glu engine funcs

		// normalizes a vector
		public Vector2f Normalize(Vector2f vector)
		{
			float length = Lenght(vector);

			vector.X /= length;
			vector.Y /= length;
			return vector;
		}

		// multiply a vector with a scaler value
		public Vector2f Multiply(Vector2f vector, float scaler)
		{
			vector.X = vector.X * scaler;
			vector.Y = vector.Y * scaler;
			return vector;
		}

		// get the length of a vector
		public float Lenght(Vector2f vector)
		{
			float length = (float)System.Math.Sqrt((vector.X * vector.X) + (vector.Y * vector.Y));
			return length > 0 ? length : 0;
		}