Love2d, drawing an animated line

main.lua

local lg = love.graphics
local floor = math.floor
local insert = table.insert

local image = lg.newImage("Line.png") --I used a 64x64 image to test
image:setWrap("repeat","repeat")
local iw, ih = image:getDimensions()

--Options
local frames = 20 -- Frames per line section
--

local points -- Predicted points
local quads -- Drawn quads
local quadsPos -- Quad's drawn position
local rotations -- Quad's rotation
local index = frames

local sqrt = math.sqrt
local pow2 = function(n) return n*n end
local function magSqrt(x, y)
	return sqrt(pow2(x) + pow2(y)) 
end

local atan2 = math.atan2
local pi = math.pi
local function rotation(x, y)
	return atan2(y, x) - pi
end

local function calculateQuads()
	quads = {}
	quadsPos = {}
	rotations = {}
	local lineOffset = 0
	for i = 3, #points, 2 do
		local dx = points[i-2] - points[i] --Vector to next point
		local dy = points[i-1] - points[i+1]
		insert(rotations, rotation(dx, dy))
		local mag = magSqrt(dx, dy) --Length of line
		local ux = dx / mag --Normalize vector
		local uy = dy / mag 
		insert(quadsPos, points[i-2]-uy*ih/2) --Calculating centre offset
		insert(quadsPos, points[i-1]+ux*iw/2)
		for q = 0, frames-1 do
			insert(quads, lg.newQuad(lineOffset+iw*q*(iw/frames),ih,mag,ih,iw,ih))
		end
		lineOffset = lineOffset + mag --Offset to contine line
	end
end

local function CalculatePoints(height)
	local h = floor(height/2)
	h = h + 50 -- Just to make things less cramped
	points = { --Example set of points, more fine they are less corners there will be
			50, h,
			100,h - 30,
			150,h - 60,
			200,h - 80,
			250,h - 50,
			300,h + 10,
			350,h + 50,
		}
	--points = {200,h,500,h,500,h-200} --debug
	calculateQuads()
end

function love.load()
	local _, h = lg.getDimensions()
	CalculatePoints(h)
end

local delta = 0
function love.update(dt)
	delta = delta + dt
	while delta > 0.05 do
		delta = delta - 0.05
		index = index - 1
		if index < 1 then
			index = frames
		end
	end
end

function love.draw()
	lg.print(1*2-1)
	lg.line(points) -- Debug to show the line
	for i = 1, #quads / frames do -- Probably a better way to do the loop
		local qx = quadsPos[i*2-1]
		local qy = quadsPos[i*2]
    		local frame = index+i*frames-frames
		lg.print(tostring(qx)..";"..tostring(qy)..";"..tostring(frame),10,i*20) -- "x;y;frame"
		lg.draw(image, quads[frame],qx,qy,rotations[i])
	end
end

function love.resize(_, h) CalculatePoints(h) end