ComfyFactorio/maps/scrapyard/collapse.lua

local Global = require 'utils.global'
local Public = {}

local math_floor = math.floor
local table_shuffle_table = table.shuffle_table

local collapse = {}
Global.register(
    collapse,
    function(tbl)
        collapse = tbl
    end
)

local directions = {
	["north"] = function(position)
		local width = collapse.surface.map_gen_settings.width
		if width > collapse.max_line_size then width = collapse.max_line_size end
		local a = width * 0.5 + 1
		collapse.vector = {0, -1}
		collapse.area = {{position.x - a, position.y - 1}, {position.x + a, position.y}}
	end,
	["south"] = function(position)
		local width = collapse.surface.map_gen_settings.width
		if width > collapse.max_line_size then width = collapse.max_line_size end
		local a = width * 0.5 + 1
		collapse.vector = {0, 1}
		collapse.area = {{position.x - a, position.y}, {position.x + a, position.y + 1}}
	end,
	["west"] = function(position)
		local width = collapse.surface.map_gen_settings.height
		if width > collapse.max_line_size then width = collapse.max_line_size end
		local a = width * 0.5 + 1
		collapse.vector = {-1, 0}
		collapse.area = {{position.x - 1, position.y - a}, {position.x, position.y + a}}
	end,
	["east"] = function(position)
		local width = collapse.surface.map_gen_settings.height
		if width > collapse.max_line_size then width = collapse.max_line_size end
		local a = width * 0.5 + 1
		collapse.vector = {1, 0}
		collapse.area = {{position.x, position.y - a}, {position.x + 1, position.y + a}}
	end,
}

local function print_debug(a)
	print("Collapse error #" .. a)
end

local function set_collapse_tiles(surface)
	game.forces.player.chart(surface, collapse.area)
	collapse.tiles = surface.find_tiles_filtered({area = collapse.area})
	if not collapse.tiles then return end
	collapse.size_of_tiles = #collapse.tiles
	if collapse.size_of_tiles > 0 then table_shuffle_table(collapse.tiles) end
	collapse.position = {x = collapse.position.x + collapse.vector[1], y = collapse.position.y + collapse.vector[2]}
	local v = collapse.vector
	local area = collapse.area
	collapse.area = {{area[1][1] + v[1], area[1][2] + v[2]}, {area[2][1] + v[1], area[2][2] + v[2]}}
	game.forces.player.chart(surface, collapse.area)
end

local function progress()
	local surface = collapse.surface

	if not collapse.start_now then return end

	local tiles = collapse.tiles
	if not tiles then
		set_collapse_tiles(surface)
		tiles = collapse.tiles
	end
	if not tiles then return end

	for _ = 1, collapse.amount, 1 do
		local tile = tiles[collapse.size_of_tiles]
		if not tile then collapse.tiles = nil return end
		collapse.size_of_tiles = collapse.size_of_tiles - 1
		if not tile.valid then return end
		if collapse.kill then
			local position = {tile.position.x + 0.5, tile.position.y + 0.5}
			for _, e in pairs(surface.find_entities_filtered({area = {{position[1] - 2, position[2] - 2}, {position[1] + 2, position[2] + 2}}})) do
				if e.valid and e.health then e.die() end
			end
		end
		surface.set_tiles({{name = "out-of-map", position = tile.position}}, true)
	end
end

function Public.set_surface(surface)
	if not surface then print_debug(1) return end
	if not surface.valid then print_debug(2) return end
	if not game.surfaces[surface.index] then print_debug(3) return end
	collapse.surface = surface
end

function Public.set_direction(direction)
	if not directions[direction] then print_debug(11) return end
	directions[direction](collapse.position)
end

function Public.set_speed(speed)
	if not speed then print_debug(8) return end
	speed = math_floor(speed)
	if speed < 1 then speed = 1 end
	collapse.speed = speed
end

function Public.set_amount(amount)
	if not amount then print_debug(9) return end
	amount = math_floor(amount)
	if amount < 0 then amount = 0 end
	collapse.amount = amount
end

function Public.set_position(position)
	if not position then print_debug(4) return end
	if not position.x and not position[1] then print_debug(5) return end
	if not position.y and not position[2] then print_debug(6) return end
	local x = 0
	local y = 0
	if position[1] then x = position[1] end
	if position[2] then y = position[2] end
	if position.x then x = position.x end
	if position.y then y = position.y end
	collapse.position = {x = x, y = y}
end

function Public.get_position()
	return collapse.position
end

function Public.start_now(status)
	if status == true then
		collapse.start_now = true
	elseif status == false then
		collapse.start_now = false
	end
	return collapse.start_now
end

function Public.set_max_line_size(size)
	if not size then print_debug(22) return end
	size = math_floor(size)
	if size <= 0 then print_debug(21) return end
	collapse.max_line_size = size
end

function Public.set_kill_entities(a)
	collapse.kill = a
end

local function on_init()
	Public.set_surface(game.surfaces.nauvis)
	Public.set_position({0, 32})
	Public.set_max_line_size(256)
	Public.set_direction("north")
	Public.set_kill_entities(true)
	collapse.tiles = nil
	collapse.speed = 1
	collapse.amount = 8
	collapse.start_now = false
end

local function on_tick()
	if game.tick % collapse.speed ~= 0 then return end
	progress()
end

local Event = require 'utils.event'
Event.on_init(on_init)
Event.add(defines.events.on_tick, on_tick)

return Public