neoscore.western.beam_group

class neoscore.western.beam_group.BeamGroup[source]

Bases: PositionedObject, HasMusicFont

A beam group spanning a collection of Chordrests.

This analyzes the given chordrests to determine a reasonable beam layout. The beaming algorithm does not take into account metric subdivisions; instead it greedily tries to beam together as many notes as possible. Subdivisions can be specified by setting Chordrest.beam_break_depth, which indicates a break after the chord to the given beam count.

While in most situations, beamlet “hooks” (as in a dotted 8th note followed by a 16th note) unambiguously must point right or left, there are some cases where it is ambiguous. For example, a 16th note between two 8th notes could have its beamlet point left or right. In these situations, BeamGroup will point it left by default, but users can override this by setting Chordrest.beam_hook_dir.

The beam direction and slant angle are determined automatically based on the given notes. The direction can be overridden in BeamGroup’s constructor.

Beam layout automatically modifies spanned chordrests by snapping their stems to the beam line and, if this causes a stem flip, correcting the chordrest component layout.

This currently has some limitations:

  • It does not support beamed rests

  • It does not respond well to mutations. If being used in interactive or animated situations, the group likely will need to be destroyed and recreated after any changes affecting its chordrests.

__init__(chordrests: List[Chordrest], direction: Optional[DirectionY] = None, font: Optional[MusicFont] = None, brush: Optional[Union[Brush, str]] = None, pen: Optional[Union[Pen, str]] = None)[source]
Parameters

  • chordrests – The notes or rests to beam across. This must have at least 2 items, all of which must be of durations requiring flags.

  • direction – Override for the beam direction. Otherwise, the beam direction is automatically chosen based on the given chordrests.

  • brush – The brush to fill shapes with.

  • pen – The pen to draw outlines with. To ensure perfect overlaps with stems, this should have the same thickness of stems, derived from the MusicFont engraving default "stemThickness.

property direction: DirectionY
property chordrests: List[Chordrest]
property beams: List[Beam]
property music_font: MusicFont

The music font used by this object.

remove()[source]

Remove this object from the document tree.