[Shader graph]Working on getting previews again.

UnityProject/Assets/UnityShaderEditor/Editor/Source/BaseMaterialGraph.cs

                 RemoveEdge(edge);
             }
 
-            var newEdge = new Edge(new SlotReference(outputSlot.nodeGuid, outputSlot.name), new SlotReference(inputSlot.nodeGuid, inputSlot.name));
+            var newEdge = new Edge(new SlotReference(outputSlot.owner.guid, outputSlot.name), new SlotReference(inputSlot.owner.guid, inputSlot.name));
             m_Edges.Add(newEdge);
 
             Debug.Log("Connected edge: " + newEdge);
                     continue;
 
                 var typeName = GetTypeSerializableAsString(node.GetType());
-                var data = JsonUtility.ToJson(node);
+                var data = JsonUtility.ToJson(node, true);
 
                 if (string.IsNullOrEmpty(typeName) || string.IsNullOrEmpty(data))
                     continue;

UnityProject/Assets/UnityShaderEditor/Editor/Source/Drawing/DrawableMaterialNode.cs

                 return;
             }
 
-            //TODO:DATA
-            /*
             if (m_Node.hasPreview 
                 && m_Node.drawMode != DrawMode.Collapsed 
                 && m_PreviewArea.width > 0
                 GUI.DrawTexture(m_PreviewArea, m_Node.RenderPreview(new Rect(0, 0, m_PreviewArea.width, m_PreviewArea.height)), ScaleMode.StretchToFill, false);
                 GL.sRGBWrite = false;
-            }*/
+            }
 
             base.Render(parentRect, canvas);
         }

UnityProject/Assets/UnityShaderEditor/Editor/Source/Light/BaseLightFunction.cs

         public override string GetSurfaceOutputStructureName() { return "SurfaceOutputStandard"; }
         public override void DoSlotsForConfiguration(PixelShaderNode node)
         {
-            node.AddSlot(new Slot(node.guid, kAlbedoSlotName, kAlbedoSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kNormalSlotName, kNormalSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kMetallicSlotName, kMetallicSlotName, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kSmoothnessSlotName, kSmoothnessSlotName, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kOcclusion, kOcclusion, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kAlphaSlotName, kAlphaSlotName, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
+            node.AddSlot(new Slot(node, kAlbedoSlotName, kAlbedoSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
+            node.AddSlot(new Slot(node, kNormalSlotName, kNormalSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
+            node.AddSlot(new Slot(node, kMetallicSlotName, kMetallicSlotName, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
+            node.AddSlot(new Slot(node, kSmoothnessSlotName, kSmoothnessSlotName, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
+            node.AddSlot(new Slot(node, kOcclusion, kOcclusion, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
+            node.AddSlot(new Slot(node, kAlphaSlotName, kAlphaSlotName, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
           
             // clear out slot names that do not match the slots 
             // we support
         public override string GetSurfaceOutputStructureName() { return "SurfaceOutputStandardSpecular"; }
         public override void DoSlotsForConfiguration(PixelShaderNode node)
         {
-            node.AddSlot(new Slot(node.guid, kAlbedoSlotName, kAlbedoSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kNormalSlotName, kNormalSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kSpecularSlotName, kSpecularSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kEmissionSlotName, kEmissionSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kSmoothnessSlotName, kSmoothnessSlotName, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kOcclusion, kOcclusion, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
-            node.AddSlot(new Slot(node.guid, kAlphaSlotName, kAlphaSlotName, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
+            node.AddSlot(new Slot(node, kAlbedoSlotName, kAlbedoSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
+            node.AddSlot(new Slot(node, kNormalSlotName, kNormalSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
+            node.AddSlot(new Slot(node, kSpecularSlotName, kSpecularSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
+            node.AddSlot(new Slot(node, kEmissionSlotName, kEmissionSlotName, Slot.SlotType.Input, SlotValueType.Vector3, Vector4.zero));
+            node.AddSlot(new Slot(node, kSmoothnessSlotName, kSmoothnessSlotName, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
+            node.AddSlot(new Slot(node, kOcclusion, kOcclusion, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
+            node.AddSlot(new Slot(node, kAlphaSlotName, kAlphaSlotName, Slot.SlotType.Input, SlotValueType.Vector1, Vector4.zero));
 
