[Good first issue] Reduce LaTeX dependency to the minimal required

[edwardchalstrey1]

Requested enahancement or feature

Currently, draw_tree requires texlive-full to work, see installation. This is quite a large install (~1.5GB), so it would be better if we could rely on a smaller LaTeX distribution.

The package relies on the ability to create TikZ code and also needs to be able to call pdflatex for both PDF and PNG generation - see https://github.com/gambitproject/draw_tree/blob/main/src/draw_tree/core.py#L1806

[manthanawgan]

@edwardchalstrey1
Hi! I'd like to work on this issue.

I have two approaches in mind and would love feedback on which direction to go:

Approach 1: Minimal apt install
Replace texlive-full with a minimal set of packages that still supports the current pdflatex-based workflow:

apt-get install -y --no-install-recommends \
  texlive-latex-base \
  texlive-latex-extra \
  texlive-pictures \
  texlive-fonts-extra

I'd verify this on a clean Docker container by running the existing test suite and manually testing PDF/PNG generation with sample .ef files, then update .github/workflows/test.yml and the README accordingly. No code changes needed, just infrastructure and docs.

Approach 2: Switch to Tectonic
Use Tectonic as the LaTeX engine instead of pdflatex. Tectonic is a self-contained engine that automatically downloads only the packages it needs on first run, so users wouldn't need to manage LaTeX package installation at all. This would involve:

• Swapping the pdflatex call in core.py with tectonic
• Optionally detecting which engine is available and falling back gracefully
• Updating docs and CI to install tectonic instead of any texlive packages

The main tradeoff is that Tectonic requires an internet connection on first run to fetch packages, which I'd document clearly.

Happy to go with whichever approach fits the project's goals best, or combine both if that makes sense!

[edwardchalstrey1]

Hi @manthanawgan have you come across this as a result of participating in GSoC? If so, we encourage you to apply following the guidance here (if you didn't already). We are planning to use some "good first issues" to evaluate applicants alongside their applications. This issue may be looked at by students interested in Project 2. If you submit an application highlighting your interest in that project then we may get back to you asking to take this on, or perhaps another issue. If you submit an application with an interest in another project(s) from the list, we may direct you to different issues.

[manthanawgan]

Hi @edwardchalstrey1 , yes I came across this through GSoC and I'm planning to apply for Idea 3 (the layout algorithm project).

I'll be submitting my application shortly. Happy to take on this issue or whichever one you think is most relevant to that project just let me know!

[sincerelyyyash]

Hi @edwardchalstrey1, I've submitted PR #45 for this issue. My investigation found the root cause: newpxtext/newpxmath fonts pull in texlive-fonts-extra (~650 MB). Switching to lmodern reduces the total requirement from ~1.5 GB to ~165 MB. I'm applying for GSoC 2026 and interested in Project 2 (GameInterpreter). Happy to incorporate any feedback.