let fft;

let particles = [];

let glyphs = ['?', '!', '-', '='];

const num = 5000; //initial number of particles 

const noiseScale = 0.001;

​

function preload() {

  song = loadSound('I got this short.mp3');  

}

​

function setup() {

  createCanvas(800, 500);

  colorMode(RGB);

    for (let i = 0; i < num; i++) {

        let particle = {

            position: createVector(random(width), random(height)),

            glyph: random(glyphs) // Assign a random glyph

        };

        particles.push(particle);

    }

  stroke(53,52,64);

  strokeWeight(5); 

  fft = new p5.FFT();

  song.play();

}

​

function draw() {

  background(193,203,217, 30); //second value messes with how fast the trails disappear

  let spectrum = fft.analyze();

  let bass = fft.getEnergy(40, 100); //kick drum frequency range

  let volume = fft.getEnergy(150, 10000); //adjust the range 

  for (let i = 0; i < num; i++) {

    let p = particles[i];

    let prevX = p.x;

    let prevY = p.y;

​

    let freqValue = spectrum[i % spectrum.length];

    let minSize = 2; 

    let maxSize = 3; 

    let dynamicSize = map(freqValue, 0, 255, 0, maxSize - minSize); 

    let particleSize = minSize - dynamicSize; 

    strokeWeight(particleSize * 5);

​

    point(p.x, p.y); // Draw particle

​

    let n = map(freqValue, 0, 255, 0, 1);

    let noiseFactor = noise(p.x * noiseScale, p.y * noiseScale) * TAU * 2;

    let a = TAU * n + noiseFactor;

    let speed = map(volume, 0, 255, 1, 10); //speed based on volume

    //react more strongly to bass frequencies

    if (bass > 180) { //threshold for bass 

      speed *= 5; 

      particleSize *= bass; 

    }

    //if (volume > ){

        //}

​

    //move particle

    p.x += cos(a^(random(1,10))) * speed;

    p.y += sin(a) * speed;

    //line(prevX, prevY, p.x, p.y);

    if (!onScreen(p)) {

      p.x = random(width);

      p.y = random(height);

    }

  }

​

}

​

function onScreen(v) {

  //checks whether or not a particle is on the screen

  return v.x >= 0 && v.x <= width && v.y >= 0 && v.y <= height;

}

​