Merge pull request #606 from kmikkel/master

Fixed issue with GazeManager not hitting the closest UI element when raycasting.

Author: StephenHodgson

Assets/HoloToolkit/Input/Scripts/Gaze/GazeManager.cs

@@ -225,7 +225,7 @@ private void RaycastUnityUI()
             // Graphics raycast
             raycastResultList.Clear();
             EventSystem.current.RaycastAll(UnityUIPointerEvent, raycastResultList);
-            RaycastResult uiRaycastResult = FindFirstRaycastInLayermasks(raycastResultList, RaycastLayerMasks);
+            RaycastResult uiRaycastResult = FindClosestRaycastHitInLayermasks(raycastResultList, RaycastLayerMasks);
             UnityUIPointerEvent.pointerCurrentRaycast = uiRaycastResult;
 
             // If we have a raycast result, check if we need to overwrite the 3D raycast info
@@ -287,32 +287,35 @@ private void RaycastUnityUI()
         #region Helpers
 
         /// <summary>
-        /// Find the first (closest) raycast in the list of RaycastResults that is also included in the LayerMask list.  
+        /// Find the closest raycast hit in the list of RaycastResults that is also included in the LayerMask list.  
         /// </summary>
         /// <param name="candidates">List of RaycastResults from a Unity UI raycast</param>
         /// <param name="layerMaskList">List of layers to support</param>
         /// <returns>RaycastResult if hit, or an empty RaycastResult if nothing was hit</returns>
-        private RaycastResult FindFirstRaycastInLayermasks(List<RaycastResult> candidates, LayerMask[] layerMaskList)
+        private RaycastResult FindClosestRaycastHitInLayermasks(List<RaycastResult> candidates, LayerMask[] layerMaskList)
         {
             int combinedLayerMask = 0;
             for (int i = 0; i < layerMaskList.Length; i++)
             {
                 combinedLayerMask = combinedLayerMask | layerMaskList[i].value;
             }
 
+            RaycastResult? minHit = null;
             for (var i = 0; i < candidates.Count; ++i)
             {
                 if (candidates[i].gameObject == null || !IsLayerInLayerMask(candidates[i].gameObject.layer, combinedLayerMask))
                 {
                     continue;
                 }
-
-                return candidates[i];
+                if (minHit == null || candidates[i].distance < minHit.Value.distance)
+                {
+                    minHit = candidates[i];
+                }
             }
 
-            return new RaycastResult();
+             return minHit ?? new RaycastResult();
         }
-
+        
         /// <summary>
         /// Look through the layerMaskList and find the index in that list for which the supplied layer is part of
         /// </summary>