opengl.renderer.lean: Add extra checks for GL errors.

3-mid/opengl/source/lean/renderer/opengl-renderer-lean.adb

@@ -600,9 +600,12 @@ is
 
    begin
       Tasks.check;
+      Errors.log;
 
-      if clear_Frame then
+      if clear_Frame
+      then
          Self.clear_Frame;
+         Errors.log;
       end if;
 
       ---------------------
@@ -624,12 +627,14 @@ is
                or (    the_Visual.Model.opaque_Geometries = null
                    and the_Visual.Model. lucid_Geometries = null)
             then
+               Errors.log;
                the_Visual.Model.create_GL_Geometries (Self.Textures'Access, Self.Fonts);
                --  put_Line ("Rebuild");
 
             elsif the_Visual.Model.is_Modified
             then
                the_Visual.Model.modify;
+               Errors.log;
             end if;
 
             declare
@@ -660,6 +665,9 @@ is
 
             end;
          end;
+
+         put_Line ("the_Visuals (" & Each'Image & ") =>");
+         Errors.log;
       end loop;
 
       Errors.log;