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call instrno, iactime, idur[, ip4, ip5,..., ipn]
calld instrno, iactime, idur[, ip4 , ip5 ,..., ipn]
callm instrno, iactime[, ip3, ip4,ip5,..., ipn]
callmd instrno, iactime, idur[, ip4, ip5,..., ipn]
Activate an instrument from within another instrument at performance time(subroutine call)
instrno - instrument number to be activated
iactime - action time in seconds (should be zero when using call)
idur - duration of the note to be activated
ip3, ip4, ip5, ..., ipn - p-fields of the instrument to be activated
An instrument containing call (instrument call), calld (delayed instrument call), callm (MIDI-oriented instrument call) orcallmd (delayed MIDI-oriented instrument call) opcodes, can activate an instance of another instrument of the same orchestra during the performance.
These opcodes can be thought of as subroutine calls. Any number of additional init-rate arguments (ip4,ip5,ip6 etc.) can be sent to the target instruments, in the same way as p-fields in a score note event.
More instances of call, calld, callm and callmdcan coexist in the same calling instrument, so chords of more notes (played by different target instruments) can be activated by a single MIDI note-on event, as well as by a single i-statement in the score. This possibility allows the user to do several things, for example, to easily implement multi-layered instruments, or to inherit the features of one instrument by a more specialized instrument (by using these opcodes together with the parmXX and rtrnXX opcode family, see below).
Multiple inheritance of several instruments can be also implemented by using these opcodes in Csound.
call plays the target note immediately (so iactime argument must be set to zero), and its duration is idur seconds, even if the calling instrument is turned off beforehand or afterward. This opcode has no output and operates at i-rate only.
calld can schedule the target note activation 'iactime' seconds after the caller instrument init-time. Again, the target note duration is 'idur' seconds, even if the caller instrument is turned off beforehand or afterward. This opcode has no output and operates at k-rate.
callm plays the target note immediately (so iactime argument must be set to zero), but its duration is indeterminate and depends by a midi midi note-off message recognized by the caller instrument. This opcode is useful when the caller instrument is activated by MIDI. In fact in this case it is impossible to know the caller duration beforehand. Notice that it is still possible to use call and calld with a MIDI-activated caller instrument instead of callm. In that case the target notes will be simply turned off after idur seconds, whether the caller instr is turned off before or after idur seconds are elapsed or it isn't. callm has no output and operates at k-rate.
callmd can schedule the target note activation iactime seconds after the caller instrument init-time. The duration of the target note is indeterminate (so idur parameter is meaningless) and depends by a midi note-off message recognized by the caller instrument. The target note is not allocated until iactime seconds are elapsed. callmd has no output and operates at k-rate.
Notice that each of these opcodes makes the processing point not to return to the caller until all the target instrument initializations have been completed.
;EXAMPLE 1: call and calld =====================
gifn ftgen 1,0,1024,10,1,0,0,0,0,0,0,.5,0,0,0,0,0.2
instr 1 ;caller instrument
ifreq cpsmidi
call 2,0,2, 2000,ifreq
calld 2,1,4, 2000,ifreq*1.2
calld 2,3,6, 2000,ifreq*1.77
calld 2,5,8, 2000,ifreq*2.1
calld 2,8,10,2000,ifreq*2.4555
endin
instr 2 ;target instrument
k1 linseg 0,p3/2,1,p3/2,0
a1 oscili p4,p5,gifn
out a1*k1
endin
;EXAMPLE 2: callm and callmd ==================
gifn ftgen 1,0,1024,10,1,0,0,0,0,0,0,.5,0,0,0,0,0.2
instr 1 ;caller instrument
iamp ampmidi 2000
ifreq cpsmidi
callm 2,0,2 ,iamp,
ifreq callmd 2,1,4 ,iamp * .5, ifreq * 1.2
callmd 2,3,6 ,iamp * .25,ifreq * 1.77
callmd 2,6,8 ,iamp * .2, ifreq * 2.1
callmd 2,8,10,iamp * .1, ifreq * 2.4555
endin
instr 2 ;target instrument
k1 linenr 1,p3/2,p3/2,.03
a1 oscili p4,p5,gifn
out a1*k1
endin
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