class Aabb2 {
 final Vector2 _min;
 final Vector2 _max;

 Vector2 get min => _min;
 Vector2 get max => _max;

 Vector2 get center {
   Vector2 c = new Vector2.copy(_min);
   return c.add(_max).scale(.5);
 }

 Aabb2() :
   _min = new Vector2.zero(),
   _max = new Vector2.zero() {}

 Aabb2.copy(Aabb2 other) :
   _min = new Vector2.copy(other._min),
   _max = new Vector2.copy(other._max) {}

 Aabb2.minmax(Vector2 min_, Vector2 max_) :
   _min = new Vector2.copy(min_),
   _max = new Vector2.copy(max_) {}

 void copyMinMax(Vector2 min_, Vector2 max_) {
   max_.setFrom(_max);
   min_.setFrom(_min);
 }

 void copyCenterAndHalfExtents(Vector2 center, Vector2 halfExtents) {
   center.setFrom(_min);
   center.add(_max);
   center.scale(0.5);
   halfExtents.setFrom(_max);
   halfExtents.sub(_min);
   halfExtents.scale(0.5);
 }

 void copyFrom(Aabb2 o) {
   _min.setFrom(o._min);
   _max.setFrom(o._max);
 }

 void copyInto(Aabb2 o) {
   o._min.setFrom(_min);
   o._max.setFrom(_max);
 }

 Aabb2 transform(Matrix3 T) {
   Vector2 center = new Vector2.zero();
   Vector2 halfExtents = new Vector2.zero();
   copyCenterAndHalfExtents(center, halfExtents);
   T.transform2(center);
   T.absoluteRotate2(halfExtents);
   _min.setFrom(center);
   _max.setFrom(center);

   _min.sub(halfExtents);
   _max.add(halfExtents);
   return this;
 }

 Aabb2 rotate(Matrix3 T) {
   Vector2 center = new Vector2.zero();
   Vector2 halfExtents = new Vector2.zero();
   copyCenterAndHalfExtents(center, halfExtents);
   T.absoluteRotate2(halfExtents);
   _min.setFrom(center);
   _max.setFrom(center);

   _min.sub(halfExtents);
   _max.add(halfExtents);
   return this;
 }

 Aabb2 transformed(Matrix3 T, Aabb2 out) {
   out.copyFrom(this);
   return out.transform(T);
 }

 Aabb2 rotated(Matrix3 T, Aabb2 out) {
   out.copyFrom(this);
   return out.rotate(T);
 }

 /// Set the min and max of [this] so that [this] is a hull of [this] and [other].
 void hull(Aabb2 other) {
   min.x = Math.min(_min.x, other.min.x);
   min.y = Math.min(_min.y, other.min.y);
   max.x = Math.max(_max.x, other.max.x);
   max.y = Math.max(_max.y, other.max.y);
 }

 /// Return if [this] contains [other].
 bool contains(Aabb2 other) {
   return min.x < other.min.x &&
          min.y < other.min.y &&
          max.y > other.max.y &&
          max.x > other.max.x;
 }

 /// Return if [this] intersects with [other].
 bool intersectsWith(Aabb2 other) {
   return min.x <= other.max.x &&
          min.y <= other.max.y &&
          max.x >= other.min.x &&
          max.y >= other.min.y;
 }

}