let vel = null

let velAngle = null

let posBall = null

let isRunning = false

​

function degreesToRadians(degrees) {

  return degrees * (Math.PI / 180);

}

​

function setup() {

  createCanvas(400, 400);

  vel = createVector(0, 0);

  velAngle = createVector(0,0)

  posBall = createVector(width/2, height/2)

}

​

function draw() {

  background('#fae');

  ellipse(posBall.x, posBall.y, 50, 50)

  stroke("red")

  line(posBall.x, posBall.y, velAngle.x * 10,

       velAngle.y * 10)

  stroke('green')

  line(posBall.x, posBall.y, vel.x,

       vel.y)

  if(isRunning) {

    posBall.add(vel)  

  }

}

​

function keyPressed() {

  if(keyCode === DOWN_ARROW) {

    angle -= 0.001

  } else if (keyCode === UP_ARROW) {

    angle += 0.001

  } else if (keyCode === ENTER) {

    isRunning = !isRunning

    vel = p5.Vector.mult(p5.Vector.normalize(p5.Vector.sub(posBall, velAngle)), -1)

    console.log(vel)

  }

  velAngle = createVector(cos(angle), 

                            sin(angle))

  console.log(angle)

}