Godot ゲームローカリゼーション完全ガイド

# TranslationServer is Godot's built-in localization system.
# It loads translations at startup and resolves keys via tr().

# Set the game's locale
TranslationServer.set_locale("ja")

# Get the current locale
var current = TranslationServer.get_locale()  # "ja"

# Translate a key — works everywhere in GDScript
var text = tr("MENU_START")  # "ゲームスタート"

# Translate with context (Godot 4.x)
var text = tr("OPEN", "verb")    # "Open" (action)
var text = tr("OPEN", "adj")     # "Open" (state)

# translations.csv
# First column = key, subsequent columns = locale codes
keys,en,ja,de,es
MENU_START,Start Game,ゲームスタート,Spiel starten,Iniciar juego
MENU_SETTINGS,Settings,設定,Einstellungen,Configuración
MENU_QUIT,Quit,終了,Beenden,Salir
ITEM_SWORD,Sword,剣,Schwert,Espada
ITEM_SHIELD,Shield,盾,Schild,Escudo
DIALOG_GREETING,"Hello, adventurer!",冒険者よ、こんにちは！,"Hallo, Abenteurer!","¡Hola, aventurero!"

# In Godot Editor:
# 1. Place your .csv file in the project (e.g., res://translations.csv)
# 2. Godot auto-imports it — creates .translation resources
# 3. Go to Project > Project Settings > Localization > Translations
# 4. Add the generated .translation files

# translations.po — Gettext format for Godot
# Place in res://locale/ja.po

msgid ""
msgstr ""
"Language: ja\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Plural-Forms: nplurals=1; plural=0;\n"

# Simple translation
msgid "MENU_START"
msgstr "ゲームスタート"

# Translation with context (disambiguates identical source strings)
msgctxt "verb"
msgid "OPEN"
msgstr "開く"

msgctxt "adj"
msgid "OPEN"
msgstr "開いている"

# Plural form
msgid "You collected %d coin."
msgid_plural "You collected %d coins."
msgstr[0] "%d枚のコインを集めました。"

# Project Settings > Localization > Translations
# Add each .po file:
#   res://locale/en.po
#   res://locale/ja.po
#   res://locale/de.po
#   res://locale/es.po

# Or load programmatically:
func _ready():
    var translation = load("res://locale/ja.po")
    TranslationServer.add_translation(translation)

extends Control

func _ready():
    # Simple key lookup
    $TitleLabel.text = tr("MENU_START")

    # With string formatting (positional)
    $GreetingLabel.text = tr("DIALOG_GREETING_NAME") % [player_name]

    # With multiple placeholders
    $StatusLabel.text = tr("PLAYER_STATUS") % [player_name, level, health]

    # Context-aware translation (Godot 4.x)
    $ActionButton.text = tr("OPEN", "verb")

    # Update UI when locale changes
    TranslationServer.set_locale("de")
    _update_ui()

func _update_ui():
    # Re-apply all translated strings
    $TitleLabel.text = tr("MENU_START")
    $GreetingLabel.text = tr("DIALOG_GREETING_NAME") % [player_name]

# locale_manager.gd — Register as Autoload in Project Settings
extends Node

signal locale_changed(new_locale: String)

const SUPPORTED_LOCALES = ["en", "ja", "de", "es", "fr", "ko", "zh"]

func _ready():
    var system_locale = OS.get_locale_language()
    if system_locale in SUPPORTED_LOCALES:
        set_locale(system_locale)
    else:
        set_locale("en")

func set_locale(locale: String):
    TranslationServer.set_locale(locale)
    locale_changed.emit(locale)

func get_locale() -> String:
    return TranslationServer.get_locale()

# Godot uses Gettext PO plural rules.
# Each language defines its own plural formula.

# English (2 forms: one, other)
msgid "You collected %d coin."
msgid_plural "You collected %d coins."
msgstr[0] "You collected %d coin."
msgstr[1] "You collected %d coins."

# Japanese (1 form: other — no singular/plural distinction)
msgid "You collected %d coin."
msgid_plural "You collected %d coins."
msgstr[0] "%d枚のコインを集めました。"

# Russian (3 forms: one, few, many)
msgid "You collected %d coin."
msgid_plural "You collected %d coins."
msgstr[0] "Вы собрали %d монету."
msgstr[1] "Вы собрали %d монеты."
msgstr[2] "Вы собрали %d монет."

# GDScript string formatting with tr()

# Positional placeholders with %
var msg = tr("SCORE_MSG") % [score]        # "Score: %d" → "Score: 1500"
var msg = tr("STATS") % [name, level, hp]  # "%s — Lv %d — HP: %d"

# Named placeholders (manual replacement)
var template = tr("WELCOME_BACK")
var msg = template.replace("{player}", name).replace("{days}", str(days))

# Godot 4.x supports font fallback chains.
# When a glyph is missing from the primary font, fallbacks are checked in order.

