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When @hacdias.com posted about our conversation about post topics I couldn’t stay behind to also formulate my part of it in a blogpost.

Currently I have various feeds for various post types. I don’t want to link them all here, in case I want to change them around, but I have different feeds that only show my likes, my photos, my replies, etc (you can probably guess the URLs).

These feeds are relatively easy to set up: does it have a photo? Then it’s a photo. Does it have a title? Then it’s an article. This post doesn’t have any, so it’s a note. I have a few of those rules set up and they fill these pages.

But when you scroll through my photo feed, you will also see drawings. When you scroll through my notes, there are various topics represented. It is not that bad right now, but that is mainly because I don’t post as much as I could, because I don’t want to bore my readers with topics they don’t want to follow.

On social media, we live a siloed life, and the people on the IndieWeb are trying to bring that all back to their own site. But, in the siloed life, we can pick the silo for the post. ‘Insta is for friends, Twitter is more business, Reddit is shitposting’, something like that. Sometimes the silo is aimed at a certain kind of post, sometimes it is just the kind of bubble you created for yourself on that silo that makes you post a certain way.

On the IndieWeb, I have only one site. Of course I can get multiple – I have – but I like having all my posts in one place. But I also want to give people options for how to follow me, different persona to share posts with.

I do have tags but most are not that useful. Most of them only contain one post, and also, most of them are very specific. I like the indieweb and vim tags, for they are quite topical, but those are exceptions.

At one point (not now) I would like to divide posts up into probably five rough categories. The homepage might still show a selection of all, and there will also be a place to actually see everything, but I think these categories make sense to me:

  • professional / helpful for all those posts in which I share something about IndieWeb, Vim, something about programming, something I learned
  • personal for stories about what happened in my life, maybe also some tweets, the more human connection
  • too personal for checkins, books I’ve read, food I’ve eaten, movies I’ve watched, still about life but without commentary
  • art for those good pictures, occasional drawings, fiction stories, the things I post too little

I said five and I posted four, because I don’t think this is final. I might also want to add a ‘current obsession’ category, to blog about those things I am deeply into. (There has been posts about keyboards here, you missed Getting Things Done, currently I am into the game of Go again.)

A last category I might also need is ‘thinking out loud’, as this is a post that would fall into that. For what is worth, I’ll post it anyway.

Faster copy to clipboard in Vim

tl;dr: I just mapped Y to "+y and I am very pleased with it.

A coworker saw me copying some text out of Vim and humored me: everything seemed to happen like magic in my editor, but for a simple thing as copy and paste I needed a lot of keys.

It is true: in order to copy text within Vim, you can use the y command, combined with the motion of what you want to yank. So: yiw will yank inside a word, ggyG will go to the top of the file and then yank until the bottom (so, the whole file), yy will yank a full line. But these yanks are only pastable (with p) within Vim itself.

In order to get text out of Vim, you need to use a special register. Registers are a sort of named boxes, letters a to z, in which you can put snippets of text. To use it, you prefix your yank (or delete) with a quote: "ayi( will select register a and then yank the text within parentheses. To get to your system clipboard (the one all other programs use), you select the special register with "+.

Thus: my coworker saw me hunting for the "+y combination, probably. I almost always look at my keyboard when I do that, so awkward is the combination. But I just found a solution: Y.

nmap Y "+y
vmap Y "+y

By default, Y does a yy, which I never use, because it's inconsistent with other commands. D, for example is equivalent to d$, delete until the end of the line, same for C as c$. I guess it makes Y play along with V (line-wise visual select) and S (subsitute full line), but I always use yy anyway, so Y is free to use. When I now want to yank to my system clipboard, I just use Y instead of y and that's it.

You can also consider adding this as gy, which does not have a meaning, but g combines with various commands to activate variation of their meaning, so it's not a bad choice either. I mapped it to both and will see which one sticks.

