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.
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Controllers, gamepads, and joysticks¶
Redot supports hundreds of controller models thanks to the community-sourced SDL game controller database.
Controllers are supported on Windows, macOS, Linux, Android, iOS, and HTML5.
Note that more specialized devices such as steering wheels, rudder pedals and HOTAS are less tested and may not always work as expected. Overriding force feedback for those devices is also not implemented yet. If you have access to one of those devices, don't hesitate to report bugs on GitHub.
In this guide, you will learn:
How to write your input logic to support both keyboard and controller inputs.
How controllers can behave differently from keyboard/mouse input.
Troubleshooting issues with controllers in Redot.
Supporting universal input¶
Thanks to Redot's input action system, Redot makes it possible to support both keyboard and controller input without having to write separate code paths. Instead of hardcoding keys or controller buttons in your scripts, you should create input actions in the Project Settings which will then refer to specified key and controller inputs.
Input actions are explained in detail on the Using InputEvent page.
Note
Unlike keyboard input, supporting both mouse and controller input for an action (such as looking around in a first-person game) will require different code paths since these have to be handled separately.
Which Input singleton method should I use?¶
There are 3 ways to get input in an analog-aware way:
When you have two axes (such as joystick or WASD movement) and want both axes to behave as a single input, use
Input.get_vector()
:
# `velocity` will be a Vector2 between `Vector2(-1.0, -1.0)` and `Vector2(1.0, 1.0)`.
# This handles deadzone in a correct way for most use cases.
# The resulting deadzone will have a circular shape as it generally should.
var velocity = Input.get_vector("move_left", "move_right", "move_forward", "move_back")
# The line below is similar to `get_vector()`, except that it handles
# the deadzone in a less optimal way. The resulting deadzone will have
# a square-ish shape when it should ideally have a circular shape.
var velocity = Vector2(
Input.get_action_strength("move_right") - Input.get_action_strength("move_left"),
Input.get_action_strength("move_back") - Input.get_action_strength("move_forward")
).limit_length(1.0)
// `velocity` will be a Vector2 between `Vector2(-1.0, -1.0)` and `Vector2(1.0, 1.0)`.
// This handles deadzone in a correct way for most use cases.
// The resulting deadzone will have a circular shape as it generally should.
Vector2 velocity = Input.GetVector("move_left", "move_right", "move_forward", "move_back");
// The line below is similar to `get_vector()`, except that it handles
// the deadzone in a less optimal way. The resulting deadzone will have
// a square-ish shape when it should ideally have a circular shape.
Vector2 velocity = new Vector2(
Input.GetActionStrength("move_right") - Input.GetActionStrength("move_left"),
Input.GetActionStrength("move_back") - Input.GetActionStrength("move_forward")
).LimitLength(1.0);
When you have one axis that can go both ways (such as a throttle on a flight stick), or when you want to handle separate axes individually, use
Input.get_axis()
:
# `walk` will be a floating-point number between `-1.0` and `1.0`.
var walk = Input.get_axis("move_left", "move_right")
# The line above is a shorter form of:
var walk = Input.get_action_strength("move_right") - Input.get_action_strength("move_left")
// `walk` will be a floating-point number between `-1.0` and `1.0`.
float walk = Input.GetAxis("move_left", "move_right");
// The line above is a shorter form of:
float walk = Input.GetActionStrength("move_right") - Input.GetActionStrength("move_left");
For other types of analog input, such as handling a trigger or handling one direction at a time, use
Input.get_action_strength()
:
# `strength` will be a floating-point number between `0.0` and `1.0`.
var strength = Input.get_action_strength("accelerate")
// `strength` will be a floating-point number between `0.0` and `1.0`.
float strength = Input.GetActionStrength("accelerate");
For non-analog digital/boolean input (only "pressed" or "not pressed" values),
such as controller buttons, mouse buttons or keyboard keys,
use Input.is_action_pressed()
:
# `jumping` will be a boolean with a value of `true` or `false`.
var jumping = Input.is_action_pressed("jump")
// `jumping` will be a boolean with a value of `true` or `false`.
bool jumping = Input.IsActionPressed("jump");
Note
If you need to know whether an input was just pressed in the previous
frame, use Input.is_action_just_pressed()
instead of
Input.is_action_pressed()
. Unlike Input.is_action_pressed()
which
returns true
as long as the input is
held, Input.is_action_just_pressed()
will only return true
for one
frame after the button has been pressed.
In Redot versions before 3.4, such as 3.3, Input.get_vector()
and
Input.get_axis()
aren't available. Only Input.get_action_strength()
and Input.is_action_pressed()
are available in Redot 3.3.
Vibration¶
Vibration (also called haptic feedback) can be used to enhance the feel of a game. For instance, in a racing game, you can convey the surface the car is currently driving on through vibration, or create a sudden vibration on a crash.
Use the Input singleton's start_joy_vibration method to start vibrating a gamepad. Use stop_joy_vibration to stop vibration early (useful if no duration was specified when starting).
