Add loot API and use it in tsm_railcorridors

mods/CORE/mcl_loot/description.txt

@@ -0,0 +1 @@
+API for filling a chest with random treasures.

mods/CORE/mcl_loot/init.lua

@@ -0,0 +1,89 @@
+mcl_loot = {}
+
+--[[
+Select a number of itemstacks out of a pool of treasure definitions randomly.
+
+Parameters:
+* loot_definitions: Probabilities and information about the loot to select. Syntax:
+
+{
+	stacks_min = 1,	-- Mamimum number of item stacks to get
+	stacks_max = 3, -- Number of repetitions, maximum
+	items = { -- Table of possible loot items. This function selects between stacks_min and stacks_max of these.
+		{
+		itemstring = "example:item1", -- Which item to select
+		amount_min = 1,		-- Minimum size of itemstack. Optional (default: 1)
+		amount_max = 10,	-- Maximum size of item stack. Must not exceed item definition's stack_max. Optional (default: 1)
+		wear_min = 1,		-- Minimum wear value. Must be at lest 1. Optional (default: no wear)
+		wear_max = 1,		-- Maxiumum wear value. Must be at lest 1. Optional (default: no wear)
+		weight = 5,		-- Likelihood of this item being selected
+		},
+		{ -- more tables like above, one table per item stack }
+	}
+}
+* pr: PseudoRandom object
+
+How weight works: The probability of a single item stack being selected is weight/total_weight, with
+total_weight being the sum of all weight values in the items table.
+
+Returns: Table of itemstrings
+]]
+function mcl_loot.get_loot(loot_definitions, pr)
+	local items = {}
+
+	local total_weight = 0
+	for i=1, #loot_definitions.items do
+		total_weight = total_weight + loot_definitions.items[i].weight
+	end
+
+	local stacks = pr:next(loot_definitions.stacks_min, loot_definitions.stacks_max)
+	for s=1, stacks do
+		local r = pr:next(1, total_weight)
+
+		local accumulated_weight = 0
+		local item
+		for i=1, #loot_definitions.items do
+			accumulated_weight = accumulated_weight + loot_definitions.items[i].weight
+			if accumulated_weight >= r then
+				item = loot_definitions.items[i]
+				break
+			end
+		end
+		if item then
+			local itemstring = item.itemstring
+			if item.amount_min and item.amount_max then
+				itemstring = itemstring .. " " .. pr:next(item.amount_min, item.amount_max)
+			end
+			if item.wear_min and item.wear_max then
+				if not item.amount_min and not item.amount_max then
+					itemstring = itemstring .. " 1"
+				end
+				itemstring = itemstring .. " " .. pr:next(item.wear_min, item.wear_max)
+			end
+			table.insert(items, itemstring)
+		else
+			minetest.log("error", "[mcl_loot] INTERNAL ERROR! Failed to select random loot item!")
+		end
+	end
+
+	return items
+end
+
+--[[
+Repeat mcl_loot.get_loot multiple times for various loot_definitions.
+Useful for filling chests.
+
+* multi_loot_definitions: Table of loot_definitions (see mcl_loot.get_loot)
+* pr: PseudoRandom object
+
+Returns: Table of itemstrings ]]
+function mcl_loot.get_multi_loot(multi_loot_definitions, pr)
+	local items = {}
+	for m=1, #multi_loot_definitions do
+		local group = mcl_loot.get_loot(multi_loot_definitions[m], pr)
+		for g=1, #group do
+			table.insert(items, group[g])
+		end
+	end
+	return items
+end

