-- Functions


function SPRING.Create(self, mass, force, damping, speed)
	local spring	= {
		Target		= Vector3.new();
		Position	= Vector3.new();
		Velocity	= Vector3.new();
		
		Mass		= mass or 1;
		Force		= force or 50;
		Damping		= damping or 2;
		Speed		= speed or 1;
	}
	
	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	= math.min(dt * self.Speed, 0.1) / ITERATIONS
		
		for i = 1, ITERATIONS do
			local force			= self.Target - self.Position
			local acceleration	= (force * 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
