Expand generated terrain with biome-driven props

world/generation/terrain_prop_catalog.gd

@@ -0,0 +1,85 @@
+class_name TerrainPropCatalog
+extends Resource
+
+@export var definitions: Array[TerrainPropDefinition] = []
+
+
+func definition_for_id(stable_id: StringName) -> TerrainPropDefinition:
+	for definition: TerrainPropDefinition in definitions:
+		if definition != null and definition.stable_id == stable_id:
+			return definition
+	return null
+
+
+func procedural_definitions(
+	group: StringName,
+	chunk_tags: PackedStringArray,
+) -> Array[TerrainPropDefinition]:
+	var result: Array[TerrainPropDefinition] = []
+	for definition: TerrainPropDefinition in definitions:
+		if (
+			definition != null
+			and definition.procedural_group == group
+			and definition.supports_chunk_tags(chunk_tags)
+		):
+			result.append(definition)
+	return result
+
+
+func validation_errors() -> PackedStringArray:
+	var errors := PackedStringArray()
+	var seen_ids: Dictionary[StringName, bool] = {}
+	for index: int in definitions.size():
+		var definition := definitions[index]
+		if definition == null:
+			errors.append("Prop definition %d is empty." % index)
+			continue
+		if definition.stable_id == &"":
+			errors.append("Prop definition %d has no stable ID." % index)
+		elif seen_ids.has(definition.stable_id):
+			errors.append("Prop ID %s is duplicated." % definition.stable_id)
+		else:
+			seen_ids[definition.stable_id] = true
+		if definition.packed_scene == null:
+			errors.append("%s has no PackedScene." % definition.stable_id)
+		if (
+			definition.is_procedural()
+			and definition.required_chunk_tags.is_empty()
+		):
+			errors.append(
+				"%s is procedural but has no required chunk tags."
+				% definition.stable_id
+			)
+		if (
+			not definition.preferred_nearby_prop_groups.is_empty()
+			and definition.preferred_nearby_radius <= 0.0
+		):
+			errors.append(
+				"%s prefers nearby props but defines no search radius."
+				% definition.stable_id
+			)
+		var has_collision_radius := definition.collision_radius > 0.0
+		var has_collision_height := definition.collision_height > 0.0
+		if has_collision_radius != has_collision_height:
+			errors.append(
+				"%s must define both collision radius and height."
+				% definition.stable_id
+			)
+		if (
+			definition.has_cylinder_collision()
+			and definition.has_box_collision()
+		):
+			errors.append(
+				"%s defines more than one collision shape."
+				% definition.stable_id
+			)
+		if (
+			definition.collision_box_size.x < 0.0
+			or definition.collision_box_size.y < 0.0
+			or definition.collision_box_size.z < 0.0
+		):
+			errors.append(
+				"%s has a negative box collision dimension."
+				% definition.stable_id
+			)
+	return errors