Struct MainLoop
Abstract base class for the game's main loop.
struct MainLoop
;
MainLoop is the abstract base class for a Godot project's game loop. It is inherited by SceneTree, which is the default game loop implementation used in Godot projects, though it is also possible to write and use one's own MainLoop subclass instead of the scene tree.
Upon the application start, a MainLoop implementation must be provided to the OS; otherwise, the application will exit. This happens automatically (and a SceneTree is created) unless a main Script is provided from the command line (with e.g. godot -s my_loop, which should then be a MainLoop implementation.
Here is an example script implementing a simple MainLoop:
extends MainLoop
var time_elapsed = 0 var keys_typed = [] var quit = false
func initialize(): print("Initialized:") print(" Starting time: %s" % str(time_elapsed))
func idle(delta): time_elapsed += delta # Return true to end the main loop. return quit
func input_event(event): # Record keys. if event is InputEventKey and event.pressed and !event.echo: keys_typed.append(OS.get_scancode_string(event.scancode)) # Quit on Escape press. if event.scancode == KEY_ESCAPE: quit = true # Quit on any mouse click. if event is InputEventMouseButton: quit = true
func finalize(): print("Finalized:") print(" End time: %s" % str(time_elapsed)) print(" Keys typed: %s" % var2str(keys_typed))
Methods
| Name | Description |
|---|---|
_dropFiles
|
Called when files are dragged from the OS file manager and dropped in the game window. The arguments are a list of file paths and the identifier of the screen where the drag originated. |
_finalize
|
Called before the program exits. |
_globalMenuAction
|
Called when the user performs an action in the system global menu (e.g. the Mac OS menu bar). |
_idle
|
Called each idle frame with the time since the last idle frame as argument (in seconds). Equivalent to Node.
If implemented, the method must return a boolean value. true ends the main loop, while false lets it proceed to the next frame.
|
_init
|
Should not be called manually, override initialize instead. Will be removed in Godot 4.0.
|
_initialize
|
Called once during initialization. |
_inputEvent
|
Called whenever an InputEvent is received by the main loop.
|
_inputText
|
Deprecated callback, does not do anything. Use inputEvent to parse text input. Will be removed in Godot 4.0.
|
_iteration
|
Called each physics frame with the time since the last physics frame as argument (in seconds). Equivalent to Node.
If implemented, the method must return a boolean value. true ends the main loop, while false lets it proceed to the next frame.
|
finish
|
Should not be called manually, override finalize instead. Will be removed in Godot 4.0.
|
idle
|
Should not be called manually, override idle instead. Will be removed in Godot 4.0.
|
inputEvent
|
Should not be called manually, override inputEvent instead. Will be removed in Godot 4.0.
|
inputText
|
Should not be called manually, override inputText instead. Will be removed in Godot 4.0.
|
iteration
|
Should not be called manually, override iteration instead. Will be removed in Godot 4.0.
|
Enums
| Name | Description |
|---|---|
Constants
|