Flashlight

let img;

​

function preload() {

  img = loadImage('https://picsum.photos/640/360/?random');

}

​

function setup() {

  createCanvas(img.width, img.height);

​

  pixelDensity(1);

}

​

function draw() {

​

  loadPixels();

  let rad = 90;

  img.loadPixels();

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

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

      let pos = (x + y * width) * 4;

      let r = img.pixels[pos];

      let g = img.pixels[pos + 1];

      let b = img.pixels[pos + 2];

​

      let d = dist(x, y, mouseX, mouseY);

​

​

      let adjustBrightness = map(d, 0, rad, 1, 0);

      r *= adjustBrightness;

      g *= adjustBrightness;

      b *= adjustBrightness;

​

​

      r = constrain(r, 0, 255);

      g = constrain(g, 0, 255);

      b = constrain(b, 0, 255);

​

​

      pixels[pos] = r;

      pixels[pos + 1] = g;

      pixels[pos + 2] = b;

      pixels[pos + 3] = 255;

    }

  }

​

  updatePixels();

}