function setup() {
 createCanvas( 780, 780);
 fill( 0 );
 noStroke();

 pg = createGraphics(780, 780);
 
 drawSquares();
}

function draw() {
}

function drawSquares() {
 background(240 );
 
 pg.background( 240 );
 for( var r = 2; r < 22; r++ ) {
 for( var c = 0; c < 32; c++ ) {
 var rand = int(round(random(0,1)));
 pg.noStroke();
 if( rand == 1 ) {
 pg.fill( 10 );
 } else {
 pg.noFill();
 }
 pg.rect( r*32, c*32, 32, 32 );
 }
 }

 rotate(-0.01);
 translate( -8, 0, 0 );
 image(pg, 0, 0);
}

function mousePressed() {
 drawSquares();
}