Godot Game Loop Time Trial

# ghost_recorder.gd
# [GDSKILLS] godot-game-loop-time-trial
# EXPORT_REFERENCE: ghost_recorder.gd

extends Node

@export var target_node: Node3D
@export var sample_rate: float = 0.1 # Seconds between samples

var recording: Array = []
var is_recording: bool = false
var time_elapsed: float = 0.0
var last_sample_time: float = 0.0

func start_recording() -> void:
	recording.clear()
	is_recording = true
	time_elapsed = 0.0
	last_sample_time = 0.0

func stop_recording() -> void:
	is_recording = false

func _physics_process(delta: float) -> void:
	if not is_recording or not target_node:
		return
		
	time_elapsed += delta
	if time_elapsed >= last_sample_time + sample_rate:
		_capture_sample()
		last_sample_time = time_elapsed

func _capture_sample() -> void:
	recording.append({
		"t": time_elapsed,
		"p": target_node.global_position,
		"r": target_node.global_rotation
	})

func get_data() -> Array:
	return recording

# ghost_replayer.gd
# [GDSKILLS] godot-game-loop-time-trial
# EXPORT_REFERENCE: ghost_replayer.gd

extends Node3D

@export var ghost_visual: Node3D
@export var interpolation_enabled: bool = true

var recording_data: Array = []
var is_playing: bool = false
var playback_time: float = 0.0
var _data_size: int = 0

func start_playback(data: Array) -> void:
	if data.is_empty():
		return
		
	recording_data = data
	_data_size = recording_data.size()
	playback_time = 0.0
	is_playing = true
	
	# Initial placement
	_apply_transform(recording_data[0])
	
	# Ensure visual is ready
	if ghost_visual:
		ghost_visual.show()

func stop_playback() -> void:
	is_playing = false
	if ghost_visual:
		ghost_visual.hide()

func _process(delta: float) -> void:
	if not is_playing:
		return
		
	playback_time += delta
	
	# Check for end of recording
	if playback_time >= recording_data[_data_size - 1].t:
		_apply_transform(recording_data[_data_size - 1])
		is_playing = false
		return
		
	_update_transform()

func _update_transform() -> void:
	# Find the current frame (Binary search could be grander, but linear is fine for <10 min runs)
	# Optimization: We assume sequential access, so we can track the last index.
	# For robustness, we'll just scan or use a simple look-ahead since samples are ordered.
	
	var idx = _find_keyframe_index(playback_time)
	if idx == -1: return

	var frame_a = recording_data[idx]
	var frame_b = recording_data[idx + 1]
	
	if not interpolation_enabled:
		_apply_transform(frame_a)
		return
		
	# Calculate t (0.0 to 1.0) between frames
	var duration = frame_b.t - frame_a.t
	if duration <= 0.0001:
		_apply_transform(frame_a)
		return
		
	var weight = (playback_time - frame_a.t) / duration
	
	var target_pos = frame_a.p.lerp(frame_b.p, weight)
	
	# Slerp for rotation requires Basis or Quat. Assuming 'r' is Vector3 (Euler) or Basis.
	# ghost_recorder saves global_rotation (Vector3 Euler) usually, but Quat is safer.
	# Let's assume recorder saves Vector3 for simplicity, but converting to Basis for slerp is better.
	var rot_a = Quaternion.from_euler(frame_a.r)
	var rot_b = Quaternion.from_euler(frame_b.r)
	var target_rot = rot_a.slerp(rot_b, weight).get_euler()
	
	if ghost_visual:
		ghost_visual.global_position = target_pos
		ghost_visual.global_rotation = target_rot

func _apply_transform(frame: Dictionary) -> void:
	if ghost_visual:
		ghost_visual.global_position = frame.p
		ghost_visual.global_rotation = frame.r

func _find_keyframe_index(time: float) -> int:
	# Returns index such that data[index].t <= time < data[index+1].t
	# Simple linear scan suitable for short replays. 
	# For long runs, store 'last_index' state to resume search.
	
	for i in range(0, _data_size - 1):
		if time < recording_data[i+1].t:
			return i
	return -1

class_name TimeTrialLeaderboardBridge
extends Node

## Helper for formatting time trial results and bridging to leaderboards.
## Converts raw milliseconds/ticks into human-readable MM:SS.mmm format.

