Stepping Physics with Rollback

addons/netfox.extras/netfox-extras.gd

@@ -31,13 +31,18 @@ const AUTOLOADS = [
 	}
 ]
 
+const PhysicsDriverToggles := preload("res://addons/netfox.extras/physics/physics-driver-toggles.gd")
+
+var _tool_menu_items := [] as Array[String]
+
 func _enter_tree():
 	for setting in SETTINGS:
 		add_setting(setting)
 
 	for autoload in AUTOLOADS:
 		add_autoload_singleton(autoload.name, autoload.path)
 
+	_render_tool_menu()
 
 func _exit_tree():
 	if ProjectSettings.get_setting("netfox/general/clear_settings", false):
@@ -47,6 +52,8 @@ func _exit_tree():
 	for autoload in AUTOLOADS:
 		remove_autoload_singleton(autoload.name)
 
+	_free_tool_menu()
+
 func add_setting(setting: Dictionary):
 	if ProjectSettings.has_setting(setting.name):
 		return
@@ -65,3 +72,41 @@ func remove_setting(setting: Dictionary):
 		return
 
 	ProjectSettings.clear(setting.name)
+
+func _render_tool_menu():
+	_free_tool_menu()
+	for driver_toggle in PhysicsDriverToggles.all():
+		var prefix := "Enable" if not driver_toggle.is_enabled() else "Disable"
+		var item := "%s %s physics driver" % [prefix, driver_toggle.get_name()]
+
+		_tool_menu_items.append(item)
+
+		add_tool_menu_item(item, func():
+			# Toggle physics driver, then re-render menu to show changes
+			_call_physics_driver_toggle(driver_toggle)
+			_render_tool_menu()
+		)
+
+func _free_tool_menu():
+	for item in _tool_menu_items:
+		remove_tool_menu_item(item)
+	_tool_menu_items.clear()
+
+func _call_physics_driver_toggle(driver_toggle: PhysicsDriverToggles.PhysicsDriverToggle):
+	var error_messages := driver_toggle.toggle()
+	if not error_messages.is_empty():
+		var error_text := "\n".join(error_messages)
+
+		var dialog := AcceptDialog.new()
+		dialog.title = "Physics driver toggle failed!"
+		dialog.dialog_text = error_text
+
+		get_editor_interface().popup_dialog_centered(dialog)
+	else:
+		var dialog := AcceptDialog.new()
+		dialog.title = "Physics driver toggle success!"
+		dialog.dialog_text = ("%s physics driver was successfully toggled! " +
+			"You might need to refresh your script or reload project.") %\
+			[driver_toggle.get_name()]
+
+		get_editor_interface().popup_dialog_centered(dialog)