Adding a prefix to TailwindCSS classes with VIM

Today we needed to add a TailwindCSS prefix to a small project we are building, to prevent clashes with other TailwindCSS classes on the same page. The setting in the tailwind.config.js was straightforward, we added this:

module.exports = {
  prefix: 'sf-',

... and now TailwindCSS will generate classes like .font-bold and .border-none as .sf-font-bold and .sf-border-none. Next up, we needed to replace all the classes in the project with their prefixed counterpart.

There were some plugins available to do this automagically in Webpack, but we decided we wanted to add them manually. A few of the classnames are dynamically set, and we doubted the plugins would find all those cases. Also: the plugins seemed to be old.

My co-worker started writing a regex for a search-and-replace, but soon stranded. You need to find the proper locations, and then within those locations, add the prefix. The prefix, however, is sometimes more of an infix, since there are other prefixes that are added before the prefix itself. See the class with md: for example:

<div className="bg-gray-100 px-4 md:px-0">
// Becomes:
<div className="sf-bg-gray-100 sf-px-4 md:sf-px-0">

While he worked on the regex and subsequently went to get coffee, I thought: I should be able to solve this in VIM in some way. I know I can make a visual selection and then type :! to get the selection as input into some shell command. If I pipe the lines to some script, I can then just split strings all I want.

One problem I ran into was that, if I make a visual selection within quotes (vi") and I then use the colon-exclamation to pipe it to some script (:'<,'>! php transform.php), I will receive the full line, as if I was using the line-wise V selection.

While searching the internet I thought: can I use a register here? And the internet had a solution for that. I ended up running the following command:

:vmap m "ay:call setreg('a', system('php transform.php', getreg('a')))<cr>gv"ap

This sets up a mapping for visual mode, and binds the m to do a series of things. It first selects the 'a' register and yanks ("ay). Since we are already in visual mode here, y is a direct yank of that selection. We are now in normal mode, so we continue to type out a command that calls a function to set register 'a' again with the output of a system call to php transform, taking in the current contents of register 'a'. We execute this command by pressing enter (<cr>). Register 'a' now contains the scripts output. We then re-select the last visual selection (gv in normal mode) and then paste from register 'a' ("ap). This effectively runs the script over the visually selected area.

I then just opened the alphabetically first file of the project and manually made visual selections that selected all the classnames. For this, I also temporary mapped m to vi", so I could just do mm once my cursor was in a className="..." (for which mouse mode is nice too: click + mm, very fast). Then, to get to each next file, just press ]f.

The project was small enough to do this last part so manually, but this at least saved me a lot of stops in between all the classnames, and also saved me the headache to scan for md: prefixes and pick the right spot. Even when the classnames were actually in a backtick-string it was no problem: as long as I defined a correct visual selection, m would replace things.

For completeness, here is transform.php:


$input = file_get_contents('php://stdin');

$classes = array_filter(explode(' ', $input));

$classes = array_map(function ($class) {
    $parts = explode(':', $class);
    $parts[count($parts)-1] = 'sf-'.$parts[count($parts)-1];
    return implode(':', $parts);
}, $classes);

echo implode(' ', $classes);
als antwoord op Henrique Dias

Nice to hear you are enjoying the series! (It turns out to be a series.) It also feels really good to have finally found a form again where I can cycle between writing code and writing blog posts about the code.

Looking forward to read your article && yaay it worked!

Edit: lol, next topic really is Webmentions: I had to manually send this one because I am certainly not parsing HTML with regex (I would never) and your rel has no quotes around it.

Next up must be Webmentions, I feel. I just posted this article with a lot of backlinks to old posts, but since I send all Webmentions in a synchronous way on first-post-visit, it took ages, and I actually got a 502 Bad Gateway out of my site. But I also need weekend, so we will see.

IndieAuth without IndieAuth.com

In February 2017, I added the ability for other people to log in to my site, both via IndieAuth and Twitter. Since June 2019 this feature is more useful, as I moved all my checkins to being ‘private’, meaning there is actually something to see (albeit sparsely posted).

