float theta, dtheta;
float x,y,xo,yo,dx,dy;
float r; // radius in ticks or pixels
float v; // velocity in mm/tick
float d;

int framecnt=0;

void setup() {
  size(400,400);
  framerate(60);
  smooth();
  background(100);
  strokeWeight(3);
  stroke(0);

  x = width/2;
  y = height/2;

  theta = 0;
  dtheta = 0.1;

  r = 25;
  d = 6;
}

void draw() {
  framecnt++;
  xo = x;  yo = y;
    
  theta += dtheta;

  //float a = (framecnt/100) * TWO_PI;
  dtheta = 0.1 * sin( framecnt/21.0 ) + random(-0.02,0.02);

  dx = d * sin(theta);
  dy = d * cos(theta);
  
  x = x + dx;
  y = y - dy;
  
   // torroidial mapping, sir
  if( x > width  ) x = 0;
  if( x < 0 ) x = width;
  if( y > height ) y = 0;
  if( y < 0 ) y = height;

  drawIcon( x,y,theta );
}

void keyPressed() {
  if( key == ']' ) {
    dtheta += 0.01;
  }
  else if( key == '[' ) {
    dtheta -= 0.01;
  }
  else if( key == ' ' ) {
    if( framerate < 10 ) 
      framerate(30);
    else
      framerate(5);
  } 
}

void drawIcon( float x, float y, float theta ) {
//  println("x="+(int)x+" y="+(int)y+"  theta="+theta);
  translate(x,y);
  rotate(theta);
  fill( (x+y)%127 + 40, 0, 100-((y+x)%127) );
  ellipse( 0,0, 20,20);
  line( 0,0, 0,-12);
}


void blech() {
  dx = r * sin(theta);
  dy = r * cos(theta);

  x = x + dx;
  y = y - dy;
  theta -= dtheta;  
  //theta %= TWO_PI;

  println("x,y="+x+","+y+"  dx,dy:"+dx+","+dy+"   r:"+r+"  framcnt:"+framecnt);

  //float th = (framecnt/30.0) * (2*PI);
  r = R * abs((sin(theta) - 0.2 * sin(theta)));
}