Language history

Sourcepole

• Geospatial software: QGIS, QGIS Web Client and more
• Developing in Python, C++, Javascript, Ruby and also Rust:
  • t-rex vector tile server

Why Rust?

History

• Originally developed at Mozilla
• Servo browser engine
• 2015: Version 1.0
• 2021: The Rust Foundation

Hello World

fn main() {
    println!("Hello world!");
}

Variables

let x = 5;
println!("The value of x is: {}", x);
x = 6; // <-- Error: error[E0384]: cannot assign twice to immutable variable `x`
println!("The value of x is: {}", x);

Mutable variable

let mut x = 5;
println!("The value of x is: {}", x);
x = 6;
println!("The value of x is: {}", x);

Data types

• u8, u16, u32, u64
• i8, i16, i32, i64
• f32, f64
• usize, isize
• bool
• Characters, Tuples, Arrays

Functions

fn area(width: u32, height: u32) -> u32 {
    width * height
}

fn main() {
    println!("area={}", area(4, 3));
}

Control Flow

if Expressions

if number % 2 == 0 {
    println!("even");
} else {
    println!("odd");
}

while Expressions

while number != 0 {
    println!("{}!", number);
    number -= 1;
}

for loop

for number in 1..4 {
    println!("{}!", number);
}

Structs

struct Rectangle {
    width: u32,
    height: u32,
}

let rect = Rectangle {
    width: 3,
    height: 4,
};

Methods

impl Rectangle {
    fn area(&self) -> u32 {
        self.width * self.height
    }
}

let area = rect.area();

Enums

enum ImageType {
    Png,
    Jpeg,
    Tiff,
}

let image_type = ImageType::Png;

Enums with data

enum Color {
    Rgb(u8, u8, u8),
    Transparent,
}

let color = Color::Rgb(255, 0, 0);

match control flow operator

match color {
    Color::Rgb(r, g, b) => println!("{}/{}/{}", r, g, b),
    Color::Transparent => println!("No Color"),
}

if let

if let Color::Rgb(r, g, b) = color {
    println!("{}/{}/{}", r, g, b);
}

Generic data types

struct Point<T> {
    x: T,
    y: T,
}

let integer = Point { x: 5, y: 10 };
let float = Point { x: 1.0, y: 4.0 };

Option

enum Option<T> {
    None,
    Some(T),
}

if let Some(v) = vec.pop() {
    println!("{}", v);
}

Traits

trait Shape {
    fn area(&self) -> u32;
}

impl Shape for Rectangle {
    fn area(&self) -> u32 {
        self.width * self.height
    }
}

Closures

for i in (1..10).filter(|&x| x % 2 == 0) {
    println!("{}", i);
}

More

• Modules
• Multi-threading
• async/await
• Error handling with Result type
• unsafe
• Efficient C bindings
• Macros

Derive-Macros

#[derive(Serialize)]
struct Rectangle {
    width: u32,
    height: u32,
}

Standard library

• Primitive types
• String, Arc, Mutex, …
• Container and collections
  • (Vec, HashMap, Iterator, …)
• I/O: Files, UDP/TCP
• Multithreading
• Macros: println, assert, …

Testing & Documentation

• Built-in Testing
• Benchmark tests
• Built-in documentation generator

https://docs.rs/

Cargo package manager

• Manage dependencies
• Format code
• Compile code
• Run application
• Run tests
• Create documentation
• Create packages for publishing
• Extensible

https://crates.io

Geospatial primitives and algorithms

• Geo - Geospatial primitives such as Point & LineString, and algorithms such as distance, convex hull, centroidcalculations.
• spade - Spatial datastructures like r-trees and delaunay triangulations for Rust.
• geographiclib-rs - A port of geographiclib (geodesic calculations).

Geospatial primitives and algorithms (bindings)

• GEOS - Bindings for the Geometry Engine - Open Source (GEOS) library.
• PROJ - Bindings for the PROJ library for coordinate transformation and projections.

Handling GIS data formats

• GeoZero - Zero-Copy reading and writing of geospatial data.
• GeoJSON - Work with GeoJSON files.
• GeoTIFF - Work with GeoTIFF raster files.
• image-tiff - TIFF decoding and encoding library in pure Rust.
• FlatGeobuf - A performant binary encoding for geographic data based on flatbuffers.
• las-rs - Read and write ASPRS las files.

Handling GIS data formats (bindings)

• GDAL - Bindings for the Geographic Data Abstraction Library (GDAL) for reading and writing raster and vector GIS files.

More crates

• osmpbfreader-rs - Read OpenStreetMap PBF files.
• rstar - R*-tree library for the rust ecosystem.

More topics:

• Raster and image processing
• Routing
• 3D (Meshes, TINs)
• Geocoding
• Map rendering

Applications

• t-rex - Vector tile server specialized on publishing MVT tiles from your own data
• Martin - Blazing fast and lightweight PostGIS vector tiles server
• WhiteboxTools - Geospatial data analysis platform with more than 445 tools for processing various types of geospatial data.
• A/B Street - A traffic simulation game exploring how small changes to roads affect cyclists, transit users, pedestrians, and drivers.

Awesome Geo Rust

https://github.com/pka/awesome-georust

Community

• https://github.com/georust/
• Discord chat

Where to start

• https://www.rust-lang.org/learn
• Books, e.g. “Programming Rust” (O’Reilly)

Thank you!

@implgeo