feat(presentations): continue the introduction of reveal.js + draft for customisation

- customisations

content/tips/presenting.md

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+---
+Title: Tools for making and giving presentations
+Date: 2024-11-03
+Author: Fabrice
+Category: Tips
+Tags: presentation, vim, latex
+Slug: presenting
+Header_Cover: ../images/covers/pts24-talk.jpg
+Summary: Some of the tools I use for making and giving presentations.
+Lang: en
+---
+
+# Introduction
+
+Over the past year, I have to give quite a few presentations in different
+contexts: internal to the company, for open-source conferences, for business
+conferences…
+
+I use this opportunity to refine a bit my presentation tools, and I just
+summarize them here for curious people.
+
+This page may be updated, for instance if I start using [typst] for slide
+making. If you have subscribed to this blog’s [RSS feed], you will be notified
+of future updates.
+
+# Making Slides
+
+For slide making, I prefer using tools that separate the content from the actual
+design. I’m thus not using fancy WYSIWYG tools for that. If you are not
+interested in that, you can already skip to the [presenting slides] section.
+
+## LaTeX Beamer
+
+As explained in the [typst article], I’m mostly using [LaTeX] to produce/typeset
+documents, and presentations are not an exception. For this purpose I’m using
+[beamer].
+
+For this purpose, my [vim setup for LaTeX] proved to be pretty useful,
+especially with the “on save compilation”. However, the backward search is not
+very accurate with beamer slides.
+
+### Overlays and Graphics
+
+The main advantage, besides my familiarity with [LaTeX], lays in the [overlay]
+system in beamer, that is quite powerful and provides a very precise way to
+display elements, especially with [TikZ] to design animated graphics.
+
+For instance in the example below, I can show the top part of the graph
+initially, then the bottom, and change the name of the last node for the second
+slide. That can be easily adjusted to have more steps in the process.
+
+```latex
+…
+\usetikzlibrary{positioning}
+…
+\begin{tikzpicture}
+  \tikzstyle{node} = [draw, rectangle, fill=blue!40, minimum height=2em]
+  \tikzstyle{arrow} = [->, >=stealth, very thick]
+  \node[node] (start) {Data};
+  \node[node, right=1cm of start] (a1) {Enc($\cdot$)};
+  \node<2->[node, below=5mm of a1] (a2) {Sig($\cdot$)};
+  \node<1>[node, right=1cm of a1] (stop) {Encrypted Data};
+  \node<2->[node, right=1cm of a1] (stop) {Encrypted and Signed Data};
+
+  \draw[arrow] (start) -- (a1);
+  \draw<2->[arrow] (start) -- (a2);
+  \draw[arrow] (a1) -- (stop);
+  \draw<2->[arrow] (a2) -- (stop);
+\end{tikzpicture}
+```
+
+Resulting in:
+
+![The last image from the above code](../examples/tikz-graph.svg "The last image from the above code"){width=66%}
+
+Moreover, you have access to the whole latex ecosystem, especially those for
+neat illustrations such as [tikzpingus].
+
+**Note:** I have to say that the above technique is unsafe under fairly
+reasonnable assumptions. Long story short you should sign first *then* encrypt
+and not do both in parallel. Please see [this paper](https://ia.cr/2001/045)
+from Crypto’01 if you want a more detailed explanation.
+
+### Customisation
+
+It is also quite easy to customise slides with beamer. For instance, with
+[metropolis], from its
+[documentation](https://ctan.tetaneutral.net/macros/latex/contrib/beamer-contrib/themes/metropolis/doc/metropolistheme.pdf),
+section 8 describe where to find specific colours. As for the fonts, if you are
+using xelatex/lualatex, a simple `\setmainfont` suffices to redefine it.
+
+For instance, if I want to have the alert text in orange:
+
+```latex
+\setbeamercolor[alerted text]{fg=orange}
+```
+
+### Drawbacks
+
+However, LaTeX starts to slow down quickly, especially with a lot of [TikZ]
+drawings… On documents, it’s not really an issue as it is possible to cache the
+drawings with the `externalize` tikz library. However, when mixing overlays and
+TikZ, it starts to [need some
+tweaks](https://tex.stackexchange.com/questions/78955/use-tikz-external-feature-with-beamer-only).
+I never included them in my workflow as they make TikZ drawings more complicated
+than they are.
+
+## Typst Touying
+
+## Pandoc and reveal.js
+
+[reveal.js] is a javascript framework to produce clean and dynamic slides. My
+settings to generate them are liberally inspired by [Pablo
+Coves](https://pcoves.gitlab.io/blog/pandoc-markdown-revealjs/).
+
+[Pandoc] on the other hand is a document converter tool that supports a very
+extensive spectrum of formats and syntax. My most use case is to convert
+markdown to some other reflowable format (usually html, and sometimes epub).
+
+Using both in conjunction allows for quick and dynamic presentations which don’t
+require _accuracy_ in placements. That may be the case for lightning talks for
+instance. The main advantage compared to the two above solutions is that
+[reveal.js] takes advantage of web browser capabilities to produce dynamic
+transitions. Those are otherwise hard to get from PDFs (some people made custom
+pdf reader for that).
+
+### Customisation
+
+- List of default [reveal.js styles]
+- Simple customisation with CSS:
+  <https://gist.github.com/jsoma/629b9564af5b1e7fa62d0a3a0a47c296#styling> see
+  <https://github.com/hakimel/reveal.js/blob/master/css/theme/template/exposer.scss>
+  as well for exposed variables.
+- However, in standalone mode, changing the font does not work well…
+- Create custom theme: <https://github.com/hakimel/reveal.js/blob/master/css/theme/README.md>
+  - <https://github.com/Chouhartem/reveal.js/tree/cryptpad-theme>
+
+# Presenting Slides {#presenting-slides}
+
+## wl-mirror
+
+## pdfpc
+
+[RSS feed]: /feeds/all.rss.xml
+[typst]: https://typst.app/
+[typst article]: {filename}../software/typst.md
+[presenting slides]: #presenting-slides
+[LaTeX]: https://www.latex-project.org/
+[beamer]: https://ctan.org/pkg/beamer
+[vim setup for LaTeX]: {filename}../software/nvim-latex.md
+[overlay]: https://www.overleaf.com/learn/latex/Beamer_Presentations%3A_A_Tutorial_for_Beginners_(Part_4)%E2%80%94Overlay_Specifications
+[TikZ]: https://www.ctan.org/pkg/pgf
+[tikzpingus]: https://github.com/EagleoutIce/tikzpingus
+[reveal.js]: https://revealjs.com/
+[reveal.js styles]: https://revealjs.com/themes/
+[pandoc]: https://pandoc.org/