Fix cases where some settings change didnt trigger a recompilation (#233)

Author: julienf-unity

com.unity.visualeffectgraph/CHANGELOG.md

@@ -50,6 +50,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Deleting a context node and a block while both are selected throws a null ref exception. [Case 315578](https://issuetracker.unity3d.com/product/unity/issues/guid/1315578/)
 - Target GameObject attach button does not allow attaching a valid VFX if the last selection was invalid. [Case 1312178](https://issuetracker.unity3d.com/product/unity/issues/guid/1312178/)
 - Deleting flow edge between Init and Update throw an invalid opeation exception [Case 1315593](https://issuetracker.unity3d.com/product/unity/issues/guid/1315593/)
+- Regression with some settings not always triggering a recompilation [Case 1322844](https://issuetracker.unity3d.com/product/unity/issues/guid/1322844/)
 - Having more than five GPU Event output leads to "unexpected token 'if" at compilation [Case 1323434](https://issuetracker.unity3d.com/product/unity/issues/guid/1323434/)
 - Deleted properties still show up in the inspector [Case 1320952](https://issuetracker.unity3d.com/product/unity/issues/guid/1320952/)
 

com.unity.visualeffectgraph/Editor/Models/Contexts/VFXSRPSubOutput.cs

@@ -66,5 +66,12 @@ public virtual IEnumerable<KeyValuePair<string, VFXShaderWriter>> GetStencilStat
         {
             return Enumerable.Empty<KeyValuePair<string, VFXShaderWriter>>();
         }
+
+        protected override void OnInvalidate(VFXModel model, InvalidationCause cause)
+        {
+            base.OnInvalidate(model, cause);
+            if (owner is VFXModel)
+                ((VFXModel)owner).Invalidate(model, cause); // Forward invalidate event to owner
+        }
     }
 }

com.unity.visualeffectgraph/Editor/Models/Operators/VFXOperator.cs

@@ -41,7 +41,7 @@ public override bool ResyncSlots(bool notify)
                 try
                 {
                     changed = base.ResyncSlots(notify);
-                    if (changed && notify)
+                    if (notify)
                         foreach (var slot in outputSlots) // invalidate expressions on output slots
                             slot.InvalidateExpressionTree();
                 }