For this, I used the now outdated and deprecated service IndieAuth.com, which back then was also used to log in to the IndieWeb wiki. Due to the confusion between IndieAuth.com (the service) and IndieAuth (the protocol), a new project called IndieLogin was started and the IndieWeb wiki moved to that one. Since it didn’t offer that login service to others, as IndieAuth.com did, I never switched.

Since this week I have a new IndieAuth endpoint for myself. (Meaning: a place I can use to prove my own identity to others.) Unfortunately, it is not compatible with the outdated IndieAuth.com, so I could not use it to prove my identity to my own site. Because this felt wrong (and because I had the IndieAuth flow in my head again now), I decided that my site needed to do that part of IndieAuth on it’s own as well.

Since I was at it, I also have Twitter login working via the new flow. That was easier, because the library support was more plug-and-play.

Juggling with cookies

Last week I wrote about my new setup where I run two applications, the old PHP and the new Elixir, behind an unusual NGINX configuration. For the aforementioned feature of authentication, I had to create even a bigger beast.

All the posts, and all the logic for showing or hiding private posts, are still in PHP. The new authentication is in Elixir. Both ends are storing the information about the current logged-in user in session cookies. How do I merge those two into one user experience?

Luckily, since both applications run under the same domain, the browser is actually unaware of the fact that there are two apps. It just sends all cookies back.

So, in PHP I ask for all headers, look for a cookie-one that is named _yak_key, and if it is there, it makes a direct localhost call to Yak, the Elixir server, with that cookie. Yak exposes one route that just returns the currently logged-in user as a JSON. If that call returns a user, PHP can set a cookie of its own.

Then for the logout, PHP used to redirect to the homepage, but now it redirects to the page that logs you out of Yak, which redirects to the homepage.

At some point this setup will change again, but for now it seems to me as a good way to make one further step in the features I want to support in the new version of my site, while keeping the old one running.

Oh yeah, you may hunt down that localhost-call that checks the login status. It is actually exposed to the outside world too. But if you can provide it with a cookie for a person that is not you, that person and I have a problem anyway, regardless of you knowing the endpoint.

Showing incorrect IndieAuth redirect_uri to the user

Last Thursday I started using my new IndieAuth endpoint, which I can use authorize apps build by others (like the Quill Micropub client), to do stuff with my site (like posting this blogpost for example). In the following weekend I added a lot more validations than just my password, making it a safer endpoint.

One of these validations is the redirect_uri. My previous endpoint already showed this to me on the login-page, so I could manually inspect it, which is a good practice. The spec, however, describes that one should fetch the client_id (which is a URL) and look for a link with the rel-value of `rel="redirect_uri", which can be either in the HTML or in the HTTP Header.

So this is what it (currently) normally looks like:

Image showing the redirect_uri in grey.

And this is what it looks like when the redirect_uri differs from scheme, domain and/or port, and is also not present in at the client_id.

Image showing the redirect_uri in red and with explanation, plus the discovered redirect_uri.

Note that it is okay for Quill not to advertise another redirect_uri, for it is redirecting to a URL with the same scheme, domain and port. It only needs to add the link if it wants a URL where one of these are different. It is now clearer that someone who is not Quill is trying to steal a token.

Yak, strangling PHP with Phoenix and NGINX

At the time of writing this blogpost, my site is written in PHP, and most of the code is many years old. One could call it a legacy application: I was not very good at organising code back when I started it, so it is a bit of a mess.

Like any legacy application, rewriting it would be costly. There are many features I don’t want to lose, but at the same time I don’t want to lock myself up and rewrite them all before I can show and use any work. This kind of ‘Big Bang release’ would eat up all my free time for the next months and my motivation probably won’t make it all the way through.

