First part of font loading/fallback support

Also supports a lot more text styling but still not all of it.

Author: valadaptive

Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "ab_glyph"
@@ -1517,7 +1517,6 @@ dependencies = [
 name = "epaint"
 version = "0.31.1"
 dependencies = [
- "ab_glyph",
  "accesskit",
  "ahash",
  "backtrace",
@@ -1527,14 +1526,15 @@ dependencies = [
  "ecolor",
  "emath",
  "epaint_default_fonts",
+ "etagere",
  "log",
  "nohash-hasher",
  "parking_lot",
  "parley",
  "profiling",
  "rayon",
  "serde",
- "swash",
+ "swash 0.2.1 (git+https://github.com/valadaptive/swash?branch=tight-bounds)",
 ]
 
 [[package]]
@@ -1563,6 +1563,25 @@ version = "3.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a5d9305ccc6942a704f4335694ecd3de2ea531b114ac2d51f5f843750787a92f"
 
+[[package]]
+name = "etagere"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc89bf99e5dc15954a60f707c1e09d7540e5cd9af85fa75caa0b510bc08c5342"
+dependencies = [
+ "euclid",
+ "svg_fmt",
+]
+
+[[package]]
+name = "euclid"
+version = "0.22.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ad9cdb4b747e485a12abb0e6566612956c7a1bafa3bdb8d682c5b6d403589e48"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "event-listener"
 version = "5.3.1"
@@ -3086,7 +3105,7 @@ dependencies = [
  "peniko",
  "serde",
  "skrifa",
- "swash",
+ "swash 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -3937,6 +3956,12 @@ version = "2.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
+[[package]]
+name = "svg_fmt"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce5d813d71d82c4cbc1742135004e4a79fd870214c155443451c139c9470a0aa"
+
 [[package]]
 name = "svgtypes"
 version = "0.13.0"
@@ -3955,7 +3980,17 @@ checksum = "13d5bbc2aa266907ed8ee977c9c9e16363cc2b001266104e13397b57f1d15f71"
 dependencies = [
  "skrifa",
  "yazi",
- "zeno",
+ "zeno 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "swash"
+version = "0.2.1"
+source = "git+https://github.com/valadaptive/swash?branch=tight-bounds#46eafa8b69e07b31da163556cb85989a9f99ba42"
+dependencies = [
+ "skrifa",
+ "yazi",
+ "zeno 0.3.2 (git+https://github.com/valadaptive/zeno?branch=tight-bounds)",
 ]
 
 [[package]]
@@ -5412,6 +5447,11 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cc0de2315dc13d00e5df3cd6b8d2124a6eaec6a2d4b6a1c5f37b7efad17fcc17"
 
+[[package]]
+name = "zeno"
+version = "0.3.2"
+source = "git+https://github.com/valadaptive/zeno?branch=tight-bounds#1c5e5eb226e05e21a8efa1925df36a58d6bbbd72"
+
 [[package]]
 name = "zerocopy"
 version = "0.7.35"

README.md

@@ -145,11 +145,11 @@ Light Theme:
 ## Dependencies
 `egui` has a minimal set of default dependencies:
 
-* [`ab_glyph`](https://crates.io/crates/ab_glyph)
 * [`ahash`](https://crates.io/crates/ahash)
 * [`bitflags`](https://crates.io/crates/bitflags)
 * [`nohash-hasher`](https://crates.io/crates/nohash-hasher)
 * [`parking_lot`](https://crates.io/crates/parking_lot)
+* [`parley`](https://crates.io/crates/parley)
 
 Heavier dependencies are kept out of `egui`, even as opt-in.
 All code in `egui` is Wasm-friendly (even outside a browser).

