Work out a dynamic splash screen that fits all screen sizes.

[richardclli]

Fixes #638

Summary of changes:

[richardclli]

This is the best I can do, not quite sure how to apply masks.

[richardclli]

Let's use this change first, may enhance it later.

[pfeerick]

Yup, it at least fixes the screen corruption issue for LVGL 8.3.

[philmoz]

This makes having a custom splash screen pretty hard for users.

Maybe the code should check for the presence of a specific file and use it instead so users can still override this new splash screen.

Probably should be something other than 'splash.png' as anyone who is using the default (old) splash screen will still have this on their radio.

[pfeerick]

I'm not sure what you mean - this only applies when /IMAGES/splash.png is not present as an override for a custom splash screen - which is also normally never present. So nothing changes for users - place /IMAGES/splash.png, enjoy custom splash screen.

This fixes the issue for NV14 where the screen isn't fully filled by the splash screen, which is more of an issue in LVGL8.3. This is also one step towards being able to have a single built-in splash screen for both of the current screen sizes, as well as the one or two more that are coming. The next step will probably be to add the version number (or branch/commit hash if it is a PR or nightly) somewhat like how was shown in #638.

[philmoz]

My mistake, you are correct. Sorry.

[pfeerick]

No problem, thanks for making me double check 😉