A Yak to shave

Yesterday I attended the first IndieWebCamp since ‘March 2020’ and I didn’t want to come empty handed. I forced myself to start a new project called Yak.

This is actually the fifth project called ‘Yak’ on my system, but it’s the first one I actually deployed. All the Yak-projects focus on a different part of the app, since there is always something you think you should do first before the rest can start.

The newest and deployed Yak consists of a new IndieAuth endpoint. I was able to shave off this part since IndieAuth tries to be decoupled from the rest of the site: its endpoint might even be on a different domain.

I didn’t go that route though: I decided to strangle.

The simple strangle

With ‘strangle’ I refer to the ‘Strangler Pattern’, after the now more friendly(?) Named term ’Strangler Fig Application’ by Martin Fowler. This plant grows around another tree, slowly taking over its shape and killing it in the process, so that eventually, all that remains is the fig.

In terms of Seblog.nl, I would like Yak to take over more and more features from the PHP-version, until finally Yak is my new CMS. I say ‘PHP-version’, be because yes, Yak is written in Elixir now. How would I go about taking over features then? My first attempt was this:

index index.html index.php;

location /auth {
    # ... proxy headers
    proxy_pass http://localhost:4001;

location / {
    try_files $uri $uri/ index.php$is_args$query_string;

location ~ \.php$ {
    fastcgi_pass unix:/var/run/php/php7.4-fpm.sock;
    fastcgi_index /var/www/seblog.nl/index.php;
    fastcgi_param SCRIPT_FILENAME $request_filename;
    fastcgi_param PATH_INFO $fastcgi_script_name;
    include fastcgi_params;

That’s a pretty normal PHP setup, but with one path as a proxy. Yak is listening to port 4001 and NGINX sends all traffic for /auth and sub-folders to it. (A firewall keeps visitors for 4001 from outside away, don’t worry.) This way I can have my IndieAuth endpoint be in a different application while still maintaining one domain to the outside.

But since this is my hobby project, I can get niftier.

Proxy all the things

The IndieAuth route is fairly well scoped and easily separated from the rest of the app. For creating posts via Micropub, I can also separate a route and then store the created posts in the same file folder (or database) since both apps run on the same machine. But not all features are that easily separated.

To make it myself easier to add new routes to Yak, I created the following monster:

index index.html;

location @yak {
    # ... proxy headers
    proxy_pass http://localhost:4001;
    proxy_intercept_errors on;
    error_page 404 = /index.php$is_args$query_string;
    error_page 502 = /index.php$is_args$query_string;

location / {
    try_files $uri @yak;

location ~ \.php$ {
    # same as previous PHP

Since Yak is pretty fast (the Phoenix framework logs its response times in microseconds instead of milliseconds), I decided to just route all traffic through Yak. If Yak has the answer, that answer will be the final answer. But all routes that get a 404 Not Found error from Yak, are given to PHP afterwards.

This way the old site still functions: PHP is not even aware that someone has looked at the request before it. I also added the 502 Bad Gateway just in case Yak is down, which I expect only to happen for brief moments during big configuration changing deployments.

A few details to note: it all starts by adding @yak as a final location to try_files. Only the last location can be a virtual one, otherwise I would have put PHP directly in that list. I did remove the $uri/ and removed index.php from the index directive at the top: without this the homepage was not delivered to Yak.

The other crucial bit is the proxy_intercept_errors on, because that traps the errors in the proxy and enables you to add cases for certain errors. With error_page 404 = /index.php$is_args$query_string I send them to PHP. Other errors from Yak, like 401 and 403, are still just rendered as they came from Yak.

Fixing my POST to Micropub

While the above does work for most of my site, it broke my Webmentions and Micropub. (Yes, I tried posting this a few hours ago.) The previously described method makes all requests in PHP come in as GET, which makes sense for rendering an error page.

