G2 support

src/core/GameVersion.lua

@@ -1,14 +1,14 @@
--- Which Gen-1 game this process is running: Red (the historical default),
--- Blue, or Yellow.  One source of truth for everything that differs by
+-- Which game this process is running: Red (the historical default), Blue,
+-- Yellow, or Gold.  One source of truth for everything that differs by
 -- version -- the accepted ROM hash, the import manifest, where the
 -- extracted cache lives, and the save-file suffix -- so the importer,
 -- cache mount, SaveData, title screen and palette all agree.
 --
 -- Red keeps the un-suffixed save paths it always used (save.lua) so existing
--- saves are untouched, but its extracted cache lives under red/ like Blue and
--- Yellow (issue #899); a legacy root cache is moved into red/ once by
--- CacheFs.migrateLegacyRedCache.  All three versions can be imported and
--- played side by side.
+-- saves are untouched, but its extracted cache lives under red/ like Blue,
+-- Yellow, and Gold (issue #899); a legacy root cache is moved into red/ once
+-- by CacheFs.migrateLegacyRedCache.  All supported versions can be imported
+-- and selected side by side.  Gold is Gen 2 (see docs/gold-phase1.md).
 --
 -- Zero requires, so it loads during love.conf and under plain Lua for tools
 -- and tests.  The active version is a process-global set once at boot from
@@ -47,10 +47,27 @@ GameVersion.VERSIONS = {
     cachePrefix = "yellow/",  -- yellow/data/generated, yellow/assets/generated
     saveSuffix = "_yellow",   -- save_yellow.lua / .bak / .tmp
   },
+  -- Gen 2, Phase 1 (docs/gold-phase1.md): a 2 MiB cart, twice the size of
+  -- the Gen 1 ROMs above, imported through RomExtractorGen2 instead of
+  -- RomExtractor.
+  gold = {
+    id = "gold",
+    label = "Gold",
+    displayName = "Pokemon Gold",
+    -- Still Gen 2 Phase work; the launcher panel / Play button say Beta so
+    -- players do not treat it like the shipped Gen 1 columns.
+    launcherName = "Gold (Beta)",
+    sha1 = "d8b8a3600a465308c9953dfa04f0081c05bdcb94",
+    manifest = "tools/rom_manifest_gold.json",
+    cachePrefix = "gold/",    -- gold/data/generated, gold/assets/generated
+    saveSuffix = "_gold",     -- save_gold.lua / .bak / .tmp
+    -- The only row that carries one; absent reads as 1 (GameVersion.generation)
+    generation = 2,
+  },
 }
 
 -- Launcher column order.
-GameVersion.ORDER = { "red", "blue", "yellow" }
+GameVersion.ORDER = { "red", "blue", "yellow", "gold" }
 
 GameVersion.current = "red"
 
@@ -71,6 +88,19 @@ function GameVersion.isYellow()
   return GameVersion.current == "yellow"
 end
 
+function GameVersion.isGold()
+  return GameVersion.current == "gold"
+end
+
+-- 1 or 2.  The mod API is shared across both (same hook names, same registry
+-- names), so the pieces that must branch -- the manifest gen2compat gate, the
+-- registry target routing, the mod.world arm -- ask this rather than each
+-- spelling out its own isGold() test.  A third generation adds a `generation`
+-- to its VERSIONS row and nothing else changes shape.
+function GameVersion.generation(id)
+  return GameVersion.info(id).generation or 1
+end
+
 -- Metadata for a version id, defaulting to the active one.
 function GameVersion.info(id)
   return GameVersion.VERSIONS[id or GameVersion.current]