float radius = 35;

float x;
float y;
float direction;

void setup() {
  fullScreen();
  pixelDensity(displayDensity());
  background(255);
  strokeWeight(2);

  x = width/2;
  y = height/2;
  direction = 0;
}

void draw() {
  direction = direction + random(-1.3, 1.3);

  x = x + 10 * cos(direction);
  y = y + 10 * sin(direction);

  if (x > width + radius) {
    x = -radius;
  }
  if (x < -radius) {
    x = width + radius;
  }
  if (y > height + radius) {
    y = -radius;
  }
  if (y < -radius) {
    y = height + radius;
  }

  float diameter = 2 * radius;
  float a = random(6);
  if (a < 1) {
    fill(221, 188, 210); // Pinkie pie
  } else if (a < 2) {
    fill(238, 239, 243); // Rarty
  } else if (a < 3) {
    fill(199, 165, 229); // Twlith sparkle
  } else if (a < 4) {
    fill(236, 189, 103); // Applejack
  } else if (a < 5) {
    fill(253, 248, 176); // Flutter shy
  } else {
    fill(180, 218, 255); // Rainbow dash
  }
         ellipse(x, y, diameter, diameter);
}