Fix Render Graph Viewer displaying incorrect store reasoning for MSAA textures

Fix https://jira.unity3d.com/browse/UUM-67987

Render Graph Viewer displays a "store reasoning message" for Raster Pass Attachments to help understand why the system selected a given store action (one of `Store`, `Resolve` , `StoreAndResolve` or `DontCare`). Because `StoreAndResolve` exists, it means that we can potentially keep both the resolved and non-resolved data from a MSAA texture, and the reasoning for both of is independently decided. Therefore for MSAA attachments, we need to display two separate store reason messages in Render Graph Viewer. This PR fixes a bug where the UI only picked the first, default store reason message.

For MSAA textures, UI looks like this:
- See separate store reason messages for "Resolved surface" and "MSAA surface"
- For non-MSAA attachments, the MSAA-specific information is not displayed.

![image](https://media.github.cds.internal.unity3d.com/user/3380/files/e4009dfb-4c68-43c0-a246-986da1aa2d02)


This PR also contains a separate UI fix for Render Graph Viewer that makes the highlight animation update smoothly. It's a simple workaround to [this issue](https://jira.unity3d.com/browse/UUM-68010) that has been flagged for UITK team.

Author: arttu-peltonen

Packages/com.unity.render-pipelines.core/Editor/RenderGraph/RenderGraphViewer.SidePanel.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using UnityEditor.UIElements;
+using UnityEditorInternal;
 using UnityEngine;
 using UnityEngine.Rendering.RenderGraphModule;
 using UnityEngine.UIElements;
@@ -343,12 +344,22 @@ void CreateTextElement(VisualElement parent, string text, string className = nul
 
                             attachmentFoldout.Add(new TextElement
                             {
-                                text = $"<b>Load action:</b> {attachmentInfo.loadAction} ({attachmentInfo.loadReason})"
+                                text = $"<b>Load action:</b> {attachmentInfo.loadAction}\n- {attachmentInfo.loadReason}"
                             });
-                            attachmentFoldout.Add(new TextElement
+
+                            bool addMsaaInfo = !string.IsNullOrEmpty(attachmentInfo.storeMsaaReason);
+                            string resolvedTexturePrefix = addMsaaInfo ? "Resolved surface: " : "";
+
+                            string storeActionText = $"<b>Store action:</b> {attachmentInfo.storeAction}" +
+                                                     $"\n - {resolvedTexturePrefix}{attachmentInfo.storeReason}";
+
+                            if (addMsaaInfo)
                             {
-                                text = $"<b>Store action:</b> {attachmentInfo.storeAction} ({attachmentInfo.storeReason})"
-                            });
+                                string msaaTexturePrefix = "MSAA surface: ";
+                                storeActionText += $"\n - {msaaTexturePrefix}{attachmentInfo.storeMsaaReason}";
+                            }
+
+                            attachmentFoldout.Add(new TextElement { text = storeActionText });
 
                             passItem.Add(attachmentFoldout);
                         }
@@ -427,12 +438,26 @@ void ScrollToFoldout(VisualElement parent, int index)
             ScrollView scrollView = parent.Q<ScrollView>();
             scrollView.Query<Foldout>(classes: Classes.kPanelListItem).ForEach(foldout =>
             {
-                if (index == (int)foldout.userData)
+                if (index == (int) foldout.userData)
                 {
                     // Trigger animation
                     foldout.AddToClassList(Classes.kPanelListItemSelectionAnimation);
+
+                    // This repaint hack is needed because transition animations have poor framerate. So we are hooking to editor update
+                    // loop for the duration of the animation to force repaints and have a smooth highlight animation.
+                    // See https://jira.unity3d.com/browse/UIE-1326
+                    EditorApplication.update += Repaint;
+
                     foldout.RegisterCallbackOnce<TransitionEndEvent>(_ =>
-                        foldout.RemoveFromClassList(Classes.kPanelListItemSelectionAnimation));
+                    {
+                        // "Highlight in" animation finished
+                        foldout.RemoveFromClassList(Classes.kPanelListItemSelectionAnimation);
+                        foldout.RegisterCallbackOnce<TransitionEndEvent>(_ =>
+                        {
+                            // "Highlight out" animation finished
+                            EditorApplication.update -= Repaint;
+                        });
+                    });
 
                     // Open foldout
                     foldout.value = true;

Packages/com.unity.render-pipelines.core/Runtime/RenderGraph/Compiler/NativePassCompiler.Debug.cs

@@ -23,13 +23,22 @@ static RenderGraph.DebugData.PassData.NRPInfo.NativeRenderPassInfo.AttachmentInf
             if (storeAudit.passId >= 0)
                 storeReason = storeReason.Replace("{pass}", $"<b>{ctx.passNames[storeAudit.passId].name}</b>");
 
+            string storeMsaaReason = string.Empty;
+            if (storeAudit.msaaReason != StoreReason.InvalidReason && storeAudit.msaaReason != StoreReason.NoMSAABuffer)
+            {
+                storeMsaaReason = StoreAudit.StoreReasonMessages[(int) storeAudit.msaaReason];
+                if (storeAudit.msaaPassId >= 0)
+                    storeMsaaReason = storeMsaaReason.Replace("{pass}", $"<b>{ctx.passNames[storeAudit.msaaPassId].name}</b>");
+            }
+
             return new RenderGraph.DebugData.PassData.NRPInfo.NativeRenderPassInfo.AttachmentInfo
             {
                 resourceName = pointTo.GetName(ctx, attachment.handle),
                 loadAction = attachment.loadAction.ToString(),
                 loadReason = loadReason,
                 storeAction = attachment.storeAction.ToString(),
                 storeReason = storeReason,
+                storeMsaaReason = storeMsaaReason
             };
         }
 

Packages/com.unity.render-pipelines.core/Runtime/RenderGraph/Compiler/PassesData.cs

@@ -430,7 +430,7 @@ internal struct StoreAudit
             "The resource is imported but the import was with the 'discard on last use' option enabled. The data is discarded.",
             "The resource is written by this pass but no later passes are using the results. The data is discarded.",
             "The resource was created as MSAA only resource, the data can never be resolved.",
-            "The resource is an single sample resource, there is no multi-sample data to handle.",
+            "The resource is a single sample resource, there is no multi-sample data to handle.",
         };
 
         public StoreReason reason;

Packages/com.unity.render-pipelines.core/Runtime/RenderGraph/RenderGraph.DebugData.cs

@@ -69,6 +69,7 @@ public class AttachmentInfo
                             public string loadReason;
                             public string storeAction;
                             public string storeReason;
+                            public string storeMsaaReason;
                         }
 
                         public struct PassCompatibilityInfo