react-map-interaction/src/geometry.js

'Add map like zooming and dragging to any element'

function clamp(min, value, max) {
  return Math.max(min, Math.min(value, max));
}

function distance(p1, p2) {
  const dx = p1.x - p2.x;
  const dy = p1.y - p2.y;
  return Math.sqrt(Math.pow(dx, 2) + Math.pow(dy, 2));
}

function midpoint(p1, p2) {
  return {
    x: (p1.x + p2.x) / 2,
    y: (p1.y + p2.y) / 2
  };
}

function touchPt(touch) {
  return { x: touch.clientX, y: touch.clientY };
}

function touchDistance(t0, t1) {
  const p0 = touchPt(t0);
  const p1 = touchPt(t1);
  return distance(p0, p1);
}

export {
  clamp,
  distance,
  midpoint,
  touchPt,
  touchDistance
};