D2 LOG 073 – Rewrites, pt.2

Still at it with the Sokol migration and rewriting “some bits” of the game.

However, this activity has grown in scope and “some bits” now means I’ve touched almost every part of the codebase. I’m paring down many parts to make the game easier to tweak & debug.

I keep the Sokol implementation in a standalone project and keep switching between it and the full game, which still runs fine. At some point I will merge the two.

D2 log 072 – Rewriting (some bits)

While migrating the rendering & platform code to Sokol I saw a lot of my own old code. It was clumsy and convoluted. That made me happy: I could do it better now.

Decided to start a clean re-implementation of buttons and menus. I broke up the logic into smaller functions. One for the hover & click. Another for timing, to enable animating the states. And another one for keyboard navigation. The old code had all this mangled together. The new version is easier to maintain, extend and reuse.

Also changed the rendering of geometry primitives in the UI to use SDF instead of the old 9-patch technique. Much better!

I will continue with a few other bits, here and there, see how that goes.

D2 log 071 – Sokol

I’m porting my rendering code from OpenGL to the Sokol library. Sokol has a very nice low-level 3D API with multiple rendering backends (GL/Metal/D3D). It makes it much easier to experiment with new rendering techniques, especially when paired with the shader cross-compiler.

Still work in progress but I’ve done proof of concept tests for all major components of the game and everything seems to be OK.

I’m also using the Sokol app and audio libraries to completely replace SDL. The project feels much more lightweight without it.

New server

For the last few years I had been using DigitalOcean to host this website & a few others, file sync and my git repos. Fairly low traffic stuff on a single VPS instance. It was nice and cheap. But still… the recent 20% price increase got me thinking…

Can I build my own server?

Turns out I could! And it was a lot of fun.

I used a 10th generation Intel NUC with a 6-core i7 CPU, 32GB RAM and a 1TB NVMe SSD. Yes, overkill. But the key parameter is power usage. The whole system draws ~7W at idle. What a wonderful little machine!

For the OS I decided to install Ubuntu (22.04 LTS). I’m familiar with it and it was useful having the same OS on both systems. Then, some housekeeping on the old server:

  • removed old disconnected websites
  • put websites under separate user accounts
  • moved from Gogs to Gitea
  • organized my git repositories
  • setup a more thorough backup procedure

When I had everything ready, I brought the NUC to the new Prague data center and turned it on. It went online and the migration could begin. I started moving websites and services one by one. A few days later, the old VPS instance was empty and I turned it off.

CPU RAM Storage
DigitalOcean 1x vCPU 2GB 50GB + $extra
Intel NUC 6x CPU / 12 threads 32GB 1000GB

There’s plenty of headroom for no extra money and I feel like I’m more self-reliant.

To elaborate a little bit on the backup procedure:

  1. daily rsync (soon → rsnapshot)
  2. daily mysql dumps
  3. /etc and apt package list versioned in git
  4. secondary NUC ready for deployment
  5. backup VPS account ready for deployment  (prepaid credit)
  6. up-to-date checklist for configuring the whole software stack

D2 log 070 – Attack tokens

It looks ridiculous when all enemies attack the player at once. And it’s frustrating. We need to globally throttle the attack rate.

Inspired by this fascinating Doom talk, I implemented a token system. Before each attack, enemies must acquire a token for it. After the attack and some cooldown period, the token goes back into the “free” pool.

Changing the number of available tokens for each attack type and tweaking the cooldown periods are an easy way to adjust overall difficulty.

The state of the token queue can be used to determine pressure on the player. This will be a useful input for the dynamic sountrack…

D2 log 069 – Editor streamlining

While making a test level to try out some gameplay-related code I realized the editor had become a bit cumbersome to use. It was time for another round of editor improvements.

Some commands got moved into a global top menu bar, which helped a lot. Not all controls need to be always visible.

Second, I added a panel with the sorely needed list of all entities in a level. It automatically pans the camera to the selected entity and the next tab shows all its properties.

The navigation mesh was a separate layer of points and links with its own custom editing mode. I converted the navpoints into regular game entities. Same for the navmesh object which pulls them together and handles path search queries. Now the only custom code is the test mode (move origin/destination points around, editor draws the resulting path).

Finally, I upgraded all the editor icons. They were a total mess and adding new ones was a pain. Now they are all in a single Pixelmator document, ready to be exported with 1 click. The icons will not be seen by players but it helps me see quickly what’s what.

D2 log 068 – Water shader

Spent some time tinkering with shaders. It was fun but also hard to come up with something actually usable in the game.

Ended up with a subtle effect which is blended on top of the pre-rendered water surface. It doesn’t tile properly but the seam is hard to notice so I’m fine with it.

I also tried distortion for the bottom layer but UV wrapping is a problem because the tiles are in a texture atlas. Putting tiles in an array texture instead of an atlas would give me more options. Maybe next time…

D2 log 067 – Tiles, pt.3

Good progress on the tileset. I made basic outlines and shapes in Blender, then exported into Pixelmator for touchups and additional dirt layers.

First time I used Geometry Nodes in Blender. Fun!

The rest though, not so much… it’s a lot of work to make everything seamless, color matched and correctly exported. Listening to podcasts & GDC talks while working on the tileset helps a lot because it stops me from overthinking it. I really need to push through this one.

Still not the final version here; there’s an off-by-one error in my Geometry Nodes setup for the curb and one of the dirt layers is disabled.