/**
* a spinning rectangle by <a href="http://www.local-guru.net/blog">Guru</a>
*/

void setup() {
  size(300,300);
  smooth();
  frameRate(25);
}
float a = 0;
void draw() {
  fill(255, 20);
  noStroke();
  rect(0,0,width, height );
  stroke( 0 );
  noFill();
  a += 0.05;
  pushMatrix();
  translate( width/2, height/2 );
  rotate( a );
  float w = abs(200 * sin(a)) + 5;
  rect( -w/2,-w/2,w,w );
  popMatrix();
}