05-breakpoints-functions.py - Multi-segments envelopes. — Pyo 1.0.4 documentation

Pyo 1.0.4 documentation

# 05-breakpoints-functions.py - Multi-segments envelopes.

Linseg and Expseg objects draw a series of line segments between specified break-points, either linear or exponential.

These objects wait for play() call to start reading the envelope.

They have methods to set loop mode, call pause/play without reset, and replace the breakpoints.

One can use the graph() method to open a graphical display of the current envelope, edit it, and copy the points (in the list format) to the clipboard (Menu “File” of the graph display => “Copy all Points …”). This makes it easier to explore and paste the result into the python script when happy with the envelope!

    from pyo import *
    import random

    s = Server().boot()

    # Randomly built 10-points amplitude envelope.
    t = 0
    points = [(0.0, 0.0), (2.0, 0.0)]
    for i in range(8):
        t += random.uniform(0.1, 0.2)
        v = random.uniform(0.1, 0.9)
        points.insert(-1, (t, v))

    amp = Expseg(points, exp=3, mul=0.3)
    amp.graph(title="Amplitude envelope")

    sig = RCOsc(freq=[150, 151], sharp=0.85, mul=amp)

    # A simple linear function to vary the amount of frequency shifting.
    sft = Linseg([(0.0, 0.0), (0.5, 20.0), (2, 0.0)])
    sft.graph(yrange=(0.0, 20.0), title="Frequency shift")

    fsg = FreqShift(sig, shift=sft).out()

    rev = WGVerb(sig + fsg, feedback=0.9, cutoff=3500, bal=0.3).out()

    def playnote():
        "Start the envelopes to play an event."
        amp.play()
        sft.play()

    # Periodically call a function.
    pat = Pattern(playnote, 2).play()

    s.gui(locals())