## Formats milliseconds into "MM:SS.mmm"
static func format_msec(msec_total: int) -> String:
	var msec := msec_total % 1000
	var seconds := (msec_total / 1000) % 60
	var minutes := (msec_total / 60000)
	return "%02d:%02d.%03d" % [minutes, seconds, msec]

## Formats physics frames into "MM:SS.mmm" based on engine tick rate
static func format_frames(frames: int) -> String:
	var ticks_per_sec = Engine.physics_ticks_per_second
	var msec_total = int((float(frames) / ticks_per_sec) * 1000.0)
	return format_msec(msec_total)

## Utility to calculate current session time
var start_tick: int = 0

func start_session() -> void:
	start_tick = Engine.get_physics_frames()

func get_elapsed_formatted() -> String:
	var current = Engine.get_physics_frames()
	return format_frames(current - start_tick)

# time_trial_manager.gd
# [GDSKILLS] godot-game-loop-time-trial
# EXPORT_REFERENCE: time_trial_manager.gd

extends Node

signal lap_started()
signal lap_finished(time: float, is_new_best: bool)
signal checkpoint_passed(index: int, split_time: float)

var best_time: float = INF
var current_lap_time: float = 0.0
var is_racing: bool = false
var current_checkpoint_index: int = -1
var total_checkpoints: int = 0

func setup_track(checkpoints_count: int) -> void:
	total_checkpoints = checkpoints_count
	current_checkpoint_index = -1

func start_lap() -> void:
	current_lap_time = 0.0
	is_racing = true
	current_checkpoint_index = -1
	lap_started.emit()

func pass_checkpoint(index: int) -> void:
	if not is_racing: return
	
	# Linear progression check
	if index == current_checkpoint_index + 1:
		current_checkpoint_index = index
		checkpoint_passed.emit(index, current_lap_time)
		
		if index == total_checkpoints - 1:
			_finish_lap()

func _finish_lap() -> void:
	is_racing = false
	var is_best = current_lap_time < best_time
	if is_best:
		best_time = current_lap_time
	
	lap_finished.emit(current_lap_time, is_best)

func _process(delta: float) -> void:
	if is_racing:
		current_lap_time += delta

# time_trial_patterns.gd
extends Node

# 1. Microsecond Precision Timing
# EXPERT NOTE: Tracks lap times using the CPU's high-resolution microsecond counter.
var _lap_start_usec := 0
func start_lap() -> void:
    _lap_start_usec = Time.get_ticks_usec()

func get_elapsed_seconds() -> float:
    return (Time.get_ticks_usec() - _lap_start_usec) / 1_000_000.0

# 2. Server-Authoritative Lap Validation
# EXPERT NOTE: Clients trigger the RPC, but only the host evaluates the win.
@rpc("any_peer", "call_local", "reliable")
func validate_checkpoint(id: int) -> void:
    if multiplayer.is_server():
        var sender_id := multiplayer.get_remote_sender_id()
        _server_check_sequence(sender_id, id)

func _server_check_sequence(_peer: int, _cp_id: int) -> void:
    # Validate that checkpoint ID follows the previous one in sequence
    pass

# 3. Area3D Checkpoint Detection
# EXPERT NOTE: Securely limits signal triggering to specific vehicle/player classes using safe casting.
func _on_checkpoint_entered(body: Node3D) -> void:
    var car := body as CharacterBody3D # Or VehicleBody3D
    if car:
        _trigger_checkpoint_logic()

func _trigger_checkpoint_logic() -> void:
    pass

# 4. Rubber-Banding Speed Adjustments
# EXPERT NOTE: Dynamically alters maximum agent speed based on distance to the leader.
func update_ai_speed(agent: RID, player_distance: float) -> void:
    var base_speed := 50.0
    var factor := 0.5
    var speed: float = base_speed + (player_distance * factor)
    NavigationServer3D.agent_set_max_speed(agent, speed)

