createCanvas(600,600);

  background("#002FA7");

}

​

function draw() {

  strokeWeight(5);

  variableLine(mouseX, mouseY, pmouseX, pmouseY);

}

​

function variableLine(x, y, px, py) {

  let mouseSpeed = abs(x - px) + abs(y - py);

  stroke(255 - mouseSpeed);

  line(width / 2, height / 2, x, y);

}