examples/research_and_tools/trochoid curve.scd

   1
   2 (
   3 a = 1.0;
   4 b = 1.8;
   5 x = { |phi, a, b| a * phi - (b * sin(phi)) };
   6 y = { |phi, a, b| a - (b * sin(phi + 0.5pi)) };
   7 )
   8
   9 GUI.cocoa;      // use CocoaGUI (Mac OS X native)
  10 GUI.swing;      // use SwingGUI (Java based GUI)
  11
  12 (
  13                 var pen = GUI.pen;
  14                 w = GUI.window.new("Trochoid", Rect(128, 64, 800, 400)).front;
  15                 w.view.background_(Color.white);
  16                 w.drawHook = {
  17                         pen.strokeColor = Color.black;
  18                         pen.moveTo(0 @ 150);
  19                         ((0..900) / 50).do { |phi|
  20                                 var x0 = x.(phi, a, b);
  21                                 var y0 = y.(phi, a, b);
  22                                 pen.lineTo((50 * x0) @ (50 * y0 + 150));
  23                         };
  24
  25                         pen.stroke
  26                 };
  27                 w.refresh;
  28 );
  29
  30
  31 (
  32 Tdef(\x, {
  33         loop {
  34                 ((0..100) / 25).do { |m|
  35                         b = m;
  36                         defer {w.refresh};
  37                         0.1.wait
  38                 }
  39         }
  40 }).play
  41 )
  42
  43
  44 // sonification of a trochoid
  45
  46
  47 p = ProxySpace.push(s.boot); // enter
  48 ~out.play;
  49
  50 (
  51 ~out = {
  52         SinOsc.ar(500).dup * ~modulation.kr(2) * 0.04
  53
  54 };
  55 )
  56
  57 (
  58 ~phi = {
  59         LFSaw.kr(3).range(0, 2pi)
  60 };
  61
  62 ~modulation = {
  63         var x, y;
  64         var a, b;
  65         a = 1.0;
  66         b = XLine.kr(0.1, 2, 30);
  67         x = { |phi, a, b| a * phi - (b * sin(phi)) }.value(~phi.kr, a, b);
  68         y = { |phi, a, b| a - (b * sin(phi + 0.5pi)) }.value(~phi.kr, a, b);
  69         [x, y]
  70 }
  71 )
  72
  73 p.clear.pop; // exit
  74
  75