let n_cols;

let radius;

let diameter;

let mid_x;

let mid_y;

​

let special_x, special_y;

​

function polygon(x, y, radius, npoints, f) {

  fill(f);

  let angle = TWO_PI / npoints;

  beginShape();

  for (let a = 0; a < TWO_PI; a += angle) {

    let sx = x + cos(a) * radius;

    let sy = y + sin(a) * radius;

    vertex(sx, sy);

  }

  endShape(CLOSE);

}

​

function setup() {

  createCanvas(500, 500);

  radius = 10;

  diameter = radius * 2;

  n_cols = (int)(width/(diameter));

  n_rows = (int)(height/(diameter));

  mid_x = width/2;

  mid_y = height/2;

  special_x = radius;

  special_y = radius;

}

​

function draw() {

  background(220);

  for (let r = 0; r < n_rows; r++) {

    for (let c = 0; c < n_cols; c++) {

      let x;

      let y;

      let col;

      if ((r == 0) && (c == 0)) {

        x = special_x;

        y = special_y;

        col = 0;

        special_x+=random(1.5);

        special_y+=random(1.5);

        if (special_y > height)

          special_y = 0;

        if (special_x > width)

          special_x = 0;

        if (special_x < 0)

          special_x = width;

        if (special_y < 0)

          special_y = height;

      } else {

        x = radius + c*diameter;

        y = radius + r*diameter;

        col = 120;

      }

      // map color from midpoint out

      //let col = 190;

      let col2 = col - random(100);

      let col3 = col2 - random(100);

      //noStroke();

      polygon(x, y, radius, 6, col);

      polygon(x-1, y+1, radius, 6, color(col+5,col+5,col+5,120));// color(col,col2,col3));    

      polygon(x+1, y-1, radius, 6, color(col-5,col-5,col-5,120));// color(col,col2,col3));    

      /*polygon(x+random(-1,1), y+random(-1,1), radius, 6, color(col,col2,col3));    

      polygon(x+random(-1,1), y+random(-1,1), radius, 6, color(col,col,col,50));    

      polygon(x+random(-1,1), y+random(-1,1), radius, 6, color(col2,col2,col2,100));    

      polygon(x+random(-1,1), y+random(-1,1), radius, 6, color(col3,col3,col3,150)); */   

    }

  }    

  //noLoop();

}