crates/egui/src/context.rs

@@ -394,7 +394,6 @@ impl ViewportRepaintInfo {
 #[derive(Default)]
 struct ContextImpl {
     fonts: Option<FontStore>,
-    font_definitions: FontDefinitions,
 
     memory: Memory,
     animation_manager: AnimationManager,
@@ -552,33 +551,29 @@ impl ContextImpl {
     fn update_fonts_mut(&mut self) {
         profiling::function_scope!();
         let input = &self.viewport().input;
-        let pixels_per_point = input.pixels_per_point();
         let max_texture_side = input.max_texture_side;
 
-        if let Some(font_definitions) = self.memory.new_font_definitions.take() {
-            // New font definition loaded, so we need to reload all fonts.
-            self.fonts = None;
-            self.font_definitions = font_definitions;
-            #[cfg(feature = "log")]
-            log::trace!("Loading new font definitions");
-        }
+        let mut new_font_definitions =
+            if let Some(font_definitions) = self.memory.new_font_definitions.take() {
+                Cow::Owned(font_definitions)
+            } else if let Some(fonts) = &self.fonts {
+                Cow::Borrowed(fonts.definitions())
+            } else {
+                Cow::Owned(FontDefinitions::default())
+            };
 
         if !self.memory.add_fonts.is_empty() {
             let fonts = self.memory.add_fonts.drain(..);
+            let font_definitions = new_font_definitions.to_mut();
             for font in fonts {
-                self.fonts = None; // recreate all the fonts
                 for family in font.families {
-                    let fam = self
-                        .font_definitions
-                        .families
-                        .entry(family.family)
-                        .or_default();
+                    let fam = font_definitions.families.entry(family.family).or_default();
                     match family.priority {
                         FontPriority::Highest => fam.insert(0, font.name.clone()),
                         FontPriority::Lowest => fam.push(font.name.clone()),
                     }
                 }
-                self.font_definitions
+                font_definitions
                     .font_data
                     .insert(font.name, Arc::new(font.data));
             }
@@ -587,28 +582,43 @@ impl ContextImpl {
             log::trace!("Adding new fonts");
         }
 
-        let mut is_new = false;
+        let mut did_change_fonts = false;
 
-        let fonts = self.fonts.get_or_insert_with(|| {
-            #[cfg(feature = "log")]
-            log::trace!("Creating new Fonts for pixels_per_point={pixels_per_point}");
+        // If we changed the font definitions this frame, or self.fonts previously did not exist, new_font_definitions
+        // must be Cow::Owned. Set the font definitions.
+        let fonts = if let Cow::Owned(new_font_definitions) = new_font_definitions {
+            did_change_fonts = true;
+            if let Some(fonts) = self.fonts.as_mut() {
+                fonts.set_definitions(new_font_definitions);
+                did_change_fonts = true;
+                fonts
+            } else {
+                self.fonts.get_or_insert_with(|| {
+                    #[cfg(feature = "log")]
+                    log::trace!("Creating new FontStore");
 
-            is_new = true;
-            profiling::scope!("FontStore::new");
-            FontStore::new(max_texture_side, self.font_definitions.clone())
-        });
+                    did_change_fonts = true;
+                    profiling::scope!("FontStore::new");
+                    FontStore::new(max_texture_side, new_font_definitions)
+                })
+            }
+        } else {
+            self.fonts
+                .as_mut()
+                .expect("new_font_definitions is borrowed, but we had nowhere to borrow it from")
+        };
 
         {
             profiling::scope!("FontStore::begin_pass");
             fonts.begin_pass(max_texture_side);
         }
 
