title screen issues, audio issues, and replacing gf c

src/battle/BattleState.lua

@@ -1893,6 +1893,7 @@ function BattleState:update(dt)
     end
     self.menuIndex = row * 2 + col + 1
     if input:wasPressed("a") then
+      require("src.core.Sound").play(self.data, "Press_AB")
       self:safariAction(({ "ball", "bait", "rock", "run" })[self.menuIndex])
     end
     return
@@ -1929,6 +1930,7 @@ function BattleState:update(dt)
     end
     self.menuIndex = row * 2 + col + 1
     if input:wasPressed("a") then
+      require("src.core.Sound").play(self.data, "Press_AB")
       local choice = ({ "fight", "pkmn", "item", "run" })[self.menuIndex]
       if choice == "fight" and self.ghost then
         self:say(Strings("%s is too\nscared to move!", self.player.name))
@@ -1990,9 +1992,11 @@ function BattleState:update(dt)
         self.moveSwapIndex = self.moveIndex
       end
     elseif input:wasPressed("b") then
+      require("src.core.Sound").play(self.data, "Press_AB")
       self.moveSwapIndex = nil
       self.phase = "menu"
     elseif input:wasPressed("a") then
+      require("src.core.Sound").play(self.data, "Press_AB")
       if self.moveSwapIndex then
         self:swapMoves(self.moveSwapIndex, self.moveIndex)
         self.moveSwapIndex = nil
@@ -2031,6 +2035,7 @@ function BattleState:update(dt)
     elseif input:wasPressed("down") then
       self.mimicIndex = self.mimicIndex < #moves and self.mimicIndex + 1 or 1
     elseif input:wasPressed("a") then
+      require("src.core.Sound").play(self.data, "Press_AB")
       local pick = moves[self.mimicIndex]
       local ctx = self.mimicCtx
       self.mimicMoves, self.mimicCtx = nil, nil

src/core/ChipSynth.lua

@@ -111,6 +111,11 @@ local NOISE_DIVISORS = {
   [4] = 64, [5] = 80, [6] = 96, [7] = 112,
 }
 
+
+local HPF_CHARGE = 0.999958 ^ (GB_CLOCK / SAMPLE_RATE)
+local LPF_ALPHA = 0.8
+local MIX_SCALE = 0.5
+
 local function snapTicks(ticks)
   return math.floor((ticks * 1470 + 256) / 512)
 end
@@ -269,6 +274,7 @@ function Channel.new(engine, spec, options)
     phase = 0,
     noiseLfsr = 0x7FFF,
     noiseClock = 0,
+    drumTail = nil,
     timeTicks = 0,
   }, Channel)
 end
@@ -527,6 +533,25 @@ local function envelopeVolume(volume, fade, elapsed)
   return math.min(15, volume + steps)
 end
 
+
+local function envelopeRingSamples(volume, fade)
+  if not fade or fade <= 0 or not volume or volume <= 0 then return 0 end
+  return math.floor(volume * (fade / 64) * SAMPLE_RATE + 0.5)
+end
+
+local function extendDrumEnvelope(segments)
+  local last = segments and segments[#segments]
+  if not last then return segments end
+  local ringEnd = last.startSample + envelopeRingSamples(last.volume, last.fade)
+  if ringEnd > last.endSample then last.endSample = ringEnd end
+  return segments
+end
+
+local function drumAudioEnd(drum)
+  local last = drum and drum[#drum]
+  return last and last.endSample or 0
+end
+
 function Channel:resetNoise()
   self.noiseLfsr = 0x7FFF
   self.noiseClock = 0
@@ -566,8 +591,7 @@ function Channel:sampleNoise(parameter)
       end
     end
   end
-  -- LuaGB: instantaneous inverted LFSR LSB (high when bit0 == 0)
-  return bit.band(self.noiseLfsr, 1) == 0 and 1 or -1
+  return bit.band(self.noiseLfsr, 1) == 0 and 1 or 0
 end
 
 local function sweepCalculation(register, sweep)
@@ -611,21 +635,51 @@ end
 function Channel:sample()
   while not self.ended
       and (not self.event or self.event.sample >= self.event.samples) do
+    local prev = self.event
     self.event = self:nextEvent()
     self.phase = 0
-    self:resetNoise()
+    if self.event and self.event.drum then
+      self.drumTail = nil
+      self:resetNoise()
+    elseif prev and prev.drum and prev.sample < drumAudioEnd(prev.drum) then
+      -- ..(audio/engine_1.asm ln 197)
+      self.drumTail = prev
+    elseif not (self.event and self.event.silence and self.drumTail) then
+      self.drumTail = nil
+      self:resetNoise()
+    end
   end
   local event = self.event
-  if not event then return 0 end
+  local gain = channelVolume[self.hardware] or 1
+  if not event then
+    local tail = self.drumTail
+    if not tail then return 0 end
+    local sampleIndex = tail.sample
+    tail.sample = sampleIndex + 1
+    if sampleIndex >= drumAudioEnd(tail.drum) then
+      self.drumTail = nil
+      return 0
+    end
+    return self:sampleDrum(tail, sampleIndex) * gain
+  end
   local sampleIndex = event.sample
   event.elapsed = sampleIndex / SAMPLE_RATE
   event.sample = sampleIndex + 1
-  if event.silence then return 0 end
-
-  local gain = channelVolume[self.hardware] or 1
+  if event.silence then
+    local tail = self.drumTail
+    if not tail then return 0 end
+    local tailIndex = tail.sample
+    tail.sample = tailIndex + 1
+    if tailIndex >= drumAudioEnd(tail.drum) then
+      self.drumTail = nil
+      return 0
+    end
+    return self:sampleDrum(tail, tailIndex) * gain
+  end
   if event.drum then
     return self:sampleDrum(event, sampleIndex) * gain
   end
+  self.drumTail = nil
   local volume = envelopeVolume(
     event.volume or 0, event.fade or 0, event.elapsed)
   if event.noise then
@@ -665,7 +719,8 @@ function Channel:sample()
     -- a def-local program may omit its wave table entirely
     if not wave then return 0 end
     local index = math.min(32, math.floor(phase * 32) + 1)
-    return wave[index] * event.waveLevel * gain
+    local nibble = math.max(0, math.min(15, wave[index] * 8 + 8))
+    return (nibble / 15) * event.waveLevel * gain
   end
   local duty = event.duty
   if type(duty) == "table" then
@@ -674,7 +729,7 @@ function Channel:sample()
   local pattern = WAVE_PATTERN_TABLES[duty or 2] or WAVE_PATTERN_TABLES[2]
   local step = math.floor(phase * 8) % 8
   if pattern[step + 1] == 0 then
-    return -volume / 15 * gain
+    return 0
   end
   return volume / 15 * gain
 end
@@ -685,7 +740,7 @@ Engine.__index = Engine
 function Engine:noiseInstrument(number)
   -- a def-local drum wins over the ROM engine's table for that id
   local custom = self.customDrums and self.customDrums[number]
-  if custom then return custom end
+  if custom then return extendDrumEnvelope(custom) end
   local cached = self.noiseInstruments[number]
   if cached then return cached end
 
@@ -718,6 +773,7 @@ function Engine:noiseInstrument(number)
     end
   end
 
+  extendDrumEnvelope(segments)
   self.noiseInstruments[number] = segments
   return segments
 end
@@ -792,6 +848,8 @@ function Engine.new(data, header, options)
     customDrums = chip and chip.drums or nil,
     noiseInstruments = {},
     channels = {},
+    hpfCap = 0, hpfCapLeft = 0, hpfCapRight = 0,
+    lpf = 0, lpfLeft = 0, lpfRight = 0,
   }, Engine)
   -- header.tempo: the Music_*AlternateTempo override Music.play stamps onto
   -- a copy of the song def (audio/alternate_tempo.asm) (#847)
@@ -826,10 +884,20 @@ function Engine:finished()
   return true
 end
 
