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oscilikt

A linearly interpolated oscillator that allows changing the table number at k-rate.

oscilikt is very similar to oscili, but allows changing the table number at k-rate. It is slightly slower than oscili (especially with high control rate), although also more accurate as it uses a 31-bit phase accumulator, as opposed to the 24-bit one used by oscili.

Syntax

ares oscilikt xamp, xcps, kfn [, iphs] [, istor]
kres oscilikt kamp, kcps, kfn [, iphs] [, istor]

Initialization

iphs (optional, defaults to 0) -- initial phase in the range 0 to 1. Other values are wrapped to the allowed range.

istor (optional, defaults to 0) -- skip initialization.

Performance

kamp, xamp -- amplitude.

kcps, xcps -- frequency in Hz. Zero and negative values are allowed. However, the absolute value must be less than sr (and recommended to be less than sr/2).

kfn -- function table number. Can be varied at control rate (useful to morph waveforms, or select from a set of band-limited tables generated by GEN30).

Examples

Here is an example of the oscilikt opcode. It uses the file oscilikt.csd.

Example of the oscilikt opcode.
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<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
; Audio out   Audio in    No messages
-odac           -iadc     -d     ;;;RT audio I/O
; For Non-realtime ouput leave only the line below:
; -o oscilikt.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

; Initialize the global variables.
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1

; Instrument #1.
instr 1
  ; Generate a uni-polar (0-1) square wave.
  kamp1 init 1 
  kcps1 init 2
  itype = 3
  ksquare lfo kamp1, kcps1, itype

  ; Use the square wave to switch between Tables #1 and #2.
  kamp2 init 20000
  kcps2 init 220
  kfn = ksquare + 1

  a1 oscilikt kamp2, kcps2, kfn
  out a1
endin


</CsInstruments>
<CsScore>

; Table #1, a sine waveform.
f 1 0 4096 10 0 1
; Table #2: a sawtooth wave
f 2 0 3 -2 1 0 -1

; Play Instrument #1 for two seconds.
i 1 0 2


</CsScore>
</CsoundSynthesizer>

See also

Basic Oscillators

Credits

Author: Istvan Varga

Example written by Kevin Conder.

New in version 4.22