cuadro que se mueve

float r = 0;
float backR;
float backG;
float backB;

void setup(){
  size(400,400);
  backR = random(0,100);
  backG = random(0,100);
  backB = random(0,100);
 
  background(random(0,255),random(255),random(255));
  rectMode(CENTER);
 
  noStroke();
  smooth();
 
}

void draw() {
  fill(backR,backG,backB,50);
  rect(width/2,height/2, width,height);
  fill(255);
  translate(mouseX,mouseY);
  rotate(r);
  rect(0,0,100,100);
 r = r + 0.05;
}