[shader graph] Add context menu for adding nodes.

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

 #define DEBUG_MAT_GEN
 
+using System;
+using System.Reflection;
+using Object = UnityEngine.Object;
 
 namespace UnityEditor.MaterialGraph
 {
                 // The following manipulator show how to work with canvas2d overlay and background rendering
                 m_Canvas.AddManipulator(new RectangleSelect());
                 m_Canvas.AddManipulator(new ScreenSpaceGrid());
+                m_Canvas.AddManipulator(new ContextualMenu(DoAddNodeMenu));
+        }
+
+        private class AddNodeCreationObject : object
+        {
+            public Vector2 m_Pos;
+            public readonly Type m_Type;
+
+            public AddNodeCreationObject(Type t, Vector2 p) { m_Type = t; m_Pos = p; }
+        };
+
+        private void AddNode(object obj)
+        {
+            var posObj = obj as AddNodeCreationObject;
+            if (posObj == null)
+                return;
+
+            var node = (BaseMaterialNode)CreateInstance(posObj.m_Type);
+            node.Init();
+            node.position = new Rect(posObj.m_Pos.x, posObj.m_Pos.y, node.position.width, node.position.height);
+            m_MaterialGraph.currentGraph.AddNode(node);
+
+            Rebuild();
+            Repaint();
+        }
+
+        public virtual bool CanAddToNodeMenu(Type type) { return true; }
+        protected bool DoAddNodeMenu(Event @event, Canvas2D parent, Object customData)
+        {
+            var gm = new GenericMenu();
+            foreach (Type type in Assembly.GetAssembly(typeof(BaseMaterialNode)).GetTypes())
+            {
+                if (type.IsClass && !type.IsAbstract && (type.IsSubclassOf(typeof(BaseMaterialNode)) || type.IsSubclassOf(typeof(PropertyNode))))
+                {
+                    var attrs = type.GetCustomAttributes(typeof(TitleAttribute), false) as TitleAttribute[];
+                    if (attrs != null && attrs.Length > 0 && CanAddToNodeMenu(type))
+                    {
+                        gm.AddItem(new GUIContent(attrs[0].m_Title), false, AddNode, new AddNodeCreationObject(type, m_Canvas.MouseToCanvas(@event.mousePosition)));
+                    }
+                }
+            }
+            gm.ShowAsContext();
+            return true;
         }
 
         private void Rebuild()

