Hi,
Couldn’t find any reference if LVGL supports displays with non-square pixels, like physical 16:9 aspect ratio with 800x480 resolution. Something like automatic font scaling, bitmaps and other stuff scaling could also be useful.
Regards,
Vas
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Hi,
This feature is not supported, and to be honest I’ve never seen a display with non-square pixels so I don’t much about it 
Are there typical pixel aspect ratios?
I’ve heard that non-square pixels are quite popular in low-priced Android devices, but I just started to scratch the surface of the topic. I’ve bought ESP32-8048S043C (ESP32-8048S043 | macsbug) and am trying to figure out what to do now lol
It looks like non 1:1 PAR is not uncommon List of common resolutions - Wikipedia
Wow, it’s really unexpected. It seems the PAR can be any ratio.
I move this topic to the future request category. If it will interesting for more people we can figure out how to support it.
My LCD is 7 inch, 800 *480 ，but the arc is not normal.Does the LVGL can support for
non-square pixels lcd?
Yes, it seems.
Okay, we got traction on this topic
You must avoid circles, it looks silly.
This display is very popular, because of good price.
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I have this issue many LCDs have non square pixels
Is there a temporary fix for this?
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There a re few complicated questions here:
- What to do with the rounded corners: LVGL need to draw ellipses (i.e. distorted circles)
- What to do with the fonts? If LVGL needs to transform them (i.e. +20% horizontal scale) it will be slow and ugly
- What to do with the images? It might be ok to use pre-transformed images.
Pre-transforming images and fonts might need to be done twice, if supporting perpendicular display axis is needed(like 0/180 can be shared, but 90/270 cannot be shared with 0/180).
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If the Pixel Aspect Ratio(PAR) diverges too far from 1.0, anti-aliasing may need updated. For PAR<1.1, it might be close enough, but when I used a display with PAR=3, we had to fix anti-aliasing it to keep lines smooth.
Wow, it’s getting very complicated. Maybe it’s easier to render all these if a vector graphics GPU available . In this case we can define a constant matrix which distorts all drawing operations.
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Wow, good to know, thank you!
It seems really difficult to handle to be honest. Especially with good performance.