Description
We would like to use LVGL 9 for a project based on a NXP LPC1788 microcontroller connected to external SDRAM and a 480x640 TFT screen.
Two memory sections are reserved in external SDRAM as frame buffers (dual frame buffer). The microcontroller sends the currently selected section via EMC to the screen, which can be considered as a mirror image of the SDRAM data.
In this setup, direct rendering mode would be perfect because we could just assign both SDRAM sections base adresses as frame buffers. It then would not require expensive intermediate buffers.
The hardware has been designed by a contractor, so we cannot change anything. Plus, for retro-compatibility reasons, we cannot change anything to the microcontroller configuration.
Our issue is the following : The display is portrait oriented, but for some reason we do not have any power on, the data has to be written rotated 90° in the SDRAM. We therefore need any invalidated area to be rotated before being written to the frame buffers. Using the flush callback is thus not an option.
What MCU/Processor/Board and compiler are you using?
NXP LPC1788
What LVGL version are you using?
9.2.2
What do you want to achieve?
Is it possible to hook into the software drawing mechanism so that any invalidated area would be rotated in the frame buffers?