[BUG] PDF doesn't resolve when zooming

[stardomains3]

Describe the bug
I have a subway map. My normal viewer is ML PDF. In your app when I pinch to zoom the map pdf, the pdf is blurry and I cannot read it. MJ PDF and I suppose normal viewers resolve the detail.

To Reproduce
Steps to reproduce the behavior:

1. Go to a detailed pdf in your app
2. Pinch to zoom
3. Stays blurry

Expected behavior
Resolves the detail of the pdf

Screenshots
If applicable, add screenshots to help explain your problem.

Smartphone (please complete the following information):

• Device: Pixel 10 Pro
• OS: Android 16
• App Version 4.5.2 F-Droid

[michaeltroger]

Hey, thx for reporting.
There is however currently no plan to improve this. The current behavior has historical reasons - this app works with plain Android PDF reader, so without any helper PDF library. At the same time, the app has this unique feature of rendering multiple PDFs at the same time. It creates also Barcodes out of these at runtime - all this means lots of Bitmap generations. The app runs on low end Android phones down to Android version 5! So there is some compromise needed between quality and running into „out of memory“ crashes.

I think it shouldn‘t be a problem for most PDFs - as I mainly target the app for PDFs meant for printing like tickets or certificates. Can it be that your PDF is more like a high resolution „digital“ PDF meant for computer displays, rather than one for printing? Also landscape format is not really supported if it‘s of that kind.

Anyhow since I created the app, phones became more powerful and probably it could be allowed to use a better resolution on high end phones. I‘m open for concrete proposals or code contributions as long as existing functionality can be kept.

[ivan-gj]

Maybe add a button to open PDF with another app? It's my biggest issue with this app. I love that it is very very simple, but the PDF render quality is terrible for cases where there's no QR, or the person wants to check some other information.