G2 support

src/ui/gen2/TitleState.lua

@@ -0,0 +1,283 @@
+-- Gen 2 title: colored TitleScreenTilemap BG, scrolling clouds, Ho-Oh
+-- wing-flap (Frameset_GSIntroHoOhLugia), spark trails, A/Start to continue.
+-- drawWidescreen fills the window with sky/clouds so widescreen has no
+-- pillarbox voids; the 160x144 art stays aspect-centered on top.
+
+-- src/render/Assets.lua is the mod-override choke point: a raw
+-- love.graphics.newImage skips overrides/ and AssetTransform output.
+local Assets = require("src.render.Assets")
+local Chrome = require("src.ui.gen2.Chrome")
+local GbcPalette = require("src.render.GbcPalette")
+local Music = require("src.core.Music")
+local Runtime = require("src.mods.Runtime")
+local SpriteAnims = require("src.ui.gen2.SpriteAnims")
+
+local TitleState = {}
+TitleState.__index = TitleState
+TitleState.isOpaque = true
+
+-- title_bg_gold.pal mid-sky shade (sampled from composed title_screen.png).
+local SKY = { 123 / 255, 165 / 255, 255 / 255, 1 }
+-- ...and its grey stand-in, for when COLOR is not GBC.  The title art is the
+-- one thing in the port baked with its colours in (see the extractor), so the
+-- window fill that matches it has to be picked the same way the sheet is.
+-- The sky is BG colour 2, and LoadTitleScreenPals' rBGP (%11011000) sends
+-- that colour to shade 1, not to shade 2 -- the grey sheet is baked through
+-- the same register, so the fill has to follow it or the surround comes out
+-- darker than the screen it surrounds.
+local SKY_GRAY = { 170 / 255, 170 / 255, 170 / 255, 1 }
+
+local function tryImage(path)
+  if not path then return nil end
+  local ok, image = pcall(Assets.image, path)
+  if ok then return image end
+  return nil
+end
+
+function TitleState:wantsFillScale() return true end
+function TitleState:drawsWidescreen() return true end
+
+function TitleState.new(game, opts)
+  opts = opts or {}
+  local self = setmetatable({}, TitleState)
+  self.game = game
+  self.onContinue = opts.onContinue
+  local title = opts.title or {}
+  self.title = title
+  self.screenColor = tryImage(title.screen
+    or "assets/generated/title/title_screen.png")
+  self.cloudsColor = tryImage(title.clouds
+    or "assets/generated/title/clouds.png")
+  self.trailColor = tryImage(title.trail or "assets/generated/title/trail.png")
+  -- The uncoloured set, absent from a cache built before COLOR existed -- in
+  -- which case pickArt falls back to the colour one and DMG simply looks the
+  -- way it did before rather than failing to draw.
+  self.screenGray = tryImage(title.screenGray)
+  self.cloudsGray = tryImage(title.cloudsGray)
+  self.trailGray = tryImage(title.trailGray)
+  -- `depixel 12, 11` less the OAM bias and the pose's own origin; see the
+  -- extractor, which writes the same pair into title.lua.
+  self.hoohX = tonumber(title.hoohX) or 48
+  self.hoohY = tonumber(title.hoohY) or 56
+  self.cloudY = tonumber(title.cloudY) or 88
+  self.cloudScrollEvery = tonumber(title.cloudScrollEvery) or 8
+
+  self.hoohColor, self.hoohGray = {}, {}
+  local paths = title.hoohFrames
+  if type(paths) == "table" then
+    for i, path in ipairs(paths) do
+      self.hoohColor[i] = tryImage(path)
+    end
+  end
+  if #self.hoohColor == 0 then
+    self.hoohColor[1] = tryImage(title.hooh or "assets/generated/title/hooh.png")
+  end
+  if type(title.hoohFramesGray) == "table" then
+    for i, path in ipairs(title.hoohFramesGray) do
+      self.hoohGray[i] = tryImage(path)
+    end
+  end
+  self.sequence = title.hoohSequence or {
+    { 1, 10 }, { 2, 9 }, { 3, 10 }, { 4, 10 }, { 3, 9 }, { 5, 10 },
+  }
+  self.seqIndex = 1
+  self.seqLeft = self.sequence[1] and self.sequence[1][2] or 10
+  self.frame = 1
+
+  -- AnimSeq_GSIntroHoOhLugia's SPRITEANIMSTRUCT_VAR1.
