Add a "Nethack Level Generation" series page and move a bunch of basic content there.

content/blog/2023/nethack-level-generator/index.md

@@ -1,6 +1,43 @@
 ---
-title: "Nethack Level Generator"
+title: "Nethack's Rooms & Corridors Generator"
 date: 2023-02-05T09:08:07-08:00
 draft: true
+series: "Nethack Level Generation"
+categories: Tech
+tags: [Nethack, Programming]
 ---
 
+## Rectangles
+
+## Placing Rooms
+
+[`makerooms`][makerooms_func] uses a "random rect" algorithm to create up to `MAXNROFROOMS` rooms. It iteratively
+generates a random rectancle
+
+`create_room`
+
+`sort_rooms`
+
+## Digging Corridors
+
+[`makecorridors`][makecorridors_func]
+
+[`join`][join_func]
+
+`dig_corridor`
+
+## Special Features
+
+`make_niches`
+
+`do_vault`
+
+`create_vault`
+
+## Special Rooms
+
+[nh36]: https://github.com/NetHack/NetHack/tree/NetHack-3.6
+[mklevc_file]: https://github.com/NetHack/NetHack/blob/NetHack-3.6/src/mklev.c
+[makerooms_func]: https://github.com/NetHack/NetHack/blob/59b117c655731bdf1f8b92c57bdb786119927f3a/src/mklev.c#L223
+[makecorridors_func]: https://github.com/NetHack/NetHack/blob/59b117c655731bdf1f8b92c57bdb786119927f3a/src/mklev.c#L319
+[join_func]: https://github.com/NetHack/NetHack/blob/59b117c655731bdf1f8b92c57bdb786119927f3a/src/mklev.c#L244

content/series/nethack-level-generation/_index.md

@@ -0,0 +1,39 @@
+---
+title: "Nethack's Level Generation"
+date: 2023-02-05T09:08:07-08:00
+draft: true
+---
+
+I recently became interested in how Nethack generates levels. It has a distinctive feel that's uniquely Nethack, and
+that can't be perfectly replicated with "room and corridor" algorithms that I've studied so far. Nethack's source code
+is freely available on Github, though as I discovered while researching for this article, having it available doesn't
+mean it's easy to understand.
+
+I'm basing this entire series on the [Nethack 3.6][nh36] branch.
+
+## Basics
+
+It's written in C, using C89 style function declarations. You see a lot of functions defined like this, with the types
+of arguments defined below the function declaration:
+
+```c
+int
+a_function(a, b, c)
+int a, b;
+char c
+{
+    // ...
+}
+```
+
+The standard Dungeons of Doom map style is a hallmark of Nethack, Hack, and Rogue. Given this long lineage, the map
+generator is (I suspect) one of the older parts of the codebase. A lot of the architectural decisions reflect a differen
+time and place: it strives to be extremely memory and CPU efficient, reuses global in-memory structures rather than
+declaring new ones, and generally makes due with less as often as possible. This includes variable names too.
+
+Most of this happens in [`mklev.c`][mklevc_file].
+
+Levels are always 80 columns by 21 rows in size.
+
+[nh36]: https://github.com/NetHack/NetHack/tree/NetHack-3.6
+[mklevc_file]: https://github.com/NetHack/NetHack/blob/NetHack-3.6/src/mklev.c