How/Where to do initial setup of application - image loading

[sww1235]

I have some data structs that are loaded via serde and contain SVG data inside them. As I need to display all the images found, I loop through all maps within them and load the images.

Right now, this is happening within the rendering process, which means it runs once a frame. Now I know the images are cached in theory and are not reloaded every frame but the looping through maps in theory still runs.

What is the best way to only run this code at application start or on demand?

[WojciechMula]

The best way to handle such cases is to have a queue of requested changes (it could be the simplest VecDeque from std). You're pushing to the queue request to load/reload images and, in each frame pop request(s) from queue and perform the appropriate action.

This gives you great freedom, as it's not important where & when you emit requests. The queue could be even pre-filled during application creation.

[sww1235]

I don't fully understand the reason for the queue here. I am trying to load a bunch of images into the image cache and create handles for them, without looping maps that potentially have thousands of items in them.

I can see it as message passing between threads, but not during application setup.

Think of what I am trying to do, is load a save file in a game. You only have to do that once, but the current implementation does that every frame.

[sww1235]

I wound up storing unique copies of the images in each of my instance structs, and updating those before the main GUI loop. Not ideal but it works.