oscilikt

Name

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

Description

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

ar oscilikt xamp, xcps, kfn [, iphs] [, istor]
kr 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 files oscilikt.orc and oscilikt.sco.

Example 15-1. Example of the oscilikt opcode.

/* oscilikt.orc */
; 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
/* oscilikt.orc */
        
/* oscilikt.sco */
; 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
/* oscilikt.sco */
        

See Also

osciliktp and oscilikts.

Credits

Author: Istvan Varga

Example written by Kevin Conder.

New in version 4.22