After a lot of trial and error, reading NGINX documentation and even trying to get Yak to proxy, I decided to localise the few POST requests I needed to be PHP and added those explicit in NGINX.

location /webmention {
    try_files $uri $uri/ /index.php$is_args$args;
location /micropub {
    try_files $uri $uri/ /index.php$is_args$args;

Once I moved these endpoints to Yak, I can remove them from my NGINX.

Homebrew Website Club London

So, I am not in London and I am not even in the precise timezone as London, but since The Situation is still keeping us home, I got to attend Homebrew Website Club London.

It was mostly just some chatting about smoke detectors, automated blinds and visits to city water reservoirs, as one does on a HWC. We had a few on-topic points as well.

I told about the upcoming birthday of Seblog.nl, tomorrow, which got us down the path of looking up old versions of websites. Much is saved, but many things are lost as well. One thing we came to: if you are starting to code your own website, please learn how to use version control as soon as possible. I (and others) have lost old versions of our sites because we kept overwriting the old files with new changes. If I had discovered Git (or any other version control) earlier, I would have had the oldest versions still.

As a note to myself: I should read Peter's article that he mentioned, which is about this 'content archeology': bringing back old home-pages. I doubt I have enough time to excavate my own first version of Seblog.nl before tomorrow.

Calum also showed his new bookshelf page. It reminded me of my own page called /bieb (short Dutch for 'library'), and now I want to revisit that page as well. The past month, I've been playing around with Obsidian and this would be one of those places where my site could integrate with it. (Both Obsidian and the current iteration of my site run on raw text files.)

I also shared some of my plans around this integration but I am not ready to share those here. (Most of my projects become vaporware, sadly.) However, I feel encouraged that my idea was not totally a bad idea. (Only slightly.) That's why I like going to HWC's: they spark ideas and / or bring them further.

als antwoord op Ako Suzuki

The reason I follow your lessons is exactly because they are in Japanese!

  1. You just learn more Japanese by using it.

  2. As a Dutch person, I’m okay with English, but I’m not native and some words just better translate to Dutch. (深夜, ‘diep in de nacht’; まずい, ‘vies’)
als antwoord op Amber Wilson

It was about Zelda, I believe, and I kept it on a floppy instead of a server. It had a “secret page”, which was linked from one of the letters of a page header. It was a pretty obvious link though: I had no idea how to get rid of the underscore with just HTML.

VIM productivity is a lie: all the time you save with your fancy commands and macros, you loose again on bragging about them to your coworkers.

Due to The Situation I only listened to Dutch podcasts for a while. Today I went for a bike ride and I wanted to listen to some dev-related talk again, and yep, I really thought someone was ringing at me when the @_bikeshed started.

Let’s talk about ‘de’ and ‘het’

Speakers of Dutch may ignore this post. Learners of Dutch might be interested.

I offered Henrique to answer questions about Dutch, because I like learning languages myself, and know a bit about it, since it’s my native language and I’ve studied it. In the past I wanted to start a learning resource for it, but I figured I can just start on my own site first.

The first question is about ‘de’ and ‘het’, the two articles in Dutch. They can be confusing. And I hate to break it: I can clear some of the confusion, but they will always be hard to learn.

Genders as groups of nouns

Articles are weird things. Dutch has two, English has one, French and Spanish also have two, but German even has three. In French and Spanish, la is considered to be feminine, and le/el is considered to be masculine. One might ask: which one is masculine in Dutch, de or het? Unfortunately, the answer is that de is both masculine and feminine.

If we look at German, we have der, die and das. Here, der is masculine, die is feminine and das is neither. In the same way in Dutch: de is der and die combined, and het is das. We call it ‘onzijdig’, having no side.

I have never really understood the whole masculine/feminine thing. There is nothing masculine in the words itself. It is just that we have divided our nouns into groups (sometimes two groups, sometimes three or even more). We then let other words ‘react’ to these groups, which helps understanding the sentence if it contains a lot of words. Over time, linguists have put labels on these groups of words, and they used ‘masculine’ and ‘feminine’ to denote them, but they could have been ‘red’ and ‘green’ too.

