haptic topic

CategoryHaptic

The SDL haptic subsystem manages haptic (force feedback) devices.

The basic usage is as follows:

  • Initialize the subsystem (SDL_INIT_HAPTIC).
  • Open a haptic device.
  • SDL_OpenHaptic() to open from index.
  • SDL_OpenHapticFromJoystick() to open from an existing joystick.
  • Create an effect (SDL_HapticEffect).
  • Upload the effect with SDL_CreateHapticEffect().
  • Run the effect with SDL_RunHapticEffect().
  • (optional) Free the effect with SDL_DestroyHapticEffect().
  • Close the haptic device with SDL_CloseHaptic().

Simple rumble example:

   SDL_Haptic *haptic = NULL;

   // Open the device
   SDL_HapticID *haptics = SDL_GetHaptics(NULL);
   if (haptics) {
       haptic = SDL_OpenHaptic(haptics[0]);
       SDL_free(haptics);
   }
   if (haptic == NULL)
      return;

   // Initialize simple rumble
   if (!SDL_InitHapticRumble(haptic))
      return;

   // Play effect at 50% strength for 2 seconds
   if (!SDL_PlayHapticRumble(haptic, 0.5, 2000))
      return;
   SDL_Delay(2000);

   // Clean up
   SDL_CloseHaptic(haptic);

Complete example:

bool test_haptic(SDL_Joystick *joystick)
{
   SDL_Haptic *haptic;
   SDL_HapticEffect effect;
   SDL_HapticEffectID effect_id;

   // Open the device
   haptic = SDL_OpenHapticFromJoystick(joystick);
   if (haptic == NULL) return false; // Most likely joystick isn't haptic

   // See if it can do sine waves
   if ((SDL_GetHapticFeatures(haptic) & SDL_HAPTIC_SINE)==0) {
      SDL_CloseHaptic(haptic); // No sine effect
      return false;
   }

   // Create the effect
   SDL_memset(&effect, 0, sizeof(SDL_HapticEffect)); // 0 is safe default
   effect.type = SDL_HAPTIC_SINE;
   effect.periodic.direction.type = SDL_HAPTIC_POLAR; // Polar coordinates
   effect.periodic.direction.dir[0] = 18000; // Force comes from south
   effect.periodic.period = 1000; // 1000 ms
   effect.periodic.magnitude = 20000; // 20000/32767 strength
   effect.periodic.length = 5000; // 5 seconds long
   effect.periodic.attack_length = 1000; // Takes 1 second to get max strength
   effect.periodic.fade_length = 1000; // Takes 1 second to fade away

   // Upload the effect
   effect_id = SDL_CreateHapticEffect(haptic, &effect);

   // Test the effect
   SDL_RunHapticEffect(haptic, effect_id, 1);
   SDL_Delay(5000); // Wait for the effect to finish

   // We destroy the effect, although closing the device also does this
   SDL_DestroyHapticEffect(haptic, effect_id);

   // Close the device
   SDL_CloseHaptic(haptic);

   return true; // Success
}

Note that the SDL haptic subsystem is not thread-safe.

Functions

sdlCloseHaptic(Pointer<SdlHaptic> haptic) → void haptic
Close a haptic device previously opened with SDL_OpenHaptic().
sdlCreateHapticEffect(Pointer<SdlHaptic> haptic, Pointer<SdlHapticEffect> effect) → int haptic
Create a new haptic effect on a specified device.
sdlDestroyHapticEffect(Pointer<SdlHaptic> haptic, int effect) → void haptic
Destroy a haptic effect on the device.
sdlGetHapticEffectStatus(Pointer<SdlHaptic> haptic, int effect) → bool haptic
Get the status of the current effect on the specified haptic device.
sdlGetHapticFeatures(Pointer<SdlHaptic> haptic) → int haptic
Get the haptic device's supported features in bitwise manner.
sdlGetHapticFromId(int instanceId) → Pointer<SdlHaptic> haptic
Get the SDL_Haptic associated with an instance ID, if it has been opened.
sdlGetHapticId(Pointer<SdlHaptic> haptic) → int haptic
Get the instance ID of an opened haptic device.
sdlGetHapticName(Pointer<SdlHaptic> haptic) → String? haptic
Get the implementation dependent name of a haptic device.
sdlGetHapticNameForId(int instanceId) → String? haptic
Get the implementation dependent name of a haptic device.
sdlGetHaptics(Pointer<Int32> count) → Pointer<Uint32> haptic
Get a list of currently connected haptic devices.
sdlGetMaxHapticEffects(Pointer<SdlHaptic> haptic) → int haptic
Get the number of effects a haptic device can store.
sdlGetMaxHapticEffectsPlaying(Pointer<SdlHaptic> haptic) → int haptic
Get the number of effects a haptic device can play at the same time.
sdlGetNumHapticAxes(Pointer<SdlHaptic> haptic) → int haptic
Get the number of haptic axes the device has.
sdlHapticEffectSupported(Pointer<SdlHaptic> haptic, Pointer<SdlHapticEffect> effect) → bool haptic
Check to see if an effect is supported by a haptic device.
sdlHapticRumbleSupported(Pointer<SdlHaptic> haptic) → bool haptic
Check whether rumble is supported on a haptic device.
sdlInitHapticRumble(Pointer<SdlHaptic> haptic) → bool haptic
Initialize a haptic device for simple rumble playback.
sdlIsJoystickHaptic(Pointer<SdlJoystick> joystick) → bool haptic
Query if a joystick has haptic features.
sdlIsMouseHaptic() → bool haptic
Query whether or not the current mouse has haptic capabilities.
sdlOpenHaptic(int instanceId) → Pointer<SdlHaptic> haptic
Open a haptic device for use.
sdlOpenHapticFromJoystick(Pointer<SdlJoystick> joystick) → Pointer<SdlHaptic> haptic
Open a haptic device for use from a joystick device.
sdlOpenHapticFromMouse() → Pointer<SdlHaptic> haptic
Try to open a haptic device from the current mouse.
sdlPauseHaptic(Pointer<SdlHaptic> haptic) → bool haptic
Pause a haptic device.
sdlPlayHapticRumble(Pointer<SdlHaptic> haptic, double strength, int length) → bool haptic
Run a simple rumble effect on a haptic device.
sdlResumeHaptic(Pointer<SdlHaptic> haptic) → bool haptic
Resume a haptic device.
sdlRunHapticEffect(Pointer<SdlHaptic> haptic, int effect, int iterations) → bool haptic
Run the haptic effect on its associated haptic device.
sdlSetHapticAutocenter(Pointer<SdlHaptic> haptic, int autocenter) → bool haptic
Set the global autocenter of the device.
sdlSetHapticGain(Pointer<SdlHaptic> haptic, int gain) → bool haptic
Set the global gain of the specified haptic device.
sdlStopHapticEffect(Pointer<SdlHaptic> haptic, int effect) → bool haptic
Stop the haptic effect on its associated haptic device.
sdlStopHapticEffects(Pointer<SdlHaptic> haptic) → bool haptic
Stop all the currently playing effects on a haptic device.
sdlStopHapticRumble(Pointer<SdlHaptic> haptic) → bool haptic
Stop the simple rumble on a haptic device.
sdlUpdateHapticEffect(Pointer<SdlHaptic> haptic, int effect, Pointer<SdlHapticEffect> data) → bool haptic
Update the properties of an effect.