function pointSub(a, b) {
  return { x: a.x - b.x, y: a.y - b.y }
}

function pointAdd(a, b) {
  return { x: a.x + b.x, y: a.y + b.y }
}

function pointDistance(a, b) {
  const diffX = a.x - b.x
  const diffY = a.y - b.y
  return Math.sqrt(diffX * diffX + diffY * diffY)
}

function pointInBounds(pt, rect) {
  return pt.x >= rect.x
    && pt.x <= rect.x + rect.w
    && pt.y >= rect.y
    && pt.y <= rect.y + rect.h
}

function rectCenter(rect) {
  return {
    x: rect.x + (rect.w / 2),
    y: rect.y + (rect.h / 2),
  }
}

function rectMoved(rect, x, y) {
  return {
    x: rect.x + x,
    y: rect.y + y,
    w: rect.w,
    h: rect.h,
  }
}

function rectCenterDistance(rectA, rectB) {
  return pointDistance(rectCenter(rectA), rectCenter(rectB))
}

export default {
  pointSub,
  pointAdd,
  pointDistance,
  pointInBounds,
  rectCenter,
  rectMoved,
  rectCenterDistance,
}