shrink method

Rect shrink(int amount)

Create a new Rect by shrinking all four sides of this rectangle inwards by the given amount. Calling with a negative amount will return an expanded Rect.

Note that this will not shrink the rectangle beyond size zero.

Implementation

Rect shrink(int amount) {
  if (amount == 0) return this;
  if (amount < 0) return expand(amount.abs());

  int t, b, l, r;

  if (size.x < amount * 2) {
    l = r = position.x;
  } else {
    l = left + amount;
    r = right - amount;
  }

  if (size.y < amount * 2) {
    t = b = position.y;
  } else {
    t = top + amount;
    b = bottom - amount;
  }

  return Rect.sides(t, r, b, l);
}