// Daniel Shiffman

// http://codingtra.in

// https://youtu.be/l__fEY1xanY

// https://thecodingtrain.com/CodingChallenges/052-random-walk.html

// chatgpt

​

let position, velocity, acceleration;

let oldPosition;

let colors;

​

function setup() {

  createCanvas(400, 400);

  position = createVector(width / 2, height / 2);

  velocity = createVector(0, 0);

  acceleration = createVector(0, 0);

  oldPosition = position.copy();

  background(0);

​

  colors = [

    "rgba(255, 0, 0, 0.8)",

    "rgba(0, 255, 0, 0.8)",

    "rgba(0, 0, 255, 0.8)",

    "rgba(255, 255, 0, 0.8)",

    "rgba(255, 0, 255, 0.8)",

    "rgba(0, 255, 255, 0.8)",

  ];

}

​

function draw() {

  // glow effect

  stroke(random(colors));

  strokeWeight(50);

  glowEffect();

  line(position.x, position.y, oldPosition.x, oldPosition.y);

​

  // location

  oldPosition.set(position);

​

  let stepSize = random([80, -80]);

  let moveVector = createVector(0, 0);

  let r = floor(random(10));

  switch (r) {

    case 0:

      moveVector.x = stepSize;

      break;

    case 1:

      moveVector.x = -stepSize;

      break;

    case 2:

      moveVector.y = stepSize;

      break;

    case 3:

      moveVector.y = -stepSize;

      break;

  }

​

  acceleration = moveVector;

​

  if (acceleration.x !== 0) {

    velocity.y = 0;

  }

  if (acceleration.y !== 0) {

    velocity.x = 0;

  }

​

​

  velocity.add(acceleration);

​

  velocity.limit(30);

​

  position.add(velocity);

  velocity.mult(0.95);

​

​

  position.x = constrain(position.x, 0, width);

  position.y = constrain(position.y, 0, height);

}

​

​

function glowEffect() {

  for (let i = 10; i > 0; i--) {

    strokeWeight(i);

    let currentColor = random(colors);

    let newAlpha = (i * 0.08).toFixed(2);

    currentColor = currentColor.replace("0.8", newAlpha);

    stroke(currentColor);

    line(position.x, position.y, oldPosition.x, oldPosition.y);

  }

}

​