/*
  In this example, a circle with random color is drawn whenever
 the mouse is pressed, with the size of the circle depending
 on the length of time that the mouse is pressed.
 */

int r, x, y;
boolean growing = false;

// This function is executed only once, at the very beginning
void setup() {
  size(500, 400);
  background(255);
  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() {
  if (mousePressed) {
    if (!growing) {
      // time to start anew
      growing = true;
      x = mouseX;
      y = mouseY;
      r = 0;
      fill(random(255), random(255), random(255));
    }
    r++;
    ellipse(x, y, r, r);
  } else {
    growing = false;
  }
}