Implement IMixedRealityHapticFeedback

Author: keveleigh

Assets/MRTK/Core/Interfaces/Devices/IMixedRealityHapticFeedback.cs

@@ -0,0 +1,24 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+namespace Microsoft.MixedReality.Toolkit.Input
+{
+    /// <summary>
+    /// Provides access to the haptic capabilities of a device.
+    /// </summary>
+    public interface IMixedRealityHapticFeedback
+    {
+        /// <summary>
+        /// Start haptic feedback by the input device.
+        /// </summary>
+        /// <param name="intensity">The 0.0 to 1.0 strength of the haptic feedback based on the capability of the input device.</param>
+        /// <param name="durationInSeconds">The duration in seconds or float.MaxValue for indefinite duration.</param>
+        /// <returns>True if haptic feedback was successfully started.</returns>
+        bool StartHapticImpulse(float intensity, float durationInSeconds = float.MaxValue);
+
+        /// <summary>
+        /// Terminates haptic feedback by the input device.
+        /// </summary>
+        void StopHapticFeedback();
+    }
+}

Assets/MRTK/Core/Interfaces/Devices/IMixedRealityHapticFeedback.cs.meta

@@ -3,6 +3,7 @@
 
 using Microsoft.MixedReality.Toolkit.Input;
 using Microsoft.MixedReality.Toolkit.Utilities;
+using Microsoft.MixedReality.Toolkit.Windows.Input;
 
 #if UNITY_WSA
 using Unity.Profiling;
@@ -19,7 +20,7 @@ namespace Microsoft.MixedReality.Toolkit.WindowsMixedReality.Input
         new[] { Handedness.Left, Handedness.Right },
         "Textures/MotionController",
         supportedUnityXRPipelines: SupportedUnityXRPipelines.LegacyXR)]
-    public class WindowsMixedRealityController : BaseWindowsMixedRealitySource
+    public class WindowsMixedRealityController : BaseWindowsMixedRealitySource, IMixedRealityHapticFeedback
     {
         /// <summary>
         /// Constructor.
@@ -283,5 +284,23 @@ private async void TryRenderControllerModelWithModelProvider()
 
         #endregion Controller model functions
 #endif // UNITY_WSA
+
+        #region Haptic feedback functions
+
+        public bool StartHapticImpulse(float intensity, float durationInSeconds = float.MaxValue) =>
+#if UNITY_WSA
+            LastSourceStateReading.source.StartHaptics(intensity, durationInSeconds);
+#else
+            false;
+#endif // UNITY_WSA
+
+        public void StopHapticFeedback()
+        {
+#if UNITY_WSA
+            LastSourceStateReading.source.StopHaptics();
+#endif // UNITY_WSA
+        }
+
+        #endregion Haptic feedback functions
     }
 }

Assets/MRTK/Providers/WindowsMixedReality/XR2018/Controllers/WindowsMixedRealityController.cs

@@ -98,7 +98,7 @@ public static bool StartHaptics(this InteractionSource interactionSource, float
             {
                 if (hapticsFeedback.Waveform.Equals(ContinuousBuzzWaveform))
                 {
-                    if (durationInSeconds.Equals(float.MaxValue))
+                    if (UnityEngine.Mathf.Approximately(durationInSeconds, float.MaxValue))
                     {
                         simpleHapticsController.SendHapticFeedback(hapticsFeedback, intensity);
                     }

Assets/MRTK/Providers/WindowsMixedReality/XR2018/Extensions/InteractionSourceExtensions.cs

@@ -14,7 +14,7 @@ namespace Microsoft.MixedReality.Toolkit.XRSDK.Input
         new[] { Handedness.Left, Handedness.Right },
         flags: MixedRealityControllerConfigurationFlags.UseCustomInteractionMappings,
         supportedUnityXRPipelines: SupportedUnityXRPipelines.XRSDK)]
-    public class GenericXRSDKController : BaseController
+    public class GenericXRSDKController : BaseController, IMixedRealityHapticFeedback
     {
         public GenericXRSDKController(
             TrackingState trackingState,
@@ -45,6 +45,11 @@ public GenericXRSDKController(
         /// </summary>
         protected Quaternion CurrentControllerRotation = Quaternion.identity;
 
+        /// <summary>
+        /// The most recent input device that this controller represents.
+        /// </summary>
+        private InputDevice lastInputDevice;
+
         private static readonly ProfilerMarker UpdateControllerPerfMarker = new ProfilerMarker("[MRTK] GenericXRSDKController.UpdateController");
 
         /// <summary>
@@ -81,6 +86,8 @@ public virtual void UpdateController(InputDevice inputDevice)
                             break;
                     }
                 }
+
+                lastInputDevice = inputDevice;
             }
         }
 
@@ -368,5 +375,27 @@ protected virtual void UpdatePoseData(MixedRealityInteractionMapping interaction
                 }
             }
         }
+
+        /// <inheritdoc />
+        public bool StartHapticImpulse(float intensity, float durationInSeconds = float.MaxValue)
+        {
+            if (lastInputDevice.TryGetHapticCapabilities(out HapticCapabilities hapticCapabilities) && hapticCapabilities.supportsImpulse)
+            {
+                if (Mathf.Approximately(durationInSeconds, float.MaxValue))
+                {
+                    lastInputDevice.SendHapticImpulse(0, intensity);
+                }
+                else
+                {
+                    lastInputDevice.SendHapticImpulse(0, intensity, durationInSeconds);
+                }
+                return true;
+            }
+
+            return false;
+        }
+
+        /// <inheritdoc />
+        public void StopHapticFeedback() => lastInputDevice.StopHaptics();
     }
 }