-        if is_new && self.memory.options.preload_font_glyphs {
+        if did_change_fonts && self.memory.options.preload_font_glyphs {
             profiling::scope!("preload_font_glyphs");
             // Preload the most common characters for the most common fonts.
             // This is not very important to do, but may save a few GPU operations.
-            for font_id in self.memory.options.style().text_styles.values() {
-                fonts.font(font_id).preload_common_characters();
+            for font_style in self.memory.options.style().text_styles.values() {
+                fonts.preload_common_characters(font_style);
             }
         }
     }
@@ -1495,11 +1505,10 @@ impl Context {
 
             let font_id = TextStyle::Body.resolve(&self.style());
             self.fonts(|f| {
-                let font = f.font(&font_id);
-                font.has_glyphs(alt)
-                    && font.has_glyphs(ctrl)
-                    && font.has_glyphs(shift)
-                    && font.has_glyphs(mac_cmd)
+                f.has_glyphs_for(&font_id, alt)
+                    && f.has_glyphs_for(&font_id, ctrl)
+                    && f.has_glyphs_for(&font_id, shift)
+                    && f.has_glyphs_for(&font_id, mac_cmd)
             })
         };
 
@@ -2909,7 +2918,7 @@ impl Context {
     }
 
     fn fonts_tweak_ui(&self, ui: &mut Ui) {
-        let mut font_definitions = self.write(|ctx| ctx.font_definitions.clone());
+        let mut font_definitions = self.fonts(|fonts| fonts.definitions().clone());
         let mut changed = false;
 
         for (name, data) in &mut font_definitions.font_data {

crates/egui/src/debug_text.rs

@@ -6,7 +6,8 @@
 //! to get callbacks on certain events ([`Context::on_begin_pass`], [`Context::on_end_pass`]).
 
 use crate::{
-    text, Align, Align2, Color32, Context, FontFamily, FontId, Id, Rect, Shape, Vec2, WidgetText,
+    text::{self, style::FontId},
+    Align, Align2, Color32, Context, Id, Rect, Shape, Vec2, WidgetText,
 };
 
 /// Register this plugin on the given egui context,
@@ -92,7 +93,7 @@ impl State {
         let mut bounding_rect = Rect::from_points(&[pos]);
 
         let color = Color32::GRAY;
-        let font_id = FontId::new(10.0, FontFamily::Proportional);
+        let font_id = FontId::system_ui(10.0);
 
         for Entry { location, text } in entries {
             {

crates/egui/src/input_state/mod.rs

@@ -1386,7 +1386,7 @@ impl InputState {
             .text_styles
             .get_mut(&crate::TextStyle::Body)
             .unwrap()
-            .family = crate::FontFamily::Monospace;
+            .family = crate::text::style::GenericFamily::Monospace.into();
 
         ui.collapsing("Raw Input", |ui| raw.ui(ui));
 

crates/egui/src/introspection.rs

@@ -1,27 +1,31 @@
 //! Showing UI:s for egui/epaint types.
+
+use epaint::text::style::GenericFamily;
+
 use crate::{
-    epaint, memory, pos2, remap_clamp, vec2, Color32, CursorIcon, FontFamily, FontId, Label, Mesh,
-    NumExt, Rect, Response, Sense, Shape, Slider, TextStyle, TextWrapMode, Ui, Widget,
+    epaint, memory, pos2, remap_clamp, text::style::FontId, vec2, Color32, ComboBox, CursorIcon,
+    Label, Mesh, NumExt, Rect, Response, Sense, Shape, Slider, TextStyle, TextWrapMode, Ui, Widget,
 };
 
-pub fn font_family_ui(ui: &mut Ui, font_family: &mut FontFamily) {
-    let families = ui.fonts(|f| f.families());
-    ui.horizontal(|ui| {
-        for alternative in families {
-            let text = alternative.to_string();
-            ui.radio_value(font_family, alternative, text);
-        }
-    });
-}
-
 pub fn font_id_ui(ui: &mut Ui, font_id: &mut FontId) {
-    let families = ui.fonts(|f| f.families());
-    ui.horizontal(|ui| {
+    let families = ui.fonts(|f| f.families().to_owned());
+    ui.horizontal_wrapped(|ui| {
         ui.add(Slider::new(&mut font_id.size, 4.0..=40.0).max_decimals(1));
-        for alternative in families {
-            let text = alternative.to_string();
-            ui.radio_value(&mut font_id.family, alternative, text);
-        }
+        ComboBox::from_id_salt(ui.next_auto_id())
+            .selected_text(font_id.family.first_family().to_string())
+            .show_ui(ui, |ui| {
+                for generic in GenericFamily::ALL {
+                    let text = generic.to_string();
+                    ui.selectable_value(&mut font_id.family, generic.into(), text);
+                }
+
+                ui.separator();
+
+                for alternative in families {
+                    let text = alternative.to_string();
+                    ui.selectable_value(&mut font_id.family, alternative.into(), text);
+                }
+            });
     });
 }
 

