screen fade function for pico8

pico8_fade.lua

-- "fa" is a number ranging from 0 to 1
-- 1 = 100% faded out
-- 0 = 0% faded out
-- 0.5 = 50% faded out, etc.

function fade_scr(fa)
	fa=max(min(1,fa),0)
	local fn=8
	local pn=15
	local fc=1/fn
	local fi=flr(fa/fc)+1
	local fades={
		{1,1,1,1,0,0,0,0},
		{2,2,2,1,1,0,0,0},
		{3,3,4,5,2,1,1,0},
		{4,4,2,2,1,1,1,0},
		{5,5,2,2,1,1,1,0},
		{6,6,13,5,2,1,1,0},
		{7,7,6,13,5,2,1,0},
		{8,8,9,4,5,2,1,0},
		{9,9,4,5,2,1,1,0},
		{10,15,9,4,5,2,1,0},
		{11,11,3,4,5,2,1,0},
		{12,12,13,5,5,2,1,0},
		{13,13,5,5,2,1,1,0},
		{14,9,9,4,5,2,1,0},
		{15,14,9,4,5,2,1,0}
	}
	
	for n=1,pn do
		pal(n,fades[n][fi],0)
	end
end