class Centipede:
    def __init__(self):
        self.location = PVector(random(width), random(height))
        self.velocity = PVector(0, 0)
        self.acceleration = PVector(0, 0)
        self.top_speed = 3

         #mouse is a private variable (set using trailing double underscores)
        follow = PVector(0, 0)
        self.dir = PVector(0, 0)

    def update(self):
        follow = PVector(0,0)
        self.dir = PVector.sub(follow, self.location)

        self.dir.normalize()
        self.dir.mult(0.5)

        self.acceleration = self.dir
        self.acceleration.mult(0.15)
        self.acceleration.mult(random(2))

        self.velocity.add(self.acceleration)
        self.velocity.limit(self.top_speed)
        self.location.add(self.velocity)

    def display(self):
        stroke(0)
        fill(255)
        ellipse(self.location.x, self.location.y, 16, 16)

class Mover:
    def __init__(self):
        self.location = PVector(random(width), random(height))
        self.velocity = PVector(0, 0)
        self.acceleration = PVector(0, 0)
        self.top_speed = 3

         #mouse is a private variable (set using trailing double underscores)
        __mouse = PVector(0, 0)
        self.dir = PVector(0, 0)

    def update(self):

        __mouse = PVector(mouseX, mouseY)
        self.dir = PVector.sub(__mouse, self.location)

        self.dir.normalize()
        self.dir.mult(0.5)

        self.acceleration = self.dir
        self.acceleration.mult(0.15)
        self.acceleration.mult(random(2))

        self.velocity.add(self.acceleration)
        self.velocity.limit(self.top_speed)
        self.location.add(self.velocity)


    def display(self):
        stroke(0)
        fill(255)
        ellipse(self.location.x, self.location.y, 16, 16)

    def checkEdges(self):
        if self.location.x > width:
            self.location.x = 0
        elif self.location.x < 0:
            self.location. x = width

        if self.location.y > height:
            self.location.y = 0
        elif self.location.y < 0:
            self.location.y = height

centipedes = [0] * 20

def setup():
    size (640, 360)

    global mover
    mover = Mover()

    global centipedes
    for index in range(20):
        centipedes[index] = Centipede()
        centipedes[index].follow = PVector.sub(mover.location, centipedes[index].location)






def draw():
    background(0)
    mover.update()
    mover.checkEdges()
    mover.display()
    for index in range(20):
        centipedes[index].update()
        centipedes[index].display()