This PR adds two small additions to `LayoutJob`:
- `LayoutJob::format_at_byte` to query the `TextFormat` of the section
covering a given byte index.
- An optimization to `LayoutJob::append` that merges newly appended text
into the previous section when the format matches and there is no
leading space.
It also documents the `LayoutJob::sections` invariant (sections are
ordered and together cover the whole text with no gaps or overlaps) and
adds `LayoutJob::debug_sanity_check`, which verifies this in debug
builds. It is called from `format_at_byte` and from the text layouter.
## Why the `easymarkeditor` snapshot changed
The `append` optimization changes how many sections a `LayoutJob` ends
up with: consecutive runs of identically-formatted text now collapse
into a single section instead of one section per `append` call. The
easymark editor produces many such adjacent same-format sections, so it
is affected.
This matters because text is **shaped per section**: `layout_section`
runs the shaper once per section, so each section is an independent
shaping run. Merging two adjacent sections into one means the text
across the old boundary is now shaped together as a single run, which
enables cross-boundary kerning (and, in principle, ligatures) that
previously did not happen. Additionally, `extra_letter_spacing` is
skipped before the first glyph of a section, so merging removes a "first
glyph" boundary and lets the spacing apply there.
The net effect is sub-pixel glyph position shifts at the former section
boundaries, which is why `easymarkeditor.png` was regenerated. The new
output is the more correct one — the text is now shaped as the author
wrote it, rather than being artificially split at `append` boundaries.
---------
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Introduces live inspection for running egui apps over a small TCP
request/response protocol, plus the `egui::Plugin` that serves it.
This is the minimal surface to get the egui mcp in, we may want to
extend this in the future to add support for the inspection gui.
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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At low apha values, premultiplied colors lose precision.
This PR makes the color picker use unmultiplied colors internally.
Before:
https://github.com/user-attachments/assets/4617a355-daa9-4911-86e6-518ac6867014
After:
https://github.com/user-attachments/assets/d9681b01-50d8-418e-b5a5-79b4bd1bbddf
The three methods for showing a `Panel` are now:
* `panel.show`: always show the panel.
* `panel.show_collapsible`: show or hide the panel, with a slide
animation in between.
* `Panel::show_switched`: animate between two different panels: a
thin/collapsed one and a thick/expanded one.
* Closes https://github.com/emilk/egui/pull/7254
You can now drag-to-close a panel. Also drag-to-expand panels.
This is a breaking change: the animated panel functions now take a
`open: &mut bool` instead of `open: bool`.
This is only enabled for resizable panels
Let apps change present_mode and desired_maximum_frame_latency at
runtime instead of only at startup.
API changes (egui-wgpu):
- New SurfaceConfig { present_mode, desired_maximum_frame_latency }.
- WgpuConfiguration now nests these as pub surface: SurfaceConfig (was
two top-level fields).
- RenderState gains pub surface_config: SurfaceConfig — the
currently-requested value.
API additions (eframe):
- Frame::wgpu_surface_config() / Frame::set_wgpu_surface_config(...) for
get/set.
- SurfaceConfig re-exported as eframe::SurfaceConfig.
How it works:
The wgpu painter compares render_state.surface_config to its
currently-applied values each paint. If they differ it updates its
config and flips
needs_reconfigure on every surface, piggybacking on the existing
deferred-reconfigure pathway.
Demo:
The backend panel (egui_demo_app) gets dropdowns for present mode and
desired max frame latency, wired through the new Frame accessors.
<img width="282" height="172" alt="image"
src="https://github.com/user-attachments/assets/0b1274b2-7e4e-4413-969b-0a014c415f79"
/>
* Related to #56 (Improve text — tracking issue)
## Summary
This PR integrates [harfrust](https://crates.io/crates/harfrust) (a
pure-Rust port of HarfBuzz) into epaint's text layout pipeline,
replacing the character-by-character glyph positioning with proper
OpenType text shaping.
### What this enables
- **GPOS kerning**: most modern fonts only ship kerning in GPOS tables
(not the legacy `kern` table). Pairs like "AV", "VA", "AT" are now
properly tightened.
- **GSUB substitutions**: ligatures (fi, fl), contextual alternates, and
other OpenType features.
