HelpSource/Classes/Sweep.schelp

   1 class:: Sweep
   2 summary:: Triggered linear ramp
   3 categories::  UGens>Triggers
   4
   5 Description::
   6
   7 Starts a linear raise by rate/sec from zero when trig input crosses from
   8 non-positive to positive.
   9
  10
  11 classmethods::
  12 private:: categories
  13
  14 method::ar, kr
  15
  16 argument::trig
  17
  18 triggers when trig input crosses from non-positive to positive.
  19
  20
  21 argument::rate
  22
  23 rate/sec raise rate
  24
  25
  26 Examples::
  27
  28 code::
  29 // using sweep to modulate sine frequency
  30 (
  31 { var trig;
  32         trig = Impulse.kr(MouseX.kr(0.5, 20, 1));
  33         SinOsc.ar(Sweep.kr(trig, 700) + 500, 0, 0.2)
  34 }.play;
  35 )
  36
  37
  38 // using sweep to index into a buffer
  39 b = Buffer.read(s, Help.dir +/+ "sounds/a11wlk01.wav");
  40
  41 (
  42 { var trig;
  43         trig = Impulse.kr(MouseX.kr(0.5, 10, 1));
  44         BufRd.ar(1, b, Sweep.ar(trig, BufSampleRate.ir(0)))
  45 }.play;
  46 )
  47
  48 // backwards, variable offset
  49 (
  50 { var trig, pos, rate;
  51         trig = Impulse.kr(MouseX.kr(0.5, 10, 1));
  52         rate = BufSampleRate.ir(0);
  53         pos = Sweep.ar(trig, rate.neg) + (BufFrames.ir(0) * LFNoise0.kr(0.2));
  54         BufRd.ar(1, b, pos)
  55 }.play;
  56 )
  57
  58 // raising rate
  59 (
  60 { var trig, rate;
  61         trig = Impulse.kr(MouseX.kr(0.5, 10, 1));
  62         rate = Sweep.kr(trig, 2) + 0.5;
  63         BufRd.ar(1, b, Sweep.ar(trig, BufSampleRate.ir(0) * rate))
  64 }.play;
  65 )
  66
  67 b.free
  68 ::
  69