feat(mods): extend contextual field actions

docs/mod-api-gen2-compat.md

@@ -486,9 +486,11 @@ has its own entry points for (`start_battle "wild" species level`, `warp`,
 **by name, before the first row runs**, so a mod never gets a half-run queue.
 `marchInPlace` still has no Gen 2 equivalent (the Gen 2 movement stream has no
 byte for it) and returns `nil, reason` rather than approximating one.
-`availableFieldActions` and `useFieldAction` expose the same contextual
+`availableFieldActions` and `useFieldAction` expose the same contextual field
-bicycle and fishing records in both games. Each engine keeps ownership of its
+item and move records in both games. Gold extends the shared ids with its own
-inventory, terrain, surfing, bike, and fishing rules.
+`headbutt`, `whirlpool`, `waterfall`, `sweet_scent`, and `squirtbottle`
+actions. Each engine keeps ownership of its inventory, badges, terrain,
+surfing, bike, fishing, and field-move rules.
 
 **Hooks and events that fire on Gold.** Every name below is the Gen 1 name
 carrying the Gen 1 payload keys, because Gold's call sites reuse them rather

docs/modding.md

@@ -147,19 +147,23 @@ Companion UIs and alternate party screens can call
 operation is accepted only during idle overworld play; menus, movement,
 scripts, battles, and transitions leave the party untouched.
 
-## Contextual field items
+## Contextual field actions
 
-`mod.world:availableFieldActions()` returns the field items that can start at
+`mod.world:availableFieldActions()` returns the field items and moves that can
-the player's current position. Red and Gold currently expose `bicycle` and
+start at the player's current position. Both games expose `bicycle`, `fish`,
-`fish`; fishing rows include the owned rods that are valid choices. The list
+`cut`, `surf`, `strength`, `flash`, `dig`, and `teleport`; Gold additionally
-is empty while the world is busy, while riding states or terrain forbid an
+exposes `headbutt`, `whirlpool`, `waterfall`, `sweet_scent`, and the
-action, or when the required item is not owned.
+contextual `squirtbottle` key item. Fishing rows include the owned rods that
+are valid choices. The list is empty while the world is busy, and omits an
+action whenever its item, move, badge, terrain, or engine state forbids it.
 
 Call `mod.world:useFieldAction(id, opts)` to perform a listed action through
 the active game's own field-item path. Fishing accepts `{ rod = "OLD_ROD" }`
 and chooses automatically when only one rod is available. Invalid, stale, and
 busy requests return `nil` plus a reason without changing game state. Mods do
-not need generation-specific bike, collision, or fishing logic.
+not need generation-specific badge, terrain, bike, fishing, or field-move
+logic. Action lists are extensible; callers should render the records they
+understand and ignore unknown ids rather than assuming a fixed list length.
 
