Sguaba: Type-safe spatial math in Rust

Jon Gjengset explains how to design a type-safe library for spatial coordinate systems and transformations in Rust.

There are a wide variety of ways to describe the locations of objects in space. To name a few, there is: WGS84, the well-known Earth-bound system of latitude and longitude; ECEF (“Earth-centered, Earth-fixed”), a Cartesian coordinate system fixed to Earth’s axes; NED (“North, East, Down”), a coordinate system that describes where in compass directions a given object is relative to an observer; or FRD (“Front, Right, Down”), which describes where a given object is relative to the facing direction of an observer. And to make matters worse, points in all of these systems except WGS84 can be expressed in Cartesian coordinates (ie, X, Y, and Z), spherical coordinates (ie, angle to pole, angle on XY plane, and radius), or horizontal coordinates (ie, azimuth, elevation, and distance). When we write software for systems that have to handle real-world coordinates, the question of what coordinate system those coordinates are in, and how they’re represented, comes up a lot. And getting it wrong in even a single place opens the door to disastrous consequences. To that end, for work, I wrote the now-open-source crate Sguaba (named after the self-navigating boat of the Celtic deity Manannán mac Lir that is navigated solely by the thoughts of its pilot). Sguaba is a Rust crate that strongly types coordinates and vectors with their respective coordinate system, and implements conversions between them. In this talk, presented at the Rust Amsterdam meetup @ BlockTech, I go into the complexities of spatial math, as well as how we can use the type system to encode those complexities away. Plus, answers to lots of questions! Sguaba open-source announcement from Helsing: blog.helsing.ai/sguaba-hard-to-misuse-rigid-body-transforms-… Sguaba on GitHub: github.com/helsing-ai/sguaba You can find the slides at jon.thesquareplanet.com/slides/sguaba/ (or an export at jon.thesquareplanet.com/slides/sguaba/export.pdf). 0:00:00 Introduction 0:01:28 Talk 0:31:40 Q&A