Adding GUI under new event loop structure

[rchiaramo]

Hi all,

I’m writing a GPU raytracer using wgpu (version 22.0.0) and winit (0.30.4). I’m rendering images to the screen successfully, and I would now like to add GUI support so that I can change some render parameters in real-time.

Imgui seemed simple. I copied the imgui-winit-support and imgui-wgpu files locally and did some simple updates to get the initialization code working. This code lives in the resumed function call, done when I initialize my window and wgpu_state (which contains my device and queue for example).

I’m struggling to understand where in the event loop scheme the actual imgui code would go. In older examples, there was a MainEventsCleared event, and it appears that all of the render timers and GUI specific code was stored there. I was thinking perhaps that this code now belongs in the new_events function, but I’m not really sure and don’t have a lot of experience with this stuff. I’ve basically been learning by example.

Essentially, I don’t understand the difference between the window_event function and the new_event function, which is called first, whether the GUI stuff needs to be handled as a window_event or can be something else, etc.

Any advice appreciated!!

[madsmtm]

MainEventsCleared was renamed to about_to_wait IIRC, but in general you should render inside WindowEvent::RedrawRequested.

[rchiaramo]

Thank you!