* 

 * A grid of points

 */

​

let gridStep = 50;

let pntSize = 50;

let randSeed = 1;

​

function setup() {

    createCanvas(500, 500);

    background(0);

}

​

function draw() {

    background(0);

    randomSeed(randSeed);

    stroke(255);

    strokeWeight(pntSize);

    for (let y=pntSize; y<=height-pntSize; y+=gridStep) {

        for (let x=pntSize; x<=width-pntSize; x+=gridStep) {

            let randVal = random(12);

            let cutOffVal = map(mouseY, 0, height, 0, 12);

      if(randVal>cutOffVal){

        point(x, y);

      }

    }

  }

}

​

function keyPressed() {

    if(key === 'r') {randSeed = random(1000);}

    if(key === '+') {gridStep+=5; pntSize+=5;}

    if(key === '-') if(gridStep>5){gridStep-=5;  pntSize-=5;}

    if(key === 'w') pntSize +=5;

    if(key === 'x') if(pntSize>0){pntSize -=5;}

  }