[gamepad]. See
Bugzilla for this specification's open bugs.
The Gamepad API provides a tightly scoped interface to gamepad devices and is focused on the most common elements of those devices, namely axis and button inputs. It specifically excludes support for more complex devices (e.g., those that do motion tracking or haptic feedback).
However, some uses of gamepads (e.g., those paired with Virtual Reality headsets) rely heavily on those more advanced features. This supplemetary spec describes extensions to the base API to accommodate those use cases. If they prove to be broadly useful, the hope is that they will be eventually merged into the main spec.
This enum defines the set of possible hands a gamepad may be held by.
enum GamepadHand {
"", /* unknown, both hands, or not applicable */
"left",
"right"
};
A {{GamepadHapticActuator}} corresponds to a configuration of motors or other actuators that can apply a force for the purposes of haptic feedback.
[Exposed=Window]
interface GamepadHapticActuator {
readonly attribute GamepadHapticActuatorType type;
boolean canPlayEffectType(GamepadHapticEffectType type);
Promise<GamepadHapticsResult> playEffect(
GamepadHapticEffectType type,
optional GamepadEffectParameters params = {});
Promise<boolean> pulse(double value, double duration);
Promise<GamepadHapticsResult> reset();
};
Instances of {{GamepadHapticActuator}} are created with the internal slots described in the following table:
| Internal slot | Initial value | Description (non-normative) |
|---|---|---|
| [[\playingEffectPromise]] | `undefined` | The {{Promise}} for the playing effect, or `undefined` if no effect is playing. |
A {{GamepadHapticActuatorType}} value representing the actuator type.
The {{GamepadHapticActuator/canPlayEffectType()}} method steps are:
The {{GamepadHapticActuator/playEffect()}} method steps are:
pulse() applies a value to the actuator for
duration milliseconds. The value passed to
pulse() is clamped to limits defined by the actuator
type. The returned Promise will resolve true once the
pulse has completed.
Repeated calls to pulse() override the previous
values.
The {{GamepadHapticActuator/reset()}} method steps are:
Add new steps to [=a new `Gamepad`=]:
A new `GamepadHapticActuator` with |type:GamepadHapticEffectType| is constructed by performing the following steps:
This specification defines an [=external now hidden algorithm=]. When the |document|'s [=visibility state=] becomes `"hidden"`, run these steps for each {{GamepadHapticActuator}} |actuator:GamepadHapticActuator|:
A {{GamepadHapticActuator}} can play effects with type |type:GamepadHapticEffectType| if the [=user agent=] can send a command to initiate effects of that type on that actuator.
An effect with {{GamepadHapticEffectType}} |type:GamepadHapticEffectType| and {{GamepadEffectParameters}} |params:GamepadEffectParameters| describes a valid effect if |params| contains all of the required parameters for |type| effects and all of the parameters have valid values. Additional parameters MUST be ignored.
A [=user agent=] that implements this API MUST provide a method to issue a haptic effect to an actuator with |type:GamepadHapticEffectType| and |params:GamepadEffectParameters|. The [=user agent=] MAY modify the effect to increase compatibility. For example, an effect intended for a rumble motor may be transformed into a waveform-based effect for a device that supports waveform haptics but lacks rumble motors.
A [=user agent=] that implements this API MUST provide a method to stop haptic effects on an actuator. When called, if there is a playing haptic effect, the [=user agent=] MUST send a command to the device to stop the effect. If a haptic effect was interrupted, the actuator SHOULD return to a motionless state as quickly as possible.
An enum representing the result of a call to {{GamepadHapticActuator}}.{{GamepadHapticActuator/playEffect()}} or {{GamepadHapticActuator}}.{{GamepadHapticActuator/reset()}}.
enum GamepadHapticsResult {
"complete",
"preempted"
};
The value the {{Promise}} returned by {{GamepadHapticActuator}}.{{GamepadHapticActuator/playEffect()}} or {{GamepadHapticActuator}}.{{GamepadHapticActuator/reset()}} will resolve to when the effect completes normally.
The value the {{Promise}} returned by {{GamepadHapticActuator}}.{{GamepadHapticActuator/playEffect()}} or {{GamepadHapticActuator}}.{{GamepadHapticActuator/reset()}} will resolve to when the operation does not complete because the {{Document}} is [=Document/hidden=] or another effect was started on the same actuator.
An enum value identifying the actuator type. Deprecated in order to allow the [=user agent=] to define compatibility between actuators and effects. Applications are expected to use {{GamepadHapticActuator}}.{{GamepadHapticActuator/canPlayEffectType()}} for capability detection.
enum GamepadHapticActuatorType {
"vibration",
"dual-rumble"
};
The value of {{GamepadHapticActuator}}.{{GamepadHapticActuator/type}} for an actuator that is exposed as an element of {{Gamepad}}.{{Gamepad/hapticActuators}}.
The value of {{GamepadHapticActuator}}.{{GamepadHapticActuator/type}} for an actuator that is exposed as {{Gamepad}}.{{Gamepad/vibrationActuator}}.
The effect type defines how the effect parameters are interpreted by the actuator.
