extends SceneTree
const EffectPlayer = preload("res://fx/effect_player.gd")
var failures := 0
func check(ok: bool, label: String) -> void:
	if not ok:
		failures += 1
		printerr("FAIL: " + label)
func _init() -> void: call_deferred("run")
func run() -> void:
	var fx := EffectPlayer.new()
	fx.build({"particles": [{"emitter": {"TimeEventLifeTime": [[0, 1.0]]}, "particle": {
		"BillboardType": 1, "RotationType": 4, "RotationSpeed": 90, "ColorOperationType": 4}}]})
	var emitter: GPUParticles3D = fx._emitters[0]
	var pm: ParticleProcessMaterial = emitter.process_material
	var material: ShaderMaterial = emitter.material_override
	check(pm.angular_velocity_min == 0 and pm.angular_velocity_max == 0, "no second angular integration")
	check(pm.anim_offset_min == 0 and pm.anim_offset_max == 1 and pm.anim_speed_max == 0, "stable per-birth sign seed")
	check(material.get_shader_parameter("random_rotation") == true, "random rotation enabled")
	check(is_equal_approx(material.get_shader_parameter("rotation_speed"), PI / 2), "full magnitude in radians")
	if DisplayServer.get_name() != "headless": await pixels(material)
	fx.free()
	print("effect_random_rotation_test: failures=%d" % failures)
	quit(1 if failures else 0)
func pixels(material: ShaderMaterial) -> void:
	var viewport := SubViewport.new()
	viewport.size = Vector2i(128, 128)
	viewport.own_world_3d = true
	viewport.render_target_update_mode = SubViewport.UPDATE_ALWAYS
	root.add_child(viewport)
	var environment := WorldEnvironment.new()
	environment.environment = Environment.new()
	environment.environment.background_mode = Environment.BG_COLOR
	environment.environment.background_color = Color.BLACK
	viewport.add_child(environment)
	var image := Image.create(2, 2, false, Image.FORMAT_RGBA8)
	image.fill(Color.WHITE)
	material.set_shader_parameter("albedo_texture", ImageTexture.create_from_image(image))
	material.set_shader_parameter("rotation_lifetime", 1.0)
	var node := MultiMeshInstance3D.new()
	node.multimesh = MultiMesh.new()
	node.multimesh.transform_format = MultiMesh.TRANSFORM_3D
	node.multimesh.use_custom_data = true
	node.multimesh.mesh = QuadMesh.new()
	node.multimesh.mesh.size = Vector2(1.2, 0.16)
	node.multimesh.instance_count = 1
	node.multimesh.set_instance_transform(0, Transform3D.IDENTITY)
	node.material_override = material
	viewport.add_child(node)
	var camera := Camera3D.new()
	camera.projection = Camera3D.PROJECTION_ORTHOGONAL
	camera.size = 2.0
	camera.position.z = 3
	viewport.add_child(camera)
	var results: Array[Image] = []
	for seed in [0.25, 0.75]:
		node.multimesh.set_instance_custom_data(0, Color(0, 0.5, seed, 1))
		await process_frame
		await RenderingServer.frame_post_draw
		results.append(viewport.get_texture().get_image())
	var positive := 0
	var negative := 0
	var mismatch := 0
	var lit := 0
	for y in 128:
		for x in 128:
			var a := results[0].get_pixel(x, y).r > 0.5
			var b := results[1].get_pixel(x, y).r > 0.5
			if a:
				lit += 1
				positive += (2 * x - 127) * (2 * y - 127)
			if b: negative += (2 * x - 127) * (2 * y - 127)
			if a != (results[1].get_pixel(127 - x, y).r > 0.5): mismatch += 1
	check(lit > 300, "rendered visible particles")
	check(positive * float(negative) < 0, "opposite rotation directions")
	check(mismatch < 60, "equal magnitude produces mirrored GPU images")
	viewport.free()
	await process_frame