 ## Rendering pipelines
 

src/ui/PartyMenu.lua

@@ -454,30 +454,7 @@ function PartyMenu:update(dt)
           refuseBadge(self)
           return
         end
-        local TextBox = require("src.render.TextBox")
+        ow:useFlashFieldMove(function() self:close() end)
-        local Transition = require("src.render.Transition")
-        -- .flash prints on any map, but the light it records is this map's:
-        -- home/overworld.asm re-arms wMapPalOffset on the next dark map, so
-        -- a FLASH used in daylight must not carry into Rock Tunnel
-        local wasDark = ow and ow.dark
-        if wasDark then self.game.save.flashLit = true end
-        self.game.stack:push(TextBox.new(self.game,
-          self.game.data.text._FlashLightsAreaText
-          or Strings("A blinding FLASH\nlights the area!"), function()
-            self:close()
-            -- setDark, not a bare field write: ADVANCED carries the darkness
-            -- in a baked atlas, so lighting the cave drops every resident map
-            -- and rebakes this one (#383).  It runs HERE, before the blink,
-            -- because start_sub_menus.asm .flash clears wMapPalOffset before
-            -- PrintText and blinks last of all: the cave is already lit by the
-            -- time GBPalWhiteOutWithDelay3 runs.  Hanging the rebuild off the
-            -- blink's completion instead left that rebuild's whole cost --
-            -- seconds of per-pixel atlas baking on a phone -- on screen as a
-            -- solid white frame with nothing under it, which reads as a
-            -- lockup (#610).
-            if wasDark then ow:setDark(false) end
-            self.game.stack:push(Transition.whiteFlash(self.game))
-          end))
         return
       elseif action == "surf" then
         -- start_sub_menus.asm .surf: SOULBADGE-gated (useSurfFieldMove),
@@ -505,12 +482,7 @@ function PartyMenu:update(dt)
           -- GBPalWhiteOutWithDelay3 blink, and the simulated pad press
           -- steps the player forward onto land (or across a connection
           -- strip when the shore is the next map's edge)
-          self.game.stack:pop()
+          ow:stopSurfing(function() self.game.stack:pop() end)
-          ow.player.surfing = false
-          require("src.core.Music").setSurfing(self.game.data, false)
-          self.game.stack:push(Transition.whiteFlash(self.game, nil, function()
-            ow:stepForwardOrCrossEdge(ow.player.facing)
-          end))
           return
         end
         local TextBox = require("src.render.TextBox")
@@ -571,26 +543,7 @@ function PartyMenu:update(dt)
           refuseBadge(self)
           return
         end
-        local TextBox = require("src.render.TextBox")
+        ow:useStrengthFieldMove(mon, function() self:close() end)
-        local Transition = require("src.render.Transition")
-        local def = self.game.data.pokemon[mon.species]
-        local name = mon.nickname or def.name
-        ow.strengthActive = true
-        local t1 = (self.game.data.text._UsedStrengthText
-          or Strings("{RAM:wNameBuffer} used\nSTRENGTH.")):gsub("{RAM:wNameBuffer}", name)
-        local t2 = (self.game.data.text._CanMoveBouldersText
-          or Strings("{RAM:wNameBuffer} can\nmove boulders.")):gsub("{RAM:wNameBuffer}", name)
-        -- like surf (#320, #385): both texts print with the party menu
-        -- still on screen, and the blink IS the menu closing afterwards,
-        -- not a flashbang on the empty map
-        self.game.stack:push(TextBox.new(self.game, t1, function()
-          self.game.stack:push(TextBox.new(self.game, t2, function()
-            self:close()
-            self.game.stack:push(Transition.whiteFlash(self.game))
-          end))
-        end, { auto = { sound = function()
-          return require("src.core.Sound").playCry(self.game.data, mon.species)
-        end } }))
         return
       elseif action == "softboiled" then
         -- field SOFTBOILED (StartMenu_Pokemon .softboiled): transfer

src/world/OverworldController.lua

@@ -784,6 +784,49 @@ function OverworldState:useBicycle()
   return true
 end
 
+-- Field-move entry points keep presentation and state transitions in the
+-- overworld.  The party menu and supported mod facade both call these, so a
+-- shortcut cannot drift from the game's own move flow.
+function OverworldState:useFlashFieldMove(onClose)
+  -- A FLASH used in daylight must not carry into the next dark map.  Lighting
+  -- also happens before the blink: setDark may rebake an ADVANCED atlas, and
+  -- putting that work in WhiteFlash:onDone caused the frozen white frame in
+  -- #610.
+  local wasDark = self.dark
+  if wasDark then Game.save.flashLit = true end
+  Game.stack:push(TextBox.new(Game,
+    Game.data.text._FlashLightsAreaText
+      or Strings("A blinding FLASH\nlights the area!"), function()
+      if onClose then onClose() end
+      if wasDark then self:setDark(false) end
+      Game.stack:push(Transition.whiteFlash(Game))
+    end))
+  return true
+end
+
+function OverworldState:useStrengthFieldMove(mon, onClose)
+  mon = mon or self:partyKnows("STRENGTH")
+  if not mon then return false end
+  local def = Game.data.pokemon[mon.species]
+  local name = mon.nickname or def.name
+  self.strengthActive = true
+  local first = (Game.data.text._UsedStrengthText
+    or Strings("{RAM:wNameBuffer} used\nSTRENGTH."))
+    :gsub("{RAM:wNameBuffer}", name)
+  local second = (Game.data.text._CanMoveBouldersText
+    or Strings("{RAM:wNameBuffer} can\nmove boulders."))
+    :gsub("{RAM:wNameBuffer}", name)
+  Game.stack:push(TextBox.new(Game, first, function()
+    Game.stack:push(TextBox.new(Game, second, function()
+      if onClose then onClose() end
+      Game.stack:push(Transition.whiteFlash(Game))
+    end))
+  end, { auto = { sound = function()
+    return require("src.core.Sound").playCry(Game.data, mon.species)
+  end } }))
+  return true
+end
+
 -- The battle transition's dungeon wipe uses the explicit map lists in
 -- data/maps/dungeon_maps.asm (field.dungeonTransitionMaps): singles plus
 -- inclusive map-id ranges -- faithful to the original's omissions
@@ -2500,6 +2543,15 @@ function OverworldState:trySurf(fx, fy, onClose)
   end))
 end
 
