avoid-creating-vector-in-update

added in: 1.6.0 warning.

Warns when a Vector2 is created inside a Component's update method.

Creating a new vector every tick can affect the performance. Instead, an existing vector should be updated.

Example

Bad:

class MyComponent extends Component {
  @override
  void update(double dt) {
    final newVector = Vector2(10, 10); // LINT
  }
}

class MyComponent extends Component {
  final vector1 = Vector2(10, 10);
  final vector2 = Vector2(20, 20);

  @override
  void update(double dt) {
    final addVector = vector1 + vector2; // LINT
    final subVector = vector1 - vector2; // LINT
  }
}

Good:

class MyComponent extends Component {
  final _temporaryVector = Vector2.zero();

  @override
  void update(double dt) {
    _temporaryVector.setValues(10, 10);
  }
}

class MyComponent extends Component {
  final vector1 = Vector2(10, 10);
  final vector2 = Vector2(20, 20);

  final _temporaryVector = Vector2.zero();

  @override
  void update(double dt) {
    _temporaryVector
      ..setFrom(vector1)
      ..add(vector2);
  }
}