V3 Perpendicular lines

function setup() {

  createCanvas(windowWidth, windowHeight);

  background(0);

}

​

function draw() {

}

​

function mouseDragged() {

  drawLine(pmouseX, pmouseY, mouseX, mouseY)

}

​

function drawLine(pX, pY, cX, cY){

  const prev = createVector(pX, pY)

  const current = createVector(cX, cY)

  const delta = p5.Vector.sub(current, prev)

  const angle = delta.heading()

  push()

  translate(pX, pY)

  rotate(angle)

  stroke('pink')

  line(0, delta.mag()/2, 0, -delta.mag()/2)

  pop()

}