+function OverworldState:stopSurfing(onClose)
+  if onClose then onClose() end
+  self.player.surfing = false
+  require("src.core.Music").setSurfing(Game.data, false)
+  Game.stack:push(Transition.whiteFlash(Game, nil, function()
+    self:stepForwardOrCrossEdge(self.player.facing)
+  end))
+end
+
 function OverworldState:tryCut(fx, fy)
   -- UsedCut (engine/overworld/cut.asm) gates on the TILESET before
   -- anything else: only OVERWORLD (tree tile $3d) and GYM (plant tile

src/world/WorldAPI.lua

@@ -6,6 +6,8 @@
 -- stays unsupported; anything a mod legitimately needs belongs here.
 
 local Logger = require("src.core.Logger")
+local FieldDefaults = require("src.world.FieldDefaults")
+local Map = require("src.world.Map")
 local MapLoader = require("src.world.MapLoader")
 local MapOverview = require("src.world.MapOverview")
 local Party = require("src.pokemon.Party")
@@ -15,6 +17,8 @@ local WorldAPI = {}
 WorldAPI.__index = WorldAPI
 
 local NO_OVERWORLD = "no overworld"
+local DIG_TILESETS = { FOREST = true, CEMETERY = true, CAVERN = true,
+                       FACILITY = true, INTERIOR = true }
 local RODS = { "OLD_ROD", "GOOD_ROD", "SUPER_ROD" }
 
 local function acceptsMenuInput(game, ow)
@@ -115,6 +119,30 @@ function WorldAPI:availableFieldActions()
       out[#out + 1] = { id = "fish", label = "FISH", rods = rods }
     end
   end
+
+  if ow:useCutFieldMove() == "ok" then
+    out[#out + 1] = { id = "cut", label = "CUT" }
+  end
+  local surf = ow:useSurfFieldMove()
+  if surf == "ok" or surf == "dismount" then
+    out[#out + 1] = { id = "surf",
+      label = surf == "dismount" and "LEAVE WATER" or "SURF" }
+  end
+
+  if not ow.strengthActive and ow:partyKnows("STRENGTH") then
+    out[#out + 1] = { id = "strength", label = "STRENGTH" }
+  end
+  if ow.dark and ow:partyKnows("FLASH") then
+    out[#out + 1] = { id = "flash", label = "FLASH" }
+  end
+  if DIG_TILESETS[ow.map.def.tileset] and ow.map.id ~= "AGATHAS_ROOM"
+      and ow:partyKnows("DIG") then
+    out[#out + 1] = { id = "dig", label = "DIG" }
+  end
+  if ow:partyKnows("TELEPORT") and Map.isOutside(ow.map.def,
+      FieldDefaults.field(game.data, "outsideTilesets")) then
+    out[#out + 1] = { id = "teleport", label = "TELEPORT" }
+  end
   return out
 end
 
