Trait egui::load::TextureLoader

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pub trait TextureLoader {
    // Required methods
    fn id(&self) -> &str;
    fn load(
        &self,
        ctx: &Context,
        uri: &str,
        texture_options: TextureOptions,
        size_hint: SizeHint
    ) -> TextureLoadResult;
    fn forget(&self, uri: &str);
    fn forget_all(&self);
    fn byte_size(&self) -> usize;

    // Provided method
    fn end_frame(&self, frame_index: usize) { ... }
}
Expand description

A TextureLoader uploads a ColorImage to the GPU, returning a SizedTexture.

egui comes with an implementation that uses Context::load_texture, which just asks the egui backend to upload the image to the GPU.

You can implement this trait if you do your own uploading of images to the GPU. For instance, you can use this to refer to textures in a game engine that egui doesn’t otherwise know about.

Implementations are expected to cache each combination of (URI, TextureOptions).

Required Methods§

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fn id(&self) -> &str

Unique ID of this loader.

To reduce the chance of collisions, include module_path!() as part of this ID.

For example: concat!(module_path!(), "::MyLoader") for my_crate::my_loader::MyLoader.

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fn load( &self, ctx: &Context, uri: &str, texture_options: TextureOptions, size_hint: SizeHint ) -> TextureLoadResult

Try loading the texture from the given uri.

Implementations should call ctx.request_repaint to wake up the ui once the texture is ready.

The implementation should cache any result, so that calling this is immediate-mode safe.

Errors

This may fail with:

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fn forget(&self, uri: &str)

Forget the given uri.

If uri is cached, it should be evicted from cache, so that it may be fully reloaded.

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fn forget_all(&self)

Forget all URIs ever given to this loader.

If the loader caches any URIs, the entire cache should be cleared, so that all of them may be fully reloaded.

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fn byte_size(&self) -> usize

If the loader caches any data, this should return the size of that cache.

Provided Methods§

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fn end_frame(&self, frame_index: usize)

Implementations may use this to perform work at the end of a frame, such as evicting unused entries from a cache.

Implementors§