Toot 12: Tables & Labels
This is by far our most complex instrument. In it we have designed the ability to store pitches in a table and then index them in three different ways: 1) directly, 2) via an lfo, and 3) randomly. As a means of switching between these three methods, we will use Csound's program control statements and logical and conditional operations.
instr 12
iseed = p8
iamp = ampdb(p4)
kdirect = p5
imeth = p6
ilforate = p7 ; lfo and random index rate
itab = 2
itablesize = 8
if (imeth == 1) igoto direct
if (imeth == 2) kgoto lfo
if (imeth == 3) kgoto random
direct: kpitch table kdirect, itab ; index "f2" via p5
kgoto contin
lfo: kindex phasor ilforate
kpitch table kindex * itablesize, itab
kgoto contin
random: kindex randh int(7), ilforate, iseed
kpitch table abs(kindex), itab
contin: kamp linseg 0, p3 * .1, iamp, p3 * .9, 0 ; amp envelope
asig oscil kamp, cpspch(kpitch), 1 ; audio osc
out asig
endin
f1 0 2048 10 1 ; Sine
f2 0 8 -2 8.00 8.02 8.04 8.05 8.07 8.09 8.11 9.00 ; cpspch C major scale
; method 1 - direct index of table values
; ins start dur amp index method lforate rndseed
i12 0 .5 86 7 1 0 0
i12 .5 .5 86 6 1 0
i12 1 .5 86 5 1 0
i12 1.5 .5 86 4 1 0
i12 2 .5 86 3 1 0
i12 2.5 .5 86 2 1 0
i12 3 .5 86 1 1 0
i12 3.5 .5 86 0 1 0
i12 4 .5 86 0 1 0
i12 4.5 .5 86 2 1 0
i12 5 .5 86 4 1 0
i12 5.5 2.5 86 7 1 0
s
; method 2 - lfo index of table values
; ins start dur amp index method lforate rndseed
i12 0 2 86 0 2 1 0
i12 3 2 86 0 2 2
i12 6 2 86 0 2 4
i12 9 2 86 0 2 8
i12 12 2 86 0 2 16
s
; method 3 - random index of table values
; ins start dur amp index method rndrate rndseed
i12 0 2 86 0 3 2 .1
i12 3 2 86 0 3 3 .2
i12 6 2 86 0 3 4 .3
i12 9 2 86 0 3 7 .4
i12 12 2 86 0 3 11 .5
i12 15 2 86 0 3 18 .6
i12 18 2 86 0 3 29 .7
i12 21 2 86 0 3 47 .8
i12 24 2 86 0 3 76 .9
i12 27 2 86 0 3 123 .9
i12 30 5 86 0 3 199 .1
Prepared from the
MIT Media Lab Csound Manual,
PJN, Nov 1994.