pico8-0hh1/states/loading.lua

function state_loading()
	local board = Board.new()

	local spinner = split"-,\\,|,/"
	local loading_messages = {
		"rETICULATING SPLINES",
		"aLLOCATING RESSOURCES",
		"eMULATING HARDWARE",
		"uNCLOGGING MEMORY BUS",
		"sPINNING UP ai AGENT",
		"bOOTING VIRTUAL MACHINE",
		"cOLLECTING PIXELS TO BUILD TILES",
		"lOADING RAY-TRACING ALGORITHM",
		"sWEEPING PARTICLES",
		"pRESSURIZING USER INTERFACE",
		"rECOMPUTING BOARD MATRIX"
	}

	local message = ""
	local messages_str = ""
	local messages_x = 128
	local loaded = false
	local removing_tile = 0

	local create_board = cocreate(function()
		repeat
			board:reset()
			repeat
				board:solve_step(true)
				yield()
			until board:is_complete()
		until board:is_valid()

		printh("b: " .. time())
		-- Remove tiles until randomness is unavoidable
		local previous = {board:get_tiles_copy()} -- initial state
		while true do
			board:set_tiles(previous[#previous])
			-- remove a random tile
			repeat
				removing_tile += 1
			until removing_tile == 100 or board:get_tiles_copy()[iremoving_tile] ~= 0
			if removing_tile == 100 then
				break
			end

			board:fill(removing_tile, 0)
			add(previous, board:get_tiles_copy())

			-- try to solve the board
			local solved = ""
			yield()
			repeat
				solved = board:solve_step()
			until board:is_complete() or solved == "invalid"
			if solved == "invalid" then
				deli(previous)
			end
		end -- end while
		printh("c: " .. time())

		board:set_tiles(previous[#previous])
		printh(board:tostring())
		printh(count(board:get_tiles_copy(), 0).." zeroes")

		loaded = true
	end)

	local function draw_tiles(board)
		local w = board:get_size()
		local tiles = board:get_tiles_copy()
		for k,v in ipairs(tiles) do
			if k<removing_tile and v > 0 then
				local x,y = board:draw_coords(k)
				local color = v == BLUE and 12 or 8
				if color == 1 then fillp(▒) else fillp(█) end
				rectfill2(x, y, w, w, color)
			end
		end
	end

	local function _enter()
		loaded = false

		local copy_messages = copy(loading_messages)
		messages_str = ""
		messages_x = 128
		while #copy_messages > 0 do
			local m = rnd(copy_messages)
			messages_str ..=  m .. "                "
			del(copy_messages, m)
		end
		messages_str ..= "tHANK YOU FOR YOUR PATIENCE"

		custom_font()
		startcoroutine(create_board)
	end

	local function _update()
		messages_x -= 2
		if loaded then
			set_state(states.game, board)
		end
	end

	local function  _draw()
		cls()

		board:draw_bg()
		draw_tiles(board)

		local l = print(message, 0, -100)
		if not loaded then
			print(messages_str, messages_x, 50, 7, 0)
			-- print(spinner[t()\.25%4+1], 120, 120)
		end
	end

	return {
		_enter = _enter,
		_update = _update,
		_draw = _draw,
	}
end