Lualatex and emojis

.github/workflows/python-app.yml

@@ -36,6 +36,10 @@ jobs:
       run: venv/bin/ruff check --output-format=github
     - name: Check ruff formatting
       run: venv/bin/ruff format --check --diff
+    - name: Install lualatex (temporary, until githubci docker image is updated)
+      run: |
+        apt-get update
+        apt-get install fonts-cmu fonts-noto-color-emoji texlive-luatex
     - name: Test with pytest
       run:  venv/bin/pytest
     - name: Run mypy
@@ -53,6 +57,10 @@ jobs:
     - name: Build debian packages
       run:  |
         make builddeb
+    - name: Install lualatex (temporary, until githubci docker image is updated)
+      run: |
+        apt-get update
+        apt-get install fonts-cmu fonts-noto-color-emoji texlive-luatex
     - name: Install debian package
       run:  dpkg -i ../kattis-problemtools_*.deb
     - name: Verify examples

README.md

@@ -237,7 +237,11 @@ The dependencies needed to *build/install* problemtools can be installed with:
 
 And the dependencies needed to *run* problemtools can be installed with:
 
-    sudo apt install ghostscript pandoc python3 texlive-fonts-recommended texlive-lang-cyrillic texlive-latex-extra texlive-plain-generic tidy dvisvgm
+    sudo apt install ghostscript pandoc python3 texlive-fonts-recommended texlive-latex-extra texlive-luatex texlive-plain-generic tidy dvisvgm
+
+To render problem statements to pdf with non-latin characters, also add the following fonts:
+
+    sudo apt install fonts-cmu fonts-noto-color-emoji
 
 ### Fedora
 

admin/docker/Dockerfile.runreqs

@@ -16,13 +16,15 @@ RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
     rm -f /etc/apt/apt.conf.d/docker-clean && \
     apt-get update && apt-get install -y \
         dvisvgm \
+        fonts-cmu \
+        fonts-noto-color-emoji \
         ghostscript \
         libgmp-dev \
         pandoc \
         python3 \
         python3-venv \
         texlive-fonts-recommended \
-        texlive-lang-cyrillic \
         texlive-latex-extra \
+        texlive-luatex \
         texlive-plain-generic \
         tidy

debian/control

@@ -8,7 +8,7 @@ Homepage: https://github.com/Kattis/problemtools
 
 Package: kattis-problemtools
 Architecture: any
-Depends: ${shlibs:Depends}, ${misc:Depends}, pandoc, python3, texlive-plain-generic, texlive-fonts-recommended, texlive-latex-extra, texlive-lang-cyrillic, tidy, ghostscript, dvisvgm
+Depends: ${shlibs:Depends}, ${misc:Depends}, pandoc, python3, texlive-plain-generic, texlive-fonts-recommended, texlive-latex-extra, texlive-luatex, tidy, ghostscript, dvisvgm, fonts-cmu, fonts-noto-color-emoji
 Recommends: gcc, g++
 Description: Kattis Problem Tools
  These are tools to manage and verify problem packages in the

problemtools/problem2pdf.py

@@ -102,12 +102,12 @@ def latex2pdf(options: argparse.Namespace, statement_file: Path) -> bool:
         origcwd = os.getcwd()
 
         os.chdir(texfile.parent)
-        params = ['pdflatex', '-interaction=nonstopmode']
+        params = ['lualatex', '--interaction=nonstopmode']
         output = None
         if options.quiet:
             output = open(os.devnull, 'w')
         if options.nopdf:
-            params.append('-draftmode')
+            params.append('--draftmode')
 
         params.append(str(texfile.name))
 

problemtools/templates/latex/problemset.cls

@@ -36,8 +36,6 @@
 \RequirePackage{times}            % Font choice
 \RequirePackage{amsmath}          % AMS
 \RequirePackage{amssymb}          % AMS
-\RequirePackage[OT2,T1]{fontenc}  % Cyrillic and standard % TODO: make alphabet options more general
-\RequirePackage[utf8]{inputenc}   % UTF-8 support
 \RequirePackage{fancyhdr}         % Headers
 \RequirePackage{graphicx}         % Graphics
 \RequirePackage{subfigure}        % Subfigures
@@ -55,6 +53,24 @@
 \ifplastex\else
 \RequirePackage{xstring}
 \RequirePackage{pgffor}
+% I do not understand how to do font handling well in a portable way in
+% lualatex. The default font seems to only have latin characters. If we
+% try to load a font which is not installed, rendering fails, which makes
+% problem2pdf and verifyproblem unhappy. After a lot of trial-and-error,
+% I ended up with this conditional loading of fonts (so we should degrade
+% gracefully when fonts are missing). Getting the emoji font to work was weird,
+% as apparently we need to define the fallback using lua code because the font
+% uses colors.
+\RequirePackage{fontspec}
+\RequirePackage{luacode}
+\IfFontExistsTF{CMU Serif}{
+    \IfFontExistsTF{NotoColorEmoji}{
+        \directlua{luaotfload.add_fallback("myfallback", {"NotoColorEmoji:mode=harf;"})}
+        \setmainfont{CMU Serif}[RawFeature={fallback=myfallback}]
+    }{
+        \setmainfont{CMU Serif}
+    }
+}{}
 \fi
 
 %% Commands used to set name, logo, etc of contest
@@ -291,8 +307,8 @@
 
 \newcommand{\sampletable}[4]{
   % First find widths of the two files
-  \savebox{\PS@sampleinbox}{\lstinputlisting[inputencoding=utf8/latin1,basicstyle=\ttfamily]{#2}}
-  \savebox{\PS@sampleoutbox}{\lstinputlisting[inputencoding=utf8/latin1,basicstyle=\ttfamily]{#4}}
+  \savebox{\PS@sampleinbox}{\lstinputlisting[inputencoding=utf8,basicstyle=\ttfamily]{#2}}
+  \savebox{\PS@sampleoutbox}{\lstinputlisting[inputencoding=utf8,basicstyle=\ttfamily]{#4}}
   \settowidth{\PS@sampleoutwidth}{\usebox{\PS@sampleoutbox}}
   \settowidth{\PS@sampleinwidth}{\usebox{\PS@sampleinbox}}
   \setlength{\PS@sampletotwidth}{\PS@sampleinwidth}
@@ -369,7 +385,7 @@
         \hline
         \parbox[t]{0.55\textwidth}{
           \vspace{-0.49cm}
-          \lstinputlisting[inputencoding=utf8/latin1,basicstyle=\ttfamily]{\jobname.pstmp}
+          \lstinputlisting[inputencoding=utf8,basicstyle=\ttfamily]{\jobname.pstmp}
           \vspace{-0.21cm}
         }\\
         \hline