Function egui_extras::install_image_loaders

source · 
pub fn install_image_loaders(ctx: &Context)
Expand description

Installs a set of image loaders.

Calling this enables the use of egui::Image and egui::Ui::image.

⚠ This will do nothing and you won’t see any images unless you also enable some feature flags on egui_extras:

  • file feature: file:// loader on non-Wasm targets
  • http feature: http(s):// loader
  • image feature: Loader of png, jpeg etc using the image crate
  • svg feature: .svg loader

Calling this multiple times on the same egui::Context is safe. It will never install duplicate loaders.

  • If you just want to be able to load file:// and http:// URIs, enable the all_loaders feature.
  • The supported set of image formats is configured by adding the image crate as your direct dependency, and enabling features on it:
egui_extras = { version = "*", features = ["all_loaders"] }
image = { version = "0.24", features = ["jpeg", "png"] } # Add the types you want support for

⚠ You have to configure both the supported loaders in egui_extras and the supported image formats in image to get any output!

Loader-specific information

⚠ The exact way bytes, images, and textures are loaded is subject to change, but the supported protocols and file extensions are not.

The file loader is a BytesLoader. It will attempt to load file:// URIs, and infer the content type from the extension. The path will be passed to std::fs::read after trimming the file:// prefix, and is resolved the same way as with std::fs::read(path):

  • Relative paths are relative to the current working directory
  • Absolute paths are left as is.

The http loader is a BytesLoader. It will attempt to load http:// and https:// URIs, and infer the content type from the Content-Type header.

The image loader is an ImageLoader. It will attempt to load any URI with any extension other than svg. It will also try to load any URI without an extension. The content type specified by BytesPoll::Ready::mime always takes precedence. This means that even if the URI has a png extension, and the png image format is enabled, if the content type is not one of the supported and enabled image formats, the loader will return LoadError::NotSupported, allowing a different loader to attempt to load the image.

The svg loader is an ImageLoader. It will attempt to load any URI with an svg extension. It will not attempt to load a URI without an extension. The content type specified by BytesPoll::Ready::mime always takes precedence, and must include svg for it to be considered supported. For example, image/svg+xml would be loaded by the svg loader.

See egui::load for more information about how loaders work.