Brightness image

//The image need a black background

var img, taille=10, points=[], ecart=100;

function preload(){

    img = loadImage("test.jpg");

}

function setup() {

  createCanvas(windowWidth, windowHeight);

  background(100);

  img.loadPixels();

  img.resize(width, height);

  class Point{

    constructor(x,y){

        this.x = x;

        this.y = y;

        this.velx = taille;

    }

    affiche(){

        push();

        let v = img.get(this.x,this.y);

        let b = (v[0]+v[1]+v[2])/3;

        fill(255,255,255,30+b);

        noStroke();

        ellipse(this.x, this.y, taille, taille);

        pop();

    }

    moov(){

        let v = img.get(this.x,this.y);

        let b = (v[0]+v[1]+v[2])/3/30;

        this.x += this.velx-b;

    }

    reset(){

      if(this.x >= img.width){

        this.x = 0;

      }

    }

  }

  for(var x = 0; x<img.width/ecart; x++){

    for(var y = 0; y < img.height/taille; y++){

        points.push(new Point(x*ecart,y*taille))

    }

  }

}

function draw(){

  background(0,0,0,10);

  for(var n in points){

    points[n].affiche();

    points[n].moov();

    points[n].reset();

  }

}