SourceModule load

Image loading§

If you just want to display some images, egui_extras will get you up and running quickly with its reasonable default implementations of the traits described below.

Loading process§

There are three kinds of loaders: - BytesLoader: load the raw bytes of an image - ImageLoader: decode the bytes into an array of colors - TextureLoader: ask the backend to put an image onto the GPU

The different kinds of loaders represent different layers in the loading process:

As each layer attempts to load the URI, it first asks the layer below it for the data it needs to do its job. But this is not a strict requirement, an implementation could instead generate the data it needs!

Loader trait implementations may be registered on a context with: - Context.add_bytes_loader - Context.add_image_loader - Context.add_texture_loader

There may be multiple loaders of the same kind registered at the same time. The try_load methods on Context will attempt to call each loader one by one, until one of them returns something other than LoadError.NotSupported.

The loaders are stored in the context. This means they may hold state across frames, which they can (and should) use to cache the results of the operations they perform.

For example, a BytesLoader that loads file URIs (file://image.png) would cache each file read. A TextureLoader would cache each combination of (URI, TextureOptions), and so on.

Each URI will be passed through the loaders as a plain str. The loaders are free to derive as much meaning from the URI as they wish to. For example, a loader may determine that it doesn't support loading a specific URI if the protocol does not match what it expects.