/*
  In this example, the canvas is painted with a single line going from
  the center of the canvas to the (moving) mouse position.
  
  Note well that background() is called during each draw(),
  effectively clearing the canvas each time.
*/

// This function is executed only once, at the very beginning
void setup() {
  size(500,400);
  fill(128, 128, 255);
}


// This function is repeatedly call in an implicit loop.
// A single call is responsible for drawing a single frame.
void draw() {
  background(255);
  ellipse(mouseX, mouseY, 20, 20);
}