mods/CORE/mcl_loot/mod.conf

@@ -0,0 +1 @@
+name = mcl_loot

mods/MAPGEN/tsm_railcorridors/depends.txt

@@ -1,5 +1,6 @@
 mcl_init
 mcl_util
 mcl_core
+mcl_loot
 mcl_tnt
 mcl_farming

mods/MAPGEN/tsm_railcorridors/gameconfig.lua

@@ -30,69 +30,46 @@ end
 -- MineClone 2's treasure function. Gets all treasures for a single chest.
 -- Based on information from Minecraft Wiki.
 function tsm_railcorridors.get_treasures(pr)
-	local items = {}
+	local items = mcl_loot.get_multi_loot({
-	-- First roll
+	{
-	local r1 = pr:next(1,71)
+		stacks_min = 1,
-	if r1 <= 30 then
+		stacks_max = 1,
-		table.insert(items, "mobs:nametag")
+		items = {
-	elseif r1 <= 50 then
+			{ itemstring = "mobs:nametag", weight = 30 },
-		table.insert(items, "mcl_core:apple_gold")
+			{ itemstring = "mcl_core:apple_gold", weight = 20 },
-	elseif r1 <= 60 then
+			{ itemstring = "mcl_books:book", weight = 10 }, -- TODO: Enchanted Book
-		-- TODO: Enchanted Book
+			{ itemstring = "", weight = 5},
-		table.insert(items, "mcl_books:book")
+			{ itemstring = "mcl_core:pick_iron", weight = 5 },
-	elseif r1 <= 65 then
+			{ itemstring = "mcl:core:apple_gold", weight = 1 }, -- TODO: Enchanted Golden Apple
-		-- Nothing!
+		}
-	elseif r1 <= 70 then
+	},
-		table.insert(items, "mcl_tools:pick_iron")
+	{
-	else
+		stacks_min = 2,
-		-- TODO: Enchanted Golden Apple
+		stacks_max = 4,
-		table.insert(items, "mcl_core:apple_gold")
+		items = {
-	end
+			{ itemstring = "mcl_farming:bread", weight = 15, amount_min = 1, amount_max = 3 },
-
+			{ itemstring = "mcl_core:coal_lump", weight = 10, amount_min = 3, amount_max = 8 },
-	-- Second roll
+			{ itemstring = "mcl_farming:beetroot_seeds", weight = 10, amount_min = 2, amount_max = 4 },
-	local r2stacks = pr:next(2,4)
+			{ itemstring = "mcl_farming:melon_seeds", weight = 10, amount_min = 2, amount_max = 4 },
-	for i=1, r2stacks do
+			{ itemstring = "mcl_farming:pumpkin_seeds", weight = 10, amount_min = 2, amount_max = 4 },
-		local r2 = pr:next(1,83)
+			{ itemstring = "mcl_core:iron_ingot", weight = 10, amount_min = 1, amount_max = 5 },
-		if r2 <= 15 then
+			{ itemstring = "mcl_dye:bye", weight = 5, amount_min = 4, amount_max = 9 },
-			table.insert(items, "mcl_farming:bread "..pr:next(1,3))
+			{ itemstring = "mesecons:redstone", weight = 5, amount_min = 4, amount_max = 9 },
-		elseif r2 <= 25 then
+			{ itemstring = "mcl_core:gold_ingot", weight = 5, amount_min = 1, amount_max = 3 },
-			table.insert(items, "mcl_core:coal_lump "..pr:next(3,8))
+			{ itemstring = "mcl_core:diamond", weight = 3, amount_min = 1, amount_max = 2 },
-		elseif r2 <= 35 then
+		}
-			table.insert(items, "mcl_farming:beetroot_seeds "..pr:next(2,4))
+	},
-		elseif r2 <= 45 then
+	{
-			table.insert(items, "mcl_farming:melon_seeds "..pr:next(2,4))
+		stacks_min = 3,
-		elseif r2 <= 55 then
+		stacks_max = 3,
-			table.insert(items, "mcl_farming:pumpkin_seeds "..pr:next(2,4))
+		items = {
-		elseif r2 <= 65 then
+			{ itemstring = "mcl_minecarts:rail", weight = 20, amount_min = 4, amount_max = 8 },
-			table.insert(items, "mcl_core:iron_ingot "..pr:next(1,5))
+			{ itemstring = "mcl_torches:torch", weight = 15, amount_min = 1, amount_max = 16 },
-		elseif r2 <= 70 then
+			{ itemstring = "mcl_minecarts:rail", weight = 5, amount_min = 1, amount_max = 4 }, -- TODO: Activator Rail
-			table.insert(items, "mcl_dye:blue "..pr:next(4,9))
+			{ itemstring = "mcl_minecarts:rail", weight = 5, amount_min = 1, amount_max = 4 }, -- TODO: Detector Rail
-		elseif r2 <= 75 then
+			{ itemstring = "mcl_minecarts:golden_rail", weight = 5, amount_min = 1, amount_max = 4 },
-			table.insert(items, "mesecons:redstone "..pr:next(4,9))
+		}
-		elseif r2 <= 80 then
+	}}, pr)
-			table.insert(items, "mcl_core:gold_ingot "..pr:next(1,3))
-		else
-			table.insert(items, "mcl_core:diamond "..pr:next(1,2))
-		end
-	end
-
-	-- Third roll
-	for i=1, 3 do
-		local r3 = pr:next(1,50)
-		if r3 <= 20 then
-			table.insert(items, "mcl_minecarts:rail "..pr:next(4,8))
-		elseif r3 <= 35 then
-			table.insert(items, "mcl_torches:torch "..pr:next(1,16))
-		elseif r3 <= 40 then
-			-- TODO: Activator Rail
-			table.insert(items, "mcl_minecarts:rail "..pr:next(1,4))
-		elseif r3 <= 45 then
-			-- TODO: Detector Rail
-			table.insert(items, "mcl_minecarts:rail "..pr:next(1,4))
-		else
-			table.insert(items, "mcl_minecarts:golden_rail "..pr:next(1,4))
-		end
-	end
 
 	return items
 end