Preview scaling very inaccurate with multi-line text

[Gizemquea]

Shotcut Windows 10 64bit - version independend (presumably)

Observed in the Text: Simple filter - didn't check others

Steps to reproduce:
1.) Create a 1080p project with a clip and apply Text: Simple filter.
2.) Enter 10 lines of text
3.) Turn on preview scaling 360p
Result:
Last line of text is shifted up by more than one line.

Note: there are severeal other minor inaccuracies with preview scaling in various filters - however nothing neraly that obvious AFAIK.

[ddennedy]

I think I only reproduce this when "Use font size" is enabled and a small enough font size such that the text does not completely fill the rectangle. I write "think" because it depends on what you mean by "line" - pixels or text?
Preview scaling as implemented is inherently inaccurate, and I do not know how to fix that in general. If someone figures out a way to do it that still provides the performance benefit (i.e. does not first render to project resolution and then downscale), then it will be a complete rewrite. Unfortunately, I have not found a way to fix the reported problem due to this design.

[Gizemquea]

I actually mean one whole line of text. I can provide screen shots of my exact settings and their result if needed - it will just take some time since I don't have access to my shotcut projects right now.

[Gizemquea]

I have created a small test project for this issue: The folder also contains two sample screenshots, one with and one without preview scaling.

[luzpaz]

I just loaded this into Shotcut v25.01.03 on Manjaro Linux. This is what i see my UI