rsc3/doc-schelp/HelpSource/Classes/Pseg.scrbl

99 lines
2.1 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{Pseg}
timed embedding of values@section{related}
Classes/Ptime, Classes/Pstep, Classes/Env
@section{categories}
Streams-Patterns-Events>Patterns>Time
@section{description}
Pseg defines a function of time as a breakpoint envelope using the same parameters as link::Classes/Env::. These patterns can be used to describe tempo or dynamic variations independent of the rhythmic patterns that express them.
@section{ClassMethods}
@section{method}
new
@section{argument}
levels
A link::Classes/Pattern:: that returns the levels. The first level is the initial value of the envelope, all subsequent values are interpolated.
@section{argument}
durs
A link::Classes/Pattern:: that returns segments durations in beats.
@section{argument}
curves
a link::Classes/Symbol::, link::Classes/Float::, or an link::Classes/Array:: of those. Determines the shape of the segments.
@section{argument}
repeats
a number.
The possible values are:
@section{table}
##
@racketblock[\step:: || || flat segments.
## ]
@racketblock[\linear:: || ]
@racketblock[\lin:: || linear segments, the default.
## ]
@racketblock[\exponential:: || ]
@racketblock[\exp:: || natural exponential growth and decay. In this case, the levels must all be nonzero and the have the same sign.
## ]
@racketblock[\sine:: || ]
@racketblock[\sin:: || sinusoidal S shaped segments.
## ]
@racketblock[\welch:: || ]
@racketblock[\wel:: || sinusoidal segments shaped like the sides of a Welch window.
## ]
@racketblock[\squared:: || ]
@racketblock[\sqr:: || squared segment.
## ]
@racketblock[\cubed:: || ]
@racketblock[\cub:: || cubed segment.
## a link::Classes/Float:: || || a curvature value for all segments. 0 means linear, positive and negative numbers curve the segment up and down.
## an link::Classes/Array:: of symbols or floats || || curvature values for each segment.
::
]
@section{Examples}
@racketblock[
// change a parameter
(
Pbind(
\note, Pseg( Pseq([1, 5],inf), Pseq([4, 1],inf), \linear),
\dur, 0.1
).play;
)
(
Pbind(
\freq, Pseg( Pseq([400, 1500], inf), Pseq([4, 4],inf), Pseq([\linear, \exp],inf)),
\dur, 0.1
).play;
)
::
]