Processing : mask pgraphic

mask1.pde

PGraphics s, m;
void setup(){
  size(220,220);

  // Create a cookie cutter.
  // White areas are kept. Black areas are not.
  m = createGraphics( width, height, P2D );
  m.beginDraw();
  m.background(0);
  m.fill(255);
  m.stroke(255);
  m.ellipse(100, 100, 60, 60);
  m.endDraw();
  
  // Create a pattern.
  s = createGraphics( width, height, P2D );
  s.beginDraw();
  s.smooth();
  s.translate(s.width/2, s.height/2);
  s.rotate( radians(35) );
  s.background(0,0,255);
  s.noStroke();
  s.fill( 0,255,0);
  for( int i = -300; i < 300; i+=10 ){
    s.rect( i, -300, 5, 600);
  }
  // This line uses the cookie cutter.
  s.mask( m.get() );
  s.endDraw();  
}

void draw(){
  background(128,0,0);
  image( s.get(), 0, 0);
}