experimental color emoji via opt-in egui_noto_emoji crate

.gitignore

@@ -9,3 +9,5 @@
 /.vscode
 /media/*
 .idea/
+/noto-emoji-*.zip
+multi-codepoint-emoji-support-plan.md

CHANGELOG.md

@@ -13,6 +13,14 @@ This is just the changelog for the core `egui` crate. Every crate in this reposi
 This file is updated upon each release.
 Changes since the last release can be found at <https://github.com/emilk/egui/compare/latest...HEAD> or by running the `scripts/generate_changelog.py` script.
 
+## Unreleased
+
+### Added
+* `Context::register_color_glyph` lets integrations and third-party crates register bitmap glyphs (for instance emoji atlases) directly on a context.
+
+### Changed
+* The built-in emoji atlas was split into the optional [`egui_noto_emoji`](crates/egui_noto_emoji) crate. Apps that want colorful emojis should add that crate and call `egui_noto_emoji::install(&ctx)` during startup.
+
 
 ## 0.33.2 - 2025-11-13
 ### ⭐ Added

Cargo.lock

@@ -1371,6 +1371,7 @@ dependencies = [
  "egui_demo_lib",
  "egui_extras",
  "egui_kittest",
+ "egui_noto_emoji",
  "ehttp",
  "env_logger",
  "image",
@@ -1461,6 +1462,15 @@ dependencies = [
  "wgpu",
 ]
 
+[[package]]
+name = "egui_noto_emoji"
+version = "0.33.2"
+dependencies = [
+ "egui",
+ "log",
+ "png",
+]
+
 [[package]]
 name = "egui_tests"
 version = "0.33.2"

Cargo.toml

@@ -6,6 +6,7 @@ members = [
   "crates/egui_demo_lib",
   "crates/egui_extras",
   "crates/egui_glow",
+  "crates/egui_noto_emoji",
   "crates/egui_kittest",
   "crates/egui-wgpu",
   "crates/egui-winit",
@@ -67,6 +68,7 @@ egui_demo_lib = { version = "0.33.2", path = "crates/egui_demo_lib", default-fea
 egui_glow = { version = "0.33.2", path = "crates/egui_glow", default-features = false }
 egui_kittest = { version = "0.33.2", path = "crates/egui_kittest", default-features = false }
 eframe = { version = "0.33.2", path = "crates/eframe", default-features = false }
+egui_noto_emoji = { version = "0.33.2", path = "crates/egui_noto_emoji" }
 
 accesskit = "0.21.1"
 accesskit_consumer = "0.30.1"

README.md

@@ -124,7 +124,7 @@ Still, egui can be used to create professional looking applications, like [the R
 * Widgets: label, text button, hyperlink, checkbox, radio button, slider, draggable value, text editing, color picker, spinner
 * Images
 * Layouts: horizontal, vertical, columns, automatic wrapping
-* Text editing: multiline, copy/paste, undo, emoji supports
+* Text editing: multiline, copy/paste, undo, emoji via opt-in glyph packs
 * Windows: move, resize, name, minimize and close. Automatically sized and positioned.
 * Regions: resizing, vertical scrolling, collapsing headers (sections), panels
 * Rendering: Anti-aliased rendering of lines, circles, text and convex polygons.
@@ -366,6 +366,15 @@ Default fonts:
 * `NotoEmoji-Regular.ttf`: [google.com/get/noto](https://google.com/get/noto), [SIL Open Font License](https://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=OFL)
 * `Ubuntu-Light.ttf` by [Dalton Maag](http://www.daltonmaag.com/): [Ubuntu font licence](https://ubuntu.com/legal/font-licence)
 
+Color emoji sprites now live in the separate [`egui_noto_emoji`](crates/egui_noto_emoji) crate so that core egui stays lean.
+Opt in by adding the crate to your project and calling:
+
+```rust
+egui_noto_emoji::install(&ctx);
+```
+
+You can also iterate over `egui_noto_emoji::EmojiStore::builtin()` yourself if you need finer control over which glyphs are registered.
+
 ---
 
 <div align="center">

crates/egui/Cargo.toml

@@ -25,7 +25,6 @@ rustdoc-args = ["--generate-link-to-definition"]
 
 [features]
 default = ["default_fonts"]
-
 ## [`bytemuck`](https://docs.rs/bytemuck) enables you to cast [`epaint::Vertex`], [`emath::Vec2`] etc to `&[u8]`.
 bytemuck = ["epaint/bytemuck"]
 

crates/egui/src/context.rs

@@ -1,10 +1,12 @@
 #![warn(missing_docs)] // Let's keep `Context` well-documented.
 
