[billconan]

Very nice! I once had a side project with a built-in PDF viewer. My first version used pdf.js, but when zooming in quickly, it felt sluggish and hard to keep the zoom focus in the right place.

So I built my own PDF viewer, this time using pdfium in C++ with Metal for rendering — here’s a quick demo: https://youtu.be/jJMhVn5yzEI

I implemented a tiling technique to balance memory usage and performance. I didn’t realize pdfium could be so performant in WebAssembly — and honestly, I actually prefer developing UI on the web compared to C++.

[bobsingor]

Honestly, yours looks even snappier than what I had, the way it’s handling zoom feels super fluid. Really impressive work! Makes me want to dig back in and see if I can match that speed.

[billconan]

Thank you! Smooth zooming was the main thing I focused on optimizing. I haven’t implemented text search yet, that’s a whole other rabbit hole, with challenges like stitching text objects together and handling text normalization.

My code runs natively, so users need to download a client and I have to code the rest of the ui in cpp, that’s the downside. I did consider a hybrid approach with Electron or Tauri, but dropped the idea to avoid IPC overhead and get the best possible performance.

[dotancohen]

But what it's worth, I as a user prefer native code with no Electron.

[billconan]

But it will be more difficult for me to support multiple platforms, do customizations on the ui etc.

For example, I don't even own a windows pc.

[dotancohen]

I don't own a Windows PC either.

From what I understand there are two good FOSS PDF applications for Windows. The platform that is in need of a good PDF application, where you'll acquire users, isn't Windows.