# In the Editor:
# 1. Create a LabelSettings or Theme resource
# 2. Set the primary font (e.g., Noto Sans for Latin)
# 3. Add fallback fonts: Noto Sans JP, KR, SC, Arabic

# Programmatically:
func setup_fonts():
    var font = FontFile.new()
    font.load_dynamic_font("res://fonts/NotoSans-Regular.ttf")

    var fallback_jp = FontFile.new()
    fallback_jp.load_dynamic_font("res://fonts/NotoSansJP-Regular.ttf")
    font.add_fallback(fallback_jp)

    $Label.add_theme_font_override("font", font)

# Right-to-left (RTL) support for Arabic, Hebrew, etc.

# In the Editor:
# Select your Control node > Layout > Text Direction = RTL

# Programmatically:
func setup_rtl():
    var locale = TranslationServer.get_locale()
    var rtl_locales = ["ar", "he", "fa", "ur"]

    if locale.substr(0, 2) in rtl_locales:
        $Label.text_direction = Control.TEXT_DIRECTION_RTL
        $Container.layout_direction = Control.LAYOUT_DIRECTION_RTL

# Approach 1: Translate in _ready() using tr()
extends Control

func _ready():
    $StartButton.text = tr("MENU_START")
    $SettingsButton.text = tr("MENU_SETTINGS")
    $QuitButton.text = tr("MENU_QUIT")

# Approach 2: Use auto-translate in the editor
# Set the Text property to the translation key (e.g., "MENU_START")
# and enable "Auto Translate" on the node.

# Approach 3: Locale-specific scenes for complex layouts
func load_localized_scene():
    var locale = TranslationServer.get_locale().substr(0, 2)
    var path = "res://ui/main_menu_%s.tscn" % locale
    if ResourceLoader.exists(path):
        add_child(load(path).instantiate())
    else:
        add_child(load("res://ui/main_menu_en.tscn").instantiate())

# LocaleChain for Godot — smart locale fallback
# Install from Godot AssetLib or copy addons/locale_chain/ into your project

# Problem: Godot's TranslationServer falls back directly to the default locale.
# A pt-BR player with only pt-PT translations sees English, not Portuguese.

# Solution: One-line setup
func _ready():
    LocaleChain.configure()  # Uses built-in fallback chains

# Now pt-BR falls back to pt-PT → pt → default
# es-MX falls back to es-419 → es → default
# zh-Hant-HK falls back to zh-Hant-TW → zh-Hant → default

# Custom configuration:
func _ready():
    # Override specific chains
    LocaleChain.configure({"pt-BR": ["pt"]})

    # Full custom — only your chains
    LocaleChain.configure(
        {"pt-BR": ["pt-PT", "pt"], "es-MX": ["es-419", "es"]},
        false  # don't merge defaults
    )

    # Reset to original state
    LocaleChain.reset()

# Translate your Godot locale files with AI
# CSV files:
# In your IDE, ask your AI assistant:
> Translate translations.csv to Japanese, Korean, and German

# PO files:
> Translate locale/en.po to ja, ko, de

# Or use the CLI in CI/CD:
npx i18n-agent translate locale/en.po --lang ja,ko,de

# The tool preserves:
# - CSV column structure and delimiters
# - PO msgctxt, msgid_plural, and plural forms
# - Placeholder syntax (%s, %d, {name})
# - Comments and metadata headers

my_godot_game/
├── addons/
│   └── locale_chain/              # LocaleChain plugin (optional)
│       ├── fallback_map.gd
│       ├── locale_chain.gd
│       └── plugin.cfg
├── fonts/
│   ├── NotoSans-Regular.ttf       # Primary font (Latin)
│   ├── NotoSansJP-Regular.ttf     # Japanese fallback
│   ├── NotoSansKR-Regular.ttf     # Korean fallback
│   └── NotoSansArabic-Regular.ttf # Arabic fallback
├── locale/
│   ├── en.po                      # English (source)
│   ├── ja.po                      # Japanese
│   ├── de.po                      # German
│   ├── es.po                      # Spanish
│   └── ar.po                      # Arabic
├── translations.csv               # Alternative: CSV format
├── scenes/
│   └── ui/
│       ├── main_menu.tscn
│       └── settings_menu.tscn
├── scripts/
│   ├── locale_manager.gd          # Autoload for locale management
│   └── ui/
│       └── main_menu.gd
├── project.godot
└── export_presets.cfg