Add campaign support for ferry-only bases.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/3170.

game/campaignloader/controlpointbuilder.py

@@ -0,0 +1,90 @@
+from dcs import Point
+from dcs.terrain import Airport
+
+from game.campaignloader.controlpointconfig import ControlPointConfig
+from game.theater import (
+    Airfield,
+    Carrier,
+    ConflictTheater,
+    ControlPoint,
+    Fob,
+    Lha,
+    OffMapSpawn,
+)
+
+
+class ControlPointBuilder:
+    def __init__(
+        self, theater: ConflictTheater, configs: dict[str | int, ControlPointConfig]
+    ) -> None:
+        self.theater = theater
+        self.config = configs
+
+    def create_airfield(self, airport: Airport) -> Airfield:
+        cp = Airfield(airport, self.theater, starts_blue=airport.is_blue())
+
+        # Use the unlimited aircraft option to determine if an airfield should
+        # be owned by the player when the campaign is "inverted".
+        cp.captured_invert = airport.unlimited_aircrafts
+
+        self._apply_config(airport.id, cp)
+        return cp
+
+    def create_fob(
+        self,
+        name: str,
+        position: Point,
+        theater: ConflictTheater,
+        starts_blue: bool,
+        captured_invert: bool,
+    ) -> Fob:
+        cp = Fob(name, position, theater, starts_blue)
+        cp.captured_invert = captured_invert
+        self._apply_config(name, cp)
+        return cp
+
+    def create_carrier(
+        self,
+        name: str,
+        position: Point,
+        theater: ConflictTheater,
+        starts_blue: bool,
+        captured_invert: bool,
+    ) -> Carrier:
+        cp = Carrier(name, position, theater, starts_blue)
+        cp.captured_invert = captured_invert
+        self._apply_config(name, cp)
+        return cp
+
+    def create_lha(
+        self,
+        name: str,
+        position: Point,
+        theater: ConflictTheater,
+        starts_blue: bool,
+        captured_invert: bool,
+    ) -> Lha:
+        cp = Lha(name, position, theater, starts_blue)
+        cp.captured_invert = captured_invert
+        self._apply_config(name, cp)
+        return cp
+
+    def create_off_map(
+        self,
+        name: str,
+        position: Point,
+        theater: ConflictTheater,
+        starts_blue: bool,
+        captured_invert: bool,
+    ) -> OffMapSpawn:
+        cp = OffMapSpawn(name, position, theater, starts_blue)
+        cp.captured_invert = captured_invert
+        self._apply_config(name, cp)
+        return cp
+
+    def _apply_config(self, cp_id: str | int, control_point: ControlPoint) -> None:
+        config = self.config.get(cp_id)
+        if config is None:
+            return
+
+        control_point.ferry_only = config.ferry_only