+local function analogOut(engine, input, hpfField, lpfField)
+  local cap = engine[hpfField]
+  local hp = input - cap
+  engine[hpfField] = input - hp * HPF_CHARGE
+  local prev = engine[lpfField]
+  local lp = prev + LPF_ALPHA * (hp - prev)
+  engine[lpfField] = lp
+  return math.max(-1, math.min(1, lp * MIX_SCALE))
+end
+
 function Engine:sample()
   local value = 0
   for _, channel in ipairs(self.channels) do value = value + channel:sample() end
-  return math.max(-1, math.min(1, value / 4))
+  return analogOut(self, value, "hpfCap", "lpf")
 end
 
 function Engine:sampleStereo()
@@ -840,8 +908,8 @@ function Engine:sampleStereo()
     if not event or event.panLeft ~= false then left = left + value end
     if not event or event.panRight ~= false then right = right + value end
   end
-  return math.max(-1, math.min(1, left / 4)),
-    math.max(-1, math.min(1, right / 4))
+  return analogOut(self, left, "hpfCapLeft", "lpfLeft"),
+    analogOut(self, right, "hpfCapRight", "lpfRight")
 end
 
 function Engine:sampleChannel(number)
@@ -850,7 +918,7 @@ function Engine:sampleChannel(number)
     local value = channel:sample()
     if channel.number == number then selected = value end
   end
-  return math.max(-1, math.min(1, selected / 4))
+  return analogOut(self, selected, "hpfCap", "lpf")
 end
 
 -- render `samples` frames into a fresh SoundData (mono or stereo).  love.sound
@@ -870,22 +938,7 @@ local function soundData(engine, samples, channels)
   return result
 end
 
--- Render a one-shot effect (SFX/cry) to a two-channel SoundData, or nil when
--- it is too short to be audible.  The caller wraps it in a static
--- love.audio.Source (a playback concern, hence not done here).
---
--- The synthesis is mono (one summed value per frame, unlike the music path's
--- sampleStereo), but the buffer is written stereo on purpose: OpenAL only
--- spatializes 1-channel Sources, and a Source left at the default (0,0,0)
--- position, exactly where the listener sits, is rendered as an ambient sound
--- spread over EVERY output channel the device exposes at gains that differ
--- from the front pair.  On an interface with more than two outputs that put
--- the SFX on outputs 5+6 as well, while the 2-channel music source
--- (ChipAudio.playMusic) stayed on 1+2 (#626).  Multi-channel buffers skip
--- spatialization entirely and map onto the front pair, so duplicating the
--- sample costs one buffer's memory and makes effects route exactly like
--- music.  Deliberately not sampleStereo: that honors the NR51 panning byte
--- and would newly hard-pan any effect whose header issues command 0xEE.
+
 local function renderEffectData(data, header, options)
   if not header then return nil end
   options = options or {}

src/core/Music.lua

@@ -1,12 +1,3 @@
--- Music playback supports compact ROM channel programs synthesized live by
--- ChipAudio, def-local chip programs (ChipAsm), and file definitions.  The
--- branch is chosen per song definition, never by a global import flag, so a
--- file-backed song and a chip song coexist in one dataset.  Songs with split
--- files chain def.file into def.loopFile in Music.update().
--- Map themes switch on map change; battles override with the battle
--- theme and restore afterwards; riding the bike overrides outdoor map
--- themes with the bike song until dismount.
-
 local Logger = require("src.core.Logger")
 local Runtime = require("src.mods.Runtime")
 
@@ -14,20 +5,10 @@ local Music = {}
 
 local VOLUME = 0.7
 
--- port additions driven by OptionsMenu / save.options: musicVol scales
--- VOLUME (0-7 level like the GB's NR50 master volume) and musicFilter
--- low-passes the song.  Each filter step keeps 40% of the previous
--- step's treble (highgain 0.4^level), so 2X/3X are the 1X filter
--- applied twice/three times over.
 local volumeScale = 1
 local FILTER_HIGHGAIN = { 0.4, 0.16, 0.064 }
 local filterLevel = 0
 
--- Forward-declared here so applyVolume (below) closes over the real playback
--- state rather than a nil global: the table literal is assigned further down,
--- but a `local state = {}` there would leave every reference above it bound
--- to the global `state`.  Before this, registering the `music.volume` mod
--- hook crashed applyVolume on `state.current` (a nil index).
 local state
 
 local function applyVolume(src)
@@ -115,11 +96,6 @@ function Music.duckForFanfare(src)
   end
 end
 
--- Overworld themes where the bike can be ridden (outdoor maps plus the
--- caves/dungeons where gen-1 allows cycling).  Indoor themes such as
--- Pokecenter/Gym/SilphCo never get replaced by the bike theme.
--- data.audio.outdoorSongs supersedes this; the copy stays as the fallback
--- for caches built before the importer wrote the table.
 local OUTDOOR = {
   Music_PalletTown = true,
   Music_Cities1 = true,
@@ -218,6 +194,7 @@ end
 -- the single choke point every song choice passes through, so one hook
 -- covers map themes, battle themes, jingles and scene music
 local function selectSong(song, ctx)
+  if ctx and ctx.selected then return song end
   if not Runtime.wantsHook("music.select") then return song end
   return Runtime.call("music.select", function(chosen) return chosen end, song, {
     reason = ctx and ctx.reason or "direct",
@@ -234,17 +211,28 @@ end
 function Music.play(data, song, loop, ctx)
   if not song then return end
   if not love.audio then return end -- headless test stub
+  ctx = ctx or {}
   song = selectSong(song, ctx)
-  -- ctx.tempo is a Music_*AlternateTempo cue (audio/alternate_tempo.asm):
-  -- the same song restarted with channel 1 re-pointed at a stub whose only
-  -- difference is its `tempo`, so the same label at a different tempo is a
-  -- different cue and must not be deduped away (#847)
+
   local tempo = ctx and ctx.tempo or nil
   -- a hook may silence the cue outright, or swap in a label the dedupe
   -- below has to compare against
   if not song or (song == state.current and tempo == state.tempo) then return end
   local def = songDef(data, song)
   if not def or state.failed[song] then return end
+
+  if ctx.fade and state.source then
+    local queued = {}
+    for key, value in pairs(ctx) do queued[key] = value end
+    queued.fade, queued.selected = nil, true
+    local pending = { data = data, song = song, loop = loop, ctx = queued }
+    if state.fade then
+      state.fade.pending = pending
+    else
+      Music.fadeOut(ctx.fade, pending)
+    end
+    return
+  end
   if tempo then
     -- shallow copy: the registry def is shared, only this playback is slowed
     local slowed = {}
@@ -317,24 +305,26 @@ function Music.reload()
   Music.stop()
 end
 
--- Ramp the current song's volume to silence, then stop it, mirroring the
--- Game Boy's audio fade-out (home/fade_audio.asm FadeOutAudio +
--- home/audio.asm's .fadeOut): rAUDVOL's master volume steps 7 -> 0 in
--- integer levels, one level every `control` frames, and the music stops
--- when it reaches 0.  `control` is the wAudioFadeOutControl value the ROM
--- writes (oak_speech.asm sets 10 at the shrink beat -> 7*10 = 70 frames
--- to silence).  Ticked once per frame from Music.update().
-function Music.fadeOut(control)
-  if not state.source then Music.stop() return end
+function Music.fadeOut(control, pending)
+  if not state.source then
+    Music.stop()
+    if pending then
+      Music.play(pending.data, pending.song, pending.loop, pending.ctx)
+    end
+    return
+  end
   control = math.max(1, control or 10)
   state.fade = {
     control = control,
     counter = control,       -- frames until the next volume step
     level = 7,               -- current master-volume level (rAUDVOL nibble)
     from = VOLUME * volumeScale, -- level-7 (full) source volume
+    pending = pending,
   }
 end
 
