How to display outlined fonts (for transparent background)


I’d like to display LVGL fonts with a transparent background which I don’t control.
The same way as subtitles are displayed white with a black outline
Should I do this by creating a specific multicolor outlined font (I haven’t seen this feature)
Or should there be a text_decor_outline?

What MCU/Processor/Board and compiler are you using?

arm a53

What LVGL version are you using?


What do you want to achieve?

What have you tried so far?

looking at documentation shows outline style for widgets, but not fonts

As far as I understand font itself has no background (or its bg - is transparent). You usually use labels to display text, so text/bg color determined by the label’s style.

Is it possible to create multicolor fonts? (white/black/ background)

Try to use text recolor comands.
If you want to set background color you need to add style for label, which you can configure as you need, even with gradient.

I’d like outlined fonts on all existing widgets. So creating a font is a good solution for me.
Overlapping labels is not really what I want
I’ve seen that you can specify multiple bits per pixel in a font.
Can I conclude that it is possible to create an outlined font if I customize the font converter?

You can convert any of fonts you want to use, and add it to programm.
You can use ttf-files for outlined fonts for example
Something like this with goffik

Or do you want a different bg color inside the outline of the letter?

Yes converting outlined font won’t work, as I’d like outline to be black, foreground to be white, and background to be transparent.

I think this should be a font converter feature.
But I’m not sure if font format allows this. What I see is that you can select the number of bit per pixel. But I’ve not seen anywhere what is coded with these bits.
is 0 value corresponding to background, then it is grey scale? Is 1 value corresponding to black, or grey?