addons/netfox.extras/physics/godot_driver_2d.gd.off

@@ -0,0 +1,72 @@
+extends PhysicsDriver
+
+class_name PhysicsDriver2D
+
+# Physics driver based on netfox ticks
+# Requires a custom build of Godot with https://github.com/godotengine/godot/pull/76462
+
+var scene_collision_objects: Array = []
+var collision_objects_snapshots: Dictionary[int, Dictionary] = {}
+
+func _init_physics_space() -> void:
+	physics_space = get_viewport().world_2d.space
+	PhysicsServer2D.space_set_active(physics_space, false)
+
+	get_tree().node_added.connect(node_added)
+	get_tree().node_removed.connect(node_removed)
+	scan_tree()
+
+func _physics_step(delta) -> void:
+	PhysicsServer2D.space_flush_queries(physics_space)
+	PhysicsServer2D.space_step(physics_space, delta)
+
+func _snapshot_space(tick: int) -> void:
+	var rid_states: Dictionary[RID, Array] = {}
+	for element in scene_collision_objects:
+		if element is CharacterBody2D:
+			element.force_update_transform() # force colliders to update
+
+		var rid = element.get_rid()
+		rid_states[rid] = get_body_states(rid)
+	snapshots[tick] = rid_states
+
+func _rollback_space(tick) -> void:
+	if snapshots.has(tick):
+		var rid_states = snapshots[tick]
+		for rid in rid_states.keys():
+			set_body_states(rid, rid_states[rid])
+
+		for body in scene_collision_objects:
+			if body is CharacterBody2D:
+				body.force_update_transform() # force colliders to update
+
+func get_body_states(rid: RID) -> Array:
+	var body_state: Array = [Vector3.ZERO, Quaternion.IDENTITY, Vector3.ZERO, Vector3.ZERO]
+	body_state[0] = PhysicsServer2D.body_get_state(rid, PhysicsServer2D.BODY_STATE_TRANSFORM)
+	body_state[1] = PhysicsServer2D.body_get_state(rid, PhysicsServer2D.BODY_STATE_LINEAR_VELOCITY)
+	body_state[2] = PhysicsServer2D.body_get_state(rid, PhysicsServer2D.BODY_STATE_ANGULAR_VELOCITY)
+	body_state[3] = PhysicsServer2D.body_get_state(rid, PhysicsServer2D.BODY_STATE_SLEEPING)
+	return body_state
+
+func set_body_states(rid: RID, body_state: Array) -> void:
+	PhysicsServer2D.body_set_state(rid, PhysicsServer2D.BODY_STATE_TRANSFORM, body_state[0])
+	PhysicsServer2D.body_set_state(rid, PhysicsServer2D.BODY_STATE_LINEAR_VELOCITY, body_state[1])
+	PhysicsServer2D.body_set_state(rid, PhysicsServer2D.BODY_STATE_ANGULAR_VELOCITY, body_state[2])
+	PhysicsServer2D.body_set_state(rid, PhysicsServer2D.BODY_STATE_SLEEPING, body_state[3])
+
+func scan_tree():
+	scene_collision_objects.clear()
+	scene_collision_objects = get_all_children(get_node('/root'))
+
+func get_all_children(in_node: Node) -> Array:
+	var nodes = []
+	nodes = in_node.find_children("*", "PhysicsBody2D", true, false)
+	return nodes
+
+func node_added(node: Node) -> void:
+	if node is PhysicsBody2D:
+		scene_collision_objects.append(node)
+
+func node_removed(node: Node) -> void:
+	if node is PhysicsBody2D:
+		scene_collision_objects.erase(node)

addons/netfox.extras/physics/godot_driver_2d.gd.uid.off

@@ -0,0 +1 @@
+uid://c8p8gymii2y5v

addons/netfox.extras/physics/godot_driver_3d.gd.off

@@ -0,0 +1,71 @@
+extends PhysicsDriver
+class_name PhysicsDriver3D
+
+# Physics driver based on netfox ticks
+# Requires a custom build of Godot with https://github.com/godotengine/godot/pull/76462
+
+# Maps ticks ( int ) to global snapshots ( Dictionary<RID, Array> )
+var scene_collision_objects: Array = []
+
+func _init_physics_space() -> void:
+	physics_space = get_viewport().world_3d.space
+	PhysicsServer3D.space_set_active(physics_space, false)
+
+	get_tree().node_added.connect(node_added)
+	get_tree().node_removed.connect(node_removed)
+	scan_tree()
+
+func _physics_step(delta) -> void:
+	PhysicsServer3D.space_flush_queries(physics_space)
+	PhysicsServer3D.space_step(physics_space, delta)
+
+func _snapshot_space(tick: int) -> void:
+	# Maps RIDs to physics state ( Array )
+	var rid_states := {}
+	for element in scene_collision_objects:
+		var rid = element.get_rid()
+		rid_states[rid] = get_body_states(rid)
+
+	snapshots[tick] = rid_states
+
+func _rollback_space(tick) -> void:
+	if snapshots.has(tick):
+		var rid_states = snapshots[tick]
+		for rid in rid_states.keys():
+			set_body_states(rid, rid_states[rid])
+
+		for body in scene_collision_objects:
+			if body is CharacterBody3D:
+				body.force_update_transform()
+
+
+func get_body_states(rid: RID) -> Array:
+	var body_state: Array = [Vector3.ZERO, Quaternion.IDENTITY, Vector3.ZERO, Vector3.ZERO]
+	body_state[0] = PhysicsServer3D.body_get_state(rid, PhysicsServer3D.BODY_STATE_TRANSFORM)
+	body_state[1] = PhysicsServer3D.body_get_state(rid, PhysicsServer3D.BODY_STATE_LINEAR_VELOCITY)
+	body_state[2] = PhysicsServer3D.body_get_state(rid, PhysicsServer3D.BODY_STATE_ANGULAR_VELOCITY)
+	body_state[3] = PhysicsServer3D.body_get_state(rid, PhysicsServer3D.BODY_STATE_SLEEPING)
+	return body_state
+
+func set_body_states(rid: RID, body_state: Array) -> void:
+	PhysicsServer3D.body_set_state(rid, PhysicsServer3D.BODY_STATE_TRANSFORM, body_state[0])
+	PhysicsServer3D.body_set_state(rid, PhysicsServer3D.BODY_STATE_LINEAR_VELOCITY, body_state[1])
+	PhysicsServer3D.body_set_state(rid, PhysicsServer3D.BODY_STATE_ANGULAR_VELOCITY, body_state[2])
+	PhysicsServer3D.body_set_state(rid, PhysicsServer3D.BODY_STATE_SLEEPING, body_state[3])
+
+func scan_tree():
+	scene_collision_objects.clear()
+	scene_collision_objects = get_all_children(get_node('/root'))
+
+func get_all_children(in_node: Node) -> Array:
+	var nodes = []
+	nodes = in_node.find_children("*", "PhysicsBody3D", true, false)
+	return nodes
+
+func node_added(node: Node) -> void:
+	if node is PhysicsBody3D:
+		scene_collision_objects.append(node)
+
+func node_removed(node: Node) -> void:
+	if node is PhysicsBody3D:
+		scene_collision_objects.erase(node)

