Module ff 

Force-feedback support.

evdev force feedback support is modeled after the USB Physical Input Device (PID) Class.

In general, there is no guarantee that any given driver or device will support all features or respect all Effect fields. If you intend to craft immersive experiences with haptic feedback, per-device testing may be necessary.

Effects are organized as follows:

• Effect
  • Rumble
  • Periodic
  • Constant
  • Ramp
  • Per-axis effects that wrap Condition
    • Spring
    • Friction
    • Damper
    • Inertia

All effect types can be represented as Effect, and also in a matchable enum EffectKind. The usual conversions via Into/From are supported.

Usage

Support for force-feedback features can be queried via Evdev::supported_ff_features. The number of supported effects that can be stored at the same time can be queried via Evdev::supported_ff_effects.

An appropriate effect can then be uploaded by calling Evdev::upload_ff_effect, returning the EffectId assigned by the kernel.

The uploaded effect can then be triggered via Evdev::control_ff, or erased by calling Evdev::erase_ff_effect.

Structs

Condition

An effect that applies conditionally and gradually as an axis is moved.

Constant

An effect that applies a constant force.

Damper

Damps movement along an axis.

Effect

A force-feedback effect description.

EffectId

Identifier for uploaded effects.

EffectType

A force-feedback effect type.

Envelope

An effect envelope.

Feature

Force feedback feature flags.

Friction

Applies friction to an axis as it is moved.

Inertia

Resists changes of velocity.

Periodic

A periodic waveform effect.

Ramp

An effect that ramps up or down over time.

Replay

Configures how an Effect should be scheduled.

Rumble

A vibration effect.

Spring

Makes an axis spring back to its center when moved.

Trigger

Configures which button triggers an effect (if any).

Waveform

List of waveform types for Periodic effects.

Enums

EffectKind

List of supported force-feedback effects.