# 5. Fast Distance Checking (Squared)
# EXPERT NOTE: Uses distance_squared_to to skip the expensive square-root calculation.
func is_near_finish_line(pos: Vector3, finish_pos: Vector3) -> bool:
    var threshold_sq := 10.0 * 10.0 # 10 meters
    return pos.distance_squared_to(finish_pos) < threshold_sq

# 6. Optimized Tag Comparisons with StringName
# EXPERT NOTE: Uses StringName for instant hash comparisons in checkpoint logic.
var checkpoint_tag := &"checkpoint_sector_3"
func check_gate_tag(tag: StringName) -> void:
    if tag == checkpoint_tag:
        # Proceed logic
        pass

# 7. Unreliable High-Frequency Packet Sync
# EXPERT NOTE: Sends highly-volatile racer positions quickly via raw bytes/unreliable.
func sync_transform(data: PackedByteArray) -> void:
    multiplayer.send_bytes(data, 0, MultiplayerPeer.TRANSFER_MODE_UNRELIABLE)

# 8. Dynamic Physics Material Overrides
# EXPERT NOTE: Dynamically adjusts bounce/friction when surface changes (ice, mud, road).
func set_surface_friction(body: RigidBody3D, friction_val: float) -> void:
    var mat := PhysicsMaterial.new()
    mat.friction = friction_val
    body.physics_material_override = mat

# 9. Frame-Perfect Input Buffering
# EXPERT NOTE: Forces the engine to parse immediate inputs before physics calculations.
func _unhandled_input(event: InputEvent) -> void:
    if event.is_action_pressed(&"boost"):
        Input.flush_buffered_events()
        _apply_boost()

func _apply_boost() -> void:
    pass

# 10. Curve-Based Steering Interpretation
# EXPERT NOTE: Uses visual Curve resources to evaluate complex steering dampening based on speed.
@export var steering_damp_curve: Curve
func get_steer_damp(speed_ratio: float) -> float:
    return steering_damp_curve.sample_baked(speed_ratio)

class_name TimeTrialPlaybackBuffer
extends Node

## Handles ghost playback with a jitter buffer for network-streamed data.
## Ensures smooth playback even if packets arrive out of order or in bursts.

@export var buffer_time: float = 0.5 # Seconds to buffer before starting playback
@export var ghost_visual: Node3D

var _incoming_buffer: Array[Dictionary] = []
var _is_playing: bool = false
var _playback_time: float = 0.0
var _buffer_filled: bool = false

## Call this whenever a new ghost frame arrives from the network.
func push_frame(time: float, transform: Transform3D) -> void:
	_incoming_buffer.append({"t": time, "xform": transform})
	# Keep buffer sorted by time
	_incoming_buffer.sort_custom(func(a, b): return a.t < b.t)
	
	if not _is_playing and _get_buffer_duration() >= buffer_time:
		_buffer_filled = true
		_start_playback()

func _process(delta: float) -> void:
	if not _is_playing:
		return
		
	_playback_time += delta
	_update_ghost_transform()

func _start_playback() -> void:
	if _incoming_buffer.is_empty(): return
	_playback_time = _incoming_buffer[0].t
	_is_playing = true

func _update_ghost_transform() -> void:
	if _incoming_buffer.size() < 2: return
	
	# Find interpolation frames
	var frame_a = _incoming_buffer[0]
	var frame_b = _incoming_buffer[1]
	
	# Remove old frames that are behind the playback head
	while _incoming_buffer.size() > 2 and _incoming_buffer[1].t < _playback_time:
		_incoming_buffer.remove_at(0)
		frame_a = _incoming_buffer[0]
		frame_b = _incoming_buffer[1]
	
	if ghost_visual and frame_a.t <= _playback_time:
		var span = frame_b.t - frame_a.t
		var weight = (_playback_time - frame_a.t) / span if span > 0 else 0.0
		ghost_visual.global_transform = frame_a.xform.interpolate_with(frame_b.xform, weight)

func _get_buffer_duration() -> float:
	if _incoming_buffer.size() < 2: return 0.0
	return _incoming_buffer[-1].t - _incoming_buffer[0].t