addons/netfox.extras/physics/godot_driver_3d.gd.uid.off

@@ -0,0 +1 @@
+uid://wr5ur5dqrkni

addons/netfox.extras/physics/network-rigid-body-2d.gd

@@ -0,0 +1,44 @@
+extends RigidBody2D
+
+class_name NetworkRigidBody2D
+
+## A rollback / state synchronizer class for RigidBody2D.
+## Set state property path to physics_state to synchronize the state of this body.
+
+@onready var direct_state = PhysicsServer2D.body_get_direct_state(get_rid())
+
+var physics_state: Array:
+	get: return get_state()
+	set(v): set_state(v)
+
+enum {
+	ORIGIN,
+	ROT,
+	LIN_VEL,
+	ANG_VEL,
+	SLEEPING
+}
+
+func _notification(notification: int):
+	if notification == NOTIFICATION_READY:
+		add_to_group("network_rigid_body")
+
+func get_state() -> Array:
+	var body_state: Array = [Vector3.ZERO, Quaternion.IDENTITY, Vector3.ZERO, Vector3.ZERO, false]
+	body_state[ORIGIN] = direct_state.transform.origin
+	body_state[ROT] = direct_state.transform.get_rotation()
+	body_state[LIN_VEL] = direct_state.linear_velocity
+	body_state[ANG_VEL] = direct_state.angular_velocity
+	body_state[SLEEPING] = direct_state.sleeping
+	return body_state
+
+func set_state(remote_state: Array) -> void:
+	direct_state.transform = Transform2D(remote_state[ROT], remote_state[ORIGIN])
+	direct_state.linear_velocity = remote_state[LIN_VEL]
+	direct_state.angular_velocity = remote_state[ANG_VEL]
+	direct_state.sleeping = remote_state[SLEEPING]
+
+## Override and apply any logic, forces or impulses to the rigid body as you would in physics_process
+## The physics engine will run its simulation during rollback_tick with other nodes
+func _physics_rollback_tick(_delta, _tick):
+	pass

