SDV Multiplayer & Gamepad Audit

Static analysis for multiplayer and gamepad support. Since runtime testing of these features is difficult, this skill provides comprehensive code auditing to catch issues before manual testing.

When to Run This Audit

1. Before committing changes to any file in Managers/ or Menus/
2. After adding new state variables (fields, properties)
3. When implementing features that affect multiple players
4. Before PR creation

Multiplayer Audit Checklist

1. PerScreen Wrapper Audit

All per-player mutable state MUST use PerScreen<T>:

// WRONG: Static state shared across split-screen players
private static MenuManager menuManager;
private static int currentTab = 0;

// CORRECT: Per-screen state
private static readonly PerScreen<MenuManager> menuManager = new();
private static readonly PerScreen<int> currentTab = new(() => 0);

// Access via .Value
menuManager.Value.DoSomething();
int tab = currentTab.Value;

Audit Points:

• All static fields with mutable state use PerScreen
• PerScreen fields are readonly (prevents clearing all screens)
• PerScreen initialized with proper factory if needed: new(() => defaultValue)
• Manager classes use PerScreen in the entry point

2. Context Checks

Verify proper context gating:

// Required before accessing world state
if (!Context.IsWorldReady) return;

// Required before player interaction logic
if (!Context.IsPlayerFree) return;

// Required for host-only operations
if (!Context.IsMainPlayer) return;

// Required for save operations
if (Context.IsMainPlayer)
{
    Helper.Data.WriteSaveData("key", data);
}

Audit Points:

• Event handlers check Context.IsWorldReady before accessing Game1.player
• Save operations check Context.IsMainPlayer (farmhands can't use save API)
• Menu operations check Context.IsPlayerFree when appropriate

3. Mutex Locking (Shared Furniture)

Dressers and other shared furniture require mutex:

// CORRECT: Request lock before opening menu
if (!dresser.mutex.IsLocked())
{
    dresser.mutex.RequestLock(delegate {
        Game1.activeClickableMenu = new WardrobeMenu();
    });
}

// CRITICAL: Release on menu close
public override void emergencyShutDown()
{
    base.emergencyShutDown();
    dresserObject?.mutex?.ReleaseLock();
}

protected override void cleanupBeforeExit()
{
    base.cleanupBeforeExit();
    dresserObject?.mutex?.ReleaseLock();
}

Audit Points:

• Shared furniture access uses mutex.RequestLock()
• Menu emergencyShutDown() releases mutex
• Menu cleanupBeforeExit() releases mutex
• Null checks on mutex before release

4. Player Data Keying

Per-player save data must be uniquely keyed:

// CORRECT: Unique key per player, per save, per multiplayer session
string dataPath = $"data/favoritesData/{Game1.player.Name}_{Constants.SaveFolderName}_{Game1.player.UniqueMultiplayerID}.json";

// Also valid for modData (always prefix with mod ID)
Game1.player.modData[$"{ModId}/PlayerFlag"] = "true";

Audit Points:

• Save paths include player identifier AND save folder AND multiplayer ID
• modData keys prefixed with mod's UniqueID
• No assumptions that data paths are unique without proper keying

5. Location Iteration

Use utilities that work for farmhands:

// WRONG: Misses some locations for farmhands
foreach (var loc in Game1.locations) { }

// CORRECT: Works for all players
Utility.ForAllLocations(loc => {
    // process location
});

Gamepad Audit Checklist

1. ClickableComponent Navigation

Every clickable element needs navigation IDs:

var button = new ClickableComponent(bounds, "name");
button.myID = 1001;                    // REQUIRED: Unique ID
button.leftNeighborID = 1000;          // Left neighbor (or -99999 for none)
button.rightNeighborID = 1002;         // Right neighbor
button.upNeighborID = 900;             // Up neighbor
button.downNeighborID = 1100;          // Down neighbor

Audit Points:

• Every ClickableComponent has myID set
• Every ClickableComponent has all four neighborIDs set
• IDs are unique within the menu
• Navigation forms logical grid (no dead ends)
• Use -99999 for "no neighbor" (not 0 or -1)

2. Component List Population

public override void populateClickableComponentList()
{
    base.populateClickableComponentList();
    allClickableComponents.AddRange(labels);
    allClickableComponents.AddRange(buttons);
    allClickableComponents.AddRange(equipmentIcons);
    // Add ALL clickable elements
}

Audit Points:

• populateClickableComponentList() adds all components
• snapToDefaultClickableComponent() called after population
• Components not added after initial setup (or list repopulated)

3. Focus Management

public override void snapToDefaultClickableComponent()
{
    base.snapToDefaultClickableComponent();
    currentlySnappedComponent = getComponentWithID(defaultFocusId);
    snapCursorToCurrentSnappedComponent();
}

Audit Points:

• Menu has a logical default focus element
• Focus returns to sensible element after actions
• Child menus properly handle focus transfer

4. Button Hints

For important actions, show controller button hints:

// In draw():
if (Game1.options.gamepadControls)
{
    // Draw A button hint next to action button
    b.Draw(Game1.controllerMaps, position, sourceRect, Color.White);
}

Audit Output Format

When running this audit, report findings as:

## Multiplayer Audit Results

### Issues Found

1. **PerScreen Missing** - `Managers/MenuManager.cs:45`
   - Field `currentCategory` is static but not wrapped in PerScreen<T>
   - Fix: Change to `private static readonly PerScreen<string> currentCategory = new();`

2. **Mutex Not Released** - `Menus/WardrobeMenu.cs:312`
   - `emergencyShutDown()` doesn't release mutex
   - Fix: Add `dresserObject?.mutex?.ReleaseLock();`

### Gamepad Navigation Issues

1. **Missing neighborID** - `Menus/FavoritesMenu.cs:189`
   - `deleteButton` has no `upNeighborID` set
   - Fix: Add `deleteButton.upNeighborID = renameButton.myID;`

### Passed Checks
- [x] All PerScreen fields are readonly
- [x] Context.IsWorldReady checks present in event handlers
- [x] Save operations check Context.IsMainPlayer

Quick Reference

Split-Screen Player Access

// Current screen's value
var current = perScreenField.Value;

// Specific screen's value
var screen0 = perScreenField.GetValueForScreen(0);

// Current screen ID
int screenId = Context.ScreenId;

Common Navigation ID Ranges

// Use ranges to organize IDs
const int LABELS = 10000;
const int BUTTONS = 20000;
const int CATEGORIES = 30000;
const int OUTFIT_CARDS = 40000;

// Then: button.myID = BUTTONS + index;