new function

functions/biter_raffle.lua

@@ -0,0 +1,143 @@
+--[[
+Use roll(entity_type, evolution_factor), to get a fitting enemy for the current or custom evolution factor.
+
+entity_type 		- can be "spitter", "biter", "mixed", "worm"
+evolution_factor 	- custom evolution factor (optional)
+]]
+
+local Public = {}
+
+local math_random = math.random
+local math_floor = math.floor
+
+local function get_biter_raffle_table(level)
+	local raffle = {
+		["small-biter"] = 1000 - level * 1.75,		
+		["medium-biter"] = level,		
+		["big-biter"] = 0,		
+		["behemoth-biter"] = 0,
+	}
+	
+	if level > 500 then
+		raffle["medium-biter"] = 500 - (level - 500)
+		raffle["big-biter"] = (level - 500) * 2
+	end
+	if level > 900 then
+		raffle["behemoth-biter"] = (level - 900) * 3
+	end
+	for k, v in pairs(raffle) do
+		if raffle[k] < 0 then raffle[k] = 0 end
+	end
+	return raffle
+end
+
+local function get_biter_name(evolution_factor)
+	local raffle = get_biter_raffle_table(math_floor(evolution_factor * 1000))
+	local max_chance = 0
+	for k, v in pairs(raffle) do
+		max_chance = max_chance + v
+	end
+	local r = math.random(0, math.floor(max_chance))	
+	local current_chance = 0
+	for k, v in pairs(raffle) do
+		current_chance = current_chance + v
+		if r <= current_chance then return k end
+	end
+end
+
+local function get_spitter_raffle_table(level)
+	local raffle = {
+		["small-spitter"] = 1000 - level * 1.75,		
+		["medium-spitter"] = level,		
+		["big-spitter"] = 0,		
+		["behemoth-spitter"] = 0,
+	}
+	
+	if level > 500 then
+		raffle["medium-spitter"] = 500 - (level - 500)
+		raffle["big-spitter"] = (level - 500) * 2
+	end
+	if level > 900 then
+		raffle["behemoth-spitter"] = (level - 900) * 3
+	end
+	for k, v in pairs(raffle) do
+		if raffle[k] < 0 then raffle[k] = 0 end
+	end
+	return raffle
+end
+
+local function get_spitter_name(evolution_factor)
+	local raffle = get_spitter_raffle_table(math_floor(evolution_factor * 1000))
+	local max_chance = 0
+	for k, v in pairs(raffle) do
+		max_chance = max_chance + v
+	end
+	local r = math.random(0, math.floor(max_chance))	
+	local current_chance = 0
+	for k, v in pairs(raffle) do
+		current_chance = current_chance + v
+		if r <= current_chance then return k end
+	end
+end
+
+local function get_worm_raffle_table(level)
+	local raffle = {
+		["small-worm-turret"] = 1000 - level * 1.75,		
+		["medium-worm-turret"] = level,		
+		["big-worm-turret"] = 0,		
+		["behemoth-worm-turret"] = 0,
+	}
+	
+	if level > 500 then
+		raffle["medium-worm-turret"] = 500 - (level - 500)
+		raffle["big-worm-turret"] = (level - 500) * 2
+	end
+	if level > 900 then
+		raffle["behemoth-worm-turret"] = (level - 900) * 3
+	end
+	for k, v in pairs(raffle) do
+		if raffle[k] < 0 then raffle[k] = 0 end
+	end
+	return raffle
+end
+
+local function get_worm_name(evolution_factor)
+	local raffle = get_worm_raffle_table(math_floor(evolution_factor * 1000))
+	local max_chance = 0
+	for k, v in pairs(raffle) do
+		max_chance = max_chance + v
+	end
+	local r = math.random(0, math.floor(max_chance))	
+	local current_chance = 0
+	for k, v in pairs(raffle) do
+		current_chance = current_chance + v
+		if r <= current_chance then return k end
+	end
+end
+
+local function get_unit_name(evolution_factor)
+	if math_random(1, 3) == 1 then
+		return get_spitter_name(evolution_factor)
+	else
+		return get_biter_name(evolution_factor)
+	end
+end
+
+local type_functions = {
+	["spitter"] = get_spitter_name,
+	["biter"] = get_biter_name,
+	["mixed"] = get_unit_name,
+	["worm"] = get_worm_name,
+}
+
+function Public.roll(entity_type, evolution_factor)
+	if not entity_type then return end
+	if not type_functions[entity_type] then return end
+	local evo = evolution_factor
+	if not evo then evo = game.forces.enemy.evolution_factor end
+	
+	local name = type_functions[entity_type](evo)
+	game.print(name)
+end
+
+return Public