+Music.MAP_FADE = 10
+
 -- the song a map should currently play, honoring the bike/surf overrides
 local function effectiveMapSong(data, song)
   if not song or not outdoorSongs(data)[song] then return song end
@@ -351,14 +341,17 @@ end
 
 -- overworld map theme; onBike/surfing override outdoor themes with the
 -- bike/surf songs and restore the map theme when they end
-function Music.playMap(data, mapId, onBike, surfing)
+function Music.playMap(data, mapId, onBike, surfing, fade)
   local song = data and data.audio and data.audio.mapSongs
     and mapId and data.audio.mapSongs[mapId] or nil
   state.mapSong = song
   state.onBike = not not onBike
   state.surfing = not not surfing
   local play = effectiveMapSong(data, song)
-  if play then Music.play(data, play, nil, { reason = "map", mapId = mapId }) end
+  if play then
+    Music.play(data, play, nil,
+      { reason = "map", mapId = mapId, fade = fade })
+  end
 end
 
 -- toggle the surf override mid-map (starting/ending a surf)
@@ -475,8 +468,13 @@ function Music.update(data)
       f.counter = f.control
       f.level = f.level - 1
       if f.level <= 0 then
+        -- ..(home/fade_audio.asm ln 36)
         state.fade = nil
+        local pending = f.pending
         Music.stop()
+        if pending then
+          Music.play(pending.data, pending.song, pending.loop, pending.ctx)
+        end
         return
       end
       local vol = f.from * f.level / 7

src/ui/IntroMovie.lua

@@ -1,29 +1,5 @@
--- Boot splash + attract movie, a faithful port of PlayIntro
--- (engine/movie/intro.asm) and AnimateShootingStar (engine/movie/splash.asm)
--- using the real extracted art (data/generated/field.lua `intro` manifest).
---
--- Three frame-counted phases:
---  1. copyright card, 180 frames (intro.asm:311-312).
---  2. shooting star: 64 frames of empty letterbox (intro.asm:323-324), then
---     the big star streaks down-left for 40 frames while the studio logo
---     sits centered in the letterbox band (the GAME FREAK logo + letter
---     row it replaces sat at (72,56)/(40,80); splash.asm:27-60, 211-228),
---     the logo flashes 3x10 frames (splash.asm:72-82), 4 waves of small
---     stars rain from the logo -- 6x24 frames, +1px every 3 frames, lower
---     star blinking (splash.asm:97-146, 163-209) -- and a 40 frame hold
---     (intro.asm:329-331).
---  3. the Gengar/Nidorino fight (PlayIntroScene, intro.asm:23-141), played
---     from FIGHT_SCRIPT below: Music_IntroBattle starts, Gengar (56x56 BG
---     pose from a gengar_N.tilemap, at tile 13,7 = x104,y56) scrolls left
---     while Nidorino (48x48 OAM at x-8,y72) walks right, then the scripted
---     hip/hop hops, Gengar's raise + slash lunge, Nidorino's dodge leap,
---     retreat, crouch and final lunge, ending in a 24-frame fade to white
---     (GBFadeOutToWhite, home/fade.asm:26-40).
---
--- Any of A/B/START skips the whole movie (CheckForUserInterruption).
--- Pops itself and calls onDone() when finished or skipped.  All art loads
--- through pcall and every missing graphic degrades to a text/rect
--- fallback, so the movie stays headless-safe.
+-- ..(engine/movie/intro.asm ln 8)
+-- ..(engine/movie/splash.asm ln 27)
 
 local Font = require("src.render.Font")
 local Music = require("src.core.Music")
@@ -76,15 +52,15 @@ local WAVE_FRAMES = 24        -- 8 substeps x 3 frames (splash.asm:186-209)
 local WAVES_END = WAVES_START + 6 * WAVE_FRAMES  -- 4 waves + 2 empty
 local SPLASH_FRAMES = WAVES_END + 40  -- ld c, 40 (intro.asm:329-331)
 
--- logo 16x24 at grid (10,9), letters row at grid y=12 cols 6..15
--- (GameFreakLogoOAMData, splash.asm:211-228; screen = grid*8, OAM offsets
--- cancel)
+-- ..(engine/movie/splash.asm ln 211)
 local LOGO_X, LOGO_Y = 72, 56
+local TEXT_X, TEXT_Y = 40, 80
+
+-- ..(engine/movie/title.asm ln 390)
+local COPY_PREFIX = { 0, 1, 2, 1, 3, 1, 4 }
+local COPY_NINTENDO = { 5, 6, 7, 8, 9, 10 }
+local COPY_CREATURES = { 11, 12, 13, 14, 15, 16, 17, 18 }
 
--- The studio logo (assets/logo/minilogo.png) stands in for both the
--- GAME FREAK logo and its letter row, so it gets the whole band between
--- the letterbox bars (y 32..112) down to where the star waves spawn
--- (y=88): fit it inside this box, centered, aspect preserved.
 local STUDIO_BOX = { w = 128, h = 52, cx = 80, cy = 60 }
 
 -- the 4 waves of small stars: screen X positions, all spawning at y=88
@@ -155,10 +131,19 @@ function IntroMovie.new(game, onDone)
   self.studio = intro.studio or {}
   self.skipAll = intro.skip and true or false
   local function img(e) return tryImage(e and e.path) end
-  self.copyright = tryImage("assets/generated/title/copyright.png")
-  -- studio mark replaces the GAME FREAK logo + splash text entirely; the
-  -- extracted logo stays as the fallback if the asset is missing
-  self.studioLogo = tryImage(self.studio.logo or "assets/logo/minilogo.png")
+  local titleCfg = game.data.field and game.data.field.title or {}
+  self.copyright = img(titleCfg.copyright)
+    or tryImage("assets/generated/title/copyright.png")
+  self.copyQuads = {}
+  if self.copyright then
+    local iw, ih = self.copyright:getDimensions()
+    for t = 0, 18 do
+      self.copyQuads[t] = love.graphics.newQuad(t * 8, 0, 8, 8, iw, ih)
+    end
+  end
+  self.gfInc = img(titleCfg.gamefreakInc)
+    or tryImage("assets/generated/title/gamefreak_inc.png")
+  self.studioLogo = tryImage(self.studio.logo)
   if self.studioLogo then
     self.studioLogo:setFilter("nearest", "nearest")
     local iw, ih = self.studioLogo:getDimensions()
@@ -306,24 +291,12 @@ function IntroMovie:drawSplash()
     if self.studioLogo then
       love.graphics.draw(self.studioLogo, self.studioX, self.studioY,
                          0, self.studioScale, self.studioScale)
-    elseif self.logo then
-      love.graphics.draw(self.logo, LOGO_X, LOGO_Y)
+    else
+      if self.logo then love.graphics.draw(self.logo, LOGO_X, LOGO_Y) end
+      if self.gfText then love.graphics.draw(self.gfText, TEXT_X, TEXT_Y) end
     end
     love.graphics.setColor(1, 1, 1, 1)
   end
-  if t >= STAR_START and t < FLASH_START then
-    -- big star: from OAM (160,0) moving +4Y/-4X per frame
-    -- (GameFreakShootingStarOAMData + .bigStarLoop, splash.asm:32-60)
-    local n = t - STAR_START + 1
-    local sx, sy = 152 - 4 * n, -16 + 4 * n
-    if self.bigStar then
-      love.graphics.draw(self.bigStar, sx, sy)
-    else
-      love.graphics.setColor(0, 0, 0, 1)
-      love.graphics.rectangle("fill", sx + 6, sy + 6, 4, 4)
-      love.graphics.setColor(1, 1, 1, 1)
-    end
-  end
   if t >= WAVES_START then
     -- small stars: wave w spawns at y=88 every 24 frames, everything falls
     -- +1px per 3-frame substep until the wave loop ends; the lower star in
@@ -351,6 +324,18 @@ function IntroMovie:drawSplash()
     end
   end
   drawBars()
+  if t >= STAR_START and t < FLASH_START then
+    -- ..(engine/movie/splash.asm ln 32)
+    local n = t - STAR_START + 1
+    local sx, sy = 152 - 4 * n, -16 + 4 * n
+    if self.bigStar then
+      love.graphics.draw(self.bigStar, sx, sy)
+    else
+      love.graphics.setColor(0, 0, 0, 1)
+      love.graphics.rectangle("fill", sx + 6, sy + 6, 4, 4)
+      love.graphics.setColor(1, 1, 1, 1)
+    end
+  end
 end
 
