let cols;

let rows;

let current;

let previous;

let amplitude;

​

let dampening = 0.99;

​

function preload(){

  audio = loadSound('waterdrop.mp3');

}

​

function setup() {

  pixelDensity(1);

  createCanvas(600, 400);

  cols = width;

  rows = height;

  current = new Array(cols).fill(220).map(n => new Array(rows).fill(0));

  previous = new Array(cols).fill(220).map(n => new Array(rows).fill(0));

  amplitude = new p5.Amplitude();

}

​

function mouseDragged (){

    //previous[mouseX][mouseY] = 2500;

}

​

function mousePressed(){

  audio.play();

}

​

function mouseReleased(){

  audio.stop();

}

​

function draw() {

  background(112, 146, 204);

  //print(amplitude.getLevel());

  if(amplitude.getLevel() > 0.06){

    previous[mouseX][mouseY] = 2500;

  }

​

  loadPixels();

  for (let i = 1; i < cols - 1; i++) {

    for (let j = 1; j < rows - 1; j++) {

      current[i][j] =

        (previous[i - 1][j] +

          previous[i + 1][j] +

          previous[i][j - 1] +

          previous[i][j + 1]) /

          2 -

        current[i][j];

      current[i][j] = current[i][j] * dampening;

      let index = (i + j * cols) * 4;

      pixels[index + 0] = current[i][j];

      pixels[index + 1] = current[i][j];

      pixels[index + 2] = current[i][j];

    }

  }

  updatePixels();

​

  let temp = previous;

  previous = current;

  current = temp;

}

​

​

// https://thecodingtrain.com/CodingChallenges/102-2d-water-ripple.html