ksig -- input signal
kthreshold -- trigger threshold
kmode -- can be 0 , 1 or 2
Normally trigger outputs zeroes: only each time ksig crosses kthreshold trigger outputs a 1. There are three modes of using ktrig:
kmode = 0 - (down-up) ktrig outputs a 1 when current value of ksig is higher than kthreshold, while old value of ksig was equal to or lower than kthreshold.
kmode = 1 - (up-down) ktrig outputs a 1 when current value of ksig is lower than kthreshold while old value of ksig was equal or higher than kthreshold.
kmode = 2 - (both) ktrig outputs a 1 in both the two previous cases.
Here is an example of the trigger opcode. It uses the files trigger.orc and trigger.sco.
Example 387. Example of the trigger opcode.
/* trigger.orc */ ; Initialize the global variables. sr = 44100 kr = 4410 ksmps = 10 nchnls = 1 ; Instrument #1. instr 1 ; Use a square-wave low frequency oscillator as the trigger. klf lfo 1, 10, 3 ktr trigger klf, 1, 2 ; When the value of the trigger isn't equal to 0, print it out. if (ktr == 0) kgoto contin ; Print the value of the trigger and the time it occurred. ktm times printks "time = %f seconds, trigger = %f\\n", 0, ktm, ktr contin: ; Continue with processing. endin /* trigger.orc */
/* trigger.sco */ ; Play Instrument #1 for one second. i 1 0 1 e /* trigger.sco */
Its output should include lines like this:
time = 0.050340 seconds, trigger = 1.000000 time = 0.150340 seconds, trigger = 1.000000 time = 0.250340 seconds, trigger = 1.000000 time = 0.350340 seconds, trigger = 1.000000 time = 0.450340 seconds, trigger = 1.000000 time = 0.550340 seconds, trigger = 1.000000 time = 0.650340 seconds, trigger = 1.000000 time = 0.750340 seconds, trigger = 1.000000 time = 0.850340 seconds, trigger = 1.000000 time = 0.950340 seconds, trigger = 1.000000