NAME

Audio::Hydrogen::Pattern - a single pattern

DESCRIPTION

A Pattern comprises a set of notes each associated with a specific instrument arranged over time. The unit of "time" or position is 48 parts per quarter note (MIDI uses 24 for MIDI clock, some hardware sequencers may do 96 or even higher,) thus a "bar" with the 4/4 time signature has a length of 192 possible positions.

METHODS

attribute name

This is a short name that will be used in the Hydrogen UI and is referenced by the Song's "pattern group". It is required and should be unique when used in a Song.

attribute category

This is a free text category name, it defaults to "not_categorized". Specific categories may be used by the software but there isn't a list.

attribute size

This is a positive Int which is the length of the pattern, this is based on 48 per quarter note (so 1/192 of a note is the minimum resolution.) The default is 192 which would represent a single bar at the 4/4 time signature.

attribute note-list

This is a list of Audio::Hydrogen::Playlist::Note objects which may be ordered by position,

attribute position

The Int position in 48ppqn as described between 0 and size - 1 where 0 is the beginning of the bar. Because the resolution may be finer than that configured in the UI, some notes may not show up aligned to the grid in the UI, you may need to increase the UI resolution to correctly edit these notes.

attribute lead-lag

This is an integer in the 1/48 parts that indicates the delay between the note position and the note actually sounding, it defaults to 0.

attribute velocity

This is a Rat between 0 and 1.0 that specifies the "velocity" of the note, which may affect the volume of the note as played or which layer is selected to be played for an instrument with more than one layer.

The default is 1.0 for newly created objects but Hydrogen itself seems to default to 0.8.

attribute instrument

This is the Int instrument id of the instrument that this note is to be played on. It must refer to a valid instrument in the Song in which the pattern is used to be played, it is possible for a pattern to be saved standalone so it can be left blank.

attribute pan-left

The Rat amount the sound is panned to the left in the output, it defaults to 0.5

attribute pan-right

The Rat amount the sound is panned to the right in the output, it defaults to 0.5

attribute pitch

An Int pitch factor for pitched instruments, it defaults to 0.

attribute note

This is the note that would be played for a pitched instrument it defaults to 'C'.

attribute length

This is the note length in 48ppqn "ticks", it is only used for pitched instruments. Hydrogen defaults this to -1 but it can be left empty.

attribute note-off

This is a Bool to indicate whether the length should be used, it defaults to False.