A couple improvements to centered and right-aligned text edits:
- Fix text selection in centered and right aligned text edits
(ironically, this broke in #8076)
- Fix cursor movement in centered and right aligned text edits
(horizontal cursor position will be retained on vertical movement)
- Multiline text edit exceeding available width if there are atoms
- Added atoms & alignment options to text edit demo
- Improve how vertical_align and horizontal_align are applied
- Textedit atom is grow now, removing the need for the extra seperate
grow atom
- This allows us to apply the `align` on the text edit atom instead of
the whole AtomLayout
- Fixes https://github.com/emilk/egui/pull/8022
- Fixes https://github.com/emilk/egui/issues/7999
* 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>
- 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/3524
This is a breaking change, as it changes the how embedded viewports
work.
Before it was up to the user to display a `egui::Window` if they wanted.
Now egui creates an `egui::Window` for you, so you only need to add the
contents.
To signal this change in behavior, `ViewportClass::Embedded` is gone and
is now called `ViewportClass::EmbeddedWindow`.
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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>
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
Selected text now gets the color of `visuals.selection.stroke.color`.
This means you can have inverted colors for selected text, like in the
new test:
<img width="154" height="46" alt="image"
src="https://github.com/user-attachments/assets/2666361d-d7e2-4d50-8e4d-2fcc128f1a81"
/>
It also means the color of selected text in labels matches that of the
text color of selected buttons.
This adds a new mode, `UPDATE_SNAPSHOTS=force`, which will lower the
threshold to zero, overwriting every image that is not _exactly_ the
same.
Most comparisons has a threshold because different GPUs render slightly
differently. However, setting that threshold accurately can be hard.
Sometimes a test will pass locally, but fail on CI. In those cases you
want to force an update of the failing test. You can use
`UPDATE_SNAPSHOTS=force` for that.
And sometimes a small change _should_ update all images, but the change
is so tiny that it falls under the threshold. Still, you want to make a
point of showing that these images have changes. You can use
`UPDATE_SNAPSHOTS=force` for that.
Today each widget does its own custom layout, which has some drawbacks:
- not very flexible
- you can add an `Image` to `Button` but it will always be shown on the
left side
- you can't add a `Image` to a e.g. a `SelectableLabel`
- a lot of duplicated code
This PR introduces `Atoms` and `AtomLayout` which abstracts over "widget
content" and layout within widgets, so it'd be possible to add images /
text / custom rendering (for e.g. the checkbox) to any widget.
A simple custom button implementation is now as easy as this:
```rs
pub struct ALButton<'a> {
al: AtomicLayout<'a>,
}
impl<'a> ALButton<'a> {
pub fn new(content: impl IntoAtomics) -> Self {
Self { al: content.into_atomics() }
}
}
impl<'a> Widget for ALButton<'a> {
fn ui(mut self, ui: &mut Ui) -> Response {
let response = ui.ctx().read_response(ui.next_auto_id());
let visuals = response.map_or(&ui.style().visuals.widgets.inactive, |response| {
ui.style().interact(&response)
});
self.al.frame = self
.al
.frame
.inner_margin(ui.style().spacing.button_padding)
.fill(visuals.bg_fill)
.stroke(visuals.bg_stroke)
.corner_radius(visuals.corner_radius);
self.al.show(ui)
}
}
```
The initial implementation only does very basic layout, just enough to
be able to implement most current egui widgets, so:
- only horizontal layout
- everything is centered
- a single item may grow/shrink based on the available space
- everything can be contained in a Frame
There is a trait `IntoAtoms` that conveniently allows you to construct
`Atoms` from a tuple
```
ui.button((Image::new("image.png"), "Click me!"))
```
to get a button with image and text.
