Scale coastal crab spawning by habitat

tests/generated_world_runtime_validation.gd

@@ -12,6 +12,9 @@ const GeneratedLakePool: FishPool = preload(
 const GeneratedRiverPool: FishPool = preload(
 	"res://fish/pools/generated_river_pool.tres"
 )
+const Gatherables: GatherableCatalog = preload(
+	"res://gathering/catalog/gatherable_catalog.tres"
+)
 const PrecipitationOcclusionType = preload(
 	"res://world/environment/precipitation_occlusion.gd"
 )
@@ -402,7 +405,7 @@ func _validate_generated_region(
 			+ generator.stacked_elevated_placement_keys().size()
 		)
 	)
-	_validate_elevated_cliff_feature(generator)
+	_validate_elevated_cliff_feature(region, generator)
 
 	var shop := region.get_node("Interactables/FishingShopWorld") as Node3D
 	var storage := region.get_node("Interactables/PlayerStorageBox") as Node3D
@@ -536,6 +539,7 @@ func _validate_generated_region(
 		-INF,
 		0.35,
 	)
+	_validate_crab_spawn_surfaces(region)
 	_validate_water_recovery_positions(
 		region,
 		grass_prop_surface_triangles,
@@ -691,6 +695,7 @@ func _validate_generated_region(
 
 
 func _validate_elevated_cliff_feature(
+	region: GeneratedWorldRegion,
 	generator: TerrainChunkGenerator,
 ) -> void:
 	var elevated_coordinates: Dictionary[Vector2i, StringName] = {}
@@ -824,6 +829,27 @@ func _validate_elevated_cliff_feature(
 			or generator.placement_keys()[low_index].begins_with("chunk_spawn@")
 		)
 	assert(found_primary_ramp == not primary_is_third_tier)
+	var primary_surface_height := (
+		generator.elevated_cliff_level_height
+		* (2.0 if primary_is_third_tier else 1.0)
+	)
+	var primary_surface_position := generator.to_global(
+		generator.chunk_position(feature_center)
+		+ Vector3.UP * primary_surface_height
+	)
+	assert(
+		region.is_home_exterior_position_accessible(primary_surface_position)
+		== not primary_is_third_tier
+	)
+	assert(region.is_home_exterior_position_accessible(generator.to_global(
+		generator.chunk_position(feature_center)
+	)))
+	# A higher surface sharing a ramp-accessible base cell is still invalid
+	# unless that elevation has its own authored ramp connection.
+	assert(not region.is_home_exterior_position_accessible(generator.to_global(
+		generator.chunk_position(feature_center)
+		+ Vector3.UP * (generator.elevated_cliff_level_height * 2.0)
+	)))
 
 	var generated := generator.get_generated_chunks_root()
 	assert(generated != null)
@@ -1251,6 +1277,58 @@ func _validate_decoration_transform(
 	)
 
 
+func _validate_crab_spawn_surfaces(region: GeneratedWorldRegion) -> void:
+	var brown := Gatherables.get_entry(&"crab_brown")
+	var blue := Gatherables.get_entry(&"crab_blue")
+	assert(brown != null and blue != null)
+	assert(is_equal_approx(
+		region.get_saltwater_surface_height(),
+		GeneratedWorldRegion.WATER_HEIGHT,
+	))
+	var brown_minimum := maxf(
+		brown.minimum_surface_y,
+		GeneratedWorldRegion.WATER_HEIGHT + brown.waterline_margin,
+	)
+	var blue_maximum := minf(
+		blue.maximum_surface_y,
+		GeneratedWorldRegion.WATER_HEIGHT - blue.waterline_margin,
+	)
+	assert(brown_minimum > blue_maximum)
+	var brown_triangles := region.get_spawn_surface_triangles(
+		brown.surface_materials,
+		brown_minimum,
+		0.6,
+		brown.maximum_surface_y,
+	)
+	var blue_triangles := region.get_spawn_surface_triangles(
+		blue.surface_materials,
+		blue.minimum_surface_y,
+		0.6,
+		blue_maximum,
+	)
+	assert(not brown_triangles.is_empty())
+	assert(not blue_triangles.is_empty())
+	assert(
+		brown.target_population_for_surface_area(
+			_surface_triangle_area(brown_triangles)
+		) > brown.population
+	)
+	assert(
+		blue.target_population_for_surface_area(
+			_surface_triangle_area(blue_triangles)
+		) > blue.population
+	)
+
+
+func _surface_triangle_area(triangles: Array[PackedVector3Array]) -> float:
+	var area := 0.0
+	for triangle: PackedVector3Array in triangles:
+		area += (triangle[1] - triangle[0]).cross(
+			triangle[2] - triangle[0]
+		).length() * 0.5
+	return area
+
+
 func _triangle_surface_height_at(
 	position: Vector3,
 	triangles: Array[PackedVector3Array],