Mover[] movers = new Mover[20];

void setup() {
	size(200,200);
	smooth();
	background(255);
	for (int i = 0; i < movers.length; i++) {
		movers[i] = new Mover(); 
	}
}

void draw() {
	noStroke();
	fill(255,10);
	rect(0,0,width,height);
	for (int i = 0; i < movers.length; i++) {
		movers[i].update();
		movers[i].checkEdges();
		movers[i].display(); 
	}
}

class Mover {
	PVector location;
	PVector velocity;
	PVector acceleration;
	float topspeed;

	Mover() {
		location = new PVector(random(width),random(height));
		velocity = new PVector(0,0);
		topspeed = 4;
	}

	void update() {
		PVector mouse = new PVector(mouseX,mouseY);
		PVector dir = PVector.sub(mouse,location);
		dir.normalize();     // Normalize
		dir.mult(0.5);       // Scale 
		acceleration = dir;  // Set to acceleration
		velocity.add(acceleration);
		velocity.limit(topspeed);
		location.add(velocity);
	}

	void display() {
		stroke(0);
		fill(175);
		ellipse(location.x,location.y,16,16);
	}

	void checkEdges() {
		if (location.x > width) {
 			location.x = 0;
		} else if (location.x < 0) {
			location.x = width;
		}
		if (location.y > height) {
			location.y = 0;
		}  else if (location.y < 0) {
			location.y = height;
		}
	}
}