stabilize movement reconciliation states

player/player.gd

@@ -1036,6 +1036,8 @@ func _simulate_movement_physics(delta: float) -> void:
 			or (_network_authoritative_simulation and _network_jump_pending)
 		)
 	)
+	if jump_requested:
+		_cancel_sitting_for_jump()
 	# Sitting deliberately stops movement processing, so never allow a stale
 	# grounded flag or a reconciled network state to leave an airborne avatar in
 	# that early-return path. Preserve the intent and sit once landing is real.
@@ -1635,6 +1637,7 @@ func _complete_retract_animation() -> void:
 func toggle_sitting() -> void:
 	if _sit_after_landing:
 		_sit_after_landing = false
+		_set_sitting(false, local_control_enabled)
 		return
 	var should_sit: bool = not _sitting
 	if should_sit:
@@ -1667,12 +1670,12 @@ func _set_sitting(
 	should_sit: bool,
 	is_local_intent: bool = false,
 ) -> void:
-	if _sitting == should_sit:
-		return
-	_sitting = should_sit
 	if is_local_intent:
 		_sitting_intent_pending = true
 		_sitting_intent_sequence = -1
+	if _sitting == should_sit:
+		return
+	_sitting = should_sit
 	if _sitting:
 		velocity = Vector3.ZERO
 	_character_animation_name = &""
@@ -1687,11 +1690,23 @@ func _can_begin_sitting() -> bool:
 	return is_on_floor() and velocity.y <= 0.0
 
 
+func _cancel_sitting_for_jump() -> void:
+	if not _sitting and not _sit_after_landing:
+		return
+	_sit_after_landing = false
+	_set_sitting(false, local_control_enabled)
+
+
 func get_network_sitting_state() -> bool:
 	return _sitting
 
 
 func get_network_sitting_intent() -> bool:
+	# Jumping is an explicit cancellation of both a current sit and a deferred
+	# sit. Input capture can run before the matching physics frame, so suppress
+	# the stale seated bit as soon as the reliable jump intent is queued.
+	if _local_network_jump_intent_pending:
+		return false
 	return _sitting or _sit_after_landing
 
 
@@ -2352,6 +2367,21 @@ func apply_local_prediction_correction(
 		_local_prediction_hard_corrections += 1
 		_reset_local_prediction_error()
 		return
+	if _should_defer_local_prediction_correction(parsed):
+		# A host and its client do not reach the apex or landing on the same
+		# frame. Correcting that expected vertical disagreement while either
+		# side is airborne can pull the local body off narrow platforms.
+		_reset_local_prediction_error()
+		return
+	# Both simulations agree the player is standing. Let ordinary floor motion
+	# and gravity resolve the vertical component; a stale height sample must not
+	# press a locally controlled player down or turn a horizontal correction
+	# into an early floor collision.
+	error_offset.y = 0.0
+	error_distance = error_offset.length()
+	if error_distance <= LOCAL_PREDICTION_CORRECTION_THRESHOLD:
+		_reset_local_prediction_error()
+		return
 	var error_direction: Vector3 = error_offset.normalized()
 	if (
 		not _local_prediction_error_direction.is_zero_approx()
@@ -2386,22 +2416,34 @@ func apply_local_prediction_correction(
 			correction.normalized()
 			* LOCAL_PREDICTION_MAX_SOFT_CORRECTION_STEP
 		)
-	_apply_camera_safe_local_correction(correction)
-	_local_prediction_soft_corrections += 1
+	if _apply_camera_safe_local_correction(correction):
+		_local_prediction_soft_corrections += 1
 
 
-func _apply_camera_safe_local_correction(correction: Vector3) -> void:
+func _should_defer_local_prediction_correction(parsed: Dictionary) -> bool:
+	if not bool(parsed.get("grounded", true)):
+		return true
+	return _local_network_jump_intent_pending or not is_on_floor()
+
+
+func _apply_camera_safe_local_correction(correction: Vector3) -> bool:
 	if correction.is_zero_approx():
-		return
+		return false
 	var previous_visual_position: Vector3 = _visuals.global_position
 	var previous_camera_position: Vector3 = _camera_yaw.global_position
+	var previous_body_position: Vector3 = global_position
 	var base_visual_local_position: Vector3 = (
 		_visuals.position - _local_reconciliation_visual_offset
 	)
 	var base_camera_local_position: Vector3 = (
 		_camera_yaw.position - _local_reconciliation_camera_offset
 	)
-	global_position += correction
+	# Reconciliation is still physical movement. Going through the physics
+	# server prevents a delayed host audit from placing the capsule through a
+	# tree, cliff, or stepping stone on the way to the authoritative position.
+	move_and_collide(correction)
+	if global_position.is_equal_approx(previous_body_position):
+		return false
 	_visuals.global_position = previous_visual_position
 	_camera_yaw.global_position = previous_camera_position
 	_local_reconciliation_visual_offset = (
@@ -2410,6 +2452,7 @@ func _apply_camera_safe_local_correction(correction: Vector3) -> void:
 	_local_reconciliation_camera_offset = (
 		_camera_yaw.position - base_camera_local_position
 	)
+	return true
 
 
 func _reset_local_prediction_error() -> void:
@@ -2625,6 +2668,9 @@ func _parse_network_snapshot(snapshot: Dictionary) -> Dictionary:
 	if snapshot.has("casting") and typeof(snapshot.get("casting")) != TYPE_BOOL:
 		return {}
 	var casting: bool = bool(snapshot.get("casting", false))
+	if snapshot.has("grounded") and typeof(snapshot.get("grounded")) != TYPE_BOOL:
+		return {}
+	var grounded: bool = bool(snapshot.get("grounded", true))
 	if (
 		not parsed_position.is_finite()
 		or not parsed_velocity.is_finite()
@@ -2636,6 +2682,7 @@ func _parse_network_snapshot(snapshot: Dictionary) -> Dictionary:
 		"velocity": parsed_velocity,
 		"visual_yaw": visual_yaw,
 		"animation_state": animation_state,
+		"grounded": grounded,
 		"acknowledged_input": acknowledged_input,
 		"sitting": sitting,
 		"casting": casting,