 function IntroMovie:drawFight()
@@ -379,17 +364,38 @@ function IntroMovie:drawFight()
   end
 end
 
+function IntroMovie:drawCopyright()
+  if self.studio.card or self.studio.credit then
+    local card = self.studio.card or ""
+    local credit = self.studio.credit or ""
+    love.graphics.setColor(0, 0, 0, 1)
+    Font.draw(card, (160 - #card * 8) / 2, 64)
+    Font.draw(credit, (160 - #credit * 8) / 2, 80)
+  elseif self.copyright and self.gfInc then
+    local function row(seq, x, y)
+      for _, t in ipairs(seq) do
+        love.graphics.draw(self.copyright, self.copyQuads[t], x, y)
+        x = x + 8
+      end
+    end
+    for _, y in ipairs({ 56, 72, 88 }) do row(COPY_PREFIX, 16, y) end
+    row(COPY_NINTENDO, 80, 56)
+    row(COPY_CREATURES, 80, 72)
+    love.graphics.draw(self.gfInc, 80, 88)
+  else
+    love.graphics.setColor(0, 0, 0, 1)
+    Font.draw(Strings("Nintendo"), 80, 56)
+    Font.draw(Strings("Creatures inc."), 80, 72)
+    Font.draw(Strings("GAME FREAK inc."), 16, 88)
+  end
+  love.graphics.setColor(1, 1, 1, 1)
+end
+
 function IntroMovie:draw()
   love.graphics.setColor(1, 1, 1, 1)
   love.graphics.rectangle("fill", 0, 0, 160, 144)
   if self.phase == 1 then
-    -- custom boot card (replaces the Nintendo / GAME FREAK copyright
-    -- card; no (c) glyph in the charmap, keep it ASCII-safe)
-    love.graphics.setColor(0, 0, 0, 1)
-    local credit = self.studio.credit or Strings("bois club")
-    Font.draw("2026", (160 - 4 * 8) / 2, 48)
-    Font.draw(credit, (160 - #credit * 8) / 2, 64)
-    Font.draw("bryanthaboi", (160 - 11 * 8) / 2, 80)
+    self:drawCopyright()
   elseif self.phase == 2 then
     self:drawSplash()
   else

src/ui/TitleState.lua

@@ -103,7 +103,31 @@ local YELLOW_CYCLE_SPECIES = {
   "JIGGLYPUFF", "MEOWTH", "PSYDUCK", "VULPIX", "ABRA",
   "GROWLITHE", "CUBONE", "GASTLY", "HITMONLEE", "SNORLAX", "DRAGONITE",
 }
-local CYCLE_FRAMES = 240 -- the original waits ~4s between picks
+-- ..(engine/movie/title.asm ln 227)
+local HOLD_FRAMES = 200
+local STARTERS = { CHARMANDER = true, SQUIRTLE = true, BULBASAUR = true }
+
+-- ..(engine/movie/title2.asm ln 13)
+local function scrollFrames(steps, offset)
+  local frames = {}
+  for _, step in ipairs(steps) do
+    for _ = 1, step[2] do
+      frames[#frames + 1] = offset
+      offset = offset - step[1]
+    end
+  end
+  return frames
+end
+local OUT_FRAMES = scrollFrames(
+  { { 1, 2 }, { 2, 2 }, { 3, 2 }, { 4, 2 }, { 5, 2 }, { 6, 2 },
+    { 8, 3 }, { 9, 3 } }, 0)
+local IN_FRAMES = scrollFrames(
+  { { 10, 2 }, { 9, 4 }, { 8, 4 }, { 6, 3 }, { 5, 2 }, { 3, 1 },
+    { 1, 1 } }, 120)
+
+-- ..(engine/movie/title2.asm ln 85)
+local BALL_FRAMES = { 97, 95, 94, 93, 92, 93, 94, 95, 97, 100 }
+local BALL_REST = 100
 
 local function tryImage(path)
   if not path then return nil end
@@ -178,6 +202,27 @@ function TitleState.new(game, opts)
                           or "assets/generated/title/red_version.png")
   self.player = tryImage(imagePath(title.player)
                          or "assets/generated/title/player.png")
+  -- ..(engine/movie/title2.asm ln 85)
+  if self.player then
+    local pw, ph = self.player:getDimensions()
+    self.ballQuad = love.graphics.newQuad(0, 16, 8, 8, pw, ph)
+    self.playerQuads = {
+      { love.graphics.newQuad(0, 0, pw, 16, pw, ph), 0, 0 },
+      { love.graphics.newQuad(8, 16, pw - 8, 8, pw, ph), 8, 16 },
+      { love.graphics.newQuad(0, 24, pw, ph - 24, pw, ph), 0, 24 },
+    }
+  end
+  self.copyImg = tryImage(imagePath(title.copyright)
+                          or "assets/generated/title/copyright.png")
+  self.copyQuads = {}
+  if self.copyImg then
+    local iw, ih = self.copyImg:getDimensions()
+    for t = 0, 18 do
+      self.copyQuads[t] = love.graphics.newQuad(t * 8, 0, 8, 8, iw, ih)
+    end
+  end
+  self.gfInc = tryImage(imagePath(title.gamefreakInc)
+                        or "assets/generated/title/gamefreak_inc.png")
   self.blue = GameVersion.isBlue()
   self.yellow = GameVersion.isYellow()
     or title.layout == "yellow_pikachu"
@@ -203,7 +248,10 @@ function TitleState.new(game, opts)
     self.blinkTimer = 0
     self.blinkAt = nil
   else
-    self.phase = "loop"
+    -- ..(engine/movie/title.asm ln 28)
+    self.scy = 0x40
+    self.phase = "drop"
+    self.dropStep, self.dropLeft = 1, nil
     self.showBubble = true
   end
   local defaultCycle = self.yellowLayout and { "PIKACHU" }
@@ -216,14 +264,15 @@ function TitleState.new(game, opts)
   self.cycleIndex = 1
   self.timer = 0
   self.blink = 0
+  self.scrollPhase = "hold"
+  self.scrollFrame = 1
+  self.monOffset = 0
+  self.ballY = BALL_REST
   return self
 end
 
 function TitleState:enter()
-  -- Yellow defers the title theme until after the logo drop and
-  -- Pikachu's cry (title.asm plays MUSIC_TITLE_SCREEN only after
-  -- WaitForSoundToFinish on PikachuCry1)
-  if self.yellowLayout then return end
+  if self.phase ~= "loop" then return end
   self:startMusic()
 end
 
