How to avoid fill_normal after update an image


I am now using a screen sized img
as background(1024×600 equal to the display) ,and set its pos to (0,0).of course there are few object here as childrens to it.everey frame some of those chindrens update like chaging img_src or getting rotated.the lvgl process is like this : fill_normal(white) >map_normal(background)>map_normal(obj) in fact fill_normal is not needed and cost extra cpu because the background img could cover the dirty area ,so how to optimize? appreciate……

What MCU/[Processor]

cortex m7

What LVGL version are you using?


What do you want to achieve?

avoid useless fill action