feat: add Nodes.new, Nodes.isFallow and Noise.propagate

src/nodes.lua

@@ -0,0 +1,75 @@
+-- Renewable resource nodes scattered on the map: an ore vein pays out
+-- crafting essence (crafting.lua's forging currency) and a gem seam yields a
+-- raw tier-1 gem outright, both without spending a single turn in combat -
+-- a genuine second income alongside killing monsters (Crafting.essenceFor),
+-- not a strictly better replacement for it. Each node holds a fixed number
+-- of charges before it plays out; a played-out node does not vanish, it goes
+-- fallow and slowly reopens on its own, so a floor already cleared of
+-- monsters still rewards a return visit. Nodes are plain data on
+-- level.nodes, exactly like level.shrines and level.cauldrons, so they
+-- serialize with no special save-format handling.
+
+local Crafting = require("crafting")
+
+local Nodes = {}
+
+Nodes.ORE = "ore"
+Nodes.GEM = "gem"
+
+Nodes.glyphs = { [Nodes.ORE] = "O", [Nodes.GEM] = "M" }
+
+Nodes.MAX_CHARGES = 3
+Nodes.REGEN_TURNS = 40
+Nodes.ORE_YIELD_MIN = 3
+Nodes.ORE_YIELD_MAX = 7
+
+-- A freshly placed node at full charges, never on cooldown. Builder stamps
+-- x/y directly onto the returned table, matching how it stamps every other
+-- floor feature (shrines, cauldrons, vault levers).
+function Nodes.new(kind, element)
+  return { kind = kind, element = element, charges = Nodes.MAX_CHARGES, cooldown = 0 }
+end
+
+function Nodes.isFallow(node)
+  return node.charges <= 0
+end
+
+function Nodes.glyph(node)
+  return Nodes.glyphs[node.kind]
+end
+
+-- Extracts one charge's worth of resource from `node` into `game.player`.
+-- Returns (false, line) without touching the node when it has nothing left
+-- to give, or (true, line) once a charge is spent - dropping the node into
+-- cooldown the instant that spends its last one.
+function Nodes.harvest(game, node)
+  if Nodes.isFallow(node) then
+    return false, "the vein is played out; give it time to reopen"
+  end
+  node.charges = node.charges - 1
+  if node.charges <= 0 then node.cooldown = Nodes.REGEN_TURNS end
+  local player = game.player
+  if node.kind == Nodes.ORE then
+    local amount = math.floor(game.rng:range(Nodes.ORE_YIELD_MIN, Nodes.ORE_YIELD_MAX) * game:essenceMultiplier())
+    player.essence = player.essence + amount
+    return true, string.format("you chip %d essence from the ore vein", amount)
+  end
+  local gem = Crafting.gem(node.element, 1)
+  player.inventory[#player.inventory + 1] = gem
+  return true, "you pry a " .. gem.name .. " loose from the seam"
+end
+
+-- Advances every fallow node's cooldown one world round, exactly like
+-- hazards.step advances fire and gas - called once per round, not per actor,
+-- so a seeded run always reopens a vein on the identical turn regardless of
+-- how many actors acted that round.
+function Nodes.step(level)
+  for _, node in ipairs(level.nodes) do
+    if node.cooldown > 0 then
+      node.cooldown = node.cooldown - 1
+      if node.cooldown <= 0 then node.charges = Nodes.MAX_CHARGES end
+    end
+  end
+end
+
+return Nodes