Here is my code, I can't really say more to it. I mean, it works fine, but is it really the most effiecient way? It looks so dirt. D:
public int GetDistanceFromEntity(Entity Entity)
{
int OurEntityX = this.PositionX.ToString().StartsWith("-") ? -this.PositionX : this.PositionX;
int OurEntityY = this.PositionY.ToString().StartsWith("-") ? -this.PositionY : this.PositionY;
int OtherEntityX = Entity.PositionX.ToString().StartsWith("-") ? -Entity.PositionX : Entity.PositionX;
int OtherEntityY = Entity.PositionY.ToString().StartsWith("-") ? -Entity.PositionY : Entity.PositionY;
return (int)Math.Sqrt(Math.Pow(OtherEntityX - OurEntityX, 2) + Math.Pow(OtherEntityY - OurEntityY, 2));
}