UnityProject/Assets/UnityShaderEditor/Graphs/GlowMud.ShaderGraph

   style: node
   position:
     serializedVersion: 2
-    x: 1056
-    y: -24
-    width: 310
-    height: 445
+    x: 1053.9392
+    y: -22.969591
+    width: 312.0608
+    height: 443.9696
   showEmptySlots: 1
   m_SlotDefaultValues:
   - m_DefaultVector: {x: 1, y: 1, z: 1, w: 1}
   style: node
   position:
     serializedVersion: 2
-    x: -2742.6306
-    y: -1199.2351
-    width: 1940.6306
-    height: 1184.2351
+    x: -2476.4543
+    y: -376.32608
+    width: 1674.4543
+    height: 361.32608
   showEmptySlots: 1
   m_SlotDefaultValues:
   - m_DefaultVector: {x: 1, y: 1, z: 1, w: 1}
   m_PrecisionNames:
   - half
   m_SwizzleChannel: 3
+--- !u!114 &11428364
+MonoBehaviour:
+  m_ObjectHideFlags: 1
+  m_PrefabParentObject: {fileID: 0}
+  m_PrefabInternal: {fileID: 0}
+  m_GameObject: {fileID: 0}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: f80af444cd4235c419b356216d784b57, type: 3}
+  m_Name: Sin Time
+  m_EditorClassIdentifier: 
+  m_Slots:
+  - type: 1
+    m_Title: Sin Time
+    m_Name: SinTime
+    m_DataTypeString: 
+  m_Properties: []
+  m_GenericTypeString: 
+  color: 0
+  style: node
+  position:
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+    y: -848.0728
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+    height: 263.7843
+  showEmptySlots: 1
+  m_SlotDefaultValues:
+  - m_DefaultVector: {x: 1, y: 1, z: 1, w: 1}
+    m_Editable: 1
+    m_SlotName: SinTime
+    m_Node: {fileID: 11428364}
+  m_PrecisionNames:
+  - half
+--- !u!114 &11434830
+MonoBehaviour:
+  m_ObjectHideFlags: 1
+  m_PrefabParentObject: {fileID: 0}
+  m_PrefabInternal: {fileID: 0}
+  m_GameObject: {fileID: 0}
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+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 088fb5bde3ece0f4190136b3ab43f7c4, type: 3}
+  m_Name: MultiplyNode
+  m_EditorClassIdentifier: 
+  m_Slots:
+  - type: 1
+    m_Title: Output
+    m_Name: Output
+    m_DataTypeString: 
+  - type: 0
+    m_Title: Input 0
+    m_Name: Input0
+    m_DataTypeString: 
+  - type: 0
+    m_Title: Input 1
+    m_Name: Input1
+    m_DataTypeString: 
+  - type: 0
+    m_Title: Input 2
+    m_Name: Input2
+    m_DataTypeString: 
+  m_Properties: []
+  m_GenericTypeString: 
+  color: 0
+  style: node
+  position:
+    serializedVersion: 2
+    x: 425.1977
+    y: -656.4171
+    width: 0
+    height: 0
+  showEmptySlots: 1
+  m_SlotDefaultValues:
+  - m_DefaultVector: {x: 1, y: 1, z: 1, w: 1}
+    m_Editable: 1
+    m_SlotName: Output
+    m_Node: {fileID: 11434830}
+  - m_DefaultVector: {x: 1, y: 1, z: 1, w: 1}
+    m_Editable: 1
+    m_SlotName: Input0
+    m_Node: {fileID: 11434830}
+  - m_DefaultVector: {x: 1, y: 1, z: 1, w: 1}
+    m_Editable: 1
+    m_SlotName: Input1
+    m_Node: {fileID: 11434830}
+  - m_DefaultVector: {x: 1, y: 1, z: 1, w: 1}
+    m_Editable: 1
+    m_SlotName: Input2
+    m_Node: {fileID: 11434830}
+  m_PrecisionNames:
+  - half
 --- !u!114 &11441414
 MonoBehaviour:
   m_ObjectHideFlags: 1
   - {fileID: 11451638}
   - {fileID: 11422894}
   - {fileID: 11459506}
+  - {fileID: 11428364}
+  - {fileID: 11434830}
   edges:
   - m_FromNode: {fileID: 11498308}
     m_ToNode: {fileID: 11406334}
     m_FromSlotName: Output
     m_ToSlotName: UV
     color: {r: 1, g: 1, b: 1, a: 1}
+  - m_FromNode: {fileID: 11428364}
+    m_ToNode: {fileID: 11434830}
+    m_FromSlotName: SinTime
+    m_ToSlotName: Input0
+    color: {r: 1, g: 1, b: 1, a: 1}
+    m_ToNode: {fileID: 11434830}
+    m_FromSlotName: Output
+    m_ToSlotName: Input1
+    color: {r: 1, g: 1, b: 1, a: 1}
+  - m_FromNode: {fileID: 11434830}
     m_ToNode: {fileID: 11400400}
     m_FromSlotName: Output
     m_ToSlotName: Albedo
   style: node
   position:
     serializedVersion: 2
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-    y: -1141.3364
-    width: 1731.4495
-    height: 1221.3364
+    x: -2271.2732
+    y: -318.42752
+    width: 1465.2732
+    height: 398.42755
   showEmptySlots: 1
   m_SlotDefaultValues:
   - m_DefaultVector: {x: 1, y: 1, z: 1, w: 1}
   style: node
   position:
     serializedVersion: 2
-    x: -2128.9863
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-    width: 1458.9863
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+    width: 1192.811
+    height: 453.2167
   showEmptySlots: 1
   m_SlotDefaultValues:
   - m_DefaultVector: {x: 1, y: 1, z: 1, w: 1}