When learning another language, these labels actually don’t make sense. Some words that are masculine in one language, end up feminine in the other. The same for German and Dutch: a word being das in German probably has a higher chance of being a het-word in Dutch, but there are no guarantees at all. (This is why I never dare to speak German, although I can understand it when written or spoken slowly.)

Is it ‘de’ or is it ‘het’?

Spanish has this nice rule where a lot of nouns end in either an -a or an -o sound. There are endings in German that will predict the gender of a word too. They are not really relyable though, and for Dutch, I don’t know of such rules. To be honest: you just have to ‘hear’ it.

This is the most horrible advise Dutch people will give with regards to de and het: I just hear it. There is nothing in the words itself that gives away why it will ‘sound good’. What Dutch people mean, is that they always hear a certain word – like ‘hond’ (dog) or ‘paard’ (horse) – in combination with a certain article (‘de hond’, ‘het paard’). We hear it so often, that we get used to it.

If I would have to give an advice for learning it: repeat the words. Hearing the combinations ‘de hond’ and ‘het paard’ often, make the connection. Try to feel that it ‘sounds good’ to hear ‘het dorp’ and ‘een bruin paard’. There is nothing more to it.

But I hope this helps: most words are de-words, but among common words, there are a lot of het-words. Said differently: try to focus on the het-words, for there are a lot of common words among them. Once you know a lot of common words, chances are that this new word you don’t know yet is just a de-word.

The one exception to all of this, are diminutive words, on which I might blog later. If it ends with -tje, -pje, -kje or -je in general, it’s probably a ‘verkleinwoordje’, and thus a het-word. So: ‘de hond’, ‘het hondje’; ‘het paard’, ‘het paardje’; ‘de piano’, ‘het pianootje’. If it got small, turned into a het-word.

The changing contexts

Earlier I said that other words ‘react’ to the gender of the noun. German has a reputation for this, and luckily Dutch lost almost all of it’s conjugations in this part. Except for one: sometimes, the ending -e gets lost for het-words. Let me give you some examples:

  • De hond is bruin. De bruine hond.
    The dog is brown. The brown dog.
  • Het paard is wit. Het witte paard.
    The horse is white. The white horse.
  • Een hond is grappig. Een grappige hond.
    A dog is funny. A funny dog.
  • Een paard is kalm. Een kalm paard.
    A horse is calm. A calm horse.

Note that in the last example, there is no extra -e on the adjective. This has nothing to do with the word ‘kalm’, but everything to do with the combination of ‘een’ and the het-word ‘paard’. In the context of een, the extra -e disappears for het-words, just to mess with you. (The difference between de/het and een is exactly the same as the and a/an in English.)

To add examples:

  • De kalme hond.
  • Een grappig paard.
  • Een wit paard.
  • Een bruin schaap. Het bruine schaap.
  • Een rode hond. De rode hond.
  • Een rood hondje. Het rode hondje.

Here, also, I would say that the only way out is to try and ‘feel’ that it ‘sounds good’ this way. But with these rules, you can at least find the other form that should ‘sound good’ based on the one pair you know that ‘sounds good’.

Hope this helps. I promise, Swedish is worse when it comes to nouns.

On Private Commenting Systems

Jan-Lukas wrote about an article by Matt from Write.as called Towards a Commenting System. The article describes a commenting system with two flavour: private and public. For private comments, an e-mail to the author is used; for public comments, one is prompted to publish the comment on their own space first and then notify the original post. It feels very IndieWeb friendly.

Then, Jan-Lukas points out his own site already does this with webmention (as does mine), and that he also has a contact form, which people could use to reply private (at the time of writing I have no contact form).

I like the idea of private comments taking another route than public comments. Just having a contact page is not the same though: to complete the idea you can link it with a call-to-action underneath your posts. Let’s not have illusions here: most people will probably not read my posts on my site but in their reader or some other syndicated copy. But, it would give a nice UX for those on my site.

