aho_08_mouse.pde

float x1,y1,x2,y2,radius;

void setup() {
  size(300,300);
  ellipseMode(CENTER_DIAMETER);  
}

void loop() {
//  background(100);
  x1=mouseX;
  y1=mouseY;
  x2=width-mouseX;
  y2=height-mouseY;
  
  if(mousePressed) {
    radius=50;
    fill(255,0,0);
  }  
  else {
    radius=10;
    fill(255,180,0);
  }
  
  ellipse(x1,y1, radius,radius);
  ellipse(x2,y1, radius,radius);
  ellipse(x2,y2, radius,radius);
  ellipse(x1,y2, radius,radius);

   
}