DrawGizmo - Accessing Editor script in DrawGizmo

I have been making a custom editor for a hexagon grid, and also a custom gizmo for that grid using the [DrawGizmo] attribute.

It currently works basically like this:

• I've got the HexGrid class, that contains all the functionality for storing and communicating with the hex grid:

     public class HexGrid : MonoBehaviour
       {
           public float HexRadius;
       
           public Color GizmoColor;
           public int GizmoDrawRange;
       
           // Rest of class...
       }
  
  

• And then I've got the HexGridEditor class that also contains the HexGridGizmo method, that uses the [DrawGizmo] attribute:

     [CustomEditor(typeof(HexGrid))]
       public class HexGridEditor : Editor
       {
  
       // Variables, references, functions...
       
           [DrawGizmo(GizmoType.NotInSelectionHierarchy | GizmoType.InSelectionHierarchy | GizmoType.Pickable)]
           static void HexGridGizmo(HexGrid hexGrid, GizmoType gizmoType)
           {
               Color color = hexGrid.GizmoColor;
               int DrawRange = hexGrid.GizmoDrawRange;
  
               // Rest of gizmo functionality...
           }
       }
  
  

This works fine, but it's not how I want it organized. I ideally want all editor and gizmo functionality to be contained in the HexGridEditor class, and have the HexGrid class only contain runtime functionality. So to be more precise, I want the GizmoColor and GizmoDrawRange fields to be contained in the editor class, but I can't get that to work.

• If I just put the GizmoColor and GizmoDrawRange fields in the HexGridEditor class I can't reference them from the HexGridGizmo function, because it's a static function. And it has to be static according to the script reference.

    [CustomEditor(typeof(HexGrid))]
        public class HexGridEditor : Editor
        {
   
        public Color GizmoColor;
        public int GizmoDrawRange;
        
            [DrawGizmo(GizmoType.NotInSelectionHierarchy | GizmoType.InSelectionHierarchy | GizmoType.Pickable)]
            static void HexGridGizmo(HexGrid hexGrid, GizmoType gizmoType)
            {
                Color color = GizmoColor;
                int DrawRange = GizmoDrawRange;
   
                // DOES NOT WORK:
                // Can't reference GizmoColor and GizmoDrawRange from static method.
            }
        }
  
  

• The renderer function takes as its first argument the object for which the gizmo is being drawn, and as we saw in my current setup (first two code snippets) that lets me reference that objects fields, so what if I use the HexGridEditor class as that argument instead of the HexGrid class? That doesn't work either and throws a strange (and seemingly undocumented) error: classID != -1.

   [CustomEditor(typeof(HexGrid))]
         public class HexGridEditor : Editor
         {
    
         public Color GizmoColor;
         public int GizmoDrawRange;
         
             [DrawGizmo(GizmoType.NotInSelectionHierarchy | GizmoType.InSelectionHierarchy | GizmoType.Pickable)]
             static void HexGridGizmo(HexGridEditor hexGridEditor, GizmoType gizmoType)
             {
                 Color color = HexGridEditor.GizmoColor;
                 int DrawRange = HexGridEditor.GizmoDrawRange;
    
                 // THROWS ERROR (in Unity): classID != -1.
             }
         }
  
  

So how do I solve this in a tidy way? Is there some way to pass the HexGridEditor class into the gizmo function? Some other way, where editor and runtime functionality is neatly separated?

Much thanks in advance!