. Relatedness is measured by row overlap.
# That means we have to modify the staff bounding box to lead
# from the leftmost to the rightmost column. This holds
# especially for the staff_grouping symbols.
for s in staffs:
st, sl, sb, sr = s.bounding_box
sl = 0
sr = max(sr, node.right)
if node.overlaps((st, sl, sb, sr)):
link_nodes(node, s, check_that_nodes_have_the_same_document=False)
##########################################################################
logging.info('Adding rest --> staff relationships.')
for class_name, cs in list(rest_symbols.items()):
for node in cs:
closest_staff = min([s for s in staffs],
key=lambda x: ((x.bottom + x.top) / 2. - (
node.bottom + node.top) / 2.) ** 2)
link_nodes(node, closest_staff, check_that_nodes_have_the_same_document=False)
##########################################################################
logging.info('Adding notehead relationships.')
# NOTE:
# This part should NOT rely on staffspace masks in any way!
# They are highly unreliable.
# Sort the staff objects top-down. Assumes stafflines do not cross,
# and that there are no crazy curves at the end that would make the lower
# stafflines stick out over the ones above them...
stafflines = [c for c in nodes if c.class_name == _CONST.STAFFLINE_CLASS_NAME]
stafflines = sorted(stafflines, key=lambda c: c.top)
staffspaces = [c for c in nodes if c.class_name == _CONST.STAFFSPACE_CLASS_NAME]
staffspaces = sorted(staffspaces, key=lambda c: c.top)
staves = [c for c in nodes if c.class_name == _CONST.STAFF_CLASS_NAME]
staves = sorted(staves, key=lambda c: c.top)
logging.info('Stafflines: {0}'.format(len(stafflines)))
logging.info('Staffspaces: {0}'.format(len(staffspaces)))
logging.info('Staves: {0}'.format(len(staves)))
# Indexing data structures.
#
# We need to know:
# - per staffline and staffspace: its containing staff
_staff_per_ss_sl = {}
# - per staffline and staffspace: its index (top to bottom) within the staff
_ss_sl_idx_wrt_staff = {}
# Reverse indexes:
# If I know which staff (by id) and which index of staffline/staffspace,
# I want to retrieve the given staffline/staffspace Node:
_staff_and_idx2ss = collections.defaultdict(dict)
_staff_and_idx2sl = collections.defaultdict(dict)
# Build the indexes
for _staff in staves:
# Keep the top-down ordering from above:
_s_stafflines = [_staffline for _staffline in stafflines
if _staff.id in _staffline.inlinks]
_s_staffspaces = [_staffspace for _staffspace in staffspaces
if _staff.id in _staffspace.inlinks]
for i, _sl in enumerate(_s_stafflines):
_staff_per_ss_sl[_sl.id] = _staff
_ss_sl_idx_wrt_staff[_sl.id] = i
_staff_and_idx2sl[_staff.id][i] = _sl
logging.debug('Staff {0}: stafflines {1}'.format(_staff.id,
_staff_and_idx2sl[_staff.id]))
for i, _ss in enumerate(_s_staffspaces):
_staff_per_ss_sl[_ss.id] = _staff
_ss_sl_idx_wrt_staff[_ss.id] = i
_staff_and_idx2ss[_staff.id][i] = _ss
logging.debug(pprint.pformat(dict(_staff_and_idx2ss)))
for class_name, cs in list(notehead_symbols.items()):
for node in cs:
ct, cl, cb, cr = node.bounding_box
################
# Add relationship to given staffline or staffspace.
# If notehead has leger lines, skip it for now.
has_leger_line = False
for outlink in node.outlinks:
if id_to_node_mapping[outlink].class_name == _CONST.LEGER_LINE_CLASS_NAME:
has_leger_line = True
break
if has_leger_line:
# Attach to the appropriate staff:
# meaning, staff closest to the innermost leger line.
leger_lines = [id_to_node_mapping[o] for o in node.outlinks
if id_to_node_mapping[o].class_name == _CONST.LEGER_LINE_CLASS_NAME]
# Furthest from notehead's top is innermost.
# (If notehead is below staff and crosses a ll., one
# of these numbers will be negative. But that doesn't matter.)
ll_max_dist = max(leger_lines, key=lambda leger_line: leger_line.top - node.top)
# Find closest staff to max-dist leger ine
staff_min_dist = min(staves,
key=lambda ss: min((ll_max_dist.bottom - ss.top) ** 2,
(ll_max_dist.top - ss.bottom) ** 2))
distance_of_closest_staff = (ll_max_dist.top + ll_max_dist.bottom) / 2 \
- (staff_min_dist.top + staff_min_dist.bottom) / 2
if numpy.abs(distance_of_closest_staff) > (50 + 0.5 * staff_min_dist.height):
logging.debug('Trying to join notehead with leger line to staff,'
' but the distance is larger than 50. Notehead: {0},'
' leger line: {1}, staff: {2}, distance: {3}'
''.format(node.uid, ll_max_dist.uid, staff_min_dist.id,
distance_of_closest_staff))
else:
link_nodes(node, staff_min_dist, check_that_nodes_have_the_same_document=False)