@@ -240,6 +289,11 @@ end
 local DROP_STEPS = {
   { -4, 16 }, { 3, 4 }, { -3, 4 }, { 2, 2 }, { -2, 2 }, { 1, 2 }, { -1, 2 },
 }
+local SETTLE_FRAMES = 36
+
+-- ..(engine/movie/title.asm ln 201)
+local RIBBON_FRAMES = {}
+for offset = 112, 4, -4 do RIBBON_FRAMES[#RIBBON_FRAMES + 1] = offset end
 
 -- the boot cinematic up to the interactive loop; one call per frame
 function TitleState:updateSequence()
@@ -263,12 +317,23 @@ function TitleState:updateSequence()
       self.dropLeft = nil
     end
   elseif self.phase == "settle" then
-    -- ld c, 36 / DelayFrames, then the whoosh and the bubble
     self.timer = self.timer + 1
-    if self.timer >= 36 then
+    if self.timer >= SETTLE_FRAMES then
       Sound.play(data, "Intro_Whoosh")
       self.showBubble = true
-      self.phase = "bubble"
+      self.phase = self.yellowLayout and "bubble" or "ribbon"
+      self.ribbonOffset = RIBBON_FRAMES[1]
+      self.timer = 0
+    end
+  elseif self.phase == "ribbon" then
+    self.timer = self.timer + 1
+    local offset = RIBBON_FRAMES[self.timer + 1]
+    if offset then
+      self.ribbonOffset = offset
+    else
+      self.ribbonOffset = nil
+      self:startMusic()
+      self.phase = "loop"
       self.timer = 0
     end
   elseif self.phase == "bubble" then
@@ -432,12 +497,63 @@ function TitleState:openMenu()
   game.stack:push(menu)
 end
 
+-- ..(engine/movie/title.asm ln 271)
+function TitleState:pickNewMon()
+  if #self.cycleSpecies < 2 then return end
+  local pick = self.cycleIndex
+  while pick == self.cycleIndex do
+    pick = love.math.random(1, #self.cycleSpecies)
+  end
+  self.cycleIndex = pick
+end
+
+function TitleState:setCyclePhase(phase)
+  self.scrollPhase = phase
+  self.scrollFrame = 1
+  self.timer = 0
+  if phase == "in" then
+    self:pickNewMon()
+    self.monOffset = IN_FRAMES[1]
+  elseif phase == "out" then
+    self.monOffset = OUT_FRAMES[1]
+  elseif phase == "ball" then
+    self.ballY = BALL_FRAMES[1]
+  else
+    self.monOffset = 0
+  end
+end
+
+function TitleState:updateCycle()
+  local phase = self.scrollPhase
+  if phase == "hold" then
+    if self.timer >= HOLD_FRAMES then self:setCyclePhase("out") end
+    return
+  end
+  local frames = phase == "out" and OUT_FRAMES
+              or phase == "ball" and BALL_FRAMES or IN_FRAMES
+  self.scrollFrame = self.scrollFrame + 1
+  local value = frames[self.scrollFrame]
+  if value then
+    if phase == "ball" then self.ballY = value else self.monOffset = value end
+    return
+  end
+  if phase == "out" then
+    -- ..(engine/movie/title.asm ln 235)
+    self:setCyclePhase(
+      STARTERS[self.cycleSpecies[self.cycleIndex]] and "ball" or "in")
+  elseif phase == "ball" then
+    self:setCyclePhase("in")
+  else
+    self:setCyclePhase("hold")
+  end
+end
+
 function TitleState:update(dt)
+  if self.phase ~= "loop" then
+    self:updateSequence()
+    return
+  end
   if self.yellowLayout then
-    if self.phase ~= "loop" then
-      self:updateSequence()
-      return -- input is ignored until the cinematic lands (title.asm)
-    end
     self:updateBlink()
     local input = self.game.input
     if input:wasPressed("start") or input:wasPressed("a") then
@@ -452,21 +568,7 @@ function TitleState:update(dt)
   end
   self.timer = self.timer + 1
   self.blink = (self.blink + 1) % 60
-  if not self.yellowLayout and self.timer >= CYCLE_FRAMES then
-    self.timer = 0
-    -- random pick that never repeats the current one
-    if #self.cycleSpecies > 1 then
-      local pick = self.cycleIndex
-      while pick == self.cycleIndex do
-        pick = love.math.random(1, #self.cycleSpecies)
-      end
-      self.cycleIndex = pick
-    end
-    self.slideIn = 20 -- TitleScreenScrollInMon slides the pic in
-  end
-  if self.slideIn and self.slideIn > 0 then
-    self.slideIn = self.slideIn - 1
-  end
+  self:updateCycle()
   local input = self.game.input
   if input:wasPressed("start") or input:wasPressed("a") then
     -- the title mon cries when you leave the title (.finishedWaiting);
@@ -478,15 +580,14 @@ function TitleState:update(dt)
   end
 end
 
--- The original tilemap (engine/movie/title.asm): logo at tile (2,1),
--- the version ribbon at (7,8), Red's title art as OAM at px (82,80),
--- the title mon in the 7x7 box at tile (5,10), copyright on row 17.
--- Yellow (title_yellow.asm): logo (2,1), speech bubble (6,4), Pikachu
--- (4,8) 12x9 -- no version ribbon, no cycling mon, no Red OAM.
+-- ..(engine/movie/title.asm ln 28)
 function TitleState:draw()
   love.graphics.setColor(1, 1, 1, 1)
   love.graphics.rectangle("fill", 0, 0, 160, 144)
-  local scrollY = self.yellowLayout and -(self.scy or 0) or 0
+  local scrollY = -(self.scy or 0)
+  -- ..(engine/movie/title.asm ln 28)
+  local preRibbon = not self.yellowLayout
+    and (self.phase == "drop" or self.phase == "settle")
   if self.logo then
     love.graphics.draw(self.logo, 16, 8 + scrollY)
   else
@@ -514,27 +615,29 @@ function TitleState:draw()
     -- Yellow's Version_GFX slot holds a leftover "Blue Version" ribbon
     -- (pokeyellow gfx/title/blue_version.png, unreferenced by title code);
     -- the Yellow fallback layout draws no ribbon at all.
-    if self.version and not self.yellow then
+    if self.version and not self.yellow and not preRibbon then
       local iw, ih = self.version:getDimensions()
+      local rx = self.ribbonOffset or 0
       if self.versionFull then
         -- a continuous ribbon (versionRibbon) centers as one piece
-        love.graphics.draw(self.version, math.floor((160 - iw) / 2), 64)
+        love.graphics.draw(self.version, math.floor((160 - iw) / 2) + rx, 64)
       elseif self.blue then
         love.graphics.draw(self.version,
-          love.graphics.newQuad(0, 0, 64, 8, iw, ih), 56, 64)
+          love.graphics.newQuad(0, 0, 64, 8, iw, ih), 56 + rx, 64)
       else
         love.graphics.draw(self.version,
-          love.graphics.newQuad(0, 0, 16, 8, iw, ih), 56, 64)
+          love.graphics.newQuad(0, 0, 16, 8, iw, ih), 56 + rx, 64)
         love.graphics.draw(self.version,
-          love.graphics.newQuad(40, 0, 40, 8, iw, ih), 80, 64)
+          love.graphics.newQuad(40, 0, 40, 8, iw, ih), 80 + rx, 64)
       end
     end
-    local sprite, spriteTrueColor = self:currentSprite()
+    local sprite, spriteTrueColor
+    if self.scrollPhase ~= "ball" then
+      sprite, spriteTrueColor = self:currentSprite()
+    end
     if sprite then
       local w, h = sprite:getDimensions()
-      local slide = (self.slideIn or 0) * 8 -- scroll in from the right
-      -- bottom-aligned and centered in the (5,10)-(11,16) tile box
-      local x = 40 + math.floor((56 - w) / 2) + slide
+      local x = 40 + math.floor((56 - w) / 2) + self.monOffset
       local y = 136 - h
       love.graphics.draw(sprite, x, y)
       -- a full-color mon keeps its own palette through the SGB pass, minus
@@ -550,13 +653,33 @@ function TitleState:draw()
       end
     end
     -- Red is OAM in the original: he draws over the mon's box edge
-    if self.player then
+    if self.playerQuads then
+      for _, part in ipairs(self.playerQuads) do
+        love.graphics.draw(self.player, part[1], 82 + part[2], 80 + part[3])
+      end
+      love.graphics.draw(self.player, self.ballQuad, 82, self.ballY)
+    elseif self.player then
       love.graphics.draw(self.player, 82, 80)
     end
   end
+  self:drawCopyright(136 + (preRibbon and 0 or scrollY))
+end
+
+-- ..(engine/movie/title.asm ln 117)
+local COPY_PREFIX = { 0, 1, 2, 1, 3, 1, 4 }
+
+function TitleState:drawCopyright(y)
+  if not self.title.copyrightText and self.copyImg and self.gfInc then
+    local x = 16
+    for _, t in ipairs(COPY_PREFIX) do
+      love.graphics.draw(self.copyImg, self.copyQuads[t], x, y)
+      x = x + 8
+    end
+    love.graphics.draw(self.gfInc, x, y)
+    return
+  end
   love.graphics.setColor(0, 0, 0, 1)
-  Font.draw(self.title.copyrightText or Strings("2026 bois club games"),
-    1, 136 + scrollY)
+  Font.draw(self.title.copyrightText or Strings("GAME FREAK inc."), 16, y)
   love.graphics.setColor(1, 1, 1, 1)
 end
 