addons/netfox.extras/physics/network-rigid-body-2d.gd.uid

@@ -0,0 +1 @@
+uid://c8hw7ol53m55g

addons/netfox.extras/physics/network-rigid-body-3d.gd

@@ -0,0 +1,46 @@
+extends RigidBody3D
+
+class_name NetworkRigidBody3D
+
+## A rollback / state synchronizer class for RigidBody3D.
+## Set state property path to physics_state to synchronize the state of this body.
+
+@onready var direct_state = PhysicsServer3D.body_get_direct_state(get_rid())
+
+var physics_state: Array:
+	get: return get_state()
+	set(v): set_state(v)
+
+enum {
+	ORIGIN,
+	QUAT,
+	LIN_VEL,
+	ANG_VEL,
+	SLEEPING
+}
+
+func _notification(notification: int):
+	if notification == NOTIFICATION_READY:
+		add_to_group("network_rigid_body")
+
+func get_state() -> Array:
+	var body_state: Array = [Vector3.ZERO, Quaternion.IDENTITY, Vector3.ZERO, Vector3.ZERO, false]
+	body_state[ORIGIN] = direct_state.transform.origin
+	body_state[QUAT] = direct_state.transform.basis.get_rotation_quaternion()
+	body_state[LIN_VEL] = direct_state.linear_velocity
+	body_state[ANG_VEL] = direct_state.angular_velocity
+	body_state[SLEEPING] = direct_state.sleeping
+	return body_state
+
+func set_state(remote_state: Array) -> void:
+	direct_state.transform.origin = remote_state[ORIGIN]
+	direct_state.transform.basis = Basis(remote_state[QUAT])
+	direct_state.linear_velocity = remote_state[LIN_VEL]
+	direct_state.angular_velocity = remote_state[ANG_VEL]
+	direct_state.sleeping = remote_state[SLEEPING]
+
+
+## Override and apply any logic, forces or impulses to the rigid body as you would in physics_process
+## The physics engine will run its simulation during rollback_tick with other nodes
+func _physics_rollback_tick(_delta, _tick):
+	pass

addons/netfox.extras/physics/network-rigid-body-3d.gd.uid

@@ -0,0 +1 @@
+uid://bklxcdyxgbjg2

addons/netfox.extras/physics/physics-driver-toggles.gd

@@ -0,0 +1,74 @@
+extends Object
+
+class PhysicsDriverToggle:
+	const INACTIVE_SUFFIX := ".off"
+
+	func get_name() -> String:
+		return "???"
+
+	func get_files() -> Array[String]:
+		return []
+
+	func get_error_messages() -> Array[String]:
+		return []
+
+	func is_enabled() -> bool:
+		return get_files().any(func(it): return FileAccess.file_exists(it))
+
+	func toggle() -> Array[String]:
+		var errors := get_error_messages()
+		if not errors.is_empty():
+			return errors
+
+		var enable := not is_enabled()
+
+		var uid_files := get_files().map(func(it): return it + ".uid")
+		var renames = (get_files() + uid_files).map(func(it):
+			if enable: return [it + INACTIVE_SUFFIX, it]
+			else: return [it, it + INACTIVE_SUFFIX]
+		)
+
+		for rename in renames:
+			var result := DirAccess.rename_absolute(rename[0], rename[1])
+			if result != OK:
+				errors.append(
+					"Failed rename \"%s\" -> \"%s\"; reason: %s" %
+					[rename[0], rename[1], error_string(result)]
+				)
+		return errors
+
+class RapierPhysicsDriverToggle extends PhysicsDriverToggle:
+	func get_name() -> String:
+		return "Rapier"
+
+	func get_files() -> Array[String]:
+		return [
+			"res://addons/netfox.extras/physics/rapier_driver_2d.gd",
+			"res://addons/netfox.extras/physics/rapier_driver_3d.gd",
+		]
+
+	func get_error_messages() -> Array[String]:
+		if not ClassDB.class_exists("RapierPhysicsServer2D") or not ClassDB.class_exists("RapierPhysicsServer3D"):
+			return ["Rapier physics is not available! Is the extension installed?"]
+		return []
+
+class GodotPhysicsDriverToggle extends PhysicsDriverToggle:
+	func get_name() -> String:
+		return "Godot"
+
+	func get_files() -> Array[String]:
+		return [
+			"res://addons/netfox.extras/physics/godot_driver_3d.gd",
+			"res://addons/netfox.extras/physics/godot_driver_2d.gd"
+		]
+
+	func get_error_messages() -> Array[String]:
+		if not PhysicsServer3D.has_method("space_step") or not PhysicsServer2D.has_method("space_step"):
+			return ["Physics stepping is not available! Is this the right Godot build?"]
+		return []
+
+static func all() -> Array[PhysicsDriverToggle]:
+	return [
+		RapierPhysicsDriverToggle.new(),
+		GodotPhysicsDriverToggle.new()
+	]

addons/netfox.extras/physics/physics-driver-toggles.gd.uid

@@ -0,0 +1 @@
+uid://bu4ppfj0ovkbr