## Summary
Creatures (pets following, monsters chasing, NPCs approaching) would **oscillate — "pace back and forth really fast"** at concave obstacles (reported at the Britain Inn L-desk: a pet at `(1493,1614,20)` never reaching its master at `(1494,1605,21)`) instead of routing around them.
**Root cause** (the A* pathfinder itself was correct): all goal-seeking funnels through `MoveTo` and `WalkMobileRange` → `MoveTowardsOrAwayFrom`, which step greedily via `DoMove(dir, badStateOk:true)`. `DoMove` returns `true` even when the direct step was blocked and the creature merely **auto-turned and sidestepped** (`MoveResult.SuccessAutoTurn`), and the caller then set `Path = null`, discarding the `PathFollower`. So at a concave obstacle a non-progressing sidestep was mistaken for progress and the creature never committed to a route. (AOS pet-follow runs at `CurrentSpeed = 0.1`, hence the "really fast" shuffle.)
## What changed
- **New centralized `BaseAI.ApproachTarget(target, run, range)` primitive.** A greedy step is committed only when it **fully succeeds (`MoveResult.Success`) and actually gets closer**; otherwise the creature commits to a **persistent `PathFollower`** that routes around the obstacle and is never discarded by a greedy step. The open-terrain fast path (one greedy step, no pathfinding) is preserved. `MoveTo`, `MoveTowardsOrAwayFrom`, and `MoveToWithCollisionAvoidance` all delegate to it — public signatures unchanged, so no AI-class call site changes.
- **Best-distance give-up + idle.** A creature that cannot reach a **stationary** in-range goal stops shuffling and idles after `ApproachGiveUpTicks` (40) ticks without lowering its closest-ever distance; a **moving** goal (active chase) never gives up. It resumes the moment the goal moves.
- **Pathfinder fix (required):** `BitmapAStarAlgorithm.IsBlockedByDynamic` now skips the dynamic mobile-block check **at the goal cell only** (`MoveImpl.Goal`). Previously A* returned `null` whenever the target mobile stood on the goal cell, so creatures could never pathfind *toward* another mobile — only toward empty ground. The follower stops within `range` short of it. Static/item blocking and all non-goal mobile blocking are unchanged.
## Tests
New AI-loop integration tests in `ApproachTargetTests.cs` drive the real `BaseAI` primitives against live Britain Inn map statics: exact-repro pet follow, open-terrain (asserts zero pathfinding), `MoveTo` chase (static + walking-away target), route-around-a-dynamic-wall, and walled-off give-up-and-idle.
- Pathfinding + AI subset: **52/52** pass.
- Full `UOContent.Tests`: **301/301** pass. (Note: the test host lingers on shutdown — a pre-existing infra quirk unrelated to this change; all tests complete and pass.)
- Full solution build: clean (0 warnings / 0 errors).
## Notes
- Branched off `main`; independent of the in-flight step-cache work.
- Out of scope (future work): proactive "SmartAI" look-ahead pathfinding so clever creatures plan a route before walking into the obstacle, rather than reacting after they hit it.
## Test Plan
- [X] In-game: order a pet to `follow`/`come` across the Britain Inn L-desk; confirm it routes around and reaches you instead of pacing.
- [X] Aggro a monster and kite it around a building/treeline; confirm it chases around obstacles.
- [X] Confirm open-terrain following/chasing feels unchanged (no extra latency).
- [X] Confirm a creature with a genuinely unreachable target idles rather than shuffling forever.
## Summary
- Fixes pets falling behind mounted masters in AOS+ by setting `CurrentSpeed = 0.1` when following master
- Fixes AI timer permanently stopping when `Obey()`/`Think()` returns `false` for transient conditions
- Fixes controlled pets losing AI in inactive sectors (pet follows owner across sector boundary, sector deactivates, AI dies)
- Adds defense-in-depth: AI timer restarts on pet resurrection and order changes
## AI Timer Permanent Stop (Bug Fix)
`AITimer.OnTick()` called `Stop()` when `Obey()` or `Think()` returned `false`. By that point, `ShouldStop()` had already validated the creature is alive, on a valid map, and in an active sector — so any `false` return was a **transient** condition, not terminal. The timer stopped permanently with no mechanism to restart it.
**Scenarios that triggered permanent AI death:**
- Dead bonded pet with attack order (`DoOrderAttack` returned `false` for `IsDeadPet`)
- Failed pet transfer — loyalty refusal, combat, disconnected player, or pending trade (`DoOrderTransfer` returned `false` for 5 different transient conditions)
- Unknown `OrderType` or `ActionType` (defensive defaults)
**Fixes:**
- Removed `Stop()` from the `Obey()`/`Think()` failure path — timer skips the tick and fires again next interval
- Changed `DoOrderAttack()` and all five `DoOrderTransfer()` failure paths to return `true` (correct semantics: these are recoverable states, not "stop AI forever" signals)
- Added `Activate()` call in `ResurrectPet()` — ensures dead bonded pets have AI running after resurrection
- Added `Activate()` call in `OnCurrentOrderChanged()` — self-heals timer if any voice command is issued to a pet with a stopped timer
## Controlled Pet Sector Deactivation (Bug Fix)
`ShouldStop()` stopped the AI timer for **all** `PlayerRangeSensitive` creatures in inactive sectors, including controlled pets. But `Deactivate()` intentionally exempted controlled pets. The exemption was dead code — `ShouldStop()` bypassed it.
