big ass modding update

src/world/Encounter.lua

@@ -3,10 +3,21 @@
 -- rand(0..255) < map encounter rate; the slot is picked with the original
 -- probability buckets.
 
+local FieldDefaults = require("src.world.FieldDefaults")
+
 local Encounter = {}
 
--- cumulative slot thresholds out of 256 (engine/battle/wild_encounters.asm)
-local SLOT_BUCKETS = { 51, 102, 141, 166, 191, 216, 229, 242, 253, 256 }
+-- Cumulative slot thresholds out of 256 (engine/battle/wild_encounters.asm),
+-- now constants.encounterBuckets.  An encounter def may also carry its own
+-- `buckets` of any length, as long as the last entry is 256 and there are
+-- as many slots as buckets.
+local buckets = FieldDefaults.CONSTANTS.encounterBuckets
+
+-- Collision.load's idiom: the overworld hands the dataset over on entry so
+-- the pure roll stays free of a Data reference.
+function Encounter.load(data)
+  buckets = FieldDefaults.constant(data, "encounterBuckets")
+end
 
 function Encounter.roll(encounterDef, rng)
   rng = rng or love.math.random
@@ -15,7 +26,7 @@ function Encounter.roll(encounterDef, rng)
   if not grass or grass.rate == 0 then return nil end
   if rng(0, 255) >= grass.rate then return nil end
   local pick = rng(0, 255)
-  for i, threshold in ipairs(SLOT_BUCKETS) do
+  for i, threshold in ipairs(grass.buckets or buckets) do
     if pick < threshold then
       local slot = grass.slots[i]
       if slot then