It also reminds me of how stories on Instagram work. There is a text box underneath it, which the user can tab to type a message. This message is then sent as a direct message to the creator of the story, and not visible to anyone but the creator and the commenter. It seems to work in that context: I do reply to friends in that way sometimes, because it feels very personal.

Another point is that this keeps private comments easier to implement for some and actually possible for those with static generated sites. My site has a way for visitors to log in, and I can build some form of private comments in that way. It is, however, way more work to build and maintain a site that does this, and not everyone is willing to do so. Doing private comments via a different channel makes it easier to have them.

The flip-side is that private comments cannot be shared among a group in this way. If you open a post to a certain circle of friends on, say, Facebook, all those friends can comment and also comment on each other’s comments. This kind of interaction is very hard to do, though, if you don’t have the luxury of a central service that guards access to all the posts — like Facebook does.

The conversation is also more likely to be ephemeral, for there are only two readers, both responsible for keeping their copies, with no help of, say, the Internet Archive.

I remember a moment at IndieWebCamp Brighton when a session about private posts was about to start. Jeremy Keith walked out of the room while making a comment that he didn’t see private pages as something the Web needed. This does not mean I can’t have them, but it did make me think about why I want them and what they would mean to the Web and the world.

By putting the private comments on a separate channel, you are also removing them from the Web. This makes the Web a place for open and public conversations again. (Again: one could argue that thing on the ‘Private Web’ are not on the Web either.) The last few months I’ve been reading more blogs and I must say I really enjoy that open Web.

The separation of private comments creates a clearer boundary between the open and the private, and maybe that’s a good thing. It makes an easier question: it’s harder to answer “which people should be able to read this post?”, than it is to answer “does this concern only me and the author, or could there possibly be someone out there who’s interested?”.

No real plans for removal yet, but I keep being torn about private posts.

RSS is not dead you know (nor is Atom)

Quite a while I wrote about building a social reader[^ Then called IndieWeb reader, but social reader is the better term.], but these days I have to admit it went nowhere. The biggest problem with it being that I myself don’t really use any reader to consume stuff: I was not used to keeping up with blogs, I only used to mindlessly scroll through Instagram. These days I got the Twitter app back on my phone again, so I make my scrolls there too.

What does seem to work over the past two months or so, is that I occasionally look at the NetNewsWire Mac app, which I pinned to my dock. Seeing the icon makes me click on it, and this way I do read or skim blogs I follow. I organised stuff by social distance, or something close to it, like Ton suggested. I notice that it makes me sad some people I want to follow as a person are not available via RSS/Atom.

The experience on NetNewsWire is not quite the way I want it, but I figured it is better to use an imperfect setup than no setup at all. I really enjoy being in the loop with content I actually care about, sorted by how much I care about it (thanks Ton). Maybe from here I can improve things (including but not limited to my own RSS format).

NetNewsWire just released an iOS app, so I have to check that out too.

Random generators again

When I started coding around 2005, two questions kept me going: how on earth does a .php file on a server produce a different page if you append ?p=22 to it’s URL; and how do I make my own random generator? The magic of the former now disappeared behind pretty URL schemas (also: there isn’t much depth to it, it turned out), but the latter still catches me from time to time.

Back then, I was intrigued by the site Seventh Sanctum, which was and still is home to many generators. Want a wacky gadget, a quick name, or a wrestling move? One click of a button and you have 15. Heck, I wanted to give three examples so I clicked the ‘random generator’ button three times and it gave me these, like a generator that generates generators.

I made several generators myself, most notably: Randomon, an unfinished and thus empty picture with the height and name of a Poké/Digimon-like creature; the Stamboomgenerator, which draws a wacky family tree with Dutch names and surnames; and various attempts to generate artificial languages. Since I did not know about version control back then I probably lost a lot of it.