-use std::{borrow::Cow, cell::RefCell, panic::Location, sync::Arc, time::Duration};
+use std::{
+    borrow::Cow, cell::RefCell, collections::BTreeMap, panic::Location, sync::Arc, time::Duration,
+};
 
 use emath::GuiRounding as _;
 use epaint::{
-    ClippedPrimitive, ClippedShape, Color32, ImageData, Pos2, Rect, StrokeKind,
+    ClippedPrimitive, ClippedShape, Color32, ColorImage, ImageData, Pos2, Rect, StrokeKind,
     TessellationOptions, TextureId, Vec2,
     emath::{self, TSTransform},
     mutex::RwLock,
@@ -367,6 +369,8 @@ impl ViewportRepaintInfo {
 #[derive(Default)]
 struct ContextImpl {
     fonts: Option<Fonts>,
+    /// Registry of opt-in bitmap glyphs (e.g. emojis) that should be replayed into every font atlas.
+    color_glyphs: BTreeMap<char, Arc<ColorImage>>,
     font_definitions: FontDefinitions,
 
     memory: Memory,
@@ -409,6 +413,13 @@ struct ContextImpl {
 }
 
 impl ContextImpl {
+    fn register_color_glyph_arc(&mut self, character: char, image: Arc<ColorImage>) {
+        self.color_glyphs.insert(character, image.clone());
+        if let Some(fonts) = self.fonts.as_mut() {
+            fonts.register_color_glyph(character, image.clone());
+        }
+    }
+
     fn begin_pass(&mut self, mut new_raw_input: RawInput) {
         let viewport_id = new_raw_input.viewport_id;
         let parent_id = new_raw_input
@@ -580,9 +591,15 @@ impl ContextImpl {
             )
         });
 
-        {
+        let fonts_recreated = {
             profiling::scope!("Fonts::begin_pass");
-            fonts.begin_pass(max_texture_side, text_alpha_from_coverage);
+            fonts.begin_pass(max_texture_side, text_alpha_from_coverage)
+        };
+
+        if is_new || fonts_recreated {
+            for (&character, image) in &self.color_glyphs {
+                fonts.register_color_glyph(character, image.clone());
+            }
         }
     }
 
@@ -3601,6 +3618,20 @@ impl Context {
         }
     }
 
+    /// Register a bitmap glyph (such as an emoji sprite) that should be rendered verbatim whenever
+    /// the given character appears in text.
+    ///
+    /// Call this during initialization, before you start queuing lots of text, to avoid
+    /// unnecessary atlas churn.
+    pub fn register_color_glyph(&self, character: char, image: crate::ColorImage) {
+        self.register_color_glyph_arc(character, Arc::new(image));
+    }
+
+    /// Same as [`Self::register_color_glyph`], but lets you share the underlying image allocation.
+    pub fn register_color_glyph_arc(&self, character: char, image: Arc<crate::ColorImage>) {
+        self.write(|ctx| ctx.register_color_glyph_arc(character, image));
+    }
+
     /// Release all memory and textures related to images used in [`Ui::image`] or [`crate::Image`].
     ///
     /// If you attempt to load any images again, they will be reloaded from scratch.

crates/egui/src/lib.rs

@@ -598,20 +598,9 @@ macro_rules! github_link_file {
 /// The minus character: <https://www.compart.com/en/unicode/U+2212>
 pub(crate) const MINUS_CHAR_STR: &str = "−";
 
-/// The default egui fonts supports around 1216 emojis in total.
-/// Here are some of the most useful:
-/// ∞⊗⎗⎘⎙⏏⏴⏵⏶⏷
-/// ⏩⏪⏭⏮⏸⏹⏺■▶📾🔀🔁🔃
-/// ☀☁★☆☐☑☜☝☞☟⛃⛶✔
-/// ↺↻⟲⟳⬅➡⬆⬇⬈⬉⬊⬋⬌⬍⮨⮩⮪⮫
-/// ♡
-/// 📅📆
-/// 📈📉📊
-/// 📋📌📎📤📥🔆
-/// 🔈🔉🔊🔍🔎🔗🔘
-/// 🕓🖧🖩🖮🖱🖴🖵🖼🗀🗁🗋🗐🗑🗙🚫❓
-///
-/// NOTE: In egui all emojis are monochrome!
+/// egui ships with monochrome glyphs (sourced from Ubuntu/Noto), but no longer bundles a color emoji atlas by default.
+/// Opt into color sprites by adding the `egui_noto_emoji` crate to your project and calling
+/// [`egui_noto_emoji::install`] early during startup.
 ///
 /// You can explore them all in the Font Book in [the online demo](https://www.egui.rs/#demo).
 ///