The [=user agent=] MAY modify the behavior of {{GamepadHapticActuator}}.{{GamepadHapticActuator/playEffect}} to extend support for new {{GamepadHapticEffectType}} values and {{GamepadEffectParameter}} attributes. Implementations MUST NOT modify the definition of a [=valid effect=] for effect types defined in this specification.
enum GamepadHapticEffectType {
"dual-rumble"
};
{{GamepadHapticEffectType/"dual-rumble"}} describes a haptics configuration with an eccentric rotating mass (ERM) vibration motor in each handle of a standard gamepad. In this configuration, either motor is capable of vibrating the whole gamepad. The vibration effects created by each motor are unequal so that the effects of each can be combined to create more complex haptic effects.
A {{GamepadHapticEffectType/"dual-rumble"}} effect is a fixed-length, constant-intensity vibration effect intended for an actuator of this type. {{GamepadHapticEffectType/"dual-rumble"}} effects are defined by {{GamepadEffectParameters/startDelay}}, {{GamepadEffectParameters/duration}}, {{GamepadEffectParameters/strongMagnitude}}, and {{GamepadEffectParameters/weakMagnitude}}, none of which are required.
{{GamepadEffectParameters/startDelay}} sets the duration of the delay after {{GamepadHapticActuator/playEffect()}} is called until vibration is started, in milliseconds. During the delay interval, the actuator must not vibrate. An effect with negative {{GamepadEffectParameters/startDelay}} is not a [=valid effect=]. If the {{GamepadEffectParameters/startDelay}} is not specified, the default delay is 0 milliseconds.
{{GamepadEffectParameters/duration}} sets the duration in milliseconds that the actuator will vibrate. If {{GamepadEffectParameters/duration}} is not specified, the default duration is 0 milliseconds.
{{GamepadEffectParameters/strongMagnitude}} and {{GamepadEffectParameters/weakMagnitude}} set the vibration intensity levels for the low-frequency and high-frequency rumble motors, normalized to the range `[0,1]`, default 0. An effect with magnitude values outside of this range is not a [=valid effect=].
A GamepadEffectParameters dictionary contains keys for
parameters used by haptic effects. The meaning of each key is defined
by the haptic effect, and some keys may be unused.
To mitigate unwanted long-running effects, the [=user agent=] MAY limit the total effect duration for a [=valid effect=] to some maximum duration. It is RECOMMENDED that the [=user agent=] use a maximum of 5 seconds.
dictionary GamepadEffectParameters {
double duration = 0.0;
double startDelay = 0.0;
double strongMagnitude = 0.0;
double weakMagnitude = 0.0;
};
This interface defines the gamepad's position, orientation, velocity, and acceleration.
[Exposed=Window]
interface GamepadPose {
readonly attribute boolean hasOrientation;
readonly attribute boolean hasPosition;
readonly attribute Float32Array? position;
readonly attribute Float32Array? linearVelocity;
readonly attribute Float32Array? linearAcceleration;
readonly attribute Float32Array? orientation;
readonly attribute Float32Array? angularVelocity;
readonly attribute Float32Array? angularAcceleration;
};
hasOrientation attribute MUST return whether the
gamepad is capable of tracking its orientation.
hasPosition attribute MUST return whether the
gamepad is capable of tracking its position.
Position of the gamepad as a 3D vector, given in meters from an origin point, which is determined by the gamepad hardware and MAY be the position of the gamepad when first polled if no other reference point is available. The coordinate system uses these axis definitions, assuming the user is holding the gamepad in the forward orientation:
MUST be null if the gamepad is incapable of providing
positional data. When not null, MUST be a
three-element array.
null if the sensor is incapable of providing linear
velocity. When not null, MUST be a three-element array.
null if the sensor is incapable of providing linear
acceleration. When not null, MUST be a three-element
array.
[0, 0, 0, 1] is considered to be forward.
The forward direction MUST be determined by the gamepad hardware. The
forward direction MAY be the orientation of the hardware when it was
first polled if no other reference orientation is available. If the
sensor is incapable of providing orientation data, the orientation
MUST be null. When not null, the
orientation MUST be a four-element array.
null if the sensor is incapable of providing angular
velocity. When not null, the
angularVelocity MUST be a three-element array.
null if the sensor is incapable of providing angular
acceleration. When not null,
angularAcceleration MUST be a three-element array.
This interface defines a single touch event on a gamepad device that supports input. The event consists of a touch id that uniquely identifies the touch point from the time the input medium (e.g. finger, stylus, etc) makes contact with the touch device, up to the time the input medium is no longer making contact with the touch device.
[Exposed=Window, SecureContext]
interface GamepadTouch {
readonly attribute unsigned long touchId;
readonly attribute octet surfaceId;
readonly attribute Float32Array position;
readonly attribute Uint32Array? surfaceDimensions;
};
null, MUST be a two-element array.
This partial interface supplements the Gamepad interface described in the main Gamepad spec.
partial interface Gamepad {
readonly attribute GamepadHand hand;
readonly attribute FrozenArray<GamepadHapticActuator> hapticActuators;
readonly attribute GamepadPose? pose;
readonly attribute FrozenArray<GamepadTouch>? touchEvents;
[SameObject] readonly attribute GamepadHapticActuator? vibrationActuator;
};
null.
null if the device does not support touch events.