I have ported LVGL on RH850 successfully,and have some issue to optimize

1.I use lv_canvas_rotate to draw a rotating pin,but it use up too many resources to slows down my program, Now I use the RGL of the RH850 to solve this problem,is it have some idea to solve it by LVGL。
2.Sometimes,at lv_port_disp.c, I want to know which LVGL image or font was drew,how can i get the information.

You cannot (easily) retrieve that information. The display driver is only handed a bitmap to flush to the display, not information about individual widgets.

Yes,I know that,I want to get the information to allocated memory dynamically, the question is how to modify LVGL for this purpose,and want to get some idea.