crates/egui_demo_app/Cargo.toml

@@ -47,6 +47,7 @@ eframe = { workspace = true, default-features = false, features = ["web_screen_r
 egui = { workspace = true, features = ["callstack", "default"] }
 egui_demo_lib = { workspace = true, features = ["default", "chrono"] }
 egui_extras = { workspace = true, features = ["default", "image"] }
+egui_noto_emoji.workspace = true
 image = { workspace = true, default-features = false, features = [
   # Ensure we can display the test images
   "png",

crates/egui_demo_app/src/wrap_app.rs

@@ -182,6 +182,8 @@ impl WrapApp {
     pub fn new(cc: &eframe::CreationContext<'_>) -> Self {
         // This gives us image support:
         egui_extras::install_image_loaders(&cc.egui_ctx);
+        // Opt-in emoji support now lives in a separate crate, so demos stay representative.
+        egui_noto_emoji::install(&cc.egui_ctx);
 
         #[cfg(feature = "accessibility_inspector")]
         cc.egui_ctx

crates/egui_demo_lib/benches/benchmark.rs

@@ -209,7 +209,10 @@ pub fn criterion_benchmark(c: &mut Criterion) {
 
             let mut rng = rand::rng();
             b.iter(|| {
-                fonts.begin_pass(max_texture_side, egui::epaint::AlphaFromCoverage::default());
+                let _ = fonts.begin_pass(
+                    max_texture_side,
+                    egui::epaint::AlphaFromCoverage::default(),
+                );
 
                 // Delete a random character, simulating a user making an edit in a long file:
                 let mut new_string = string.clone();

crates/egui_noto_emoji/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+name = "egui_noto_emoji"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+authors = ["Emil Ernerfeldt <[email protected]>"]
+description = "Optional Noto emoji bundle for egui"
+homepage = "https://github.com/emilk/egui/tree/main/crates/egui_noto_emoji"
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/emilk/egui/tree/main/crates/egui_noto_emoji"
+
+[lints]
+workspace = true
+
+[features]
+default = []
+
+## Bundle the low-resolution vibrant emoji atlas instead of the default mid-resolution one.
+emoji_low_res = []
+
+## Bundle the high-resolution vibrant emoji atlas instead of the default mid-resolution one.
+emoji_high_res = []
+
+## Turn on the `log` feature, so we can log texture loading failures.
+log = ["dep:log"]
+
+[dependencies]
+egui = { workspace = true }
+png = "0.17"
+log = { workspace = true, optional = true }

crates/egui_noto_emoji/src/lib.rs

@@ -0,0 +1,38 @@
+//! Optional emoji bundle for egui.
+//!
+//! This crate keeps the heavy atlas and loader in a separate crate so core egui stays lean.
+
+mod store;
+
+pub use store::{EmojiEntry, EmojiStore};
+
+use egui::Context;
+
+/// Register the bundled emoji atlas on the provided [`egui::Context`].
+///
+/// Call this once during startup, right after you have access to the context.
+pub fn install(ctx: &Context) {
+    register_store(ctx, &EmojiStore::builtin());
+}
+
+/// Register every emoji entry in a store.
+pub fn register_store(ctx: &Context, store: &EmojiStore) {
+    for entry in store.entries() {
+        register_entry(ctx, entry);
+    }
+}
+
+/// Register a single emoji sprite, keeping ASCII digits/#/* rendered by the base fonts.
+pub fn register_entry(ctx: &Context, entry: &EmojiEntry) {
+    if is_keycap_component(entry.ch()) {
+        return;
+    }
+
+    ctx.register_color_glyph_arc(entry.ch(), entry.image_arc());
+}
+
+/// Single ASCII characters that are part of the keycap emoji sequences.
+/// Those sequences require multiple code points, so keep the plain glyphs rendered by the base fonts.
+fn is_keycap_component(c: char) -> bool {
+    matches!(c, '#' | '*' | '0'..='9')
+}