itype (optional, default=0) -- determine the waveform of the oscillator. Default is 0.
itype = 0 - sine
itype = 1 - triangles
itype = 2 - square (bipolar)
itype = 3 - square (unipolar)
itype = 4 - saw-tooth
itype = 5 - saw-tooth(down)
The sine wave is implemented as a 4096 table and linear interpolation. The others are calculated.
Here is an example of the lfo opcode. It uses the files lfo.orc and lfo.sco.
Example 15-1. Example of the lfo opcode.
/* lfo.orc */
; Initialize the global variables.
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1
; Instrument #1.
instr 1
kamp = 10
kcps = 5
itype = 4
k1 lfo kamp, kcps, itype
ar oscil p4, p5+k1, 1
out ar
endin
/* lfo.orc */
/* lfo.sco */
; Table #1: an ordinary sine wave.
f 1 0 32768 10 1
; p4 = amplitude of the output signal.
; p5 = frequency (in cycles per second) of the output signal.
; Play Instrument #1 for two seconds.
i 1 0 2 10000 220
e
/* lfo.sco */