​

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(c);

  let snake = createVector(100,300);

  let ocelot = createVector(300,100);

  let mouse = createVector(mouseX-300,mouseY-100);

  let dir_ocelot_to_snake = p5.Vector.sub(snake, ocelot);

  dir_ocelot_to_snake.normalize();

  let ocelot_dir = mouse.copy();

  ocelot_dir.normalize();

  let dot = ocelot_dir.dot(dir_ocelot_to_snake);

  if (dot > 0.86) {

    c = 0; 

  }

  else {

    c = 220; 

  }

  fill(0,255,0);

  circle(snake.x, snake.y, 20);

  fill(255,0, 0);

  circle(ocelot.x, ocelot.y, 20);

  translate(300,100);

  line(0,0,mouse.x, mouse.y);

}