continue
# - Find the related staffline.
# - Because of curved stafflines, this has to be done w.r.t.
# the horizontal position of the notehead.
# - Also, because stafflines are NOT filled in (they do not have
# intersections annotated), it is necessary to use a wider
# window than just the notehead.
# - We will assume that STAFFLINES DO NOT CROSS.
# (That is a reasonable assumption.)
#
# - For now, we only work with more or less straight stafflines.
overlapped_stafflines = []
overlapped_staffline_idxs = []
for i, s in enumerate(stafflines):
# This is the assumption of straight stafflines!
if (ct <= s.top <= cb) or (ct <= s.bottom <= cb):
overlapped_stafflines.append(s)
overlapped_staffline_idxs.append(i)
if node.id < 10:
logging.info('Notehead {0} ({1}): overlaps {2} stafflines'.format(node.uid, node.bounding_box,
len(overlapped_stafflines)))
if len(overlapped_stafflines) == 1:
s = overlapped_stafflines[0]
dtop = s.top - ct
dbottom = cb - s.bottom
logging.info('Notehead {0}, staffline {1}: ratio {2:.2f}'
''.format(node.id, s.id, min(dtop, dbottom) / max(dtop, dbottom)))
if min(dtop, dbottom) / max(dtop, dbottom) < ON_STAFFLINE_RATIO_TRHESHOLD:
# Staffspace?
#
# To get staffspace:
# - Get orientation (below? above?)
_is_staffspace_above = False
if dtop > dbottom:
_is_staffspace_above = True
# - Find staffspaces adjacent to the overlapped staffline.
# NOTE: this will fail with single-staffline staves, because
# they do NOT have the surrounding staffspaces defined...
_staffline_idx_wrt_staff = _ss_sl_idx_wrt_staff[s.id]
if _is_staffspace_above:
_staffspace_idx_wrt_staff = _staffline_idx_wrt_staff
else:
_staffspace_idx_wrt_staff = _staffline_idx_wrt_staff + 1
# Retrieve the given staffsapce
_staff = _staff_per_ss_sl[s.id]
tgt_staffspace = _staff_and_idx2ss[_staff.id][_staffspace_idx_wrt_staff]
# Link to staffspace
link_nodes(node, tgt_staffspace, check_that_nodes_have_the_same_document=False)
# And link to staff
_c_staff = _staff_per_ss_sl[tgt_staffspace.id]
link_nodes(node, _c_staff, check_that_nodes_have_the_same_document=False)
else:
# Staffline!
link_nodes(node, s, check_that_nodes_have_the_same_document=False)
# And staff:
_c_staff = _staff_per_ss_sl[s.id]
link_nodes(node, _c_staff, check_that_nodes_have_the_same_document=False)
elif len(overlapped_stafflines) == 0:
# Staffspace!
# Link to the staffspace with which the notehead has
# greatest vertical overlap.
#
# Interesting corner case:
# Sometimes noteheads "hang out" of the upper/lower
# staffspace, so they are not entirely covered.
overlapped_staffspaces = {}
for _ss_i, s in enumerate(staffspaces):
if s.top <= node.top <= s.bottom:
overlapped_staffspaces[_ss_i] = min(s.bottom, node.bottom) - node.top
elif node.top <= s.top <= node.bottom:
overlapped_staffspaces[_ss_i] = s.bottom - max(node.top, s.top)
if len(overlapped_staffspaces) == 0:
logging.warning('Notehead {0}: no overlapped staffline object, no leger line!'
' Expecting it will be attached to leger line and staff later on.'
''.format(node.uid))
continue
_ss_i_max = max(list(overlapped_staffspaces.keys()),
key=lambda x: overlapped_staffspaces[x])
max_overlap_staffspace = staffspaces[_ss_i_max]
link_nodes(node, max_overlap_staffspace, check_that_nodes_have_the_same_document=False)
_c_staff = _staff_per_ss_sl[max_overlap_staffspace.id]
link_nodes(node, _c_staff, check_that_nodes_have_the_same_document=False)
elif len(overlapped_stafflines) == 2:
# Staffspace between those two lines.
s1 = overlapped_stafflines[0]
s2 = overlapped_stafflines[1]
_staff1 = _staff_per_ss_sl[s1.id]
_staff2 = _staff_per_ss_sl[s2.id]
if _staff1.id != _staff2.id:
raise ValueError('Really weird notehead overlapping two stafflines'
' from two different staves: {0}'.format(node.uid))
_staffspace_idx = _ss_sl_idx_wrt_staff[s2.id]
s = _staff_and_idx2ss[_staff2.id][_staffspace_idx]
link_nodes(node, s, check_that_nodes_have_the_same_document=False)
# And link to staff:
_c_staff = _staff_per_ss_sl[s.id]
link_nodes(node, _c_staff, check_that_nodes_have_the_same_document=False)
elif len(overlapped_stafflines) > 2:
logging.warning('Really weird notehead overlapping more than 2 stafflines:'
' {0} (permissive: linking to middle staffline)'.format(node.uid))
# use the middle staffline -- this will be an error anyway,
# but we want to export some MIDI more or less no matter what
s_middle = overlapped_stafflines[len(overlapped_stafflines) // 2]
link_nodes(node, s_middle, check_that_nodes_have_the_same_document=False)
# And staff:
_c_staff = _staff_per_ss_sl[s_middle.id]
link_nodes(node, _c_staff, check_that_nodes_have_the_same_document=False)
return nodes