ModernUO/Projects/UOContent/Mobiles/Familiars/BaseFamiliar.cs
Kamron Batman 1e891094fe
fix(ai): FamiliarAI owns familiar movement and combat; herding reaches its tile; ForcedAI read once (#2644)
## Problem

`BaseFamiliar.OnThink` drove its own movement (`WalkMobileRange` toward the master) while the familiar was also a controlled pet running `Obey()`. `Summon → SetControlMaster` issues `Come`; `DoOrderCome` converts it to `Stay` within two tiles and anchors `Home`; from then on `OnThink` walked toward the caster while `DoOrderStay` greedy-stepped back toward the stale post — the backtracking. Combat never approached anything: main only copied `Combatant` while already adjacent to the caster. `CurrentSpeed = 0.01` was a 10 ms think / 50 ms step sprint hack, and `RangeCheck` teleported the familiar to a spot eight tiles *from* the caster.

## Change

A dedicated `FamiliarAI : BaseAI` (registered through `ForcedAI`, like `CloneAI`) owns every familiar decision, for both the controlled (`Obey`) and uncontrolled (`Think`) dispatch:

1. **Lifecycle** — caster gone → drop pack, delete. Caster on another map → stand down and wait for `TeleportPets`.
2. **Herding** (Dark Tides) — stands down, then `CheckHerding()`. Outranks combat.
3. **Assist** — combat-capable familiars (dark wolf, vampire bat, horde minion) engage the caster's target; otherwise anything in a fight with the caster's side — attacked the caster or the familiar, or attacked by the caster (a pet's attack is credited to the caster) — that is still fighting the caster, the familiar, or one of the caster's pets. Leashed to `RangePerception` of the caster; dropped when the caster hides. Shadow wisp and death adder never fight (`AssistsMaster => false`, enforced at the `Combatant` setter so no path can hand them a target).
4. **Follow** — `MoveTo(master, 1)` through the centralized `ApproachTarget` (greedy step / persistent `PathFollower` / stall detection).
5. **Keep-up** — snap to a validated tile beside the caster (on the caster's floor) when outpaced on open ground beyond 10 tiles, or when `ApproachTarget` gave up; never while a detour is working.

**Command immunity** is expressed inside the order machinery rather than around it: `FamiliarAI.IssueOrder` does nothing and rests the order on `Come`, so `TeleportPets` keeps working and no system-issued `Attack` (retaliation on ML's stand-down rule) can strand the familiar. `StandsDownOnCommand => false` so the ML rule never mutes it.

**Visibility** mirrors the caster from the familiar's own state (a step reveals a hidden NPC in `Mobile.OnMove`; the old cache compared the caster's previous state), `RevealingAction` is suppressed while the caster is hidden, and becoming hidden drops Warmode so no swing gives the caster away.

**Speed** is a flat 0.1 (`ReduceSpeedWithDamage => false`).

### Engine-side (all `Projects/UOContent`)

- `ApproachTarget` records which exit it took in `BaseAI.LastApproach` (`ApproachOutcome`: Arrived / Waiting / DirectProgress / Routing / Blocked / GaveUp / InvalidGoal). Callers' booleans are unchanged; keep-up reads this instead of running a second scheduler. `MoveTo`'s arrival return now also clears the move intent, as `ApproachTarget`'s own arrival does.
- `MoveToPoint(goal, range = 1)`; `CheckHerding` passes 0. **Fixes a main regression from #2591:** herding stopped one tile short, never cleared `TargetLocation`, and left the creature pinned to the herding pace — affects the shepherd's crook and the Dark Tides scroll fetch for every herded creature, not just familiars.
- `ChangeAIType` reads `ForcedAI` once. It read it twice, and each `BaseAI` ctor activates its timer for a non-sector-gated creature, so a `ForcedAI` creature with `PlayerRangeSensitive => false` got an orphan AI ticking it.

## Tests

`FamiliarAITests` are timer-wheel driven (the real `AITimer` thinks and moves; `PetPacingTests` style) against live Trammel statics, gated on client map data: follow without backtracking, the five-way assist theory, leash, retaliation, aggressor fallback (caster's own `Combatant` expired; caster's pet in the fight), target dropped when it stops fighting, keep-up on open ground / not while routing / after give-up, hidden mirror across steps, herding priority with a visible fighting caster, stand-down when left behind, no stale move intent. `ApproachOutcomeTests`, `HerdingTests` (fails on main), `ForcedAITests` (fails on main) cover the engine-side pieces.

