From 668a3d2216c7ceb1a71aaf0b6f8b6a17ae26862d Mon Sep 17 00:00:00 2001
From: Travis Milne <travis.milne@masterpiecevr.com>
Date: Thu, 12 Mar 2020 14:56:02 -0400
Subject: [PATCH 1/2] FIX: Fixed interaction with dropdown UI

---
 .../Plugins/UI/InputSystemUIInputModule.cs    | 27 +++++++++++++++----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/Packages/com.unity.inputsystem/InputSystem/Plugins/UI/InputSystemUIInputModule.cs b/Packages/com.unity.inputsystem/InputSystem/Plugins/UI/InputSystemUIInputModule.cs
index 8f7ea56c4f..299fef48cf 100644
--- a/Packages/com.unity.inputsystem/InputSystem/Plugins/UI/InputSystemUIInputModule.cs
+++ b/Packages/com.unity.inputsystem/InputSystem/Plugins/UI/InputSystemUIInputModule.cs
@@ -157,19 +157,36 @@ private RaycastResult PerformRaycast(ExtendedPointerEventData eventData)
             // the first shot.
             if (eventData.pointerType == UIPointerType.Tracked && TrackedDeviceRaycaster.s_Instances.length > 0)
             {
+                //Store the closest result
+                RaycastResult raycastResult = default;
+                //Store the closest graphic's distance
+                float distance = float.MaxValue;
+                //The current TrackedDeviceRaycaster we are looking at
+                TrackedDeviceRaycaster trackedDeviceRaycaster;
                 for (var i = 0; i < TrackedDeviceRaycaster.s_Instances.length; ++i)
                 {
-                    var trackedDeviceRaycaster = TrackedDeviceRaycaster.s_Instances[i];
+                    trackedDeviceRaycaster = TrackedDeviceRaycaster.s_Instances[i];
                     m_RaycastResultCache.Clear();
                     trackedDeviceRaycaster.PerformRaycast(eventData, m_RaycastResultCache);
                     if (m_RaycastResultCache.Count > 0)
                     {
-                        var raycastResult = m_RaycastResultCache[0];
-                        m_RaycastResultCache.Clear();
-                        return raycastResult;
+                        //Iterate through the list of result to determine the closest hit graphic
+                        foreach (RaycastResult raycast in m_RaycastResultCache)
+                        {
+                            if (raycast.distance < distance)
+                            {
+                                //Update the closest distance
+                                distance = raycast.distance;
+                                //Store the result
+                                raycastResult = raycast;
+                            }
+                        }
                     }
                 }
-                return default;
+                //Clear the cache as we are done with it
+                m_RaycastResultCache.Clear();
+                //Return the closest result or default if none exist
+                return raycastResult;
             }
 
             // Otherwise pass it along to the normal raycasting logic.

From 66c42ff5009a798c693e2181f1cfbf81c9805364 Mon Sep 17 00:00:00 2001
From: Travis Milne <travis.milne@masterpiecevr.com>
Date: Thu, 12 Mar 2020 16:44:19 -0400
Subject: [PATCH 2/2] Added additional check to determine canvas sorting order
 of hit objects, this covers the case of overlapping UI elements

---
 .../InputSystem/Plugins/UI/InputSystemUIInputModule.cs | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Packages/com.unity.inputsystem/InputSystem/Plugins/UI/InputSystemUIInputModule.cs b/Packages/com.unity.inputsystem/InputSystem/Plugins/UI/InputSystemUIInputModule.cs
index 299fef48cf..c7b0fcc747 100644
--- a/Packages/com.unity.inputsystem/InputSystem/Plugins/UI/InputSystemUIInputModule.cs
+++ b/Packages/com.unity.inputsystem/InputSystem/Plugins/UI/InputSystemUIInputModule.cs
@@ -163,6 +163,10 @@ private RaycastResult PerformRaycast(ExtendedPointerEventData eventData)
                 float distance = float.MaxValue;
                 //The current TrackedDeviceRaycaster we are looking at
                 TrackedDeviceRaycaster trackedDeviceRaycaster;
+                //Owning canvas of the new comparison
+                Canvas raycastCanvas;
+                //Owning canvas of current result
+                Canvas raycastResultCanvas;
                 for (var i = 0; i < TrackedDeviceRaycaster.s_Instances.length; ++i)
                 {
                     trackedDeviceRaycaster = TrackedDeviceRaycaster.s_Instances[i];
@@ -173,7 +177,10 @@ private RaycastResult PerformRaycast(ExtendedPointerEventData eventData)
                         //Iterate through the list of result to determine the closest hit graphic
                         foreach (RaycastResult raycast in m_RaycastResultCache)
                         {
-                            if (raycast.distance < distance)
+                            raycastCanvas = raycast.gameObject.GetComponentInParent<Canvas>();
+                            raycastResultCanvas = raycastResult.gameObject?.GetComponentInParent<Canvas>();
+                            //Update result if the the new raycast's owning canvas is of a higher sorting order OR if the sorting order is the same and the new raycast is closer
+                            if (raycastResultCanvas == null || (raycastCanvas.sortingOrder > raycastResultCanvas.sortingOrder || (raycastCanvas.sortingOrder == raycastResultCanvas.sortingOrder && raycast.distance < distance)))
                             {
                                 //Update the closest distance
                                 distance = raycast.distance;
@@ -183,7 +190,6 @@ private RaycastResult PerformRaycast(ExtendedPointerEventData eventData)
                         }
                     }
                 }
-                //Clear the cache as we are done with it
                 m_RaycastResultCache.Clear();
                 //Return the closest result or default if none exist
                 return raycastResult;