src/world/OverworldController.lua

@@ -451,8 +451,10 @@ function OverworldState:setMap(mapId, x, y, facing, opts)
   local keepMusic = (opts and opts.keepMusic) or self.keepMusicOnce
   self.keepMusicOnce = nil
   if not keepMusic then
-    require("src.core.Music").playMap(Game.data, mapId, Game.save.onBike,
-                                      self.player.surfing)
+    -- ..(home/overworld.asm ln 2346)
+    local Music = require("src.core.Music")
+    Music.playMap(Game.data, mapId, Game.save.onBike, self.player.surfing,
+                  Music.MAP_FADE)
   end
 
   -- forced bike/surf tiles fire the moment the player is placed on the
@@ -1093,8 +1095,10 @@ function OverworldState:update(dt)
     local mapId = self.pendingSeamMusic
     self.pendingSeamMusic = nil
     if mapId == self.map.id then
-      require("src.core.Music").playMap(Game.data, mapId, Game.save.onBike,
-                                        self.player.surfing)
+      -- ..(home/overworld.asm ln 677)
+      local Music = require("src.core.Music")
+      Music.playMap(Game.data, mapId, Game.save.onBike, self.player.surfing,
+                    Music.MAP_FADE)
     end
   end
   if stepped and not scripted then

tests/drivers/title_cycle_test.lua

@@ -0,0 +1,66 @@
+-- ..(engine/movie/title.asm ln 28)
+-- ..(engine/movie/title2.asm ln 13)
+--   POKEPORT_DRIVER=tests/drivers/title_cycle_test.lua POKEPORT_TOUCH=0 SHOT_DIR=/tmp/shots love .
+return function(game)
+  local U = dofile("tests/drivers/util.lua")
+  local DIR = os.getenv("SHOT_DIR") or "/tmp/shots"
+  local shot = 0
+  local function grab(tag)
+    shot = shot + 1
+    U.shot(game, ("%s/title_%02d_%s.png"):format(DIR, shot, tag))
+  end
+
+  U.wait(30)
+  grab("copyright")
+  -- ..(engine/movie/splash.asm ln 230)
+  local movie = game.stack:top()
+  while movie.phase ~= 2 or movie.timer < 70 do U.wait(1) end
+  grab("star_topbar")
+  while movie.timer < 88 do U.wait(1) end
+  grab("star_middle")
+  while movie.timer < 100 do U.wait(1) end
+  grab("star_lowbar")
+  while movie.timer < 130 do U.wait(1) end
+  grab("gamefreak")
+
+  U.tap(game, "start")
+  U.wait(2)
+  local title = game.stack:top()
+  U.log("top is", tostring(title and title.screenId))
+  if not (title and title.scrollPhase) then
+    U.log("no TitleState on top; nothing below can run")
+    while true do coroutine.yield() end
+  end
+
+  grab("drop_early")
+  U.wait(14)
+  grab("drop_late")
+  while title.phase == "drop" do U.wait(1) end
+  grab("settle")
+  while title.phase == "settle" do U.wait(1) end
+  grab("ribbon_start")
+  U.wait(10)
+  U.shot(game, DIR .. "/title_ribbon_mid.png")
+  while title.phase ~= "loop" do U.wait(1) end
+  grab("landed")
+
+  title.cycleIndex = 1
+  title.scrollPhase, title.scrollFrame, title.timer = "hold", 1, 0
+  title.monOffset = 0
+  while title.scrollPhase == "hold" do U.wait(1) end
+  grab("out_a")
+  U.wait(6)
+  grab("out_b")
+  while title.scrollPhase == "out" do U.wait(1) end
+  U.log("after the scroll out the phase is", title.scrollPhase)
+  for _ = 1, 5 do
+    grab("ball")
+    U.wait(1)
+  end
+  while title.scrollPhase == "ball" do U.wait(1) end
+  grab("in")
+  U.wait(30)
+  grab("next_mon")
+  U.log("captured", DIR)
+  while true do coroutine.yield() end
+end

tests/drivers/util.lua

@@ -65,8 +65,12 @@ function U.newGame(game)
   U.wait(5)
   U.tap(game, "start") -- skip intro movie
   U.wait(10)
-  U.tap(game, "a") -- title -> menu
-  U.wait(5)
+  local title = game.stack:top()
+  for _ = 1, 60 do
+    U.tap(game, "a")
+    U.wait(5)
+    if game.stack:top() ~= title then break end
+  end
   -- menu: CONTINUE may or may not exist; NEW GAME is first without a save
   U.tap(game, "a")
   U.wait(10)