@@ -130,6 +158,19 @@ function WorldAPI:useFieldAction(id, opts)
 
   if id == "bicycle" then
     if ow:useBicycle() then return true end
+  elseif id == "cut" then
+    local x, y = ow.player:facingCell()
+    if ow:tryCut(x, y) then return true end
+  elseif id == "surf" then
+    local mode = ow:useSurfFieldMove()
+    if mode == "dismount" then
+      ow:stopSurfing()
+      return true
+    elseif mode == "ok" then
+      local x, y = ow.player:facingCell()
+      ow:trySurf(x, y)
+      return true
+    end
   elseif id == "fish" then
     local rod = opts and opts.rod
     if not rod and #found.rods == 1 then rod = found.rods[1].id end
@@ -137,6 +178,13 @@ function WorldAPI:useFieldAction(id, opts)
       if choice.id == rod and ow:useFishingRod(rod) then return true end
     end
     return nil, "fishing rod unavailable"
+  elseif id == "strength" then
+    if ow:useStrengthFieldMove() then return true end
+  elseif id == "flash" then
+    if ow:useFlashFieldMove() then return true end
+  elseif id == "dig" or id == "teleport" then
+    ow:beginTeleportOut()
+    return true
   end
   return nil, "field action unavailable"
 end

src/world/gen2/WorldAPI.lua

@@ -36,6 +36,18 @@ WorldAPI.__index = WorldAPI
 
 local NO_OVERWORLD = "no overworld"
 local RODS = { "OLD_ROD", "GOOD_ROD", "SUPER_ROD" }
+local FIELD_ACTIONS = {
+  { id = "cut", move = "CUT" },
+  { id = "surf", move = "SURF" },
+  { id = "strength", move = "STRENGTH" },
+  { id = "flash", move = "FLASH" },
+  { id = "headbutt", move = "HEADBUTT" },
+  { id = "whirlpool", move = "WHIRLPOOL" },
+  { id = "waterfall", move = "WATERFALL" },
+  { id = "sweet_scent", move = "SWEET_SCENT" },
+  { id = "dig", move = "DIG" },
+  { id = "teleport", move = "TELEPORT" },
+}
 
 function WorldAPI.new(game, modId)
   return setmetatable({ game = game, modId = modId }, WorldAPI)
@@ -96,6 +108,26 @@ function WorldAPI:availableFieldActions()
       out[#out + 1] = { id = "fish", label = "FISH", rods = rods }
     end
   end
+
+  for _, row in ipairs(FIELD_ACTIONS) do
+    if not (row.move == "STRENGTH" and world.strengthActive) then
+      local mon = FieldMoves.partyMoveUser(context.party, row.move, context)
+      if mon then
+        context.mon = mon
+        local result = FieldMoves.fromMenu(row.move, context)
+        if result.ok then
+          out[#out + 1] = { id = row.id,
+            label = row.move:gsub("_", " ") }
+        end
+      end
+    end
+  end
+
+  if (inventory.SQUIRTBOTTLE or 0) > 0
+      and world:squirtbottleTreeScript() then
+    out[#out + 1] = { id = "squirtbottle",
+      label = itemLabel(game, "SQUIRTBOTTLE") }
+  end
   return out
 end
 
@@ -123,6 +155,18 @@ function WorldAPI:useFieldAction(id, opts)
       end
     end
     return nil, "fishing rod unavailable"
+  elseif id == "squirtbottle" then
+    local outcome = world:useFieldItem("SQUIRTBOTTLE")
+    if outcome and outcome ~= "nowhere" then return true end
+  end
+  for _, row in ipairs(FIELD_ACTIONS) do
+    if row.id == id then
+      local context = world:fieldContext()
+      local mon = FieldMoves.partyMoveUser(context.party, row.move, context)
+      local result = mon and world:useFieldMove(row.move, mon)
+      if result and result.ok then return true end
+      return nil, "field action unavailable"
+    end
   end
   return nil, "field action unavailable"
 end

tests/modkit/cases/world_field_items.lua

@@ -1,11 +1,13 @@
--- Contextual bicycle and fishing actions share one public contract in both
+-- Contextual field actions share one public contract in both generations
--- generations while each engine keeps ownership of its own field-item path.
+-- while each engine keeps ownership of its own field-item and move paths.
 
