cngoto — Transfers control on every pass when a condition is not true.
cngoto condition, label
where label is in the same instrument block and is not an expression, and where condition uses one of the Relational operators (<, =, <=, ==, !=) (and = for convenience, see also under Conditional Values).
Here is an example of the cngoto opcode. It uses the file cngoto.csd.
Example 151. Example of the cngoto opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<CsoundSynthesizer> <CsOptions> ; Audio out Audio in -odac -iadc ;;;RT audio I/O ; -o cngoto.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; Initialize the global variables. sr = 44100 ksmps = 10 nchnls = 1 ; Instrument #1. instr 1 ; Change kval linearly from 0 to 2 over ; the period set by the third p-field. kval line 0, p3, 2 ; If kval *is not* greater than or equal to 1 then play ; the high note. Otherwise, play the low note. cngoto (kval >= 1), highnote kgoto lownote highnote: kfreq = 880 goto playit lownote: kfreq = 440 goto playit playit: ; Print the values of kval and kfreq. printks "kval = %f, kfreq = %f\\n", 1, kval, kfreq a1 oscil 10000, kfreq, 1 out a1 endin </CsInstruments> <CsScore> ; Table: a simple sine wave. f 1 0 32768 10 1 ; Play Instrument #1 for two seconds. i 1 0 2 e </CsScore> </CsoundSynthesizer>
Its output should include lines like:
kval = 0.000000, kfreq = 880.000000 kval = 0.999732, kfreq = 880.000000 kval = 1.999639, kfreq = 440.000000