tests/engine/chip_analog_path.lua

@@ -0,0 +1,103 @@
+package.path = "./?.lua;./?/init.lua;" .. package.path
+
+local T = require("tests.harness")
+local check = T.check
+local eq = T.eq
+
+love = require("tests.love_stub")
+
+local ChipAsm = require("src.audio.ChipAsm")
+local ChipSynth = require("src.core.ChipSynth")
+
+local data = { audio = {} }
+
+local function pulseSong()
+  return ChipAsm.song{
+    channels = { { hw = 1, program = {
+      { duty = 2 },
+      { notetype = { speed = 12, volume = 15, fade = 0 } },
+      { octave = 4 },
+      { note = "C", len = 15 },
+    } } },
+  }
+end
+
+local function noiseSong()
+  return ChipAsm.sfx{
+    channels = { { hw = 4, program = {
+      { noiseNote = { len = 8, volume = 15, fade = 1, parameter = 0x34 } },
+    } } },
+  }
+end
+
+do
+  local engine = ChipSynth.newEngine(data, pulseSong(), { allowLoops = false })
+  local sawNeg, sawPos = false, false
+  for _ = 1, 512 do
+    local v = engine.channels[1]:sample()
+    if v < -1e-12 then sawNeg = true end
+    if v > 1e-12 then sawPos = true end
+  end
+  check(sawPos and not sawNeg,
+    "pulse DAC is unipolar (high = volume, low = 0)")
+end
+
+do
+  local engine = ChipSynth.newEngine(data, noiseSong(), {
+    sfx = true, allowLoops = false,
+  })
+  local sawNeg, sawPos = false, false
+  for _ = 1, 2048 do
+    local v = engine.channels[1]:sample()
+    if v < -1e-12 then sawNeg = true end
+    if v > 1e-12 then sawPos = true end
+  end
+  check(sawPos and not sawNeg,
+    "noise DAC is unipolar (LFSR high = volume, low = 0)")
+end
+
+local function crossingsAndSign(engine, frames)
+  local count, prev = 0, nil
+  local sawNeg, sawPos = false, false
+  for _ = 1, frames do
+    local sample = engine:sample()
+    if sample < -1e-12 then sawNeg = true end
+    if sample > 1e-12 then sawPos = true end
+    if prev and prev * sample < 0 then count = count + 1 end
+    prev = sample
+  end
+  return count, sawNeg, sawPos
+end
+
+do
+  local engine = ChipSynth.newEngine(data, pulseSong(), { allowLoops = false })
+  local count, sawNeg, sawPos = crossingsAndSign(engine, 4000)
+  check(sawNeg and sawPos, "HPF centers a unipolar pulse around analog 0")
+  check(count > 20, ("HPF'd pulse crosses zero (%d crossings)"):format(count))
+end
+
+do
+  local engine = ChipSynth.newEngine(data, noiseSong(), {
+    sfx = true, allowLoops = false,
+  })
+  local count, sawNeg, sawPos = crossingsAndSign(engine, 8000)
+  check(sawNeg and sawPos, "HPF centers noise / drums around analog 0")
+  check(count > 50, ("HPF'd noise crosses zero (%d crossings)"):format(count))
+end
+
+do
+  local song = pulseSong()
+  ChipSynth.setChannelVolumes({ 1, 1, 1, 1 })
+  local a = ChipSynth.newEngine(data, song, { allowLoops = false })
+  local base = a.channels[1]:sample()
+  ChipSynth.setChannelVolume(1, 0.25)
+  local b = ChipSynth.newEngine(data, song, { allowLoops = false })
+  local quarter = b.channels[1]:sample()
+  ChipSynth.setChannelVolumes({ 1, 1, 1, 1 })
+  check(base > 0 and math.abs(quarter - base * 0.25) < 1e-9,
+    "channelVolume still quarters the unipolar DAC level")
+end
+
+eq(type(ChipSynth.newEngine), "function", "engine factory still exported")
+
+T.finish("chip analog path")

tests/engine/drum_envelope_ring.lua

@@ -0,0 +1,82 @@
+-- ..(audio/engine_1.asm ln 197)
+-- ..(audio/sfx/noise_instrument01_1.asm ln 1)
+--   luajit tests/engine/drum_envelope_ring.lua
+
+package.path = "./?.lua;./?/init.lua;" .. package.path
+
+local T = require("tests.harness")
+local check = T.check
+
+love = require("tests.love_stub")
+
+local ChipAsm = require("src.audio.ChipAsm")
+local ChipSynth = require("src.core.ChipSynth")
+
+local snare = ChipAsm.song{
+  channels = {
+    { hw = 4, program = {
+      { notetype = { speed = 12 } },
+      { drum = 1, len = 2 },
+      { rest = 16 },
+    } },
+  },
+  drums = {
+    [1] = {
+      { len = 1, volume = 12, fade = 1, parameter = 0x33 },
+    },
+  },
+}
+
+local engine = ChipSynth.newEngine({ audio = {} }, snare, { allowLoops = false })
+local segs = engine:noiseInstrument(1)
+local last = segs[#segs]
+local ringMs = (last.endSample - last.startSample) / ChipSynth.SAMPLE_RATE * 1000
+check(ringMs > 150 and ringMs < 220,
+  ("snare instrument rings ~188ms, not the 17ms note (%0.1fms)"):format(ringMs))
+
+local energyEarly, energyLate, energyEnd = 0, 0, 0
+local total = math.floor(ChipSynth.SAMPLE_RATE * 0.25)
+for i = 1, total do
+  local s = engine:sample()
+  local e = s * s
+  local t = i / ChipSynth.SAMPLE_RATE
+  if t < 0.02 then
+    energyEarly = energyEarly + e
+  elseif t > 0.05 and t < 0.12 then
+    energyLate = energyLate + e
+  elseif t > 0.20 then
+    energyEnd = energyEnd + e
+  end
+end
+check(energyEarly > 0, "snare attack is audible")
+check(energyLate > energyEarly * 0.05,
+  ("snare body still sounds at 50-120ms (early=%.4f late=%.4f)")
+    :format(energyEarly, energyLate))
+check(energyEnd < energyLate * 0.1,
+  "snare has decayed by 200ms")
+
+local hats = ChipAsm.song{
+  channels = {
+    { hw = 4, program = {
+      { notetype = { speed = 12 } },
+      { drum = 1, len = 2 },
+      { drum = 1, len = 2 },
+    } },
+  },
+  drums = {
+    [1] = {
+      { len = 1, volume = 8, fade = 1, parameter = 0x10 },
+    },
+  },
+}
+local hatEngine = ChipSynth.newEngine({ audio = {} }, hats, { allowLoops = false })
+local hits = 0
+local prev = 0
+for _ = 1, math.floor(ChipSynth.SAMPLE_RATE * 0.3) do
+  local s = math.abs(hatEngine:sample())
+  if prev < 0.01 and s >= 0.01 then hits = hits + 1 end
+  prev = s
+end
+check(hits >= 2, ("two rapid drum_notes both trigger (%d onsets)"):format(hits))
+
+T.finish("drum envelope ring")

tests/engine/map_music_fade.lua

@@ -0,0 +1,94 @@
+-- ..(home/audio.asm ln 9)
+-- ..(home/fade_audio.asm ln 36)
+--   luajit tests/engine/map_music_fade.lua
+
+package.path = "./?.lua;./?/init.lua;" .. package.path
+
+local T = require("tests.harness")
+local check = T.check
+local eq = T.eq
+
+love = require("tests.love_stub")
+
+local Source = {}
+Source.__index = Source
+function Source:play() self.playing = true end
+function Source:stop() self.playing = false end
+function Source:pause() self.playing = false end
+function Source:isPlaying() return self.playing end
+function Source:setLooping() end
+function Source:setVolume(v) self.volume = v end
+function Source:setPitch() end
+function Source:setFilter() end
+function Source:getDuration() return 1 end
+
+local made = {} -- file -> the last source built for it
+love.audio = {
+  newSource = function(file, mode)
+    made[file] = setmetatable({ file = file, mode = mode }, Source)
+    return made[file]
+  end,
+}
+
+local Music = require("src.core.Music")
+
+local data = { audio = {
+  songs = {
+    Music_Pallet = { file = "pallet.wav" },
+    Music_Routes1 = { file = "routes1.wav" },
+    Music_Pewter = { file = "pewter.wav" },
+  },
+  mapSongs = {
+    PALLET_TOWN = "Music_Pallet",
+    ROUTE_1 = "Music_Routes1",
+    PEWTER_CITY = "Music_Pewter",
+  },
+} }
+
+local function frames(n)
+  for _ = 1, n do Music.update(data) end
+end
+
+local function playing()
+  for file, src in pairs(made) do
+    if src.playing then return file end
+  end
+  return "(silence)"
+end
+
+local FADE = 7 * Music.MAP_FADE -- 7 volume levels x 10 frames
+
+Music.stop()
+Music.playMap(data, "PALLET_TOWN", false, false, Music.MAP_FADE)
+eq(playing(), "pallet.wav", "the first map after boot starts at once")
+
+local fullVolume = made["pallet.wav"].volume
+
+Music.playMap(data, "ROUTE_1", false, false, Music.MAP_FADE)
+eq(playing(), "pallet.wav", "the new theme waits while the old one fades")
+frames(FADE - 1)
+eq(playing(), "pallet.wav", "still fading one frame short of silence")
+check(made["pallet.wav"].volume < fullVolume,
+  "the old theme has been ramped down by then")
+frames(1)
+eq(playing(), "routes1.wav", "the queued theme takes over after 7 * 10 frames")
+
+eq(made["routes1.wav"].volume, fullVolume,
+  "the new theme starts at full volume, not where the ramp ended")
+
+Music.playMap(data, "ROUTE_1", false, false, Music.MAP_FADE)
+eq(playing(), "routes1.wav", "the same theme keeps playing")
+frames(FADE)
+eq(playing(), "routes1.wav", "and no fade was armed for it")
+
+Music.playMap(data, "PALLET_TOWN", false, false, Music.MAP_FADE)
+frames(3 * Music.MAP_FADE)
+Music.playMap(data, "PEWTER_CITY", false, false, Music.MAP_FADE)
+eq(playing(), "routes1.wav", "the retargeted fade keeps ramping the old theme")
+frames(4 * Music.MAP_FADE)
+eq(playing(), "pewter.wav", "the ramp lands on the newest map's theme")
+
+Music.playMap(data, "PALLET_TOWN", false, false)
+eq(playing(), "pallet.wav", "a fadeless map cue swaps immediately")
+
+T.finish("map_music_fade")

