MapEditor.GUIUpdateTexture C# (CSharp) Method

    void GUIUpdateTexture(Texture2D tex, int idx, Dictionary<string, int> names)
    {
        Map m = (Map)target;
        string name = "MAP_TEX_"+idx;
        names[name] = idx;
        GUI.SetNextControlName(name);
        Texture2D nextTex = (Texture2D)EditorGUILayout.ObjectField(
            tex == specPlaceholderTexture ? null : tex,
            typeof(Texture2D),
            false,
            GUILayout.Height(64),
            GUILayout.Width(64)
        );
        GUI.SetNextControlName("");
        if(tex != nextTex) {
            if(tex == specPlaceholderTexture && nextTex == null) {
                //ignore, no real change
            } else {
                //are we on the bonus item?
                if(idx == m.TileSpecCount) {
                    //if so, add a new spec
                    RegisterUndo("Add Tile Spec");
                    m.AddTileSpec(nextTex);
                } else {
                    //otherwise, just update
                    RegisterUndo("Change Tile Spec");
                    m.UpdateTileSpecAt(specSelectedSpec, nextTex);
                }
              if(nextTex != null) {
                    string path = AssetDatabase.GetAssetPath(nextTex);
            TextureImporter textureImporter = AssetImporter.GetAtPath(path) as TextureImporter;
                    textureImporter.textureType = TextureImporterType.Advanced;
                    textureImporter.anisoLevel = 1;
                    textureImporter.filterMode = FilterMode.Bilinear;
                    textureImporter.maxTextureSize = 1024;
                    textureImporter.textureFormat = TextureImporterFormat.AutomaticCompressed;
            textureImporter.mipmapEnabled = false;
            textureImporter.isReadable = true;
                    AssetDatabase.ImportAsset(path);
                }
            }
        }
    }