Both @cissyspeaks.bsky.social and Sean Vanaman were kind enough to comment on it on Twitter back when I uploaded it

In the middle of my little production, news broke that a production company had acquired the rights for a film adaptation @keithcalder.com

I shot it in Manning Park, BC. After weeks of research I found a lookout that looks very similar to the one in the game: Monument 83

YouTube video by Lennart Breede FIREWATCH - Title Sequence

Going through my backlog of short films I made and stumbled across my favorite project, a title sequence for Firewatch: youtu.be/mDCWPsSlQOM?...

I wrote it all up — including a Python implementation — in my latest post:
How Hash Maps Work (From Scratch)

🛠️ Buckets, hashes, resizing, the whole thing:
👉 lbreede.github.io/quartz/how-h...

#BuildSlowThings
#TIL
#programming #hashmaps #rust #python #dataStructures

That’s what makes hash maps fast:

Good hashing
Resizing at the right time
Rehashing keys to rebalance the buckets
All this work to make map["key"] feel instant.

When the load factor (length / capacity) crosses ~0.7, we double the array size...

…and then we rehash every key.

Because:

hf("some key") % 3 == 1
hf("some key") % 20 == 10

Changing the capacity changes everything.

Okay, but what happens if you keep inserting?

Buckets get longer → scan time goes up → things get slow.
So we resize.

Insertion = scan the bucket.
If the key exists, update the value.
If not, append it.

Lookup? Same thing:
Hash, mod, scan the bucket for a match.

But what if two keys land in the same slot?
We don’t overwrite — we use separate chaining:

[
[],
[("a", 1), ("b", 2)],
[]
]

Each bucket is a list of key–value pairs.

You start with a hash function: something like
hf(key) -> int

Hash the key → turn it into an index with % capacity → store it in an array.

Simple, right?

TIL how hash maps actually work under the hood.
(aka: how dict, map, or HashMap magically give you fast lookups.)

Turns out… it's not magic — it's buckets, hashing, and resizing.

Let’s build one from scratch.

🧵👇

Thank you!

Moving away from Rust is sad but man it feels good to just write code without fighting with your borrow-checker

Huge shoutout to @gingerbill.org for his gamedev live streams. I was on my own for my fights agains xml and csv though.. skill issue?

Rewrote my little isometric game engine in #Odin and #raylib
Now that it supports tile sets and maps from Tiled, it's much more fun to run around in it #gamedev #indiegame

Press F5 for debug mode #indiegame #rust #raylib

State machines are fun. The `Pickup` state basically blocks player input for a couple of frames until switching to `Idle` once the animation is over #indiegame #rust #raylib

He's a runner #indiegame #rust #raylib