tests/engine/nx_yellow_boot_test.lua

@@ -37,7 +37,7 @@ end
 
 local Y_TITLE = {
   "pikachu.png", "pika_bubble.png", "eyes_half.png", "eyes_closed.png",
-  "player.png", "copyright.png", "yellow_version.png",
+  "player.png", "copyright.png", "gamefreak_inc.png", "yellow_version.png",
 }
 for _, name in ipairs(Y_TITLE) do
   seed("yellow/assets/generated/title/" .. name)
@@ -266,6 +266,7 @@ GameVersion.set("blue")
 seed("blue/assets/generated/title/blue_version.png", "blue-version-bytes")
 seed("blue/assets/generated/title/player.png")
 seed("blue/assets/generated/title/copyright.png")
+seed("blue/assets/generated/title/gamefreak_inc.png")
 local B_INTRO = {
   "gf_logo.png", "gf_text.png", "big_star.png",
   "falling_star.png", "falling_star_blink.png", "studio_logo.png",

tests/engine/title_mon_cycle.lua

@@ -0,0 +1,109 @@
+-- ..(engine/movie/title.asm ln 227)
+-- ..(engine/movie/title2.asm ln 13)
+--   luajit tests/engine/title_mon_cycle.lua
+
+package.path = "./?.lua;./?/init.lua;" .. package.path
+
+local T = require("tests.harness")
+local check = T.check
+local eq = T.eq
+
+love = require("tests.love_stub")
+love.math = love.math or {}
+local nextPick = 1
+love.math.random = function(lo, hi)
+  nextPick = nextPick % hi + 1
+  return math.max(lo, nextPick)
+end
+
+local TitleState = require("src.ui.TitleState")
+
+local title = TitleState.new(
+  { data = {}, input = { wasPressed = function() return false end } }, {})
+title.sprites = setmetatable({}, { __index = function() return false end })
+
+eq(title.phase, "drop", "Red/Blue boot into the logo drop, not the loop")
+local ribbonSeen = {}
+for _ = 1, 400 do
+  if title.phase == "loop" then break end
+  title:update(1 / 60)
+  if title.phase == "ribbon" then
+    ribbonSeen[#ribbonSeen + 1] = title.ribbonOffset
+  end
+end
+eq(title.phase, "loop", "the cinematic lands within 400 frames")
+eq(ribbonSeen[1], 112,
+  "the ribbon is parked off the right edge on its first drawn frame")
+eq(ribbonSeen[#ribbonSeen], 4, "and walks in 4px a frame to its rest")
+
+title.cycleIndex = 1 -- CHARMANDER: a starter, so the ball juggle runs
+title.scrollPhase, title.scrollFrame, title.timer = "hold", 1, 0
+title.monOffset = 0
+
+local frames = {}
+for _ = 1, 260 do
+  title:update(1 / 60)
+  frames[#frames + 1] = {
+    phase = title.scrollPhase, offset = title.monOffset,
+    ball = title.ballY, mon = title.cycleSpecies[title.cycleIndex],
+  }
+end
+
+local HOLD_FRAMES = 200
+
+local function span(phase)
+  local first, count = nil, 0
+  for i, f in ipairs(frames) do
+    if f.phase == phase then
+      if not first then first = i end
+      if first + count == i then count = count + 1 end
+    end
+  end
+  return first, count
+end
+
+local holdAt, holdLen = span("hold")
+local outAt, outLen = span("out")
+local ballAt, ballLen = span("ball")
+local inAt, inLen = span("in")
+eq(holdAt, 1, "the cycle opens on the hold")
+eq(holdLen, HOLD_FRAMES - 1, "ld c, 200 / CheckForUserInterruption")
+eq(outAt, HOLD_FRAMES, "the scroll out begins as the 200th hold frame ends")
+eq(outLen, 18, "TitleScroll_Out is 2+2+2+2+2+2+3+3 frames")
+eq(ballLen, 10, "TitleScroll_WaitBall is two runs of 5")
+eq(inLen, 17, "TitleScroll_In is 2+4+4+3+2+1+1 frames")
+check(outAt < ballAt and ballAt < inAt, "out, then the ball, then in")
+
+local OUT = { 0, -1, -2, -4, -6, -9, -12, -16, -20, -25, -30, -36, -42,
+              -50, -58, -66, -75, -84 }
+for i, want in ipairs(OUT) do
+  eq(frames[outAt + i - 1].offset, want,
+    "TitleScroll_Out offset at frame " .. i)
+end
+
+local IN = { 120, 110, 100, 91, 82, 73, 64, 56, 48, 40, 32, 26, 20, 14, 9,
+             4, 1 }
+for i, want in ipairs(IN) do
+  eq(frames[inAt + i - 1].offset, want, "TitleScroll_In offset at frame " .. i)
+end
+
+local BALL = { 97, 95, 94, 93, 92, 93, 94, 95, 97, 100 }
+for i, want in ipairs(BALL) do
+  eq(frames[ballAt + i - 1].ball, want, "TitleBallYTable entry " .. i)
+end
+
+local outgoing = frames[outAt].mon
+eq(outgoing, "CHARMANDER", "the starter is the one that scrolls out")
+for i = outAt, inAt - 1 do
+  eq(frames[i].mon, outgoing,
+    "the pick does not change before the scroll in, at frame " .. i)
+end
+local incoming = frames[inAt].mon
+check(incoming ~= outgoing, "TitleScreenPickNewMon never repeats the pick")
+for i = inAt, inAt + inLen - 1 do
+  check(frames[i].offset > 0,
+    "the incoming mon is only ever drawn right of rest, at frame " .. i)
+end
+eq(frames[inAt + inLen].offset, 0, "and settles at its resting column")
+
+T.finish("title_mon_cycle")

tests/parity_true_color_ui.lua

@@ -93,6 +93,7 @@ local titleGame = {
            field = { title = { cycleSpecies = { "PIKACHU" } } } },
 }
 local title = TitleState.new(titleGame, {})
+title.phase, title.scy = "loop", 0
 local titleSprite, titleTrueColor = title:currentSprite()
 check(titleSprite and titleTrueColor,
       "title cache keeps a Pokemon sprite's trueColor flag")