Fix shader property ids not changing

Author: adamgraham

Editor/ShaderPropertyPropertyDrawer.cs

@@ -7,16 +7,29 @@ namespace Zigurous.Graphics.Editor
     public sealed class ShaderPropertyPropertyDrawer : PropertyDrawer
     {
         private SerializedProperty _name;
+        private SerializedProperty _id;
 
         public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
         {
             if (_name == null) {
                 _name = property.FindPropertyRelative("_name");
             }
 
+            if (_id == null) {
+                _id = property.FindPropertyRelative("_id");
+            }
+
             EditorGUI.BeginProperty(position, label, property);
             position = EditorGUI.PrefixLabel(position, GUIUtility.GetControlID(FocusType.Passive), label);
-            _name.stringValue = EditorGUI.TextField(position, _name.stringValue);
+
+            string name = EditorGUI.TextField(position, _name.stringValue);
+
+            if (name != _name.stringValue)
+            {
+                _name.stringValue = name;
+                _id.intValue = Shader.PropertyToID(name);
+            }
+
             EditorGUI.EndProperty();
         }
 

Runtime/ShaderProperty.cs

@@ -9,6 +9,8 @@ namespace Zigurous.Graphics
     [System.Serializable]
     public struct ShaderProperty
     {
+        [SerializeField]
+        [HideInInspector]
         private int _id;
 
         /// <summary>