- **Combining marks**: diacritics (e.g. ɔ̃) are positioned via anchor
tables instead of being rendered as standalone replacement glyphs.
### Before/After
#### Kerning, etc.
<img width="838" height="726" alt="before_main"
src="https://github.com/user-attachments/assets/f0f26d5f-b117-43a6-b39c-ea40d2e73836"
/>
<img width="838" height="726" alt="after_harfrust"
src="https://github.com/user-attachments/assets/d983e5da-486c-4f39-bd4f-5782a90c6b39"
/>
#### Ligatures
<img width="1117" height="698" alt="before_closeup"
src="https://github.com/user-attachments/assets/7a3b08b4-cf6f-45b7-98ba-07c473cd3b02"
/>
<img width="1117" height="698" alt="after_closeup"
src="https://github.com/user-attachments/assets/6cfc5f21-d32f-4f09-be0c-59c8c553d44f"
/>
### Architecture
The shaping integrates into the existing pipeline without changing the
public API:
1. **`Font::segment_into_runs`** — segments text into contiguous runs by
font face (grapheme-cluster aware, never splits combining sequences)
2. **`FontFace::shape_text`** — calls harfrust to shape each run,
returning glyph IDs + positioned advances/offsets
3. **`layout_shaped_run`** — emits `Glyph` structs from the shaping
output, with NOTDEF fallback to other font faces for missing glyphs
4. **Buffer recycling** — `FontsImpl` pools a `harfrust::UnicodeBuffer`
to avoid per-layout allocations
### Disclaimer
I'm far from being a good Rust programmer. Claude Code did most of the
heavy lifting here. I did my best and used my limited knowledge to avoid
making too many mistakes. If this PR isn't up to quality standards,
please don't hesitate to close it.
## Test plan
- [x] `cargo test -p epaint` — all 18 text tests pass, including 6 new
ones
- [x] `cargo clippy -p epaint --all-features` — clean
- [x] `cargo fmt` — clean
- [ ] Snapshot tests need regeneration (expected: shaping changes glyph
positions)
- New tests added:
- `test_gpos_kerning` — verifies GPOS kerning tightens "AV", "VA", "AT"
pairs
- `test_combining_diacritics` — combining tilde doesn't add extra width
- `test_shaping_basic_latin` — sanity check for Latin text
- `test_shaping_empty_string` — empty input doesn't panic
- `test_shaping_multiple_newlines` — newline splitting works correctly
- `test_shaping_mixed_font_fallback` — Latin + emoji in same string
---------
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Enable these new clippy lints and fix all warnings:
* `format_push_string` — use `write!` instead of `s += &format!(…)` to
avoid extra allocations
* `ignored_unit_patterns` — use `()` instead of `_` when matching unit
* `missing_fields_in_debug` — ensure manual `Debug` impls account for
all fields
* `needless_raw_string_hashes` — remove unnecessary `r#` on string
literals
* `ref_option` — prefer `Option<&T>` over `&Option<T>` in function
signatures
* Fix for https://github.com/emilk/eframe_template/issues/223
* Related: https://github.com/gfx-rs/wgpu/pull/9319
By default, we would only turn on the WebGPU backend on web, which means
browsers without WebGPU support would just crash.
You can still opt-out of all the default `wgpu` features by enabling
`eframe/wgpu_no_default_features` instead of `eframe/wgpu`
* [x] I have followed the instructions in the PR template
This updates wgpu to v29 across the egui crate stack.
There a a few API changes due to the requirement to provide a display
handle up front to properly support GLES on linux. I have done my best
to make the api changes as reasonable as possible, but I don't have all
the greater project context, so lmk if things should be done a bit
differently.
I've also updated glow to 0.17 to make cargo deny happy, there are no
source changes. I'm not sure how you want to land these.
---------
Co-authored-by: lucasmerlin <hi@lucasmerlin.me>
- fix for https://github.com/rerun-io/reality/pull/1075
The galleys row size was calculated by looking at the last glyphs pos_x,
which got changed to be rounded to integers when we added subpixel
binning. This introduced a subtle bug which caused the width of galleys
to be slightly off.
