Audiovisuals with SC - Example10b - voices not objects

See /f0blog/audiovisuals-with-sc/

//Example10b - voices not objects
//a little bit different from Example10a.  the one in the main loop where we invert the mapping.
(
s.latency= 0.05;
s.waitForBoot{

  //--window setup
  var width= 640, height= 480;
  var w= Window("Example10b - voices not objects", Rect(99, 99, width, height), false);
  var u= UserView(w, Rect(0, 0, width, height));

  //--variables
  var syns= {
    SynthDef(\av, {|freq= 300, amp= 0, pan= 0|
      var z= LPF.ar(LFSaw.ar(freq), freq+2000, amp);
      Out.ar(0, Pan2.ar(z, pan));
    }).play(s);
  }.dup(50);  //max 50 voices
  s.sync;

  //--interface
  ~num= 48;
  ~spreadx= 100;
  ~spready= 150;

  //--main loop
  u.drawFunc= {
    Pen.translate(width*0.5, height*0.5);  //offset drawing to the centre
    Pen.fillColor= Color.white;  //always fill with white color
    50.do{|i|
      var x= (i*~spreadx).fold(width* -0.4, width*0.4);
      var y= (i*~spready).fold(height* -0.4, height*0.4);
      if(i<~num, {
        Pen.fillOval(Rect.aboutPoint(Point(x, y), 10, 10));
        syns[i].set(\amp, 0);
      }, {
        i= i-~num;
        syns[50-i].set(
          \freq, y.linexp(height* -0.4, height* 0.4, 2000, 200),
          \amp, 0.05,
          \pan, x.linlin(width* -0.4, width*0.4, -1, 1)
        );
      }, {

      });
    };
  };

  //--window management
  u.clearOnRefresh= true;
  u.background= Color.black;
  w.onClose= {syns.do{|x| x.free}};
  w.front;
  CmdPeriod.doOnce({w.close});
  Routine({
    var nextTime;
    while({w.isClosed.not}, {
      nextTime= Main.elapsedTime+(1/60);
      u.refresh;
      (nextTime-Main.elapsedTime).max(0.001).wait;
    });
  }).play(AppClock);
};
)

//change these while the program is running
~num= 47;
~num= 46;
~num= 10;
~num= 2;
~spreadx= 150;
~spreadx= 5;
~spready= 180;
~spready= 179;
~num= 40;
~spreadx= 3;
~spready= 3;
~spready= 30;
~num= 4;
~num= 2;
~num= 1;

Routine({101.do{|i| ~num= i.fold(0, 50)+1; 0.1.wait}}).play;

//close the window to stop or press cmd+.