openjpeg VS egui

mkdir ~/install cd ~/install wget https://github.com/uclouvain/openjpeg/archive/master.zip unzip master.zip cd openjpeg-master/ mkdir build cd build cmake -DCMAKE_BUILD_TYPE=Release .. make sudo make install sudo make clean cd

Details here, if you like reading bug reports. It took the cooperation of developers at all four levels to fix this. I wrote a test project to reproduce the problem, the jpeg2k developer was able to reproduce the problem under valgrind (a tool for finding bad pointer references in C, seldom needed by Rust users), an OpenJPEG developer fixed the C code, and everybody in the chain updated versions. Thanks to everyone who had a part in this.

> The whole file is effectively a write-what-where primitive2. In addition to that, the Count Info Table is not bounds checked either...

File formats like that, with many offsets in the file, are troublesome. There used to be more formats like that. Microsoft Word .doc is the classic example.

OpenJPEG 2000 has a similar problem. I just hit that yesterday.[1] Valgrind is finding references to un-initialized data which affect control flow, and running the JPEG decoder on valid but truncated files (which is allowed) is causing bad memory reference crashes and errors.

New formats like this are rare. People have learned. A modern exception is Unreal Engine 5's Nanite has much offset data, and there may be an attack surface there for hostile game content. Nanite is a way to store a graphics mesh with both multiple levels of detail and common submeshes. It's a hierarchy of directed acyclic graphs, flattened into a linear file with offsets. And, sure enough, there are many crash reports. At least Unreal provides a validator for the format.

(If only C/C++ had slices in the language. Most of the things for which pointer arithmetic is used can be done with slices. Slices really are pointer arithmetic, with sanity.)

[1] https://github.com/uclouvain/openjpeg/issues/1459

JPEG 2000 decoder crashes Trying to read files at reduced resolution crashes with memory access errors. This is jpeg2k (Rust) calling jpeg2000-sys (Rust glue to C foreign function interfaces) calling OpenJPEG (all C). The problem can now be reproduced at the C level alone, under Valgrind. The developers of the top two levels have been very helpful, but the trouble is down in the rather painful C code at the bottom. The OpenJPEG maintainers are way behind on fixes, despite being funded.

It certainly was a risk in 2013, when the open source libraries were slow and riddled with bugs. Today, there are two stable, well maintained and fast open source libraries available:

https://github.com/uclouvain/openjpeg

Thanks for the feedback!

It is definitely fixable. Take a look at https://github.com/emilk/egui/issues/996 for some examples of how others have styled egui, or try out https://app.rerun.io/

Styling is done with `ctx.set_style`, but creating a nice style isn't very easy at the moment (basically you'll have to tweak constants in code, and then recompile). I'm working on making it easier as we speak though!

Nothing is wrong with that, it’s rather a workaround, ultimately I am trying to have one language only including the UI too (been playing with egui),so I don’t have to use JavaScript.

https://github.com/emilk/egui

FWIW, I opened an issue: https://github.com/emilk/egui/issues/4046

That's fair. I don't have experience with other immediate mode libraries. It's good to hear that it's not an intrinsic limitation

https://github.com/emilk/egui?tab=readme-ov-file#layout Here the author discusses the issue directly. They note that there are solutions to the issue, but that they all come with (in their opinion) significant drawbacks.

For my use case, if I have to do a lot of manual work to achieve what I consider behavior that should be handled by the framework, then I don't find that compelling and am inclined to use a retained mode implementation.

It totally depends on what IoT and what purpose, for example:

IIoT/PLC/industrial automation: most likely you will have to use vendors software, most if the time it’s crap, and a mix of several tech stacks like MSSQL/C#/C++

Sensors and such: depends on what are you building or using the sensors: the protocol mostly is MQTT, and if you would store it in a db postrrsql, elasticsearch, surreldb, influxdb among the most I used.

Robots/drones: on what I build, I use protobuf/grpc for performance and cross-language and direct linux socket io, and where needed websocket but mostly for any web interaction rather than the protocol itself. The tech stack for those, the embedded side is up to you or sometimes based on the sdk you are dealing with, the backend/frontend however, I used to use go/nodejs and for frontend svelte or a simple js library/framework, but recently I’m shifting and redoing everything in rust, embedded, backend and frontend (using something like egui https://github.com/emilk/egui).

When it comes to IoT, I try as much as possible to stay away from python unless you are scripting something else done in go/c++/rust, look at python as a glorified bash script, it’s useful for that or other data science work, but not in IoT.

Same goes with other tech you mentioned, it might suit one case but not another, for example, MQTT is good for sensor IoT type, but good luck controlling a drone with it, mongodb might be great to store a fleet of robots with its access credentials and such, but if you try to use it to store realtime data, it might not perform as expected, and so on.

AFAIK the Rust equivalent to C++'s Dear ImGui is egui.

The creator of Rerun (Emil Ernerfeldt) also created egui [1], an immediate GUI library for Rust. The library is similar to Dear ImGui but it is written in Rust and can be used for desktop and web apps (compiles to WASM and uses WebGL, demo [2]). Desktop apps can target OpenGL (does not display correct colors on macOS, does not work in VirtualBox on Windows) or WGPU (uses native APIs for each platform, works without any problems, but the binary is a big larger).

[1] https://github.com/emilk/egui

> [...] you can build UIs that are snappy and keyboard driven.

That's not an advantage that is exclusive to TUIs; after all, you're running your TUI inside a graphical application that emulates a terminal. (Unless you're rocking an actual VT102, in which case I bow down to you.)

In fact there's an entire class of applications that are extremely snappy and keyboard driven, by their very nature: games.

Some people have taken to writing GUI apps like you'd write a game, and the effects range from OK to fantastic. Check out Lagrange (https://gmi.skyjake.fi/lagrange/), AppManager (https://tildegit.org/solene/AppManager), Dear ImGUI (https://github.com/ocornut/imgui), egui (https://github.com/emilk/egui), and many others.

Honestly, frontend development especially with all these crowded frameworks and libraries always confused me so pardon my ignorance, which is why in a project I’m working on right now I’m trying not to use js, instead I’m using egui [1]

Zola is a static site generator and it’s crazy fast, using one binary only [2], also there’s Blades [3], same concept but supposedly faster, never tried it though.

[1] https://github.com/emilk/egui

[2] https://www.getzola.org

[3] https://getblades.org