worldToLocal method
Implementation
Vector2 worldToLocal(Vector2 world) {
final double a = this.a, b = this.b, c = this.c, d = this.d;
final double invDet = 1 / (a * d - b * c);
final double x = world.x - worldX, y = world.y - worldY;
world
..x = (x * d * invDet - y * b * invDet)
..y = (y * a * invDet - x * c * invDet);
return world;
}