On mobile devices, you can also use
vibrate_handheld to vibrate the
device itself (independently from the gamepad). On Android, this requires the
VIBRATE
permission to be enabled in the Android export preset before
exporting the project.
Note
Vibration can be uncomfortable for certain players. Make sure to provide an in-game slider to disable vibration or reduce its intensity.
Differences between keyboard/mouse and controller input¶
If you're used to handling keyboard and mouse input, you may be surprised by how controllers handle specific situations.
Dead zone¶
Unlike keyboards and mice, controllers offer axes with analog inputs. The
upside of analog inputs is that they offer additional flexibility for actions.
Unlike digital inputs which can only provide strengths of 0.0
and 1.0
,
an analog input can provide any strength between 0.0
and 1.0
. The
downside is that without a deadzone system, an analog axis' strength will never
be equal to 0.0
due to how the controller is physically built. Instead, it
will linger at a low value such as 0.062
. This phenomenon is known as
drifting and can be more noticeable on old or faulty controllers.
Let's take a racing game as a real-world example. Thanks to analog inputs, we
can steer the car slowly in one direction or another. However, without a
deadzone system, the car would slowly steer by itself even if the player isn't
touching the joystick. This is because the directional axis strength won't be
equal to 0.0
when we expect it to. Since we don't want our car to steer by
itself in this case, we define a "dead zone" value of 0.2
which will ignore
all input whose strength is lower than 0.2
. An ideal dead zone value is high
enough to ignore the input caused by joystick drifting, but is low enough to not
ignore actual input from the player.
Redot features a built-in deadzone system to tackle this problem. The default
value is 0.5
, but you can adjust it on a per-action basis in the Project
Settings' Input Map tab. For Input.get_vector()
, the deadzone can be
specified as an optional 5th parameter. If not specified, it will calculate the
average deadzone value from all of the actions in the vector.
"Echo" events¶
Unlike keyboard input, holding down a controller button such as a D-pad direction will not generate repeated input events at fixed intervals (also known as "echo" events). This is because the operating system never sends "echo" events for controller input in the first place.
If you want controller buttons to send echo events, you will have to generate class_InputEvent objects by code and parse them using Input.parse_input_event() at regular intervals. This can be accomplished with the help of a class_Timer node.
Window focus¶
Unlike keyboard input, controller inputs can be seen by all windows on the operating system, including unfocused windows.
While this is useful for third-party split screen functionality, it can also have adverse effects. Players may accidentally send controller inputs to the running project while interacting with another window.
If you wish to ignore events when the project window isn't focused, you will
need to create an autoload called Focus
with the following script and use it to check all your inputs:
# Focus.gd
extends Node
var focused := true
func _notification(what: int) -> void:
match what:
NOTIFICATION_APPLICATION_FOCUS_OUT:
focused = false
NOTIFICATION_APPLICATION_FOCUS_IN:
focused = true
func input_is_action_pressed(action: StringName) -> bool:
if focused:
return Input.is_action_pressed(action)
return false
func event_is_action_pressed(event: InputEvent, action: StringName) -> bool:
if focused:
return event.is_action_pressed(action)
return false
Then, instead of using Input.is_action_pressed(action)
, use
Focus.input_is_action_pressed(action)
where action
is the name of
the input action. Also, instead of using event.is_action_pressed(action)
,
use Focus.event_is_action_pressed(event, action)
where event
is an
InputEvent reference and action
is the name of the input action.
Power saving prevention¶
Unlike keyboard and mouse input, controller inputs do not inhibit sleep and power saving measures (such as turning off the screen after a certain amount of time has passed).
To combat this, Redot enables power saving prevention by default when a project is running. If you notice the system is turning off its display when playing with a gamepad, check the value of Display > Window > Energy Saving > Keep Screen On in the Project Settings.
On Linux, power saving prevention requires the engine to be able to use D-Bus. Check whether D-Bus is installed and reachable if running the project within a Flatpak, as sandboxing restrictions may make this impossible by default.
Troubleshooting¶
See also
You can view a list of known issues with controller support on GitHub.
My controller isn't recognized by Redot.¶
First, check that your controller is recognized by other applications. You can use the Gamepad Tester website to confirm that your controller is recognized.
On Windows Redot only supports up to 4 controllers at a time. This is because Redot uses the XInput API, which is limited to supporting 4 controllers at once. Additional controllers above this limit are ignored by Redot.
My controller works on a given platform, but not on another platform.¶
Linux¶
If you're using a self-compiled engine binary, make sure it was compiled with
udev support. This is enabled by default, but it is possible to disable udev
support by specifying udev=no
on the SCons command line. If you're using an
engine binary supplied by a Linux distribution, double-check whether it was
compiled with udev support.
Controllers can still work without udev support, but it is less reliable as regular polling must be used to check for controllers being connected or disconnected during gameplay (hotplugging).
HTML5¶
HTML5 controller support is often less reliable compared to "native" platforms. The quality of controller support tends to vary wildly across browsers. As a result, you may have to instruct your players to use a different browser if they can't get their controller to work.