This PR fixes this by looking at the actual cursor position instead,
which is not rounded.
Also added a test to ensure this is correct. Previously, for the second
and last line, the `x` was too close to the `0`.
<img width="48" height="67" alt="image"
src="https://github.com/user-attachments/assets/a69a4cc3-b3f3-4553-ab92-73cb2e7a358c"
/>
---------
Co-authored-by: lucasmerlin <8009393+lucasmerlin@users.noreply.github.com>
* Part of https://github.com/emilk/egui/issues/5605
This changes the default style of egui.
The problem with "expanding" widgets is that they now want to paint
outside their own bounds, which then requires all parent UIs to have
proper margins.
It also means hovered things are no longer properly aligned with every
other widget.
* Part of https://github.com/emilk/egui/issues/5113
* Part of https://github.com/emilk/egui/issues/3524
## What
This deprecates `eframe::App::update` and replaces it with two new
functions:
```rs
pub trait App {
/// Called just before `ui`, and in the future this will
/// also be called for background apps when needed.
fn logic(&mut self, ctx: &egui::Context, frame: &mut Frame) { }
/// Show your user interface to the user.
fn ui(&mut self, ui: &mut egui::Ui, frame: &mut Frame);
…
}
```
Similarly, `Context::run` is deprecated in favor of `Context::run_ui`.
`Plugin`s are now handed a `Ui` instead of just a `Context` in
`on_begin/end_frame`.
## TODO
…either in this PR or a later one
* [x] Deprecate `App::update`
* [x] Deprecate `Context::run`
* [x] Change plugins to get a `Ui`
* [x] Update kittest
* [x] Change viewports to get UI:s (`show_viewport_immediate` etc)
- https://github.com/emilk/egui/pull/7779
## Later PRs
* [ ] Deprecate `Panel::show`
* [ ] Deprecate `CentralPanel::show`
* [ ] Deprecate `CentralPanel` ?
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* Keep your PR:s small and focused.
* The PR title is what ends up in the changelog, so make it descriptive!
* If applicable, add a screenshot or gif.
* If it is a non-trivial addition, consider adding a demo for it to
`egui_demo_lib`, or a new example.
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Please be patient! I will review your PR, but my time is limited!
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* Closes N/A
* [x] I have followed the instructions in the PR template
I'll probably come back to this and clean it up a bit. This PR
reimplements ab_glyph's functionality on top of Skrifa, a somewhat
lower-level font API that's being used in Chrome now.
Skrifa doesn't perform rasterization itself, so I'm using
[vello_cpu](https://github.com/linebender/vello) from the Linebender
project for rasterization. It's still in its early days, but I believe
it's already quite fast. It also supports color and gradient fills, so
color emoji support will be easier.
Skrifa also supports font hinting, which should make text look a bit
nicer / less blurry.
Here's the current ab_glyph rendering:
<img width="1592" height="1068" alt="image"
src="https://github.com/user-attachments/assets/2385b66e-23f8-4c6e-b8c2-ea90e0eea4e4"
/>
Here's Skrifa *without* hinting--it looks almost identical, but there
are some subpixel differences, probably due to rasterizer behavior:
<img width="1592" height="1068" alt="image"
src="https://github.com/user-attachments/assets/a815f3e9-65ac-4940-bc00-571177bef53d"
/>
Here's Skrifa *with* hinting:
<img width="1592" height="1068" alt="image"
src="https://github.com/user-attachments/assets/d6cc0669-3537-4377-bba9-ed5ef09664db"
/>
Hinting does make the horizontal strokes look a bit bolder, which makes
me wonder once again about increasing the font weight from "light" to
"regular".
---------
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
### What
From the [lint
description](https://rust-lang.github.io/rust-clippy/master/index.html?search=or_fu#or_fun_call):
> The function will always be called. This is only bad if it allocates
or does some non-trivial amount of work.
But also:
> If the function has side-effects, not calling it will change the
semantic of the program, but you shouldn’t rely on that.
>
> The lint also cannot figure out whether the function you call is
actually expensive to call or not.
Still worth it to keep our happy paths clean, imo.
We're phasing out top-level panels (panels that use `Context` directly,
instead of being inside another `Ui`).
