test(sites): geometric contract and integration checks for the terrain showcase

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

tests/integration/run_site_terrain_integration.gd

@@ -16,8 +16,9 @@ const ReferenceBathymetryAcquisition = preload(
 const DIVE_SITE_SCENE = preload("res://game/world/sites/dive_site.tscn")
 
 const ZONE1_SITE_PATH := "res://content/sites/zone1_vigilant.tres"
+const SHOWCASE_SITE_PATH := "res://content/sites/terrain_showcase.tres"
 const GROOVE_PROBE_OFFSET_M := 25.0
-const TEST_COUNT := 31
+const TEST_COUNT := 36
 
 var _failures: Array[String] = []
 
@@ -30,6 +31,7 @@ func _run() -> void:
 	await _test_actor_matches_field()
 	await _test_dive_site_scene()
 	await _test_zone1_site()
+	await _test_showcase_site()
 
 	var exit_code := 0
 	if _failures.is_empty():
@@ -218,6 +220,45 @@ func _test_zone1_site() -> void:
 	site.queue_free()
 
 
+func _test_showcase_site() -> void:
+	await process_frame
+	var definition := load(SHOWCASE_SITE_PATH) as DiveSiteDefinition
+	_expect(definition != null, "showcase site definition loads")
+	if definition == null:
+		return
+	var started_usec := Time.get_ticks_usec()
+	var site := DIVE_SITE_SCENE.instantiate() as DiveSite
+	root.add_child(site)
+	_expect(site.configure(definition).is_empty(), "dive site scene accepts the Jardin des Formes")
+	var configure_ms := float(Time.get_ticks_usec() - started_usec) / 1000.0
+	_expect(configure_ms < 3000.0, "showcase configures under the 3 s load budget (%.0f ms)" % configure_ms)
+	await physics_frame
+	await physics_frame
+	var space := site.get_world_3d().direct_space_state
+	var terrain := site.terrain()
+	var canyon_floor := _terrain_height(space, terrain, -130.0, -135.0, [])
+	var mesa_top := _terrain_height(space, terrain, -80.0, -90.0, [])
+	_expect(mesa_top - canyon_floor >= 18.0, "collision rays find the canyon under the mesa (%.1f m vs %.1f m)" % [canyon_floor, mesa_top])
+
+	# Sensor above the canyon looking along its first leg (the acquisition probes along
+	# local +Z): rock walls and sand floor.
+	var sensor := Transform3D(Basis.IDENTITY, Vector3(-130.0, -15.0, -135.0))
+	sensor.basis = Basis.looking_at(-Vector3(40.0, 0.0, -30.0).normalized(), Vector3.UP)
+	var acquisition := ReferenceBathymetryAcquisition.new(site.get_world_3d())
+	var request := SonarCaptureRequest.new(
+		&"scan", &"session", sensor, 5.0, 95.0, deg_to_rad(76.0), deg_to_rad(64.0), 49, 31
+	)
+	var result = acquisition.capture(request)
+	var materials: Dictionary = {}
+	for sample in result.samples:
+		materials[sample.material] = true
+	_expect(
+		result.accepted and materials.has(SonarMaterial.Value.ROCK) and materials.has(SonarMaterial.Value.SAND),
+		"a scan along the canyon reads rock walls and a sand floor"
+	)
+	site.queue_free()
+
+
 ## Seabed height under (x, z), or NAN (every comparison fails) when the ray misses the terrain actor.
 func _terrain_height(
 	space: PhysicsDirectSpaceState3D,