MineClone2/mods/CORE/mcl_loot/init.lua

90 lines
2.8 KiB
Lua

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