Drawing the new city

A few weeks ago, our Dungeon Master Mike showed us the map of the city our characters had just arrived at. It looked awesome: he had drawn roads, walls and it was filled with boxes that represent houses. He’s got time too much, I thought. Also, wouldn’t it be cool if you had a generator that just generates a map like that?

I had been playing with Rust and it’s modular game engine Piston, and you thought: wow, if Rust is really that fast, I can generate a lot of stuff. It ended with me, turning the Hello, World!-example of a spinning red cube into a red cube that could be panned around, with zoom and everything. It’s almost Google Maps, I imagined. Now I just have to make the map.

It was then that the Duck lead me to an article by Amit Patel about generating maps from noise. And then that lead me to his brilliant explanation about noise and just all the rest of his site.

See, back in the day, I quickly discovered that random is both your friend and your enemy in the game of generators. Too much randomness makes certain properties unbelievable. Also, I wasn’t very good at writing and thinking about code back then. The following is literally how the Stamboomgenerator chose how many children a certain family member would have:

$kinderen = array(0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,5,5,5,5,5,5,6,6,6,6,6,7,7,7,7,8,8,8,9,9,10);
$kinderen = $kinderen[rand(0,count($kinderen)-1)];

I tweaked it by hand, by just running it a lot of times, feeling whether or not the proportion would make sense. There is zero math behind it, I’ve studied Dutch literature, you know.

Everything has already been done

Studying the Red Blob Games site, and getting extra info about the terms on other sites and Youtube, I discovered so much more world (and math) behind these generators. Turns out it’s also called ‘procedural generation’, which gives better search results. Everything already exists, but you need the proper name to Google it.

I don’t recall if I found out about Perlin noise before or after finding the Red Blob Games site, but while reading the articles I keep having “oh but you could…”s and “if you just…”s, which are most of the time resolved by just another article that shows you how to do it. And they all come with an interactive example with sliders for you to adjust as to understand it better. It is a crazy treasure to find.

The whole thing made me also wander off into the world of 3D rendering, exploring OpenGL and linear algebra. It resulted in last weekend’s fiddling with Blender and a donut. This is a totally different topic, but that’s also a field where a lot of knowledge is shared around. There is so much to learn.

Generating my own world

I kept thinking about how to combine all the elements of map making with noise with other approaches, that would give me plate tectonics. I would then like to adjust the scale of generation from millions of years to just years and play out a simulation of human influence on that map, as to finally arrive at a generated city with an actual history.

For the history to play out, I need some form of grid system to divide the planet into manageable chunks. Luckily Amit has written about that too. But unlike me, he actually reads mathematics papers about this stuff, and thus knows that it’s impossible to divide a sphere into equal hexagons and stuff. (You need 12 pentagons.)

And then of course, he also did it: he made a thing that makes planets with tectonics. Including an example that renders in your browser, with slider to change some parameters. It is both so cool and so intimidating.

It’s not that I’m discouraged by the knowledge that someone else has already done things I wanted to do. It’s impossible to be original (and also: it’s impossible to exactly copy). But the intimidating part is all the math behind his stuff, and the complete lack of it on my side.

Still, with this knowledge I might just take some shortcuts with the world and go for the simulation path. It has been done, I know, that was what lead me to Perlin noise. There are just so many fascinating aspects of this topic.

Writing this blogpost probably makes it less likely for things happen, but I owe it to people like Amit to also think out loud sometimes, to share what I have found. Maybe more about this in the future.

Oh and by the way, Mike did not draw that map himself, as I found out. ’Ik heb wel wat beters te doen,’ he said laughingly.

als antwoord op Matthias Ott

‪Strava and an Apple Watch for me. But: the Strava app is no good at all. I use the native Apple Watch Workouts app, which is quite good, and an app called HealthFit to export from HealthKit to Strava (and maybe my own site, if only I found time).‬

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