-- title:  Doom Fire
-- author: Fabien Freling
-- desc:   short description
-- script: lua

t=0
width=240
height=136
base={}
-- init with black
for i=1,width*height do
	base[i] = 0
end
for i=width*(height-1),width*height do
	base[i] = 15
end
cls(0)

function display()
	for y=1,height do
		for x=1,width do
			pix(x, y, base[x+y*width])
		end
	end
end

function dofire()
	for x=1,width do
		for y=0,height-2 do
			spreadfire(x, y)
		end
	end
end

function spreadfire(x, y)
	local rand = math.random(0, 3) -- [0,3]
	local delta = rand & 1
	local side = -rand+1 -- [-2,1]
	if x+side < 1 then side=0 end
	if x+side > width then side=0 end
	local dst=(x+side) + y*width
	local src=x + (y+1)*width
	base[dst] = base[src] - delta
	if base[dst] < 0 then base[dst]=0 end
end

function TIC()
	display()
	-- slow down fire
	if t % 2 == 0 then
		dofire()
	end
	t=t+1
end

-- <TILES>
-- 001:efffffffff222222f8888888f8222222f8fffffff8ff0ffff8ff0ffff8ff0fff
-- 002:fffffeee2222ffee88880fee22280feefff80fff0ff80f0f0ff80f0f0ff80f0f
-- 003:efffffffff222222f8888888f8222222f8fffffff8fffffff8ff0ffff8ff0fff
-- 004:fffffeee2222ffee88880fee22280feefff80ffffff80f0f0ff80f0f0ff80f0f
-- 017:f8fffffff8888888f888f888f8888ffff8888888f2222222ff000fffefffffef
-- 018:fff800ff88880ffef8880fee88880fee88880fee2222ffee000ffeeeffffeeee
-- 019:f8fffffff8888888f888f888f8888ffff8888888f2222222ff000fffefffffef
-- 020:fff800ff88880ffef8880fee88880fee88880fee2222ffee000ffeeeffffeeee
-- </TILES>

-- <WAVES>
-- 000:00000000ffffffff00000000ffffffff
-- 001:0123456789abcdeffedcba9876543210
-- 002:0123456789abcdef0123456789abcdef
-- </WAVES>

-- <SFX>
-- 000:000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000304000000000
-- </SFX>

-- <PALETTE>
-- 000:140c1c4424345d403c794a4eb23030d62424fa0000e6690cee6d10d2a12cceaa40caa13cd2aa40e6c271dad45effffff
-- </PALETTE>