Leap Motion Data Provider

Assets/MRTK/Core/Definitions/Devices/DeviceInputType.cs

@@ -32,6 +32,7 @@ public enum DeviceInputType
         Trigger,
         TriggerTouch,
         TriggerNearTouch,
+        // TriggerPress, in some cases, maps to the Grab gesture.
         TriggerPress,
         /// <summary>
         /// 6 DoF Grip with position and rotation.
@@ -53,6 +54,9 @@ public enum DeviceInputType
         TouchpadTouch,
         TouchpadNearTouch,
         TouchpadPress,
+        /// <summary>
+        /// Select maps to the Pinch/Air Tap gesture
+        /// </summary>
         Select,
         Start,
         Menu,

Assets/MRTK/Core/Providers/Hands/ArticulatedHandDefinition.cs

@@ -28,6 +28,12 @@ public ArticulatedHandDefinition(IMixedRealityInputSource source, Handedness han
         private Dictionary<TrackedHandJoint, MixedRealityPose> unityJointPoses = new Dictionary<TrackedHandJoint, MixedRealityPose>();
         private MixedRealityPose currentIndexPose = MixedRealityPose.ZeroIdentity;
 
+        // Pinch distance thresholds
+        private readonly float enterPinchDistance = 0.02f;
+        private readonly float exitPinchDistance = 0.05f;
+
+        private bool isPinching = false;
+
         /// <summary>
         /// The articulated hands default interactions.
         /// </summary>
@@ -72,6 +78,37 @@ public bool IsInPointingPose
             }
         }
 
+        /// <summary>
+        /// Calculates whether the current the current joint pose is selecting (air tap gesture).
+        /// </summary>
+        public bool IsPinching
+        {
+            get
+            {
+                MixedRealityPose thumbTip;
+                MixedRealityPose indexTip;
+                if (unityJointPoses.TryGetValue(TrackedHandJoint.ThumbTip, out thumbTip) && unityJointPoses.TryGetValue(TrackedHandJoint.IndexTip, out indexTip))
+                {
+                    float distance = Vector3.Distance(thumbTip.Position, indexTip.Position);
+
+                    if (isPinching && distance > exitPinchDistance)
+                    {
+                        isPinching = false;
+                    }
+                    else if (!isPinching && distance < enterPinchDistance)
+                    {
+                        isPinching = true;
+                    }
+                }
+                else
+                {
+                    isPinching = false;
+                }
+
+                return isPinching;
+            }
+        }
+
         /// <summary>
         /// Updates the current hand joints with new data.
         /// </summary>