+  self.hoohPhase = 0
+  self.frameCounter = 0
+  self.cloudScroll = 0
+  self.trails = {}
+  -- UpdateTitleTrailSprite / TitleTrailCoords (intro_menu.asm), in pixels.
+  self.trailSpawns = {
+    { 80, 88 }, { 104, 88 }, { 104, 88 }, { 120, 88 },
+    { 120, 88 }, { 88, 88 },
+  }
+  self.trailSpawnIndex = 1
+  -- How far past the 160px frame trails may fly (GB pixels); set each draw.
+  self.trailMaxX = 200
+  self.musicStarted = false
+  return self
+end
+
+function TitleState:enter()
+  local data = self.game and self.game.data
+  if data and data.audio and data.audio.runtime and not self.musicStarted then
+    Music.play(data, "Music_TitleScreen", true, { reason = "title" })
+    self.musicStarted = true
+  end
+  -- intro.boot.title: the last card of the GS boot cinema, up with its music
+  -- started.  Gen 2 only, like the rest of intro.boot.* (see
+  -- src/ui/gen2/CopyrightSplash.lua for why the set is new rather than shared).
+  -- Its end is the main menu opening, which src/ui/gen2/MainMenu.lua owns, so
+  -- there is no `ended` name here.  The title's MENU is a different seam again:
+  -- that is Gen 1's `ui.title_menu.items`, which Gold reaches through the main
+  -- menu rather than through this screen.
+  if Runtime.wants("intro.boot.title") then
+    Runtime.emit("intro.boot.title", { screen = self, game = self.game })
+  end
+end
+
+-- AnimSeq_GSIntroHoOhLugia (engine/sprite_anims/functions.asm): VAR1 counts up
+-- one per frame and the struct's Y offset becomes `d * sin(VAR1 * pi/32)` with
+-- d = 2 on Gold (Silver counts DOWN with d = 8).  Sprites_Sine hands back the
+-- byte the ASM leaves in a, so the down half of the wave arrives in two's
+-- complement and has to be read as a signed pixel delta here.
+function TitleState:hoohBob()
+  local value = SpriteAnims.sine(self.hoohPhase, 2)
+  if value >= 0x80 then value = value - 0x100 end
+  return value
+end
+
+function TitleState:advanceHooh()
+  self.hoohPhase = (self.hoohPhase + 1) % 256
+  self.seqLeft = self.seqLeft - 1
+  if self.seqLeft > 0 then return end
+  self.seqIndex = self.seqIndex + 1
+  if self.seqIndex > #self.sequence then self.seqIndex = 1 end
+  local step = self.sequence[self.seqIndex]
+  self.frame = step[1]
+  self.seqLeft = step[2]
+end
+
+function TitleState:spawnTrail()
+  if not (self.trailColor or self.trailGray) then return end
+  if self.frameCounter % 4 ~= 0 then return end
+  local spawn = self.trailSpawns[self.trailSpawnIndex]
+  self.trailSpawnIndex = self.trailSpawnIndex % #self.trailSpawns + 1
+  if not spawn then return end
+  self.trails[#self.trails + 1] = {
+    x = spawn[1], y = spawn[2], phase = love.math.random(0, 255),
+  }
+end
+
+function TitleState:stepTrails()
+  local alive = {}
+  local maxX = self.trailMaxX or 200
+  for _, t in ipairs(self.trails) do
+    t.x = t.x + 4
+    t.y = t.y + 1
+    t.phase = t.phase + 3
+    t.drawY = t.y + math.floor(math.sin(t.phase / 16) * 2)
+    if t.x < maxX then alive[#alive + 1] = t end
+  end
+  self.trails = alive
+end
+
+function TitleState:update(_dt)
+  self.frameCounter = self.frameCounter + 1
+  self:advanceHooh()
+  if self.frameCounter % self.cloudScrollEvery == 0 then
+    self.cloudScroll = (self.cloudScroll + 1) % 160
+  end
+  self:spawnTrail()
+  self:stepTrails()
+
+  local input = self.game.input
+  if input and (input:wasPressed("a") or input:wasPressed("start")) then
+    if self.onContinue then self.onContinue() end
+  end
+end
+
+-- Which of the two baked sets is showing.  GBC is the cart's colour; every
+-- other COLOR mode wants the grey source, and CLASSIC's green comes from the
+-- present pass over the finished frame rather than from a third set of art.
