Fix Event connected directly to Output Event (#152)

* Add missing filter in CanLink function

* Add editor test

* *Update changelog.md

* *Update comment

* *Update Comment

Author: PaulDemeulenaere

TestProjects/VisualEffectGraph_HDRP/Assets/AllTests/Editor/Tests/VFXContextTests.cs

@@ -194,6 +194,24 @@ public void MultiLinkSpawnerSpawnerAfterSpawnerInit()
             Assert.AreEqual(2, from.outputContexts.Count());
         }
 
+
+        [Test] //see fogbugz 1269756
+        public void Link_Fail_From_Event_To_OutputEvent()
+        {
+            var from = ScriptableObject.CreateInstance<VFXBasicEvent>();
+            var to = ScriptableObject.CreateInstance<VFXOutputEvent>();
+            Assert.IsFalse(VFXContext.CanLink(from, to));
+        }
+
+        [Test]
+        public void Link_Fail_From_Event_To_Initialize()
+        {
+            //For now, we can't use direct link from event to initialize context.
+            var from = ScriptableObject.CreateInstance<VFXBasicEvent>();
+            var to = ScriptableObject.CreateInstance<VFXBasicInitialize>();
+            Assert.IsFalse(VFXContext.CanLink(from, to));
+        }
+
         [Test]
         public void Link_Fail()
         {

com.unity.visualeffectgraph/CHANGELOG.md

@@ -49,6 +49,7 @@ The version number for this package has increased due to a version update of a r
 - Fix [Case 1268354](https://fogbugz.unity3d.com/f/cases/1268354/)
 - Fixed rare bug causing the vfx compilation to do nothing silently.
 - Fixed vfx compilation when a diffusion profile property is added to a vfx shadergraph  
+- Forbid incorrect link between incompatible context [Case 1269756](https://issuetracker.unity3d.com/product/unity/issues/guid/1269756/)
 
 ## [10.1.0] - 2020-10-12
 ### Added

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

@@ -245,6 +245,10 @@ public static bool CanLink(VFXContext from, VFXContext to, int fromIndex = 0, in
             if (from.m_ContextType == VFXContextType.SpawnerGPU && to.m_ContextType == VFXContextType.OutputEvent)
                 return false;
 
+            //Can't connect directly event to context (OutputEvent or Initialize) for now
+            if (from.m_ContextType == VFXContextType.Event && to.contextType != VFXContextType.Spawner)
+                return false;
+
             return true;
         }