-- Functions 


function SPRING.new(self, mass, force, damping, speed)

	local spring	= {
		Target		= Vector3.new();
		Position	= Vector3.new();
		Velocity	= Vector3.new();

		Mass		= mass or 5;
		Force		= force or 50;
		Damping		= damping or 4;
		Speed		= speed  or 4;
	}

	function spring.getstats(self)
		return self.Mass, self.Force, self.Damping, self.Speed
	end

	function spring.changestats(self, mass, force, damping, speed)
		self.Mass = mass or self.Mass
		self.Force = force or self.Force
		self.Damping = damping or self.Damping
		self.Speed = speed or self.Speed
	end

	function spring.shove(self, force)
		local x, y, z	= force.X, force.Y, force.Z
		if x ~= x or x == math.huge or x == -math.huge then
			x	= 0
		end
		if y ~= y or y == math.huge or y == -math.huge then
			y	= 0
		end
		if z ~= z or z == math.huge or z == -math.huge then
			z	= 0
		end
		self.Velocity	= self.Velocity + Vector3.new(x, y, z)
	end

	function spring.update(self, dt)
		local scaledDeltaTime = dt * self.Speed / ITERATIONS
		for i = 1, ITERATIONS do
			local iterationForce= self.Target - self.Position
			local acceleration	= (iterationForce * self.Force) / self.Mass

			acceleration		= acceleration - self.Velocity * self.Damping

			self.Velocity	= self.Velocity + acceleration * scaledDeltaTime
			self.Position	= self.Position + self.Velocity * scaledDeltaTime
		end

		return self.Position
	end

	return spring
end
