Initial commit: Godot Pong game with WebSocket accelerometer control.

Includes platform steering via calibrated accel axes, ball physics,
calibration overlay with axis detection, and runtime tuning sliders.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/calibration_overlay.gd

@@ -0,0 +1,149 @@
+extends Control
+
+signal calibration_finished(calibration: AccelCalibration)
+
+enum Phase { WAITING, RIGHT, LEFT, DONE }
+
+const TRAVEL_PX := 140.0
+const PHASE_DURATION := 4.5
+const CIRCLE_RADIUS := 44.0
+const NEEDLE_LEN := 58.0
+
+var _phase := Phase.WAITING
+var _phase_time := 0.0
+var _guide_offset := Vector2.ZERO
+var _instruction := ""
+var _calibration := AccelCalibration.new()
+var _connection_notified := false
+
+@onready var _hint_label: Label = $HintLabel
+@onready var _start_button: Button = $StartButton
+
+
+func _ready() -> void:
+	set_anchors_preset(Control.PRESET_FULL_RECT)
+	mouse_filter = Control.MOUSE_FILTER_PASS
+	_start_button.pressed.connect(_on_start_pressed)
+	_show_waiting()
+
+
+func start() -> void:
+	_calibration.reset()
+	_connection_notified = false
+	_phase = Phase.WAITING
+	_phase_time = 0.0
+	_guide_offset = Vector2.ZERO
+	visible = true
+	_start_button.visible = true
+	_show_waiting()
+	queue_redraw()
+
+
+func is_active() -> bool:
+	return _phase != Phase.DONE
+
+
+func feed_accel(accel: Vector3i) -> void:
+	match _phase:
+		Phase.RIGHT:
+			_calibration.record_right(accel)
+		Phase.LEFT:
+			_calibration.record_left(accel)
+
+
+func notify_connected() -> void:
+	if _phase != Phase.WAITING or _connection_notified:
+		return
+	_hint_label.text = "Verbunden – tippe „Kalibrierung starten“ oder warte…"
+	# Automatisch starten sobald verbunden
+	begin_calibration()
+
+
+func begin_calibration() -> void:
+	if _phase == Phase.RIGHT or _phase == Phase.LEFT:
+		return
+	_connection_notified = true
+	_start_button.visible = false
+	_begin_phase(Phase.RIGHT)
+
+
+func _on_start_pressed() -> void:
+	begin_calibration()
+
+
+func _process(delta: float) -> void:
+	if _phase == Phase.WAITING or _phase == Phase.DONE:
+		return
+
+	_phase_time += delta
+	var t := clampf(_phase_time / PHASE_DURATION, 0.0, 1.0)
+	var ease := t * t * (3.0 - 2.0 * t)
+
+	match _phase:
+		Phase.RIGHT:
+			_guide_offset.x = TRAVEL_PX * ease
+			_instruction = "Neige das Gerät nach rechts – folge dem Kreis →"
+			if _phase_time >= PHASE_DURATION:
+				_begin_phase(Phase.LEFT)
+		Phase.LEFT:
+			_guide_offset.x = -TRAVEL_PX * ease
+			_instruction = "Neige das Gerät nach links – folge dem Kreis ←"
+			if _phase_time >= PHASE_DURATION:
+				_finish()
+
+	_hint_label.text = _instruction
+	queue_redraw()
+
+
+func _begin_phase(phase: Phase) -> void:
+	_phase = phase
+	_phase_time = 0.0
+	_guide_offset = Vector2.ZERO
+	match phase:
+		Phase.RIGHT:
+			_instruction = "Neige das Gerät nach rechts – folge dem Kreis →"
+		Phase.LEFT:
+			_instruction = "Neige das Gerät nach links – folge dem Kreis ←"
+	_hint_label.text = _instruction
+	queue_redraw()
+
+
+func _finish() -> void:
+	_phase = Phase.DONE
+	visible = false
+	if _calibration.analyze():
+		calibration_finished.emit(_calibration)
+	else:
+		_hint_label.text = "Kalibrierung fehlgeschlagen – zu wenig Daten"
+		visible = true
+		_start_button.visible = true
+		_show_waiting()
+
+
+func _show_waiting() -> void:
+	_instruction = "Warte auf Verbindung zu localhost:9090…"
+	_hint_label.text = _instruction + "\n(Oder „Kalibrierung starten“ ohne Verbindung)"
+
+
+func _screen_center() -> Vector2:
+	return get_viewport_rect().size * 0.5
+
+
+func _draw() -> void:
+	if _phase == Phase.DONE:
+		return
+
+	var pos := _screen_center() + _guide_offset
+
+	draw_circle(pos, CIRCLE_RADIUS, Color(0.25, 0.72, 0.95, 0.2))
+	draw_arc(pos, CIRCLE_RADIUS, 0.0, TAU, 64, Color(0.35, 0.82, 1.0), 2.5)
+
+	var needle_tip := pos + Vector2(0.0, -NEEDLE_LEN)
+	draw_line(pos, needle_tip, Color(1.0, 1.0, 1.0, 0.95), 3.0)
+	draw_circle(needle_tip, 5.0, Color(1.0, 1.0, 1.0))
+
+	var center := _screen_center()
+	if _phase == Phase.RIGHT:
+		draw_line(center, center + Vector2(TRAVEL_PX, 0.0), Color(1.0, 1.0, 1.0, 0.12), 1.0)
+	elif _phase == Phase.LEFT:
+		draw_line(center, center + Vector2(-TRAVEL_PX, 0.0), Color(1.0, 1.0, 1.0, 0.12), 1.0)