Misc code cleanup (#3398)

* eframe README: explain how to enable copy/paste

* Implement Debug for a couple of structs

* Code cleanup

* Better docs

* profile ron serialization

* CI: Allow "exclude from changelog" as the only label

.github/workflows/labels.yml

@@ -29,4 +29,4 @@ jobs:
         with:
           mode: minimum
           count: 1
-          labels: "CI, dependencies, docs and examples, ecolor, eframe, egui_extras, egui_glow, egui_plot, egui-wgpu, egui-winit, egui, epaint, typo"
+          labels: "CI, dependencies, docs and examples, ecolor, eframe, egui_extras, egui_glow, egui_plot, egui-wgpu, egui-winit, egui, epaint, exclude from changelog, typo"

crates/eframe/README.md

@@ -28,6 +28,7 @@ You need to either use `edition = "2021"`, or set `resolver = "2"` in the `[work
 
 You can opt-in to the using [`egui_wgpu`](https://github.com/emilk/egui/tree/master/crates/egui_wgpu) for rendering by enabling the `wgpu` feature and setting `NativeOptions::renderer` to `Renderer::Wgpu`.
 
+To get copy-paste working on web, you need to compile with `export RUSTFLAGS=--cfg=web_sys_unstable_apis`.
 
 ## Alternatives
 `eframe` is not the only way to write an app using `egui`! You can also try [`egui-miniquad`](https://github.com/not-fl3/egui-miniquad), [`bevy_egui`](https://github.com/mvlabat/bevy_egui), [`egui_sdl2_gl`](https://github.com/ArjunNair/egui_sdl2_gl), and others.

crates/eframe/src/epi/icon_data.rs

@@ -14,6 +14,15 @@ pub struct IconData {
     pub height: u32,
 }
 
+impl std::fmt::Debug for IconData {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("IconData")
+            .field("width", &self.width)
+            .field("height", &self.height)
+            .finish_non_exhaustive()
+    }
+}
+
 impl IconData {
     /// Convert into [`image::RgbaImage`]
     ///

crates/eframe/src/epi/mod.rs

@@ -308,6 +308,7 @@ pub struct NativeOptions {
     pub resizable: bool,
 
     /// On desktop: make the window transparent.
+    ///
     /// You control the transparency with [`App::clear_color()`].
     /// You should avoid having a [`egui::CentralPanel`], or make sure its frame is also transparent.
     pub transparent: bool,

crates/eframe/src/native/file_storage.rs

@@ -130,6 +130,7 @@ fn save_to_disk(file_path: &PathBuf, kv: &HashMap<String, String>) {
             let mut writer = std::io::BufWriter::new(file);
             let config = Default::default();
 
+            crate::profile_scope!("ron::serialize");
             if let Err(err) = ron::ser::to_writer_pretty(&mut writer, &kv, config)
                 .and_then(|_| writer.flush().map_err(|err| err.into()))
             {

crates/egui-wgpu/src/lib.rs

@@ -123,6 +123,16 @@ pub struct WgpuConfiguration {
     pub on_surface_error: Arc<dyn Fn(wgpu::SurfaceError) -> SurfaceErrorAction>,
 }
 
+impl std::fmt::Debug for WgpuConfiguration {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("WgpuConfiguration")
+            .field("supported_backends", &self.supported_backends)
+            .field("present_mode", &self.present_mode)
+            .field("power_preference", &self.power_preference)
+            .finish_non_exhaustive()
+    }
+}
+
 impl Default for WgpuConfiguration {
     fn default() -> Self {
         Self {

crates/egui/src/load.rs

@@ -55,17 +55,20 @@
 mod bytes_loader;
 mod texture_loader;
 
-use crate::Context;
+use std::borrow::Cow;
+use std::fmt::Debug;
+use std::ops::Deref;
+use std::{error::Error as StdError, fmt::Display, sync::Arc};
+
 use ahash::HashMap;
+
 use epaint::mutex::Mutex;
 use epaint::util::FloatOrd;
 use epaint::util::OrderedFloat;
 use epaint::TextureHandle;
 use epaint::{textures::TextureOptions, ColorImage, TextureId, Vec2};
-use std::borrow::Cow;
-use std::fmt::Debug;
-use std::ops::Deref;
-use std::{error::Error as StdError, fmt::Display, sync::Arc};
+
+use crate::Context;
 
 pub use self::bytes_loader::DefaultBytesLoader;
 pub use self::texture_loader::DefaultTextureLoader;

crates/egui_demo_app/src/wrap_app.rs

@@ -165,6 +165,7 @@ pub struct WrapApp {
 
 impl WrapApp {
     pub fn new(cc: &eframe::CreationContext<'_>) -> Self {
+        // This gives us image support:
         egui_extras::install_image_loaders(&cc.egui_ctx);
 
         #[allow(unused_mut)]

crates/epaint/src/shape.rs

@@ -498,6 +498,8 @@ pub struct RectShape {
     ///
     /// To display a texture, set [`Self::fill_texture_id`],
     /// and set this to `Rect::from_min_max(pos2(0.0, 0.0), pos2(1.0, 1.0))`.
+    ///
+    /// Use [`Rect::ZERO`] to turn off texturing.
     pub uv: Rect,
 }
 

crates/epaint/src/text/font.rs

@@ -72,7 +72,7 @@ pub struct FontImpl {
     height_in_points: f32,
 
     // move each character by this much (hack)
-    y_offset: f32,
+    y_offset_in_points: f32,
 
     ascent: f32,
     pixels_per_point: f32,
@@ -111,22 +111,23 @@ impl FontImpl {
             scale_in_points * tweak.y_offset_factor
         } + tweak.y_offset;
 
-        // center scaled glyphs properly
-        let y_offset_points = y_offset_points + (tweak.scale - 1.0) * 0.5 * (ascent + descent);
+        // Center scaled glyphs properly:
+        let height = ascent + descent;
+        let y_offset_points = y_offset_points - (1.0 - tweak.scale) * 0.5 * height;
 
         // Round to an even number of physical pixels to get even kerning.
         // See https://github.com/emilk/egui/issues/382
         let scale_in_pixels = scale_in_pixels.round() as u32;
 
         // Round to closest pixel:
-        let y_offset = (y_offset_points * pixels_per_point).round() / pixels_per_point;
+        let y_offset_in_points = (y_offset_points * pixels_per_point).round() / pixels_per_point;
 
         Self {
             name,
             ab_glyph_font,
             scale_in_pixels,
             height_in_points: ascent - descent + line_gap,
-            y_offset,
+            y_offset_in_points,
             ascent: ascent + baseline_offset,
             pixels_per_point,
             glyph_info_cache: Default::default(),
@@ -283,7 +284,8 @@ impl FontImpl {
                 });
 
                 let offset_in_pixels = vec2(bb.min.x, bb.min.y);
-                let offset = offset_in_pixels / self.pixels_per_point + self.y_offset * Vec2::Y;
+                let offset =
+                    offset_in_pixels / self.pixels_per_point + self.y_offset_in_points * Vec2::Y;
                 UvRect {
                     offset,
                     size: vec2(glyph_width as f32, glyph_height as f32) / self.pixels_per_point,