Merge pull request #304 from Unity-Technologies/sub-graph-preview-fix

Sub graph preview fix

com.unity.shadergraph/Editor/Data/Graphs/Vector4MaterialSlot.cs

 
         public Vector4MaterialSlot()
         {
+            m_Labels = new[] { "X", "Y", "Z", "W" };
         }
 
         public Vector4MaterialSlot(

com.unity.shadergraph/Editor/Data/SubGraph/SubGraphOutputNode.cs

             name = "SubGraphOutputs";
         }
 
+        public override bool hasPreview
+        {
+            get { return true; }
+        }
+
+        public override PreviewMode previewMode
+        {
+            get { return PreviewMode.Preview3D; }
+        }
+
         public virtual int AddSlot()
         {
             var index = this.GetInputSlots<ISlot>().Count() + 1;

com.unity.shadergraph/Editor/Data/Util/GraphUtil.cs

             var slots = new List<MaterialSlot>();
             foreach (var activeNode in isUber ? activeNodeList.Where(n => ((AbstractMaterialNode)n).hasPreview) : ((INode)node).ToEnumerable())
             {
-                if (activeNode is IMasterNode)
+                if (activeNode is IMasterNode || activeNode is SubGraphOutputNode)
                     slots.AddRange(activeNode.GetInputSlots<MaterialSlot>());
                 else
                     slots.AddRange(activeNode.GetOutputSlots<MaterialSlot>());
                     var outputSlot = activeNode.GetOutputSlots<MaterialSlot>().FirstOrDefault();
                     if (outputSlot != null)
                         surfaceDescriptionFunction.AddShaderChunk(String.Format("if ({0} == {1}) {{ surface.PreviewOutput = {2}; return surface; }}", outputIdProperty.referenceName, activeNode.tempId.index, ShaderGenerator.AdaptNodeOutputForPreview(activeNode, outputSlot.id, activeNode.GetVariableNameForSlot(outputSlot.id))), false);
+                }
+
+                // In case of the subgraph output node, the preview is generated
+                // from the first input to the node.
+                if (activeNode is SubGraphOutputNode)
+                {
+                    var inputSlot = activeNode.GetInputSlots<MaterialSlot>().FirstOrDefault();
+                    if (inputSlot != null)
+                    {
+                        var foundEdges = graph.GetEdges(inputSlot.slotReference).ToArray();
+                        string slotValue = foundEdges.Any() ? activeNode.GetSlotValue(inputSlot.id, mode) : inputSlot.GetDefaultValue(mode);
+                        surfaceDescriptionFunction.AddShaderChunk(String.Format("if ({0} == {1}) {{ surface.PreviewOutput = {2}; return surface; }}", outputIdProperty.referenceName, activeNode.tempId.index, slotValue), false);
+                    }
                 }
 
                 activeNode.CollectShaderProperties(shaderProperties, mode);

com.unity.shadergraph/Editor/Drawing/Inspector/MasterPreviewView.cs

             var amn = masterNode as AbstractMaterialNode;
             if (amn != null)
                 amn.Dirty(scope);
+
+            // If currently editing a subgraph, dirty the output node rather than master node.
+            if (m_Graph is SubGraph)
+            {
+                var subgraph = m_Graph as SubGraph;
+                if (subgraph != null && subgraph.outputNode != null)
+                    subgraph.outputNode.Dirty(scope);
+            }
         }
 
         void OnPreviewChanged()

com.unity.shadergraph/Editor/Drawing/PreviewManager.cs

 
             if (masterRenderData.shaderData == null && masterNode != null)
                 masterRenderData.shaderData = shaderData;
+
+            var subGraphOutputNode = node as SubGraphOutputNode;
+
+            if (masterRenderData.shaderData == null && subGraphOutputNode != null)
+                masterRenderData.shaderData = shaderData;
         }
 
         void OnNodeModified(INode node, ModificationScope scope)