TIC-80 Dodge Glitch effect

dodge.lua

-- made for my Devtober2022 entry
-- you can read the corresponding devlog on: 
-- https://ko-fi.com/post/Eng-Devtober2022-4--We-got-to-have-glitch-effe-S6S1FM1IC
-- https://itch.io/jam/devtober-2022/topic/2406837/achies-devlog-shmup-game
if dodgeTimer > 0 then
		-- do it for each y level
		for i=0,7 do
			if math.random() > 0.5 then
				local startLine = math.random(-10,0)
				local endLine = math.random(0,10)
				for j=startLine,endLine do
					-- calculate the pixel index
					local decPos = math.floor(x+4)+j+((math.floor(y)+i)*240)
					-- turn it to hexa
					local hexPos = ('%X'):format(decPos)
					-- poke
					poke4(0x0000+tonumber(hexPos,16),11)
				end
			end
		end
	else
		-- draw exhaust
		draw_outline(4+idx,x+leaning,y+8,0,8)
		-- draw ship
		draw_outline(2+leaning,x,y,0,8)
		if hasShield then
			--draw shield
			local size = 8*(shield/maxShield)
			ellib(x+3,y+4,size,size,11)
		end
	end