101 lines
3.5 KiB
Lua
101 lines
3.5 KiB
Lua
mcl_loot = {}
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--[[
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Select a number of itemstacks out of a pool of treasure definitions randomly.
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Parameters:
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* loot_definitions: Probabilities and information about the loot to select. Syntax:
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{
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stacks_min = 1, -- Minimum number of item stacks to get. Default: 1
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stacks_max = 3, -- Maximum number of item stacks to get. Default: 1
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items = { -- Table of possible loot items. This function selects between stacks_min and stacks_max of these.
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{
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itemstring = "example:item1", -- Which item to select
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amount_min = 1, -- Minimum size of itemstack. Must not be larger than 6553. Optional (default: 1)
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amount_max = 10, -- Maximum size of item stack. Must not be larger than item definition's stack_max or 6553. Optional (default: 1)
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wear_min = 1, -- Minimum wear value. Must be at least 1. Optional (default: no wear)
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wear_max = 1, -- Maxiumum wear value. Must be at least 1. Optional (default: no wear)
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weight = 5, -- Likelihood of this item being selected (see below). Optional (default: 1)
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},
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{ -- more tables like above, one table per item stack }
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}
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}
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* pr: PseudoRandom object used for the randomness
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How weight works: The probability of a single item stack being selected is weight/total_weight, with
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total_weight being the sum of all weight values in the items table. If you leave out the weight for
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all items, the likelihood of each item being selected is equal.
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Returns: Table of itemstrings
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]]
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function mcl_loot.get_loot(loot_definitions, pr)
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local items = {}
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local total_weight = 0
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for i=1, #loot_definitions.items do
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total_weight = total_weight + (loot_definitions.items[i].weight or 1)
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end
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local stacks_min = loot_definitions.stacks_min
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local stacks_max = loot_definitions.stacks_max
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if not stacks_min then stacks_min = 1 end
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if not stacks_max then stacks_max = 1 end
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local stacks = pr:next(loot_definitions.stacks_min, loot_definitions.stacks_max)
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for s=1, stacks do
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local r = pr:next(1, total_weight)
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local accumulated_weight = 0
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local item
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for i=1, #loot_definitions.items do
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accumulated_weight = accumulated_weight + (loot_definitions.items[i].weight or 1)
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if accumulated_weight >= r then
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item = loot_definitions.items[i]
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break
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end
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end
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if item then
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local itemstring = item.itemstring
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if item.amount_min and item.amount_max then
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itemstring = itemstring .. " " .. pr:next(item.amount_min, item.amount_max)
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end
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if item.wear_min and item.wear_max then
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-- Sadly, PseudoRandom only allows very narrow ranges, so we set wear in steps of 10
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local wear_min = math.floor(item.wear_min / 10)
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local wear_max = math.floor(item.wear_max / 10)
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local wear = pr:next(wear_min, wear_max) * 10
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if not item.amount_min and not item.amount_max then
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itemstring = itemstring .. " 1"
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end
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itemstring = itemstring .. " " .. tostring(wear)
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end
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table.insert(items, itemstring)
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else
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minetest.log("error", "[mcl_loot] INTERNAL ERROR! Failed to select random loot item!")
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end
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end
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return items
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end
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--[[
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Repeat mcl_loot.get_loot multiple times for various loot_definitions.
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Useful for filling chests.
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* multi_loot_definitions: Table of loot_definitions (see mcl_loot.get_loot)
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* pr: PseudoRandom object used for the randomness
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Returns: Table of itemstrings ]]
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function mcl_loot.get_multi_loot(multi_loot_definitions, pr)
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local items = {}
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for m=1, #multi_loot_definitions do
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local group = mcl_loot.get_loot(multi_loot_definitions[m], pr)
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for g=1, #group do
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table.insert(items, group[g])
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end
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end
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return items
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end
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