crates/egui/src/lib.rs

@@ -464,7 +464,7 @@ pub use emath::{
 };
 pub use epaint::{
     mutex,
-    text::{FontData, FontDefinitions, FontFamily, FontId, FontTweak},
+    text::{FontData, FontDefinitions, FontTweak},
     textures::{TextureFilter, TextureOptions, TextureWrapMode, TexturesDelta},
     ClippedPrimitive, ColorImage, CornerRadius, ImageData, Margin, Mesh, PaintCallback,
     PaintCallbackInfo, Shadow, Shape, Stroke, StrokeKind, TextureHandle, TextureId,
@@ -473,8 +473,9 @@ pub use epaint::{
 pub mod text {
     pub use epaint::text::{
         cursor::{ByteCursor, Selection},
-        FontData, FontDefinitions, FontFamily, FontStore, Galley, LayoutJob, LayoutSection,
-        TextFormat, TextWrapping, TAB_SIZE,
+        style::{self, TextFormat},
+        FontData, FontDefinitions, FontStore, Galley, LayoutJob, LayoutSection, TextWrapping,
+        TAB_SIZE,
     };
 }
 

crates/egui/src/memory/mod.rs

@@ -277,6 +277,10 @@ pub struct Options {
     ///
     /// This can lead to fewer texture operations, but may use up the texture atlas quicker
     /// if you are changing [`Style::text_styles`], or have a lot of text styles.
+    ///
+    /// TODO(valadaptive): preload_font_glyphs used to do something, but the new text layout code rasterizes at subpixel
+    /// offsets, and I don't feel like rasterizing all 4 offsets for every glyph ahead of time. Is preload_font_glyphs
+    /// actually useful or just a placebo?
     pub preload_font_glyphs: bool,
 
     /// Check reusing of [`Id`]s, and show a visual warning on screen when one is found.

crates/egui/src/painter.rs

@@ -2,14 +2,14 @@ use std::sync::Arc;
 
 use emath::GuiRounding as _;
 use epaint::{
-    text::{Fonts, Galley, LayoutJob},
+    text::{style::FontId, Fonts, Galley, LayoutJob},
     CircleShape, ClippedShape, CornerRadius, PathStroke, RectShape, Shape, Stroke, StrokeKind,
 };
 
 use crate::{
     emath::{Align2, Pos2, Rangef, Rect, Vec2},
     layers::{LayerId, PaintList, ShapeIdx},
-    Color32, Context, FontId,
+    Color32, Context,
 };
 
 /// Helper to paint shapes and text to a specific region on a specific layer.

crates/egui/src/pass_state.rs

@@ -1,9 +1,12 @@
 use ahash::HashMap;
 
-use crate::{id::IdSet, style, Align, Id, IdMap, LayerId, Rangef, Rect, Vec2, WidgetRects};
+use crate::{
+    id::IdSet, style, text::style::FontId, Align, Id, IdMap, LayerId, Rangef, Rect, Vec2,
+    WidgetRects,
+};
 
 #[cfg(debug_assertions)]
-use crate::{pos2, Align2, Color32, FontId, NumExt, Painter};
+use crate::{pos2, Align2, Color32, NumExt, Painter};
 
 /// Reset at the start of each frame.
 #[derive(Clone, Debug, Default)]