Merge pull request #333 from johnjohto/fix-midstep-buttons

Gate overworld buttons on the completed step (#286)

src/world/OverworldController.lua

@@ -969,6 +969,24 @@ end
 function OverworldState:handleInput()
   local input = Game.input
 
+  -- the wall-bonk SFX cooldown ticks with any held direction, step or not
+  -- (it is a port invention, not part of JoypadOverworld, so the
+  -- wWalkCounter gate below must not freeze it mid-step)
+  if self:dirHeld() then
+    self.bumpCooldown = math.max(0, (self.bumpCooldown or 0) - 1)
+  end
+
+  -- OverworldLoop (home/overworld.asm) gates ALL of JoypadOverworld on
+  -- wWalkCounter == 0 ("if the player sprite has not yet completed the
+  -- walking animation" it jumps straight to .moveAhead): A, START and
+  -- direction initiation are only ever looked at while the player stands
+  -- on a tile, and a button pressed mid-step is simply never seen.
+  -- Without this gate a mid-step A/START pushed its TextBox/StartMenu
+  -- right there and froze Red between tiles, mid-animation (#286).  Held
+  -- directions need no buffering -- isDown below picks them up on the
+  -- landing frame.
+  if self.player.moving then return end
+
   if input:wasPressed("a") then
     self:interact()
     return
@@ -1005,7 +1023,6 @@ function OverworldState:handleInput()
           self.bumpCooldown = 16
         end
       end
-      self.bumpCooldown = math.max(0, (self.bumpCooldown or 0) - 1)
       return result
     end
   end

tests/parity_midstep_buttons.lua

@@ -0,0 +1,115 @@
+-- Parity test: A/START are never handled mid-step (#286).
+-- Self-contained: run via `luajit tests/parity_midstep_buttons.lua`; also
+-- dofile'd by tests/run_tests.lua's aggregator.
+--
+-- Oracle: home/overworld.asm OverworldLoop reads wWalkCounter and, when it
+-- is nonzero ("the player sprite has not yet completed the walking
+-- animation"), jumps straight to .moveAhead -- JoypadOverworld, and with
+-- it the START check, the A check, and every direction initiation, only
+-- ever runs while the player stands on a tile.  A button pressed mid-step
+-- is simply never seen.
+--
+-- The port ran handleInput() every frame regardless of player.moving, so a
+-- mid-step A/START press pushed its TextBox/StartMenu right there and
+-- froze Red between tiles, mid-animation (#286: running up to Nurse Joy
+-- and mashing A stops him half off the tile).
+--
+-- The invariant: while a step is in progress, A and START change nothing
+-- (no TextBox, no StartMenu, the step completes); once the player stands
+-- on the tile again, both work.
+
+package.path = "./?.lua;./?/init.lua;" .. package.path
+if not _G.love then _G.love = require("tests.love_stub") end
+local Data = require("src.core.Data")
+if not (Data.maps and Data.maps.PALLET_TOWN) then Data:load() end
+local S = require("tests.harness").suite("parity midstep buttons")
+local check, eq = S.check, S.eq
+
+require("src.render.Font").load(Data)
+local Game = require("src.core.Game")
+local Input = require("src.core.Input")
+local StateStack = require("src.core.StateStack")
+local Renderer = require("src.render.Renderer")
+local SaveData = require("src.core.SaveData")
+local OW = require("src.world.OverworldController")
+
+Game.data = Data
+Game.input = Input; Input:init()
+Game.renderer = Renderer; Renderer:init()
+Game.stack = StateStack
+StateStack:init()
+
+-- PALLET_TOWN (6,9) facing down: open grass, several free tiles south
+Game.save = SaveData.newGame()
+Game.stack:push(OW, "PALLET_TOWN", 6, 9, "down")
+local ow = Game.stack:top()
+
+local function step(pressedBtn)
+  -- the real driver: Game:step promotes pressQueue edges via Input:step()
+  -- (which also expires them) before stack:update
+  if pressedBtn then table.insert(Input.pressQueue, pressedBtn) end
+  Input:step()
+  ow:update(1 / 60)
+end
+
+-- start a step south (held direction, like hJoyHeld)
+Input.state.down = true
+step()
+Input.state.down = false
+check(ow.player.moving, "held direction starts a step")
+local startY = ow.player.cellY
+
+-- spy on interact(): a mid-step A press must not even reach it
+local interactCalls = 0
+local baseInteract = ow.interact
+ow.interact = function(self, ...)
+  interactCalls = interactCalls + 1
+  return baseInteract(self, ...)
+end
+
+-- mid-step A press: nothing may happen (the original never sees it)
+step("a")
+eq(interactCalls, 0, "mid-step A never reaches interact()")
+check(Game.stack:top() == ow, "mid-step A pushes no TextBox")
+check(ow.player.moving, "mid-step A does not interrupt the step")
+
+-- mid-step START press: no start menu either
+step("start")
+check(Game.stack:top() == ow, "mid-step START opens no menu")
+check(ow.player.moving, "mid-step START does not interrupt the step")
+
+-- run the step out: the player lands on the next tile, unfrozen
+local guard = 0
+while ow.player.moving and guard < 60 do step(); guard = guard + 1 end
+eq(ow.player.cellY, startY + 1, "the step completes onto the next tile")
+
+-- the issue's actual repro ("press A quickly/early" running up to Nurse
+-- Joy): start another step and press A on its FINAL mid-step frame
+Input.state.down = true
+step()
+Input.state.down = false
+check(ow.player.moving, "second step starts")
+guard = 0
+while ow.player.moving and guard < 60 do
+  guard = guard + 1
+  if guard == (ow.player.stepFramesCur or 16) - 1 then
+    step("a") -- the last frame before landing
+  else
+    step()
+  end
+end
+check(not ow.player.moving, "the second step completes")
+eq(interactCalls, 0, "a last-frame A press is still swallowed (no buffering)")
+check(Game.stack:top() == ow, "last-frame A pushes no TextBox")
+
+-- standing on the tile again, START and A work as always
+step("start")
+check(Game.stack:top() ~= ow, "START opens the start menu on a tile")
+while Game.stack:top() do Game.stack:pop() end
+Game.stack:push(OW, "PALLET_TOWN", 6, 9, "down")
+ow = Game.stack:top()
+interactCalls = 0 -- OW is a singleton: the spy survives the re-push
+step("a")
+eq(interactCalls, 1, "A on a tile runs interact() (the gate is movement-only)")
+
+S.finish()