Speed up game tick by caching TGO threat regions.

Still more could be done here by caching the merged poly at the theater
level, but this goes a long way.

Aircraft commit regions are already cached (in the FlightState), so
those are already fairly fast. The combined A2A commit boundary could
also potentially be cached at the theater level.

game/sim/combat/samengagementzones.py

@@ -1,12 +1,12 @@
 from __future__ import annotations
 
 from collections.abc import Iterator
-from typing import Any, Optional, TYPE_CHECKING
+from typing import TYPE_CHECKING
 
 from dcs import Point
 from shapely.ops import unary_union
 
-from game.utils import dcs_to_shapely_point, meters
+from game.utils import dcs_to_shapely_point
 
 if TYPE_CHECKING:
     from game.theater import ConflictTheater, TheaterGroundObject
@@ -36,14 +36,7 @@ class SamEngagementZones:
         individual_zones = []
         for cp in theater.control_points_for(player):
             for tgo in cp.connected_objectives:
-                if (region := cls.threat_region(tgo)) is not None:
+                if (region := tgo.threat_poly()) is not None:
                     commit_regions.append(region)
                     individual_zones.append((tgo, region))
         return SamEngagementZones(unary_union(commit_regions), individual_zones)
-
-    @classmethod
-    def threat_region(cls, tgo: TheaterGroundObject) -> Optional[ThreatPoly]:
-        threat_range = tgo.max_threat_range()
-        if threat_range <= meters(0):
-            return None
-        return dcs_to_shapely_point(tgo.position).buffer(threat_range.meters)

game/theater/theatergroundobject.py

@@ -3,10 +3,11 @@ from __future__ import annotations
 import itertools
 import uuid
 from abc import ABC
-from typing import Iterator, List, Optional, TYPE_CHECKING
+from typing import Any, Iterator, List, Optional, TYPE_CHECKING
 
 from dcs.mapping import Point
 from dcs.unittype import VehicleType
+from shapely.geometry import Point as ShapelyPoint
 
 from game.sidc import (
     Entity,
@@ -19,15 +20,16 @@ from game.sidc import (
     Status,
     SymbolSet,
 )
+from .missiontarget import MissionTarget
 from ..data.radar_db import LAUNCHER_TRACKER_PAIRS, TELARS, TRACK_RADARS
 from ..utils import Distance, Heading, meters
 
 if TYPE_CHECKING:
+    from game.ato.flighttype import FlightType
+    from game.threatzones import ThreatPoly
     from .theatergroup import TheaterUnit, TheaterGroup
     from .controlpoint import ControlPoint
-    from ..ato.flighttype import FlightType
 
-from .missiontarget import MissionTarget
 
 NAME_BY_CATEGORY = {
     "ewr": "Early Warning Radar",
@@ -69,6 +71,16 @@ class TheaterGroundObject(MissionTarget, SidcDescribable, ABC):
         self.control_point = control_point
         self.sea_object = sea_object
         self.groups: List[TheaterGroup] = []
+        self._threat_poly: ThreatPoly | None = None
+
+    def __getstate__(self) -> dict[str, Any]:
+        state = self.__dict__.copy()
+        del state["_threat_poly"]
+        return state
+
+    def __setstate__(self, state: dict[str, Any]) -> None:
+        state["_threat_poly"] = None
+        self.__dict__.update(state)
 
     @property
     def sidc_status(self) -> Status:
@@ -193,6 +205,22 @@ class TheaterGroundObject(MissionTarget, SidcDescribable, ABC):
     def threat_range(self, group: TheaterGroup, radar_only: bool = False) -> Distance:
         return self._max_range_of_type(group, "threat_range")
 
+    def threat_poly(self) -> ThreatPoly | None:
+        if self._threat_poly is None:
+            self._threat_poly = self._make_threat_poly()
+        return self._threat_poly
+
+    def invalidate_threat_poly(self) -> None:
+        self._threat_poly = None
+
+    def _make_threat_poly(self) -> ThreatPoly | None:
+        threat_range = self.max_threat_range()
+        if not threat_range:
+            return None
+
+        point = ShapelyPoint(self.position.x, self.position.y)
+        return point.buffer(threat_range.meters)
+
     @property
     def is_ammo_depot(self) -> bool:
         return self.category == "ammo"
@@ -215,6 +243,7 @@ class TheaterGroundObject(MissionTarget, SidcDescribable, ABC):
         yield self.position
 
     def clear(self) -> None:
+        self.invalidate_threat_poly()
         self.groups = []
 
     @property

game/theater/theatergroup.py

@@ -58,6 +58,7 @@ class TheaterUnit:
 
     def kill(self, events: GameUpdateEvents) -> None:
         self.alive = False
+        self.ground_object.invalidate_threat_poly()
         events.update_tgo(self.ground_object)
 
     @property