music-score-1.9.0: Musical score and part representation.

Copyright(c) Hans Hoglund 2012-2014
LicenseBSD-style
Maintainerhans@hanshoglund.se
Stabilityexperimental
Portabilitynon-portable (TF,GNTD)
Safe HaskellNone
LanguageHaskell2010

Music.Time.Position

Contents

Description

This misleadingly named module provide a way to query a value for its duration, onset and offset.

Synopsis

Documentation

module Music.Time.Duration

The HasPosition class

class HasDuration a => HasPosition a where Source

Class of values that have a position in time.

Many values such as notes, envelopes etc can in fact have many positions such as onset, attack point, offset, decay point time etc. Rather than having separate methods for a discrete set of cases, this class provides an interpolation from a local position to a global position. While the local position goes from zero to one, the global position goes from the onset to the offset of the value.

Instances should satisfy:

x ^. duration   = x ^. era . duration
x ^. position n = x ^. era . position n
(transform s x) ^. era = transform s (x ^. era)

Minimal complete definition

_position | _era

Methods

_position :: a -> Duration -> Time Source

Map a local time in value to global time.

_era :: HasPosition a => a -> Span Source

Return the conventional bounds of a value (local time zero and one).

Instances

Position and Era

position :: (HasPosition a, Transformable a) => Duration -> Lens' a Time Source

Position of the given value.

era :: (HasPosition a, Transformable a) => Lens' a Span Source

A lens to the position

Specific positions

onset :: (HasPosition a, Transformable a) => Lens' a Time Source

Onset of the given value.

midpoint :: (HasPosition a, Transformable a) => Lens' a Time Source

Midpoint of the given value, or the value between the decay and sustain phases.

offset :: (HasPosition a, Transformable a) => Lens' a Time Source

Onset of the given value.

preOnset :: (HasPosition a, Transformable a) => Lens' a Time Source

Pre-onset of the given value, or the value right before the attack phase.

postOffset :: (HasPosition a, Transformable a) => Lens' a Time Source

Post-offset of the given value, or the value right after the release phase.

postOnset :: (HasPosition a, Transformable a) => Lens' a Time Source

Deprecated: Use midpoint

Moving

startAt :: (Transformable a, HasPosition a) => Time -> a -> a Source

Move a value forward in time.

stopAt :: (Transformable a, HasPosition a) => Time -> a -> a Source

Move a value forward in time.

placeAt :: (Transformable a, HasPosition a) => Duration -> Time -> a -> a Source

Align a value to a given position.

placeAt p t places the given thing so that its position p is at time t

placeAt 0 = startAt
placeAt 1 = stopAt

Transforming relative a position

stretchRelative :: (HasPosition a, Transformable a) => Duration -> Duration -> a -> a Source

stretchRelativeOnset :: (HasPosition a, Transformable a) => Duration -> a -> a Source

stretchRelativeMidpoint :: (HasPosition a, Transformable a) => Duration -> a -> a Source

stretchRelativeOffset :: (HasPosition a, Transformable a) => Duration -> a -> a Source

delayRelative :: (HasPosition a, Transformable a) => Duration -> Duration -> a -> a Source

delayRelativeOnset :: (HasPosition a, Transformable a) => Duration -> a -> a Source

delayRelativeMidpoint :: (HasPosition a, Transformable a) => Duration -> a -> a Source

delayRelativeOffset :: (HasPosition a, Transformable a) => Duration -> a -> a Source

transformRelative :: (HasPosition a, Transformable a) => Duration -> Span -> a -> a Source

transformRelativeOnset :: (HasPosition a, Transformable a) => Span -> a -> a Source

transformRelativeMidpoint :: (HasPosition a, Transformable a) => Span -> a -> a Source

transformRelativeOffset :: (HasPosition a, Transformable a) => Span -> a -> a Source