Managed texture loading (#3297)

* add types from proposal * add load methods on `egui::Context` * implement loaders from proposal in `egui_extras` * impl `From<Vec2>` for `SizeHint` * re-export `SizeHint` from `egui` root * rework `svg` example to use new managed `Image` * split loaders into separate files + add logging * add `log_trace` * clean up `RetainedImage` from `svg` example * refactor ehttp loader response to bytes mapping * remove spammy trace * load images even without extension * fix lints * remove unused imports * use `Image2` in `download_image` * use `visuals.error_fg_color` in `Image2` error state * update lockfile * use `Arc<ColorImage>` in `ImageData` + add `forget` API * add `ui.image2` * add byte size query api * use iterators to sum loader byte sizes * add static image loading * use static image in `svg` example * small refactor of `Image2::ui` texture loading code * add `ImageFit` to size images properly * remove println calls * add bad image load to `download_image` example * add loader file extension support tests * fix lint errors in `loaders` * remove unused `poll-promise` dependency * add some docs to `Image2` * add some docs to `egui_extras::loaders::install` * explain `loaders::install` in examples * fix lint * upgrade `ehttp` to `0.3` for some crates * Remove some unused dependencies * Remove unnecessary context clone * Turn on the `log` create feature of egui_extras in all examples * rename `forget` and document it * derive `Debug` on `SizeHint` Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com> * round when converting SizeHint from vec2 Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com> * add `load` module docs * docstring `add_loader` methods * expose + document `load_include_bytes` * cache texture handles in `DefaultTextureLoader` * add `image2` doctest + further document `Image2` * use `Default` for default `Image2` options * update `image2` doc comment * mention immediate-mode safety * more fit calculation into inherent impl * add hover text on spinner * add `all-loaders` feature * clarify `egui_extras::loaders::install` behavior * explain how to enable image formats * properly format `uri` * use `thread::Builder` instead of `spawn` * use eq op instead of `matches` * inline `From<Arc<ColorImage>>` for `ImageData` * allow non-`'static` bytes + `forget` in `DefaultTextureLoader` * sort features * change `ehttp` feature to `http` * update `Image2` docs * refactor loader cache type --------- Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
2026-08-29 04:40:03 -04:00 · 2023-09-06 10:51:51 +02:00
parent 82704bebbf
commit ec671e754f
24 changed files with 1343 additions and 79 deletions
--- a/crates/egui_extras/src/loaders/svg_loader.rs
+++ b/crates/egui_extras/src/loaders/svg_loader.rs
@@ -0,0 +1,92 @@
+use egui::{
+    ahash::HashMap,
+    load::{BytesPoll, ImageLoadResult, ImageLoader, ImagePoll, LoadError, SizeHint},
+    mutex::Mutex,
+    ColorImage,
+};
+use std::{mem::size_of, path::Path, sync::Arc};
+
+type Entry = Result<Arc<ColorImage>, String>;
+
+#[derive(Default)]
+pub struct SvgLoader {
+    cache: Mutex<HashMap<(String, SizeHint), Entry>>,
+}
+
+fn is_supported(uri: &str) -> bool {
+    let Some(ext) = Path::new(uri).extension().and_then(|ext| ext.to_str()) else { return false };
+
+    ext == "svg"
+}
+
+impl ImageLoader for SvgLoader {
+    fn load(&self, ctx: &egui::Context, uri: &str, size_hint: SizeHint) -> ImageLoadResult {
+        if !is_supported(uri) {
+            return Err(LoadError::NotSupported);
+        }
+
+        let uri = uri.to_owned();
+
+        let mut cache = self.cache.lock();
+        // We can't avoid the `uri` clone here without unsafe code.
+        if let Some(entry) = cache.get(&(uri.clone(), size_hint)).cloned() {
+            match entry {
+                Ok(image) => Ok(ImagePoll::Ready { image }),
+                Err(err) => Err(LoadError::Custom(err)),
+            }
+        } else {
+            match ctx.try_load_bytes(&uri) {
+                Ok(BytesPoll::Ready { bytes, .. }) => {
+                    crate::log_trace!("started loading {uri:?}");
+                    let fit_to = match size_hint {
+                        SizeHint::Original => usvg::FitTo::Original,
+                        SizeHint::Width(w) => usvg::FitTo::Width(w),
+                        SizeHint::Height(h) => usvg::FitTo::Height(h),
+                        SizeHint::Size(w, h) => usvg::FitTo::Size(w, h),
+                    };
+                    let result =
+                        crate::image::load_svg_bytes_with_size(&bytes, fit_to).map(Arc::new);
+                    crate::log_trace!("finished loading {uri:?}");
+                    cache.insert((uri, size_hint), result.clone());
+                    match result {
+                        Ok(image) => Ok(ImagePoll::Ready { image }),
+                        Err(err) => Err(LoadError::Custom(err)),
+                    }
+                }
+                Ok(BytesPoll::Pending { size }) => Ok(ImagePoll::Pending { size }),
+                Err(err) => Err(err),
+            }
+        }
+    }
+
+    fn forget(&self, uri: &str) {
+        self.cache.lock().retain(|(u, _), _| u != uri);
+    }
+
+    fn byte_size(&self) -> usize {
+        self.cache
+            .lock()
+            .values()
+            .map(|result| match result {
+                Ok(image) => image.pixels.len() * size_of::<egui::Color32>(),
+                Err(err) => err.len(),
+            })
+            .sum()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn check_support() {
+        // inverse of same test in `image_loader.rs`
+        assert!(!is_supported("https://test.png"));
+        assert!(!is_supported("test.jpeg"));
+        assert!(!is_supported("http://test.gif"));
+        assert!(!is_supported("test.webp"));
+        assert!(!is_supported("file://test"));
+        assert!(is_supported("test.svg"));
+    }
+}