Against `origin/main` with the familiar tests dropped in: 16/16 fail, including the reported backtracking. On this branch: `UOContent.Tests` 1082 passed / 2 skipped, `Server.Tests` 891/891, solution builds with 0 warnings.
2026-09-14 23:14:30 -07:00

169 lines
4.2 KiB
C#

using ModernUO.Serialization;
using Server.Collections;
using Server.ContextMenus;
using Server.Items;
namespace Server.Mobiles;
[SerializationGenerator(0, false)]
public abstract partial class BaseFamiliar : BaseCreature
{
// Open-ground distance beyond which the familiar snaps to the caster.
public const int KeepUpRange = 10;
public BaseFamiliar() : base(AIType.AI_Melee)
{
SetSpeed(0.1, 0.1);
}
protected override BaseAI ForcedAI => new FamiliarAI(this);
public override bool BardImmune => true;
public override Poison PoisonImmune => Poison.Lethal;
public override bool Commandable => false;
public override bool IgnoreMobiles => true;
public override bool PlayerRangeSensitive => false;
// Joins the caster's fights; false never fights.
public virtual bool AssistsMaster => true;
// FamiliarAI decides whether it fights, not the ML stand-down rule.
public override bool StandsDownOnCommand => false;
// A wounded familiar still keeps up.
public override bool ReduceSpeedWithDamage => false;
// The one choke point for "never fights" / "not while the caster is hidden":
// BaseCreature.AggressiveAction assigns Combatant unconditionally. GetCPA does not inherit.
[CommandProperty(AccessLevel.GameMaster)]
public override Mobile Combatant
{
get => base.Combatant;
set
{
if (value != null && (!AssistsMaster || ControlMaster?.Hidden == true))
{
return;
}
base.Combatant = value;
}
}
public override void OnThink()
{
base.OnThink();
if (Deleted)
{
return;
}
var master = ControlMaster;
if (master?.Deleted != false)
{
DropPackContents();
Delete();
return;
}
// Compare our own state: Mobile.OnMove reveals a stepping NPC.
if (Hidden != master.Hidden)
{
Hidden = master.Hidden;
if (Hidden)
{
Warmode = false; // nulls Combatant
}
}
}
// Nothing reveals a hidden caster's familiar.
public override void RevealingAction()
{
if (ControlMaster?.Hidden != true)
{
base.RevealingAction();
}
}
public override void GetContextMenuEntries(Mobile from, ref PooledRefList<ContextMenuEntry> list)
{
base.GetContextMenuEntries(from, ref list);
if (from.Alive && Controlled && from == ControlMaster && from.InRange(this, 14))
{
list.Add(new ReleaseEntry());
}
}
public virtual void BeginRelease(Mobile from)
{
if (!Deleted && Controlled && from == ControlMaster && from.CheckAlive())
{
EndRelease(from);
}
}
public virtual void EndRelease(Mobile from)
{
if (from?.CheckAlive() != false && !Deleted && Controlled && from == ControlMaster)
{
Effects.SendLocationParticles(
EffectItem.Create(Location, Map, EffectItem.DefaultDuration),
0x3728,
1,
13,
2100,
3,
5042,
0
);
PlaySound(0x201);
Delete();
}
}
public virtual void DropPackContents()
{
var map = Map;
var pack = Backpack;
if (map == null || map == Map.Internal || pack == null)
{
return;
}
using var queue = pack.EnumerateItems();
while (queue.Count > 0)
{
queue.Dequeue().MoveToWorld(Location, map);
}
}
[AfterDeserialization(false)]
private void AfterDeserialization()
{
DropPackContents();
Delete();
}
private class ReleaseEntry : ContextMenuEntry
{
public ReleaseEntry() : base(6118, 14)
{
}
public override void OnClick(Mobile from, IEntity target)
{
if (from.CheckAlive() && target is BaseFamiliar { Deleted: false, Controlled: true } familiar &&
from == familiar.ControlMaster)
{
familiar.BeginRelease(from);
}
}
}
}