 package.path = "./?.lua;./?/init.lua;" .. package.path
 
-local T = require("tests.harness").suite("mod world field items")
+local T = require("tests.harness").suite("mod world field actions")
 
 local facingWater = false
+local redCut, redSurf = false, "no_water"
+local redMoves = {}
 local redWorld = {
   isOverworld = true,
   map = { id = "ROUTE_1", def = { tileset = "OVERWORLD" } },
@@ -14,11 +16,15 @@ local redWorld = {
   scriptMoves = {},
   bikeAllowed = function() return true end,
   facingIsShoreOrWater = function() return facingWater end,
+  useCutFieldMove = function() return redCut and "ok" or "nothing" end,
+  useSurfFieldMove = function() return redSurf end,
+  partyKnows = function(_, move) return redMoves[move] end,
   useBicycle = function(self) self.bikeUsed = true return true end,
   useFishingRod = function(self, rod) self.rodUsed = rod return true end,
 }
 local redGame = {
-  data = { items = { OLD_ROD = { name = "OLD ROD" } } },
+  data = { field = { outsideTilesets = { "OVERWORLD" } },
+    items = { OLD_ROD = { name = "OLD ROD" } } },
   save = { player = { name = "RED" }, party = {},
     inventory = { BICYCLE = 1, OLD_ROD = 1 } },
   stack = { states = { redWorld } },
@@ -30,8 +36,11 @@ local RedAPI = require("src.world.WorldAPI")
 local red = RedAPI.new(redGame, "fixture")
 local RedWorld = require("src.world.OverworldController")
 T.check(type(RedWorld.useBicycle) == "function"
-    and type(RedWorld.useFishingRod) == "function",
+    and type(RedWorld.useFishingRod) == "function"
-  "Red keeps field-item execution in its world")
+    and type(RedWorld.useFlashFieldMove) == "function"
+    and type(RedWorld.useStrengthFieldMove) == "function"
+    and type(RedWorld.stopSurfing) == "function",
+  "Red keeps field-action execution in its world")
 local actions = red:availableFieldActions()
 T.eq(actions[1].id, "bicycle", "Red lists an owned usable bicycle")
 T.check(red:useFieldAction("bicycle"), "Red accepts the listed bicycle")
@@ -55,26 +64,98 @@ ok, err = red:useFieldAction("bicycle")
 T.check(not ok and err == "world is busy",
   "Red refuses a stale action while busy")
 
