JSFiddle - React, Tailwind, and code Playground

by abhishek_soni

HTML

<!-- <svg width="440" height="44">
  <path d="M40,40 h200 a20,20 0 0 1 20,20 v200 a20,20 0 0 1 -20,20 h-20 a20,20 0 0 1 -20,-20 v-200 a20,20 0 0 1 20,-20 z" fill="none" stroke="black" stroke-width="3" />
</svg> -->

JavaScript

function createRoundedPath(coords, radius, close) {
  let path = ""
  const length = coords.length + (close ? 1 : -1)
  for (let i = 0; i < length; i++) {
    const a = coords[i % coords.length]
    const b = coords[(i + 1) % coords.length]
    const t = Math.min(radius / Math.hypot(b.x - a.x, b.y - a.y), 0.5)

    if (i > 0) path += `Q${a.x},${a.y} ${a.x * (1 - t) + b.x * t},${a.y * (1 - t) + b.y * t}`

    if (!close && i == 0) path += `M${a.x},${a.y}`
    else if (i == 0) path += `M${a.x * (1 - t) + b.x * t},${a.y * (1 - t) + b.y * t}`

    if (!close && i == length - 1) path += `L${b.x},${b.y}`
    else if (i < length - 1) path += `L${a.x * t + b.x * (1 - t)},${a.y * t + b.y * (1 - t)}`
  }
  if (close) path += "Z"
  return path
}
createRoundedPath((10,10), 20, 40);