This matters when a pet follows its owner across a sector boundary: the owner enters the next sector (active), the pet's old sector deactivates (no more players), and the pet's AI dies. The pet stops following and stands there until the player backtracks far enough to reactivate the sector.
**Fix:** Added `Controlled` check to `ShouldStop()` to match `Deactivate()`. Controlled pets now keep their AI running in inactive sectors. The overhead is negligible — controlled pets are bounded by follower slots.
## Movement Speed Simplification
- Simplifies `AITimer` to use `CurrentSpeed` directly as the tick interval (in seconds), removing the complex multiplier/floor logic in `GetBaseInterval`
- Refactors `DoMoveImpl` speed assignment into explicit if/else for clarity
- AOS+ pets following master use `CurrentSpeed = 0.1` (100ms), matching `RunMountDelay`
## Files Changed
- `AITimer.cs` — removed `Stop()` on Obey/Think failure, added `Controlled` exemption to `ShouldStop()`, simplified interval logic
- `BaseAI.cs` — renamed `_timer` to `AITimer` (public), simplified `Deactivate()`, fixed `ReturnToHome` to use `Activate()`
- `PetOrders.cs` — `DoOrderAttack` and `DoOrderTransfer` return `true` for transient failures
- `PetOrderHandlers.cs` — `OnCurrentOrderChanged()` calls `Activate()` to self-heal stopped timers
- `BaseCreature.cs` — `ResurrectPet()` calls `Activate()`, fixed `GoHome_Callback` PlayerRangeSensitive check
- `AIMovement.cs` — refactored speed assignment, AOS+ follow-master speed fix
### Summary
- Adds CanSpawnMobile(x, y, minZ, maxZ, canSwim, cantWalk, out spawnZ) overload for finding spawn surfaces within a Z range
- Adds CanSpawnItem(x, y, minZ, maxZ, out spawnZ) for item spawning with Surface+Impassable support (tables, furniture)
- Uses bitmask optimization inspired by Item.DropToWorld's m_OpenSlots pattern for O(1) surface/blocker checks
- HomeRange spawners now use surface detection to set proper Z bounds
### Key Changes
Map.cs:
- CanSpawnMobile with Z-range finds lowest valid surface for mobiles
- CanSpawnItem with Z-range finds lowest valid surface for items (including tables)
- CanFitItem for point-check item placement on Surface+Impassable tiles
- Bitmask approach eliminates nested loops and stackalloc arrays
Spawners:
- Simplified GetSpawnPosition using new Z-range methods
- HomeRange setter detects surface below spawner for proper Z bounds
- Consistent handling for mobiles and items
### Bug Fixes
- Water tiles (Impassable | Wet) no longer block swimming mobs
- Items can now spawn on tables/furniture (Surface+Impassable)
### Test Plan
- Run dotnet test - 631 tests pass
- Manual testing: multi-story spawning, water mobs, item spawning on tables
- Verify HomeRange spawner movement shifts bounds correctly
### Summary
This PR transitions the spawner system from a simple radius-based model to a flexible 3D boundary system.
### Core Changes
* **Replaced `HomeRange` with `SpawnBounds`**: Spawners now use a `Rectangle3D` to define spawn areas instead of a circular integer range.
* **Backward Compatibility**:
* The `HomeRange` property remains as a helper that generates square `SpawnBounds` centered on the spawner.
* Included a migration path (v10 to v11) that automatically converts old range data into new bounds during deserialization.
* **Dynamic Bounds Shifting**: If a spawner is moved, its `SpawnBounds` will automatically shift with it, provided the bounds are currently configured as a centered square.
* **New Spawn Logic**: Added `SpawnLocationIsHome` toggle. If enabled, spawned mobiles treat their exact spawn coordinates as their "Home" rather than the spawner's location.
### Implementation Details
* **Interface Updates**: Updated `ISpawner` to include `WalkingRange`, `SpawnBounds`, and `IsInSpawnBounds()`.
* **UI Enhancements**: The Spawner Controller Gump now displays "Custom" for complex bounds and allows copying of the new boundary properties between spawners.
* **Refactored Constructors**: Streamlined `BaseSpawner`, `ProximitySpawner`, and `RegionSpawner` constructors to support the new data types.
### Summary
* Refactors AI so it is easier to read and maintain
* Fixes NPC speed issues
* Fixes pet sector AI issue that was causing stuttering
* Fixes direction snapping for Melee/Mage AI
* Refactors pet orders
* Refactors speech commands
* Removes scale speed by dex for HS+ (it was a stupid feature anyways)
