Feature Request: Native support for standalone images (PNG, JPG, etc.) via MuPDF

[HoseaD]

Is your feature request related to a problem?
Currently, Bookokrat cannot open standalone image files.
However, it is highly useful to leverage Bookokrat's high-performance terminal rendering and file-watching capabilities as a live-viewer for diagramming tools (like PlantUML) or other workflows that output to flat image formats.

Describe the solution you'd like
Since the mupdf backend already natively supports rendering single-page image formats out of the box, we can add these extensions to the detect_format and discover_book_in_dir functions.

I have tested this locally, and MuPDF handles terminal image rendering flawlessly without any new rendering logic required.

Architectural Discussion
I would like to submit a PR for this, but I wanted to check if this aligns with the project's goals first, and if so, how you would prefer it modeled internally:

• Approach A (Minimal Code): Route the image extensions directly to the existing PDF pipeline since MuPDF handles both exactly the same way internally.

"pdf" | "png" | "jpg" | "jpeg" | "gif" | "bmp | "tif" | "tiff" => Some(BookFormat::Pdf),

• Approach B (Semantic Cleanliness): Create a new BookFormat::Image variant. This would be semantically cleaner but would require adding match arms across the codebase wherever BookFormat::Pdf currently hands off to the MuPDF worker.

[bugzmanov]

Hey. I'm a bit perplexed on this one. Bookokrat is essentially an app for reading books. I think that standalone image viewer is 1-2k lines of code. And not much would be used out of bookokrat code & architecture.

[HoseaD]

Yes, probably out of scope for the project.
But i started using the live loading feature with writing latex (live loading the updated pdf). Now i also needed a tool to live load images (png) to view diagrams generated with plantuml.
I have just added this two lines (Approach A), so images get loaded in the same pipeline as PDF, processed through MuPDF, which also supports png.

[bugzmanov]

@HoseaD interesting. Do you mind sharing your workflow around latex ?

[HoseaD]

I use Neovim and Ghostty. My setup consists of:

• Neovim + LSP + VimTeX: Handles editing and continuous compilation via latexmk every time I save.
• Ghostty: I use a window split to keep my code and PDF side-by-side.
• Bookokrat: Acts as the viewer in the adjacent split with its live-reloading feature.

Forward and Backward search would be nice, but i'm not missing it to much.