357 lines
11 KiB
Markdown

# EverQuest II Loot System
This package implements a comprehensive loot generation and management system for the EverQuest II server emulator, converted from the original C++ implementation.
## Overview
The loot system handles:
- **Loot Generation**: Probability-based item and coin generation from configurable loot tables
- **Treasure Chests**: Physical chest spawns with tier-appropriate appearances
- **Global Loot**: Level, race, and zone-based loot assignments
- **Loot Distribution**: Group loot methods and player rights management
- **Database Integration**: Persistent loot table and assignment storage
- **Client Communication**: Version-specific packet building for loot windows
## Architecture
### Core Components
#### LootDatabase (`database.go`)
- Manages all database operations for loot tables, drops, and assignments
- Caches loot data in memory for performance
- Supports real-time updates and reloading
#### LootManager (`manager.go`)
- Central coordinator for loot generation and chest management
- Implements probability-based loot algorithms
- Handles treasure chest lifecycle and cleanup
#### ChestService (`chest.go`)
- Manages treasure chest interactions (view, loot, disarm, lockpick)
- Validates player permissions and positioning
- Integrates with player and zone services
#### LootPacketBuilder (`packets.go`)
- Builds client-specific packets for loot communication
- Supports multiple client versions (v1 through v60114+)
- Handles loot window updates and interaction responses
#### LootSystem (`integration.go`)
- High-level integration layer combining all components
- Provides simplified API for common operations
- Manages system lifecycle and configuration
### Data Structures
#### LootTable
```go
type LootTable struct {
ID int32 // Unique table identifier
Name string // Descriptive name
MinCoin int32 // Minimum coin drop
MaxCoin int32 // Maximum coin drop
MaxLootItems int16 // Maximum items per loot
LootDropProbability float32 // Chance for loot to drop (0-100%)
CoinProbability float32 // Chance for coins to drop (0-100%)
Drops []*LootDrop // Individual item drops
}
```
#### LootDrop
```go
type LootDrop struct {
LootTableID int32 // Parent table ID
ItemID int32 // Item to drop
ItemCharges int16 // Item stack size/charges
EquipItem bool // Auto-equip item
Probability float32 // Drop chance (0-100%)
NoDropQuestCompletedID int32 // Required quest completion
}
```
#### TreasureChest
```go
type TreasureChest struct {
ID int32 // Unique chest ID
SpawnID int32 // Source spawn ID
ZoneID int32 // Zone location
X, Y, Z float32 // Position coordinates
Heading float32 // Orientation
AppearanceID int32 // Visual appearance
LootResult *LootResult // Contained items and coins
Created time.Time // Creation timestamp
LootRights []uint32 // Players with access rights
IsDisarmable bool // Can be disarmed
IsLocked bool // Requires lockpicking
}
```
## Database Schema
### Core Tables
#### loottable
```sql
CREATE TABLE loottable (
id INTEGER PRIMARY KEY,
name TEXT,
mincoin INTEGER DEFAULT 0,
maxcoin INTEGER DEFAULT 0,
maxlootitems INTEGER DEFAULT 6,
lootdrop_probability REAL DEFAULT 100.0,
coin_probability REAL DEFAULT 50.0
);
```
#### lootdrop
```sql
CREATE TABLE lootdrop (
loot_table_id INTEGER,
item_id INTEGER,
item_charges INTEGER DEFAULT 1,
equip_item INTEGER DEFAULT 0,
probability REAL DEFAULT 100.0,
no_drop_quest_completed_id INTEGER DEFAULT 0
);
```
#### spawn_loot
```sql
CREATE TABLE spawn_loot (
spawn_id INTEGER,
loottable_id INTEGER
);
```
#### loot_global
```sql
CREATE TABLE loot_global (
type TEXT, -- 'level', 'race', or 'zone'
loot_table INTEGER, -- Target loot table ID
value1 INTEGER, -- Min level, race ID, or zone ID
value2 INTEGER, -- Max level (for level type)
value3 INTEGER, -- Loot tier
value4 INTEGER -- Reserved
);
```
## Usage Examples
### Basic Setup
```go
// Create loot system
config := &LootSystemConfig{
DatabaseConnection: db,
ItemMasterList: itemMasterList,
PlayerService: playerService,
ZoneService: zoneService,
ClientService: clientService,
ItemPacketBuilder: itemPacketBuilder,
StartCleanupTimer: true,
}
lootSystem, err := NewLootSystem(config)
if err != nil {
log.Fatal(err)
}
```
### Generate Loot and Create Chest
```go
// Create loot context
context := &LootContext{
PlayerLevel: 25,
PlayerRace: 1,
ZoneID: 100,
KillerID: playerID,
GroupMembers: []uint32{playerID},
CompletedQuests: playerQuests,
LootMethod: GroupLootMethodFreeForAll,
}
// Generate loot and create chest
chest, err := lootSystem.GenerateAndCreateChest(
spawnID, zoneID, x, y, z, heading, context)
if err != nil {
log.Printf("Failed to create loot chest: %v", err)
}
```
### Handle Player Loot Interaction
```go
// Player opens chest
err := lootSystem.ShowChestToPlayer(chestID, playerID)
// Player loots specific item
err = lootSystem.HandlePlayerLootInteraction(
chestID, playerID, ChestInteractionLoot, itemUniqueID)
// Player loots everything
err = lootSystem.HandlePlayerLootInteraction(
chestID, playerID, ChestInteractionLootAll, 0)
```
