An interactive fractal explorer.
This is my third Mandelbrotter.
brot2 was the previous incarnation, an interactive GTK+ application.
The original brot was written in C, output only to the terminal, and has long since been lost to the mists of time.
This time around it's in Rust and has quite the history.
- brot3 1.0 started out using Tauri and OpenSeadragon for its UI.
- Version 2.0 (never released) was an attempt to rework the GUI using slint.
- The 3.0 branch is a significant overhaul, rendering on the GPU using rust-gpu, with GUI using egui.
More notes to come here when things are in less of a state of flux...
N.B. You don't necessarily need a GPU card: I find this runs just fine on a PC with integrated graphics. If rust-gpu can talk to it, it will probably work.
Credit is due to @abel465 for creating:
- easy-shader-runner, which provided a very useful way for me to get started with Rust on the GPU;
- His own mandelbrot implementation, which I drew a lot of inspiration from;
- The abels-complex crate, which is GPU-friendly.
Credit is also due to the rust-gpu team past and present for creating the platform. While Rust on the GPU does have a bit of a "cursed subset of the language" feel, which is inherent to the nature of GPU programming, I have found it workable and performant so far in this use case.
Primary:
- Debian (I develop on 13/trixie; releases are built on Ubuntu 22.04)
Secondary:
- OSX (requires OSX 10.12 on x86_64, or 11.0 on Apple silicon)
- Windows 11
Binary releases can be found in github releases.
You need a GPU, or integrated graphics chip, that rust-gpu can talk to.
I have had success with the following:
- Intel iGPU (Ultra7 265K processor)
- AMD Radeon integrated graphics (Lenovo V15 laptop with Ryzen 7 CPU)
- nVidia RTX 3070 GPU (with AMD Ryzen 7 CPU)
- nVidia GT 755M (2014 iMac)
You only really need a recent version of the cargo tool.
We use a toolchain file to select the rust-gpu recommended toolchain, which is currently a specific nightly build that you're unlikely to have to hand. This is required as rust-gpu makes significant use of compiler internals.
Cargo will automatically install the required nightly toolchain if you don't already have it.
cargo run --locked will launch the GUI in interactive mode.
The useful feature flag combinations are:
| Flags passed to cargo | Result |
|---|---|
| None | Shader compiled at build time only. Recommended if you only want to browse the Mandelbrot set! |
-F hot-reload-shader |
Runtime shader compilation with hot reload |
-F runtime-compilation |
Runtime shader compilation without hot reload |
As you might imagine, the runtime compilation options add the cost of the spirv-builder to compile-time and binary size. This is only useful if you want to hack on the shader.
There are limited unit tests and benchmarks. More may be added later.
You may care to use an alternative linker to improve build times.
For example, if you want to use the wild linker (cargo binstall wild-linker) this is what you might put in your ~/.cargo/config.toml:
[target.x86_64-unknown-linux-gnu]
linker = "clang"
rustflags = ["-C", "link-arg=--ld-path=wild"]
See MAINTENANCE.md.