Anchor beetles to generated tree surfaces

gathering/catalog/beetle_stag_common.tres

@@ -10,6 +10,8 @@ catch_data = ExtResource("2_catch")
 required_tool_id = &"crab_net"
 spawn_anchor_set_id = &"starter_reachable_tree_trunks"
 population = 3
+spawn_anchor_occupancy_ratio = 0.35
+maximum_anchor_population = 64
 requires_sneaking = false
 movement_speed = 0.0
 roam_radius = 0.1

gathering/gatherable_data.gd

@@ -18,6 +18,11 @@ enum PresentationMode {
 @export var spawn_anchor_set_id: StringName
 @export_range(-100.0, 100.0, 0.01) var minimum_surface_y: float = 0.08
 @export_range(0, 64, 1) var population: int = 0
+## Anchored gatherables can scale with authored/generated attachment geometry.
+## Zero preserves the fixed population above.
+@export_range(0.0, 1.0, 0.01) var spawn_anchor_occupancy_ratio := 0.0
+## Zero leaves the anchor count as the only ceiling.
+@export_range(0, 256, 1) var maximum_anchor_population := 0
 @export var presentation_mode: PresentationMode = PresentationMode.VISIBLE_CREATURE
 @export var requires_sneaking: bool = true
 @export_range(0.0, 120.0, 0.1) var active_lifetime_seconds: float = 0.0
@@ -78,6 +83,10 @@ func is_valid() -> bool:
 			== FishDataType.CollectionMethod.DIGGING
 		)
 		and population > 0
+		and (
+			maximum_anchor_population == 0
+			or maximum_anchor_population >= population
+		)
 		and movement_parameters_valid
 		and _quality_multipliers_are_valid(
 			quality_movement_speed_multipliers
@@ -102,6 +111,21 @@ func is_stationary_spawn() -> bool:
 	return is_stationary_hotspot() or not spawn_anchor_set_id.is_empty()
 
 
+func target_population_for_anchor_count(anchor_count: int) -> int:
+	if spawn_anchor_set_id.is_empty() or spawn_anchor_occupancy_ratio <= 0.0:
+		return population
+	if anchor_count <= 0:
+		return 0
+	var target := maxi(
+		population,
+		ceili(float(anchor_count) * spawn_anchor_occupancy_ratio),
+	)
+	target = mini(target, anchor_count)
+	if maximum_anchor_population > 0:
+		target = mini(target, maximum_anchor_population)
+	return target
+
+
 func can_be_scared() -> bool:
 	return not is_stationary_spawn() and scare_radius > 0.0