I used https://revealjs.com/ in the past for this successfully. I have very good experience with that from circa 10 years ago.

I found Presenterm [1] to be optimal for me. Simple and works in the terminal, yet powerful to export to PDF and HTML. It supports Mermaid and images. I'm also collecting a list [2] with other Markdown-first presentation tools, and according to the git stars, reveal.js seems to be the most popular. Tough for me, it was too heavy.

[1] https://github.com/mfontanini/presenterm

[2] https://www.ssp.sh/brain/markdown-presentations-or-slides/

I love it, but it was very disorienting to use `j` to move forward and `k` to move backward.

This is my favorite size project. It allows us to be pedantic about every detail.

When the key press event is triggered current is to be increased or decreased if two conditions are met. One shouldn't check just one, take action then change it back if the other condition isn't met.

   if(e.key == 'j'){ cur++; }
   if(e.key == 'k'){ cur--; }
   if(cur < 0){ cur = 0; }
   if(cur >= sl.length){ cur = sl.length - 1; }

something like...

   if(cur<sl.length && e.key=='j'){ cur++ }
   else if(cur>0 && e.key=='k'){ cur-- }

The else is there because we don't need to check the other condition if the first is true.

Not that the original code doesn't work. I just want to execute instructions needed and avoid unnecessary ones if it is simple enough. The case where we try to increase beyond the array size would still trigger the second check. Even more correct would be:

   if(e.key == 'j'){ 
    if(cur < sl.length){
      cur++; 
    }
   }else if(e.key == 'k'){
    if(cur > 0){
      cur--;
    }
   }
   

To make it uglier the if can go...

   cur<sl.length && e.key=='j' && cur++;
   cur>0 && e.key=='k' && cur-- 

As it won't check the next condition if the first fails.

This hideous bit...

   b+=("j"==d)-("k"==d)

Could be slightly less ugly and one character shorter

   b+=d=="j";b-=d=="k"

Then we can shovel the other conditions inthere too!

   b+=d=="j"&&b<l;b-=d=="k"&&b>0

You see, with just a little effort we may improve nothing.

  (i = slide.nextElementSibling)?.className == "slidenote" ? i : slide
  ]),

An alternative approach:

  slide.querySelector(":scope+.slidenote") ?? slide

(|| would work just as well as ??, but ?? feels more appropriate.)

The original code is really nice:

  // golfed minslides, 173 bytes
  let a=document.getElementsByClassName("slide"),b=0,c=a.length-1;
  document.addEventListener("keypress",({key:d})=>{b+=("j"==d)-("k"==d),b=0>b?0:b>l?l:b,a[b].scrollIntoView()})

This is really cute!

I have a special spot in my heart for tools that do a good job of explaining themselves using their own outputs.

I wonder how hard it would be to add the cute old PowerPoint style transitions using CSS

I find the notes mode confusing. You can't tell if you're viewing a note or a slide.

Why would you use it? In PowerPoint the point of notes is to have an aside view for the presenter for extra info. Here all is revealed to the viewer.

Could add clicker support (which I have done previously). Note however that clickers vary between Up/Down and PgUp/PgDown. Enabling the former was potentially annoying if you like to use the arrow keys to scroll, so I made that configurable. Alternatively you configure mappings per device outside the browser.

Haha, I see people talking about slides everywhere, from specific moment in my life... that's when I started coding slidepicker.com!

Anyway, nice work! I created something similar for our product (a list of divs that switch visibility based on keyboard input).

I use HTML for my presentations and publish them online mentioning the URL at the top, such that people can open them on their device, which is often a smart phone. I take that into account for the interactive parts of the presentation.

    if( is_numeric($_GET['current']) ){
      file_put_contents( 'current.txt',$_GET['current']);
    }

one thing that I immediately noticed is that this site has no mobile support at all.

that's why I will link this presentation I made, in just a few hours, for a school project. it has mobile support, automatic fullscreen, and is still lightweight. unfortunately, I lost the code for the engine alone, so I only have the "exported product".

https://jotalea.com.ar/tests/tpanticx

I’m sure this is great on desktop but lack of mobile support today is kindof a bummer. It doesn’t even degrade gracefully.

self plug: one of my articles also has its own slide infrastructure (exposed to the reader as well!): https://maxbo.me/a-html-file-is-all-you-need.html#:~:text=Sl...

Nice, I hv been working on engine that renders pptx (without compromising original styles) in web browsers...

Maybe it would be easy to add the shortcuts g - jump to first slide G - jump to last slide