While I’m still a bit sour that Mozilla decided to use the same name for their language as an old project of mine (which is not a new thing for Mozilla anyway, if someone remembers the days of Phoenix and Firebird), I have been looking from the sideline as the Rust language as a way forward to replace so many applications of embedded C, with a significantly safer alternative.
I have indeed been happy to see so much UEFI work happening in Rust, because it seems to me like we came far enough that we can sacrifice some of the extreme performance of C for some safety.
But one thing that I still have not seen is a good selection of graphics libraries, and that is something that I’m fairly disappointed by. Indeed, I have been told that there are Rust bindings for the classic C graphics libraries — which is pointless, as then the part that needs safety (the parsing) is still performed in C!
The reason why I’m angry about this is that I still have one project, unpaper, which I inherited as a big chunk of C and could definitely be rewritten into a safer language. But I would rather not do so in a higher level language like Python due to the already slow floating point calculations and huge memory usage.
Right now, unpaper is using libav, or ffmpeg, or something with their interface, depending on how much they fought this year. This is painful, but given that each graphic library implements interfaces in different ways, I couldn’t find a better and safe way to implement graphics processing. I was hoping that with all the focus on Rust out there, particularly from Mozilla, implementing graphics parsing libraries would be high in the list of priorities.
I think it’s librsvg that was ported to Rust — which was probably a great idea to prioritize, given it is exactly the type of format where C performs very poorly: string parsing. But I’m surprised nobody tried to make an API-compatible libpng or libtiff. It sounds to me like Rust is the perfect language for this type of work.
At any rate, if anyone finally decides to implement a generic graphic file input/output library, with at least support for TIFF, PNM and PNG, I’d love to know. And after that I would be happy to port unpaper to it — or if someone wants to take unpaper code as the basis to reimplement it as a proof of concept, that’d be awesome.
The problem for a lot of these libraries is that you have to maintain support for a long list of quirks and extensions that over time piled up on the formats. And while you can easily write tests to maintain bit-wise compatibility with the “original” C language based libraries for what concerns bitmap rendering (even for non-bitmap graphics such as JPEG and WebP), there are more things that are not obvious to implement, such as colour profiles, and metadata in general.
Actually, I think that there is a lot of space here to build up a standard set of libraries for graphics libraries and metadata, since there’s at least some overlapping between these, and having a bigger group of people working on separate, but API-similar libraries for various graphic formats would be a significant advantage for Rust over other languages.
There is an ‘image’ crate (https://crates.io/crates/image) (though I haven’t used it). It seems that it uses image encoders/decoders that are written in Rust without depending on C code.