+redWorld.player.moving = false
+facingWater, redCut, redSurf = false, true, "ok"
+redWorld.dark = true
+for _, move in ipairs({ "STRENGTH", "FLASH", "TELEPORT" }) do
+  redMoves[move] = { species = "MEW", moves = { { id = move } } }
+end
+redWorld.player.facingCell = function() return 4, 5 end
+redWorld.tryCut = function(self) self.cutUsed = true return true end
+redWorld.trySurf = function(self) self.surfUsed = true end
+redWorld.useStrengthFieldMove = function(self) self.strengthUsed = true return true end
+redWorld.useFlashFieldMove = function(self) self.flashUsed = true return true end
+redWorld.beginTeleportOut = function(self) self.teleportUsed = true end
+actions = red:availableFieldActions()
+local byId = {}
+for _, action in ipairs(actions) do byId[action.id] = action end
+T.check(byId.cut and byId.surf and byId.strength and byId.flash
+    and byId.teleport, "Red lists field moves that can start now")
+for _, id in ipairs({ "cut", "surf", "strength", "flash", "teleport" }) do
+  T.check(red:useFieldAction(id), "Red accepts listed " .. id)
+end
+T.check(redWorld.cutUsed and redWorld.surfUsed and redWorld.strengthUsed
+    and redWorld.flashUsed and redWorld.teleportUsed,
+  "Red delegates every move to its overworld path")
+
+redSurf = "dismount"
+redWorld.player.surfing = true
+redWorld.stopSurfing = function(self) self.dismounted = true end
+T.check(red:useFieldAction("surf") and redWorld.dismounted,
+  "Red delegates the contextual SURF dismount")
+redWorld.player.surfing, redSurf = false, "ok"
+
+redCut = false
+ok, err = red:useFieldAction("cut")
+T.check(not ok and err == "field action unavailable",
+  "Red revalidates a stale field move")
+
+redWorld.map.id = "ROCK_TUNNEL_1F"
+redWorld.map.def.tileset = "CAVERN"
+redMoves.DIG = { species = "MEW", moves = { { id = "DIG" } } }
+redWorld.beginTeleportOut = function(self) self.digUsed = true end
+byId = {}
+for _, action in ipairs(red:availableFieldActions()) do byId[action.id] = action end
+T.check(byId.dig and not byId.teleport,
+  "Red distinguishes dungeon DIG from outdoor TELEPORT")
+T.check(red:useFieldAction("dig") and redWorld.digUsed,
+  "Red delegates DIG to its escape path")
+
 local goldWorld = {
   map = { id = "ROUTE_29", def = { environment = "ROUTE" } },
   player = {}, playerState = "normal",
   acceptsMenuInput = function() return true end,
   playerCollision = function() return 0x00 end,
   alwaysOnBike = function() return false end,
-  fieldContext = function() return { facingColl = 0x20 } end,
   useFieldItem = function(self, item) self.itemUsed = item return "used" end,
+  squirtbottleTreeScript = function() return { { op = "end" } } end,
+  useFieldMove = function(self, move)
+    self.moveUsed = move
+    return { ok = true }
+  end,
 }
 local goldGame = {
-  data = { items = { OLD_ROD = { name = "OLD ROD" } } },
+  data = { items = { OLD_ROD = { name = "OLD ROD" },
-  save = { inventory = { BICYCLE = 1, OLD_ROD = 1 } },
+    SQUIRTBOTTLE = { name = "SQUIRTBOTTLE" } } },
+  save = { inventory = { BICYCLE = 1, OLD_ROD = 1, SQUIRTBOTTLE = 1 },
+    player = { badges = { FOG = true } },
+    party = { { moves = { { id = "SURF" }, { id = "SWEET_SCENT" },
+      { id = "TELEPORT" } } } } },
   world = goldWorld,
 }
+goldWorld.fieldContext = function(_, mon) return {
+  save = goldGame.save, party = goldGame.save.party, mon = mon,
+  facing = "right", facingColl = 0x29, playerColl = 0,
+  environment = "ROUTE", playerState = "normal", alwaysOnBike = false,
+  dark = false, canEscapeRope = false,
+} end
 
 local GoldAPI = require("src.world.gen2.WorldAPI")
 local gold = GoldAPI.new(goldGame, "fixture")
 actions = gold:availableFieldActions()
+byId = {}
+for _, action in ipairs(actions) do byId[action.id] = action end
 T.eq(actions[1].id, "bicycle", "Gold shares the bicycle action id")
-T.eq(actions[2].rods[1].id, "OLD_ROD", "Gold shares the rod shape")
+T.eq(actions[2].id, "fish", "Gold preserves the original action order")
+T.check(byId.surf and byId.sweet_scent and byId.teleport,
+  "Gold lists field moves through its generic dispatcher")
+T.eq(byId.fish.rods[1].id, "OLD_ROD", "Gold shares the rod shape")
+T.check(byId.squirtbottle,
+  "Gold lists the SquirtBottle only at its matching tree")
+T.check(gold:useFieldAction("sweet_scent"),
+  "Gold accepts a listed field move")
+T.eq(goldWorld.moveUsed, "SWEET_SCENT",
+  "Gold delegates moves to its own field-move path")
 T.check(gold:useFieldAction("fish", { rod = "OLD_ROD" }),
   "Gold accepts the same fishing request")
 T.eq(goldWorld.itemUsed, "OLD_ROD",
@@ -84,5 +165,9 @@ ok, err = gold:useFieldAction("fish", { rod = "SUPER_ROD" })
 T.check(not ok and err == "fishing rod unavailable",
   "Gold rejects an unowned rod")
 T.eq(goldWorld.itemUsed, used, "a rejected Gold rod changes nothing")
+T.check(gold:useFieldAction("squirtbottle"),
+  "Gold accepts the contextual SquirtBottle")
+T.eq(goldWorld.itemUsed, "SQUIRTBOTTLE",
+  "Gold delegates the SquirtBottle to its field-item path")
 
 T.finish()