### Create Loot Tables
```go
// Create a simple loot table
items := []QuickLootItem{
{ItemID: 1001, Charges: 1, Probability: 100.0, AutoEquip: false},
{ItemID: 1002, Charges: 5, Probability: 50.0, AutoEquip: false},
{ItemID: 1003, Charges: 1, Probability: 25.0, AutoEquip: true},
}
err := lootSystem.CreateQuickLootTable(
tableID, "Orc Warrior Loot", items, 10, 50, 3)
// Assign to spawns
spawnIDs := []int32{2001, 2002, 2003}
err = lootSystem.AssignLootToSpawns(tableID, spawnIDs)
```
## Chest Appearances
Chest appearance is automatically selected based on the highest tier item:
| Tier Range | Appearance | Chest Type |
|------------|------------|------------|
| 1-2 (Common-Uncommon) | 4034 | Small Chest |
| 3-4 (Treasured-Rare) | 5864 | Treasure Chest |
| 5-6 (Legendary-Fabled) | 5865 | Ornate Chest |
| 7+ (Mythical+) | 4015 | Exquisite Chest |
## Loot Generation Algorithm
1. **Table Selection**: Get loot tables assigned to spawn + applicable global tables
2. **Drop Probability**: Roll against `lootdrop_probability` to determine if loot drops
3. **Coin Generation**: If `coin_probability` succeeds, generate random coins between min/max
4. **Item Processing**: For each loot drop:
- Check quest requirements
- Roll against item probability
- Generate item instance with specified charges
- Stop when `maxlootitems` reached
5. **Chest Creation**: If items qualify (tier >= Common), create treasure chest
## Global Loot System
Global loot provides automatic loot assignment based on:
### Level-Based Loot
```go
err := lootSystem.CreateGlobalLevelLoot(10, 20, tableID, LootTierCommon)
```
### Race-Based Loot
```sql
INSERT INTO loot_global (type, loot_table, value1, value2)
VALUES ('race', 100, 1, 0); -- Human racial loot
```
### Zone-Based Loot
```sql
INSERT INTO loot_global (type, loot_table, value1, value2)
VALUES ('zone', 200, 150, 0); -- Zone 150 specific loot
```
## Group Loot Methods
The system supports various loot distribution methods:
- **Free For All**: Anyone can loot anything
- **Round Robin**: Items distributed in turn order
- **Master Looter**: Designated player distributes loot
- **Need/Greed**: Players roll need or greed for items
- **Lotto**: Random distribution for high-tier items
## Statistics and Monitoring
```go
// Get comprehensive statistics
stats, err := lootSystem.GetSystemStatistics()
// Check loot generation stats
genStats := lootSystem.Manager.GetStatistics()
fmt.Printf("Total loots: %d, Average items per loot: %.2f",
genStats.TotalLoots, genStats.AverageItemsPerLoot)
```
## Validation and Debugging
```go
// Validate all items in loot tables exist
errors := lootSystem.ValidateItemsInLootTables()
for _, err := range errors {
fmt.Printf("Validation error: %s\n", err.Description)
}
// Preview potential loot without generating
preview, err := lootSystem.GetLootPreview(spawnID, context)
fmt.Printf("Possible items: %d, Coin range: %d-%d",
len(preview.PossibleItems), preview.MinCoins, preview.MaxCoins)
```
## Performance Considerations
- **Memory Caching**: All loot tables are cached in memory for fast access
- **Prepared Statements**: Database queries use prepared statements for efficiency
- **Concurrent Safety**: All operations are thread-safe with proper mutex usage
- **Cleanup Timers**: Automatic cleanup of expired chests prevents memory leaks
- **Batch Operations**: Support for bulk loot table and spawn assignments
## Client Version Compatibility
The packet building system supports multiple EverQuest II client versions:
- **Version 1**: Basic loot display (oldest clients)
- **Version 373**: Added item type and icon support
- **Version 546**: Enhanced item appearance data
- **Version 1193**: Heirloom and no-trade flags
- **Version 60114**: Full modern feature set with adornments
## Migration from C++
This Go implementation maintains full compatibility with the original C++ EQ2EMu loot system:
- **Database Schema**: Identical table structure and data
- **Loot Algorithms**: Same probability calculations and item selection
- **Chest Logic**: Equivalent chest appearance and interaction rules
- **Global Loot**: Compatible global loot table processing
- **Packet Format**: Maintains client protocol compatibility
## Testing
Comprehensive test suite covers:
- Loot generation algorithms
- Database operations
- Chest interactions
- Packet building
- Statistics tracking
- Performance benchmarks
Run tests with:
```bash
go test ./internal/items/loot/...
```
## Configuration
Key configuration constants in `constants.go`:
- `DefaultMaxLootItems`: Maximum items per loot (default: 6)
- `ChestDespawnTime`: Empty chest despawn time (5 minutes)
- `ChestCleanupTime`: Force cleanup time (10 minutes)
- `LootTierCommon`: Minimum tier for chest creation
## Error Handling
The system provides detailed error reporting for:
- Missing loot tables or items
- Invalid player permissions
- Database connection issues
- Packet building failures
- Chest interaction violations
All errors are logged with appropriate prefixes (`[LOOT]`, `[CHEST]`, `[LOOT-DB]`) for easy debugging.