Overview

UWCGASDifficultySub is a World Subsystem that serves as the global manager for difficulty tiers in the Wonderscape GAS Ally plugin. It automatically initializes with each world (PIE, level streaming friendly), loads difficulty tier data assets from Project Settings, caches active tier information for O(1) runtime queries, broadcasts delegates on difficulty changes, and provides an internal API for other plugin subsystems to load difficulty-appropriate data.

Purpose

The Difficulty Subsystem orchestrates all difficulty tier management by providing:

• Automatic Initialization: Loads difficulty tier assets from Project Settings at world startup and sets the default difficulty
• Tier Registry: Maps difficulty GameplayTags to data assets (Tag → SoftPtr) for O(1) lookups via TMap
• Cached Tier Info: Maintains a sorted array of lightweight FWCGASDifficultyTierInfo structs for fast UI population without loading full assets
• Difficulty Comparison: Provides IsDifficultyAtLeast() for conditional game logic based on tier SortOrder values
• Data Asset Override Resolution: Template function GetDataAssetForDifficulty<T>() enables other subsystems to load difficulty-specific configurations
• Persistence Support: Capture and restore difficulty state via CaptureSaveData() and LoadFromSaveStruct() with migration support and detailed result feedback

How It Works

Initialization Flow

1. Subsystem Startup: When the World initializes, this subsystem automatically loads via UE's subsystem lifecycle
2. Load Plugin Settings: Retrieves configuration from UWCGASAllySettings via GetDefault<UWCGASAllySettings>()
3. Load Difficulty Tier Assets: Iterates through Settings->DifficultyTiers array, loading each UWCGASDifficultyTier synchronously
4. Build Tier Registry: For each valid tier, validates DifficultyTag and adds to RegisteredTiers TMap (Tag → SoftPtr) and LoadedTierAssets TMap (Tag → LoadedPtr)
5. Cache Tier Info: Calls Tier->ToTierInfo() to create lightweight FWCGASDifficultyTierInfo and adds to CachedTierInfos array
6. Sort by SortOrder: Sorts CachedTierInfos array ascending by SortOrder for UI display consistency