constructor(_x, _y, _mag, _color) {

    this.pos = createVector(_x, _y);

    this.mag = _mag;

    this.color = _color;

  }

​

  set(_x, _y) {

    this.pos.set(_x, _y);

  }

​

  get(_x, _y) {

    let d = dist(_x, _y, this.pos.x, this.pos.y);

    let t = map(d, 0, this.mag, 0.0, 1.0, true);

    return lerpColor(this.color, color(0), t);

  }

}

​

let squaresPerRow = 100;

let spacing;

​

let mPoint;

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  noStroke();

  spacing = width / squaresPerRow;

​

  mPoint = new PointLight(

    width / 2,

    height / 2,

    width / 2,

    color(220, 20, 120)

  );

}

​

function draw() {

  background(0);

  mPoint.set(mouseX, mouseY);

  for (let y = 0; y < height; y += spacing) {

    for (let x = 0; x < width; x += spacing) {

      fill(mPoint.get(x, y));

      rect(x, y, spacing + 1);

    }

  }

}

​