// The Coding Train / Daniel Shiffman

// https://thecodingtrain.com/CodingChallenges/160-spring-forces.html

// https://youtu.be/Rr-5HiXquhw

​

// Simple Spring: https://editor.p5js.org/codingtrain/sketches/dcd6-2mWa

// Spring Vector: https://editor.p5js.org/codingtrain/sketches/_A2pm_SSg

// Spring OOP: https://editor.p5js.org/codingtrain/sketches/9BAoEn4Po

// Soft Spring: https://editor.p5js.org/codingtrain/sketches/S5dY7qjxP

​

let y = 250;

let velocity = 0;

let restLength = 200;

let k = 0.01;

​

function setup() {

  createCanvas(600, 400);

}

​

function draw() {

  background(112, 50, 126);

  noStroke();

  fill(45, 197, 244);

  circle(300, y, 64);

​

  let x = y - restLength;

  let force = -k * x;

​

  // F = A

  velocity += force;

  y += velocity;

​

  velocity *= 0.99;

}

​