+function TitleState:gray()
+  return GbcPalette.mode ~= "gbc"
+end
+
+function TitleState:art()
+  if self:gray() then
+    return self.screenGray or self.screenColor,
+      self.cloudsGray or self.cloudsColor,
+      self.trailGray or self.trailColor,
+      (#self.hoohGray > 0) and self.hoohGray or self.hoohColor
+  end
+  return self.screenColor, self.cloudsColor, self.trailColor, self.hoohColor
+end
+
+-- Tile the cloud strip across [x0, x1) in GB pixel space (y = 0 of strip).
+function TitleState:drawCloudSpan(x0, x1)
+  local _, clouds = self:art()
+  if not clouds then return end
+  local G = love.graphics
+  local s = self.cloudScroll % 160
+  -- First tile origin such that the scroll lines up with the 160px frame.
+  local start = math.floor((x0 + s) / 160) * 160 - s
+  for x = start, x1, 160 do
+    G.draw(clouds, x, 0)
+  end
+end
+
+function TitleState:drawContent()
+  local G = love.graphics
+  local screen, _, trail, hoohFrames = self:art()
+  G.setColor(1, 1, 1, 1)
+  if screen then
+    -- title_screen.png already carries the cart's © GAME FREAK line on row 17.
+    G.draw(screen, 0, 0)
+  else
+    G.rectangle("fill", 0, 0, 160, 144)
+  end
+
+  -- Center cloud scroll (matches the side tiles from drawWidescreen).
+  G.push()
+  G.translate(0, self.cloudY)
+  self:drawCloudSpan(0, 160)
+  G.pop()
+
+  local bob = self:hoohBob()
+  local hooh = hoohFrames[self.frame] or hoohFrames[1]
+  if hooh then
+    G.draw(hooh, self.hoohX, self.hoohY + bob)
+  end
+
+  if trail then
+    for _, t in ipairs(self.trails) do
+      G.draw(trail, t.x, t.drawY or t.y)
+    end
+  end
+end
+
+-- Letterboxed fallback (non-widescreen hosts).
+function TitleState:draw()
+  self:drawContent()
+end
+
+-- Full-window sky + cloud wrap, then centered 160x144 art.
+function TitleState:drawWidescreen(winW, winH)
+  local G = love.graphics
+  local scale = Chrome.fitScale(winW, winH)
+  local ox, oy = Chrome.fitOrigin(winW, winH, scale)
+  local cloudTop = oy + self.cloudY * scale
+  -- Let trails fly into the side bands.
+  self.trailMaxX = math.ceil((winW - ox) / scale) + 16
+
+  -- Sky above the cloud line, paper white below : edge to edge.  The fill has
+  -- to match whichever baked set is showing, or the surround would stay blue
+  -- around a grey screen.
+  local sky = self:gray() and SKY_GRAY or SKY
+  G.setColor(sky[1], sky[2], sky[3], 1)
+  G.rectangle("fill", 0, 0, winW, math.max(0, cloudTop))
+  G.setColor(1, 1, 1, 1)
+  G.rectangle("fill", 0, cloudTop, winW, winH - cloudTop)
+
+  -- Clouds across the full window width, aligned to the GB cloud band.
+  G.push()
+  G.translate(ox, cloudTop)
+  G.scale(scale, scale)
+  local left = -math.ceil(ox / scale) - 160
+  local right = math.ceil((winW - ox) / scale) + 160
+  self:drawCloudSpan(left, right)
+  G.pop()
+
+  -- Centered original composition (logo / Ho-Oh / copyright / trails).
+  G.push()
+  G.translate(ox, oy)
+  G.scale(scale, scale)
+  self:drawContent()
+  G.pop()
+end
+
+return TitleState