time module reference

time module reference

Time-variant operators.

index

• *clock* (clock):  – Default clock source (60fps).
• bang-seq (opdef):  – Generate rhythms based on a sequence of delays
• clock (opdef):  – Create a clock source.
• delay! (opdef):  – Delay a !-stream event
• every (opdef):  – Emit events regularly.
• lfo (opdef):  – Low-frequency oscillator.
• ramp (opdef):  – Sawtooth LFO.
• scale-time (opdef):  – Scale clock time.
• smooth (opdef):  – Smooth out value transitions
• spring (opdef):  – Integrate impulses using easing
• tick (opdef):  – Count ticks.
• val-seq (opdef):  – Emit a sequence of values as events over time.

details

• *clock* (clock):  – Default clock source (60fps).
• bang-seq (opdef):  – Generate rhythms based on a sequence of delays

  (bang-seq [clock] delay0 delay1…)

  Emits bang!s with delays delay0, delay1, … in between.

  • clock should be a time/clock! stream. This argument can be omitted and the stream be passed as a dynamic definition in *clock* instead.
  • delay0, delay1, … must be num~ streams.
• clock (opdef):  – Create a clock source.

  (clock) (clock fps)

  Creates a new time/clock! stream.

  The clock event stream is an IO that triggers other operators at a fixed frame rate.

  • fps has to be a num= constant and defaults to 60 if omitted.
• delay! (opdef):  – Delay a !-stream event

  (delay! [clock] delay evt)

  Delays incoming evts by delay.

  • clock should be a time/clock! stream. This argument can be omitted and the stream be passed as a dynamic definition in *clock* instead.
  • delay should be a num= or num~ stream.
  • evt is a !-stream.
• every (opdef):  – Emit events regularly.

  (every [clock] period [evt])

  Emits evt as an event once every period seconds.

  • clock should be a time/clock! stream. This argument can be omitted and the stream be passed as a dynamic definition in *clock* instead.
  • period should be a num~ stream.
  • evt can be a value of any type. It defaults to bang.
  • the return type will be an event stream with the same type as evt.
• lfo (opdef):  – Low-frequency oscillator.

  (lfo [clock] freq [wave])

  Oscillates betwen 0 and 1 at the frequency freq.

  • clock should be a time/clock! stream. This argument can be omitted and the stream be passed as a dynamic definition in *clock* instead.
  • freq should be a num~ stream.
  • wave selects the wave shape from one of the following:
    • 'sin' (the default)
    • 'saw'
    • 'tri'
• ramp (opdef):  – Sawtooth LFO.

  (ramp [clock] period [max])

  Ramps from 0 to max once every period seconds.

  • clock should be a time/clock! stream. This argument can be omitted and the stream be passed as a dynamic definition in *clock* instead.
  • period should be a num~ stream.
  • max should be a num~ stream and defaults to period if omitted.
• scale-time (opdef):  – Scale clock time.

  (scale-time [clock] scale)

  Creates a new clock event stream scaled by scale.

  • clock should be a time/clock! stream. This argument can be omitted and the stream be passed as a dynamic definition in *clock* instead.
  • scale should be a num~ stream.
• smooth (opdef):  – Smooth out value transitions

  (smooth [clock] value rate)

  Creates smooth transitions when value changes.

  • clock should be a time/clock! stream. This argument can be omitted and the stream be passed as a dynamic definition in *clock* instead.
  • value should be a num~ or num! stream.
  • rate is a num~ or num= value.
• spring (opdef):  – Integrate impulses using easing

  (spring [clock] evt0 [evt1…])

  Every arriving evt triggers an impulse that is integrated as clock ticks. Returns a num~ stream that starts at 0.

  • clock should be a time/clock! stream. This argument can be omitted and the stream be passed as a dynamic definition in *clock* instead.
  • evt! are !-streams of structs. The following struct keys can be specified:
    • amp: amplitude of the impulse
    • dur: duration of the impulse (seconds)
    • del: start delay (seconds)
    • ease: easing function to use

  Instead of dur, in and out can be specified to create both an impulse and counterimpulse, which has an amplitude of -amp and is delayed so as to start immediately after the original impulse. Similarily, easein and easeout can be specified instead of the single ease value.

• tick (opdef):  – Count ticks.

  (tick [clock] period)

  Counts upwards by one every period seconds.

  • clock should be a time/clock! stream. This argument can be omitted and the stream be passed as a dynamic definition in *clock* instead.
  • period should be a num~ stream.
  • returns a num~ stream that increases by 1 every period.
• val-seq (opdef):  – Emit a sequence of values as events over time.

  (val-seq [clock] delay0 evt1 delay1 evt2 delay2…)

  Emits evt1, evt2, … as events with delays delay0, delay1, … in between.

  • clock should be a time/clock! stream. This argument can be omitted and the stream be passed as a dynamic definition in *clock* instead.
  • delay0, delay1, … must be num~ streams.
  • evt1, evt2, … must be signal streams of the same type.
  • the return type will be an event stream with the same type as the evts.