             // clear out slot names that do not match the slots 
             // we support

UnityProject/Assets/UnityShaderEditor/Editor/Source/Nodes/BaseMaterialNode.cs

         {
             get
             {
-                ValidateNode();
-                    UpdatePreviewShader();
                     m_PreviewMaterial = new Material(m_PreviewShader) {hideFlags = HideFlags.HideInHierarchy};
                     m_PreviewMaterial.hideFlags = HideFlags.HideInHierarchy;
                 }
                 m_GUID = new Guid(m_GUIDSerialized);
             else
                 m_GUID = Guid.NewGuid();
+
+            //patch up the slot owner reference
+            foreach (var slot in slots)
+                slot.owner = this;
         }
 
         public virtual float GetNodeUIHeight(float width)
 
             if (!hasError)
             {
-                //TODO:DATA
-              /*  var valid = UpdatePreviewShader();
-                if (!valid)
-                    hasError = true;*/
+                previewShaderNeedsUpdate = true;
+        public bool previewShaderNeedsUpdate { get; set; }
+
         //True if error
         protected virtual bool CalculateNodeHasError()
         {
         /// </summary>
         public Texture RenderPreview(Rect targetSize)
         {
+            if (hasError)
+                return null;
+
+            if (previewShaderNeedsUpdate)
+            {
+                UpdatePreviewShader();
+                previewShaderNeedsUpdate = false;
+            }
+
             UpdatePreviewProperties();
 
             if (s_Meshes[0] == null)

UnityProject/Assets/UnityShaderEditor/Editor/Source/Nodes/Function2Input.cs

             get { return true; }
         }
 
-        public Function2Input(BaseMaterialGraph owner)
+        protected Function2Input(BaseMaterialGraph owner)
             : base(owner)
         {
             AddSlot(GetInputSlot1());
 
         protected virtual Slot GetInputSlot1()
         {
-            return new Slot(guid, GetInputSlot1Name(), GetInputSlot1Name(), Slot.SlotType.Input, SlotValueType.Dynamic, Vector4.zero);
+            return new Slot(this, GetInputSlot1Name(), GetInputSlot1Name(), Slot.SlotType.Input, SlotValueType.Dynamic, Vector4.zero);
-            return new Slot(guid, GetInputSlot2Name(), GetInputSlot2Name(), Slot.SlotType.Input, SlotValueType.Dynamic, Vector4.zero);
+            return new Slot(this, GetInputSlot2Name(), GetInputSlot2Name(), Slot.SlotType.Input, SlotValueType.Dynamic, Vector4.zero);
-            return new Slot(guid, GetOutputSlotName(), GetOutputSlotName(), Slot.SlotType.Output, SlotValueType.Dynamic, Vector4.zero);
+            return new Slot(this, GetOutputSlotName(), GetOutputSlotName(), Slot.SlotType.Output, SlotValueType.Dynamic, Vector4.zero);
         }
         
         protected virtual string GetInputSlot1Name()

UnityProject/Assets/UnityShaderEditor/Editor/Source/Nodes/PixelShaderNode.cs

 
         protected override bool UpdatePreviewShader()
         {
-           // if (hasError)
+            if (hasError)
                 return false;
 
             var shaderName = "Hidden/PreviewShader/" + name + "_" + guid;

UnityProject/Assets/UnityShaderEditor/Editor/Source/Nodes/Slot.cs

 namespace UnityEditor.MaterialGraph
 {
     [Serializable]
-    public class Slot : ISerializationCallbackReceiver
+    public class Slot
     {
         public enum SlotType
         {
 
