render-bench VS ui-mock

render-bench -- scene update performance test fixture. This exercise rend3->wgpu->vulkan. It draws a city of identical buildings, then, from a second thread, periodically deletes half of them and re-creates them. If the stack is performing as intended, the updates from the second thread should not impact the frame rate from the main thread. But due to lock problems at the WGPU level, the frame time goes from 16ms to 700ms when the update happens.

It's quite possible to develop Rust for Windows without using Windows.

Try my open source "ui-mock".[1] This is a test of the cross-platform stack. Just get the repository with "git clone", and make sure you have Rust installed for target "x86_64-pc-windows-gnu". See the Cargo.toml file for build instructions.

This is a game-type user interface. It's just some menus and a 3D cube. It doesn't do much, but it exercises all the lower levels. This allows debugging cross-platform problems in a simple environment. The main crates used are winit (cross-plaform window event handling), wgpu (cross-plaform GPU handling), rfd (cross-platform file dialogs), keychain (cross-platform password storage), egui (Rust-native menus and dialogs), and rend3 (safe interface to wgpu). For graphics, it uses Vulkan, so it will run on Windows back to the last release of Windows 7. Not Windows 95, though; it's 64-bit. It will also run under Wine, so you don't even need a Windows system to test.

My metaverse client uses the same stack. It's compiled on Linux, and runs on both Linux and Windows. So I'm building a high-performance 3D graphics program for Windows without even owning a Windows system or using any Microsoft software.

[1] https://github.com/John-Nagle/ui-mock

Profiling on the CPU side is well handled by tracy, which is a game-oriented profiler. My programs render-bench and ui-mock are prepped for Tracy, as is Rend3, so you can try it out on them.

ui-mock -- game GUI test fixture This exercises rfd->egui->rend3->wgpu. It's a game GUI with menus and dialogs, but no game behind it, just a 3D drawing of a cube. It's useful for making bugs in that stack repeatable. That's been helpful in wringing out obscure bugs in egui.

Egui works well with Rend3. Here's my example and library for that. It's a dummy game UI; no game, but brings up menus atop Rend3 3D. Egui is very low level. Each dialog takes a lot of code. Something to generate dialogs from some kind of template would be useful. I have many of those to do. Incidentally, does anyone have examples of good color themes for egui? The default is shades of black on black, which is a bit harsh. I'd like to see some examples where the aesthetics are better.

There's an attempt to make this work for Rust desktop applications. There's the winit crate, which does cross-platform windowing and event loops. There's egui, for menus and subwindows. There's rfd, for file dialogs, which are special for security reasons. And there's wgpu, for cross-platform 3D.

I'm using all of these in my ui-mock,[1] which is a GUI for a game without the game. It has 3D graphics with 2D GUI elements on top. I'm using this to shake down all the cross-platform problems for my metaverse client. My own code, which is 100% safe Rust, has no platform dependent code.

Results are pretty good. There's minor dirty laundry in those libraries, which has been reported to the various maintainers. Stuff like this:

- You can get a file dialog hidden behind the main window, which, in a full screen program, is a real problem. Mostly a Linux problem; works fine on Windows.

- Full screen on Windows mode under Wine 7 crashes Wine. Known Wine bug.

- Warnings from WGPU, but it works around all of them with some minor performance loss.

- Cross-platform packaging, to make a Windows installer without Windows, isn't implemented yet.

So, not big stuff. A lot of stuff works that you might not expect to work, such as profiling with tracy. Wgpu is taking care of Vulkan vs Apple's Metal. (Apple just had to Think Different, to the annoyance of everybody doing 3D.) Opening a web page in the default browser is cross-platform. You can cross-compile - I build the Windows version on Linux, without using any Microsoft tools.

With some more work, I could make this work on WASM and Android as well, but that requires some special casing, mostly because WASM doesn't have proper threads.

So cross-platform desktop development is working pretty well. Most of the problems I'm running into would not appear in a more typical application.

[1] https://github.com/John-Nagle/ui-mock

I have a Rend3/Egui/WGPU program, https://github.com/John-Nagle/ui-mock