sprite_vscroll.p8

pico-8 cartridge // http://www.pico-8.com
version 36
__lua__
-- get address of a sprite
getsp=function(sp)
	n=512*(sp\16)+4*(sp%16)
	return n
end

--shift lines of a sprite
spshift=function(n,t)
	--n: sprite numner
	--t: timing
	if _t%t==0 then
		local new=getsp(n)
		local top=peek4(new+7*64)
		local vals={}
		for v=0,6 do
			local shift=new+v*64
			add(vals,peek4(shift))
		end
		for v=1,#vals do
			poke4(new+v*64,vals[v])
		end
		poke4(new,top)
	end
end

function _init()
	_t=0 -- time count
end

function _update()
	_t+=1
	spshift(1,1)
	spshift(2,8)
end

function _draw()
	cls()
	map(0,0,48,48,4,4)
end
__gfx__
0000000080808080eeeeeeee00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00000000080808080eeeeee000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
007007000000000000eeee0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
0007700080808080000ee00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00077000080808080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00700700000000000999999000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00000000888888880099990000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
00000000000000000009900000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
__map__
0101020200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
0101020200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
0101020200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
0101020200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000