         [SerializeField]
         private Vector4 m_CurrentValue;
-
-        [SerializeField]
-        private string m_NodeGUIDSerialized;
-
+        
-        private Guid m_NodeGUID;
+        private BaseMaterialNode m_Owner;
-        public Slot(Guid nodeGuid, string name, string displayName, SlotType slotType, SlotValueType valueType, Vector4 defaultValue)
+        public Slot(BaseMaterialNode owner, string name, string displayName, SlotType slotType, SlotValueType valueType, Vector4 defaultValue)
         {
             m_Name = name;
             m_DisplayName = displayName;
             m_CurrentValue = defaultValue;
-            m_NodeGUID = nodeGuid;
+            m_Owner = owner;
         }
 
         public bool isInputSlot
             get { return m_DisplayName; }
         }
 
-        public Guid nodeGuid
-        {
-            get { return m_NodeGUID; }
-        }
-
         public Vector4 defaultValue
         {
             get { return m_DefaultValue; }
             set { m_ConcreteValueType = value; }
         }
 
+        public BaseMaterialNode owner
+        {
+            get { return m_Owner; }
+            set { m_Owner = value; }
+        }
+
         public string GetInputName (BaseMaterialNode node)
         {
             return string.Format( "{0}_{1}", node.name, name);
                     break;
             }
             return EditorGUI.EndChangeCheck();
-        }
-
-        public virtual void OnBeforeSerialize()
-        {
-            m_NodeGUIDSerialized = m_NodeGUID.ToString();
-        }
-
-        public virtual void OnAfterDeserialize()
-        {
-            if (!string.IsNullOrEmpty(m_NodeGUIDSerialized))
-                m_NodeGUID = new Guid(m_NodeGUIDSerialized);
-            else
-                m_NodeGUID = Guid.NewGuid();
         }
     }
 }

UnityProject/Assets/UnityShaderEditor/Editor/Source/Nodes/Vector4Node.cs

        
         private void InternalValidate() 
         {
-            AddSlot(new Slot(guid, kOutputSlotName, kOutputSlotName, Slot.SlotType.Output, SlotValueType.Vector4, Vector4.zero));
+            AddSlot(new Slot(this, kOutputSlotName, kOutputSlotName, Slot.SlotType.Output, SlotValueType.Vector4, Vector4.zero));
         }
 
         private const string kOutputSlotName = "Value";

UnityProject/Assets/UnityShaderEditor/Editor/Source/PixelGraph.cs

         private PixelShaderNode m_PixelMasterNode;
 
         public PixelGraph(MaterialGraph owner) : base (owner)
-        {
-            m_PixelMasterNode = nodes.FirstOrDefault(x => x.GetType() == typeof(PixelShaderNode)) as PixelShaderNode;
-            if (m_PixelMasterNode == null)
-            {
-                m_PixelMasterNode = new PixelShaderNode(this);
-                AddNode(m_PixelMasterNode);
-                m_PixelMasterNode.position = new Rect(700, m_PixelMasterNode.position.y, m_PixelMasterNode.position.width, m_PixelMasterNode.position.height);
-            }
-        }
+        {}
+                // find existing node
+                if (m_PixelMasterNode == null)
+                    m_PixelMasterNode = nodes.FirstOrDefault(x => x.GetType() == typeof(PixelShaderNode)) as PixelShaderNode;
+
+                // none exists, so create!
+                if (m_PixelMasterNode == null)
+                {
+                    m_PixelMasterNode = new PixelShaderNode(this);
+                    AddNode(m_PixelMasterNode);
+                    m_PixelMasterNode.position = new Rect(700, m_PixelMasterNode.position.y, m_PixelMasterNode.position.width, m_PixelMasterNode.position.height);
+                }
                 return m_PixelMasterNode;
             }
         }