W2: several lakes per worldlet, a beach block shelving into the sea with a current that turns swimmers back; testbay test worldlet through the water, edge and boundary suites; the two ways to play (journey, one land) recorded

tests/test_water_bodies.gd

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+extends SceneTree
+## W2 (docs/WORLDLETS_DESIGN.md): several bodies of water in one world, and a
+## beach. On a test worldlet with two ponds and a beach
+## (tests/worldlets/testbay.json): the world lists both ponds and the sea,
+## water_at() knows which is which, the beach shelves gently into the sea,
+## the sea there is one surface (no second water sheet), and a swimmer out
+## past the shallows is carried back by the current. The Valley has no
+## current anywhere.
+## Run: godot --headless --path . --script res://tests/test_water_bodies.gd
+
+var _fails := 0
+var _finished := false
+
+func check(cond: bool, what: String) -> void:
+	print(("  ok   " if cond else "  FAIL ") + what)
+	if not cond:
+		_fails += 1
+
+func _initialize() -> void:
+	_run.call_deferred()
+
+func _run() -> void:
+	var S: Node = root.get_node("Saves")
+	S.root_dir = "user://test_water_worlds"
+	for w in S.list_worlds():
+		S.delete_world(w.id)
+	await _body(S)
+	check(_finished, "test ran to the end (no script errors)")
+	for w in S.list_worlds():
+		S.delete_world(w.id)
+	DirAccess.remove_absolute(S.root_dir)
+	print("RESULT: %s (%d failures)" % ["PASS" if _fails == 0 else "FAIL", _fails])
+	quit(1 if _fails > 0 else 0)
+
+func _body(S: Node) -> void:
+	var T: Script = load("res://scripts/world/terrain.gd")
+	check(not T.worldlets().any(func(w): return w.id == "testbay"), "the test worldlet is never listed (nor offered)")
+	print("the Valley: no current")
+	var v: Node3D = T.new()
+	root.add_child(v)
+	await process_frame
+	var any := false
+	for i in range(72):
+		var a := TAU * i / 72.0
+		for r in [60.0, 100.0, 110.0, 120.0]:
+			any = any or v.current_at(cos(a) * r, sin(a) * r) > 0.0
+	check(not any, "nowhere in the Valley has a current")
+	check(v.lakes.size() == 1 and v.lakes[0].center == Vector2(14, -46), "and its one lake is the old one")
+	v.free()
+
+	print("two ponds and a beach")
+	S.current_id = S.create_world("Bay", 1337, {"worldlet": "testbay"})
+	var world: Node3D = load("res://scenes/world.tscn").instantiate()
+	root.add_child(world)
+	for _i in range(8):
+		await physics_frame
+	var t: Node3D = world.terrain
+	check(world.worldlet_id() == "testbay", "the world is the test bay")
+	var bodies: Array = world.water_bodies()
+	var ponds: Array = bodies.filter(func(b): return b.type == "lake")
+	var seas: Array = bodies.filter(func(b): return b.type == "sea")
+	check(ponds.size() == 2 and seas.size() == 1, "its water: two ponds and the sea (%s)" % [bodies.map(func(b): return b.type)])
+	for p in ponds:
+		var c: Vector2 = p.center
+		var w: Dictionary = world.water_at(c.x, c.y)
+		check(w.get("type", "") == "lake" and float(w.get("depth", 0.0)) > 2.0,
+			"the pond at (%.0f, %.0f) is water, %.1f m deep" % [c.x, c.y, float(w.get("depth", 0.0))])
+	var bay: Vector2 = seas[0].center
+	var sw: Dictionary = world.water_at(bay.x, bay.y)
+	check(sw.get("type", "") == "sea", "out in the bay is the sea (%s)" % [sw])
+	check(absf(t.sea_level - t.water_level) < 0.01, "the sea off a beach is at the ponds' level (%.1f)" % t.sea_level)
+	check(t.get_node_or_null("Water") == null and t.get_node_or_null("Ocean") != null, "one water surface: the ocean, no second sheet")
+
+	print("the beach")
+	# Walking straight out from the middle of the beach: dry land, the
+	# waterline, then gently deeper (no cliff), then the current, then the wall.
+	var dir := Vector2(cos(deg_to_rad(t.beach_angle_deg)), sin(deg_to_rad(t.beach_angle_deg)))
+	var shore := -1.0
+	var current := -1.0
+	var wall := -1.0
+	var steepest := 0.0
+	var prev: float = t.sample_height(dir.x * 40.0, dir.y * 40.0)
+	var r := 41.0
+	while r < 150.0:
+		var q := dir * r
+		var h: float = t.sample_height(q.x, q.y)
+		if r > 60.0:
+			steepest = maxf(steepest, absf(h - prev))
+		prev = h
+		if shore < 0.0 and h < t.water_level:
+			shore = r
+		if current < 0.0 and t.current_at(q.x, q.y) > 0.0:
+			current = r
+		if wall < 0.0 and not t.inside_boundary(q.x, q.y):
+			wall = r
+		r += 1.0
+	check(shore > 0.0 and current > shore and wall > current, "dry land, the waterline at %.0f m, the current from %.0f m, the wall at %.0f m" % [shore, current, wall])
+	check(steepest < 0.5, "a gentle shelf, never a drop (steepest %.2f m per metre)" % steepest)
+	var depth_at_current: float = t.water_level - t.sample_height(dir.x * current, dir.y * current)
+	check(depth_at_current > 1.3, "the current starts where you're swimming, not wading (%.1f m deep)" % depth_at_current)
+
+	print("the current")
+	var player: CharacterBody3D = world.player
+	player.set_physics_process(false)   # (no swimming: just drift)
+	var start := dir * (wall - 4.0)
+	player.global_position = Vector3(start.x, t.water_level - 1.3, start.y)
+	var d0 := start.length()
+	for _i in range(60):
+		await physics_frame
+	var p := player.global_position
+	var d1 := Vector2(p.x, p.z).length()
+	check(d1 < d0 - 1.5, "a swimmer by the wall is carried back towards the shore (%.1f m in a second)" % (d0 - d1))
+	check(world._in_current, "(and told so)")
+	var near := dir * (shore + 2.0)
+	player.global_position = Vector3(near.x, t.water_level - 0.5, near.y)
+	for _i in range(30):
+		await physics_frame
+	p = player.global_position
+	check(absf(Vector2(p.x, p.z).length() - (shore + 2.0)) < 0.01, "but nothing pulls at you in the shallows")
+	check(t.find_spawn(Vector2.ZERO).y > t.water_level + 1.0, "the start is on dry land")
+	world.queue_free()
+	await process_frame
+	_finished = true