an open-source digital signal processing and sound synthesis language
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evp/evset

envelope/control function initialization and generator

    [note: This is an older envelope unit-generators. It has been generally superceded by using the Ooscili or Ooscil objects to read a function table slot for a control function/envelope for exactly one cyle through the note.

Synopsis

    #include <ugens.h>

    float evp(nsample,f1,f2,envals)
    long nsample;
    float *f1,*f2,*envals;

    evset(dur,rise,dec,nfrise,envals)
    float dur,rise,dec,*envals;
    int nfrise;

Description

evp() is an envelope generator which can be called at arbitrary times since it looks up its position according to the ratio between nsample and the total number of expected samples. Thus it can be called at arbitrary times, as in a control loop, without any extra footwork. nsample is the number of the current sample, with the first sample counting from 0. This is typically returned by the currentFrame function. f1 and f2 are the pointers to the function arrays used for rise and decay, respectively. These are set by floc. envals is a 5-location array of floats for bookkeeping purposes. evset() is the initialization routine and asks for theduration, rise, and decay time in seconds. If rise or decay are negative numbers they are interpreted as a fraction of the duration. nfrise is the number of the rise function. The size of the rise and decay functions must be the same. The decay function is sampled backwards.

See Also

floc, fsize.