createCanvas(400, 400);

}

​

function draw() {

  background(220);

  let x0 = 100;

  let y0 = 120;

  let x1 = mouseX;

  let y1 = mouseY;

  strokeWeight(2);

  stroke(100);

  line(x0, y0, x1, y1);

  strokeWeight(6);

  stroke(250, 60, 80);

  point(x0, y0);

  stroke(60, 80, 250);

  point(x1, y1);

  noStroke();

  textAlign(CENTER, CENTER);

  text("P0", x0, y0 - 12);

  text("P1", x1, y1 + 12);

  let a = x1 - x0;

  let b = y1 - y0;

  let c = sqrt(a * a + b * b);

  //let distance = dist(x0, y0, x1, y1);

  let distance = c;

  textAlign(LEFT, TOP);

  text(distance, 4, 4);

}

​