As a first step, stop using them in our demo library and application.
* Part of https://github.com/emilk/egui/issues/3524
This combines `SidePanel` and `TopBottomPanel` into a single `Panel`.
The old types are still there as type aliases, but are deprecated.
`.min_width(…)` etc are now called `.min_size(…)` etc.
Again, the old names are still there, but deprecated.
(edited by @emilk)
---------
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
* Closes https://github.com/emilk/egui/issues/5889
See the above issue for motivation.
To use glow instead, disable the default features of `eframe` and opt-in
to `glow`.
This also changes egui.rs to use wgpu, which means WebGPU when
available, and WebGL otherwise
Sometimes when moving a window, having a tooltip attached to the mouse
pointer, or scrolling a `ScrollArea`, you would see this disturbing
effect:
This is caused by us rounding many visual elements (lines, rectangles,
text, …) to physical pixels in order to keep them sharp. If the
window/tooltip itself is not rounded to a physical pixel, then you can
get this behavior.
So from now on the position of all
areas/windows/tooltips/popups/ScrollArea gets rounded to the closes
pixel.
* Unlocked by https://github.com/emilk/egui/pull/7709
* closes https://github.com/emilk/egui/issues/5674
This changes egui to create an AccessKit node for each `Ui`. I'm not
sure if this alone will directly improve accessibility, but it should
make it easier to create the correct parent / child relations (e.g.
grouping menus as children of menu buttons).
Instead of having a global stack of parent ids, they are now passed via
a parent_id field in `UiBuilder`.
If having all these `GenericContainer` nodes somehow is bad for
accessibility, the PR could also be changed to only create nodes if
there is actually some accessibility info with it (the relevant is
currently commented-out in the PR). But I think screen readers should
just ignore these nodes, so it should be fine? We could also use this as
motivation to git red of some unnecessary wrapped `Ui`s, e.g.
CentralPanel creates 3 Uis when 2 should be enough (the initial Ui and a
Frame, maybe we could even only show the `Frame` if we can give it an
UiBuilder and somehow show the Frame with `Ui::new`).
Here is a screenshot from the accessibility inspector
(https://github.com/emilk/egui/pull/7368) with this PR:
<img width="431" height="744" alt="Screenshot 2025-07-24 at 12 09 55"
src="https://github.com/user-attachments/assets/6c4e5ff6-5c38-450e-9500-0776c9018d8c"
/>
Without this PR:
https://github.com/user-attachments/assets/270e32fc-9c7a-4dad-8c90-7638c487a602
Adds an accessibility inspector plugin that shows the current AccessKit
tree:
https://github.com/user-attachments/assets/78f4f221-1bd2-4ce4-adf5-fc3b00f5c16c
Macos has a built in accessibility inspector, but it doesn't seem to
work with AccessKit / eframe so this provides some insight into the
accesskit state.
This also showed a couple issues that are easy to fix:
- [ ] Links show up as `Label` instead of links
- [ ] Not all supported actions are advertised (e.g. scrolling)
- [ ] The resize handles in windows shouldn't be focusable
- [ ] Checkbox has no value
- [ ] Menus should have the button as parent widget (not 100% sure on
this one)
Currently the plugin lives in the demo app, but I think it should be
moved somewhere else. Maybe egui_extras?
This could also be relevant for #4650
This PR is a continuation of #4915 by @frederik-uni and @lucasmerlin
that introduces support for keeping egui content within the 'safe area'
on iOS (avoiding the notch / dynamic island / menu bar etc.), with the
following changes:
- `SafeArea` now wraps `MarginF32` and has been renamed to
`SafeAreaInsets` to clarify its purpose.
- `InputState::screen_rect` is now marked as deprecated in favour of
either `viewport_rect` (which contains the entire screen), or
`content_rect` (which is the viewport rect with the safe area insets
removed).
- I added some comments to the safe area insets logic pointing out the
[safe area API coming in winit
v0.31](https://github.com/rust-windowing/winit/issues/3910).
---------
Co-authored-by: frederik-uni <147479464+frederik-uni@users.noreply.github.com>
Co-authored-by: Lucas Meurer <hi@lucasmerlin.me>
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