This PR reimplements three egui widgets based on the new AtomLayout:
- Button
- matches the old button pixel-by-pixel
- Button with image is now [properly
aligned](https://github.com/emilk/egui/pull/5830/files#diff-962ce2c68ab50724b01c6b64c683c4067edd9b79fcdcb39a6071021e33ebe772)
in justified layouts
- selected button style now matches SelecatbleLabel look
- For some reason the DragValue text seems shifted by a pixel almost
everywhere, but I think it's more centered now, yay?
- Checkbox
- basically pixel-perfect but apparently the check mesh is very slightly
different so I had to update the snapshot
- somehow needs a bit more space in some snapshot tests?
- RadioButton
- pixel-perfect
- somehow needs a bit more space in some snapshot tests?
I plan on updating TextEdit based on AtomLayout in a separate PR (so
you could use it to add a icon within the textedit frame).
This fixes bugs related to how an `Image` follows the size of an SVG.
We track the "source size" of each image, i.e. the original width/height
of the SVG, which can be different from whatever it was rasterized as.
* Closes https://github.com/emilk/egui/issues/3501
The problem occurs when you want to render the same SVG at different
scales, either at the same time in different parts of your UI, or at two
different times (e.g. the DPI changes).
The solution is to use the `SizeHint` as part of the key.
However, when you have an SVG in a resizable container, that can lead to
hundreds of versions of the same SVG. So new eviction code is added to
handle this case.
For some reason the pipeline in https://github.com/emilk/egui/pull/5698
succeeded even though the snapshots should have been updated. This
updates the snapshots.
* Closes no issue, I just needed this for an app and figured it could be
useful.
* [x] I have followed the instructions in the PR template
This PR adds an `overline` option for `egui_extras::TableRow`, which is
useful for visually grouping rows. The overline consumes no layout
space.
A screenshot of the demo app, showing every 7th row getting an overline.
<img width="704" alt="Screenshot 2025-01-25 at 14 40 08"
src="https://github.com/user-attachments/assets/9ccbee3d-296d-4afd-9290-c669e4ede1c0"
/>
---------
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
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* The PR title is what ends up in the changelog, so make it descriptive!
* If applicable, add a screenshot or gif.
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* [x] I have followed the instructions in the PR template
# Overview
This is a small change that supports draggable elements inside a
`Scene`.
When a Scene is initialized with a `Rect::Zero`, following the [example
in the
demo](https://github.com/emilk/egui/blob/master/crates/egui_demo_lib/src/demo/scene.rs#L15),
it will [automatically be reset to the `inner_rect` of the
UI](https://github.com/emilk/egui/blob/master/crates/egui/src/containers/scene.rs#L120-L123).
This centers the scene on the inner-rect contents, however the resulting
`scene_rect` doesn't fill the entire `outer_rect`. This probably isn't
an issue for most users of `Scene`.
However, I want to support draggable elements on a `Scene`, and to do
that I need to map the pointer-position in the window to the scene_rect
position.
As is, the example of draggable elements on Scene works after the user
has modified the scene rect in some way (zoom or pan), when `scene_rect`
is set to `to_global.inverse() * outer_rect`
([here](https://github.com/emilk/egui/blob/master/crates/egui/src/containers/scene.rs#L114-L118)).
Before a user modifies the scene rect, the pointer-position cannot be
reliably mapped to the scene_rect, since the scene_rect doesn't span the
entire window.
This PR just forces that translation to always run after the scene_rect
is reset to `inner_rect`. The practical result is that the scene_rect
will now always span the full outer_rect.
# Example
Here's a small app that demonstrates the functionality I'm trying to
support. I'm new to Egui so there may be better patterns for what I'm
trying to do, but if you run this against `main` and this branch you'll
notice the difference.
```rs
use eframe::egui::*;
/// Map coordinates from the src rect to the target rect
fn map_to_rect(position: Pos2, src_rect: Rect, dest_rect: Rect) -> Pos2 {
let x = (position.x - src_rect.min.x) / (src_rect.max.x - src_rect.min.x)
* (dest_rect.max.x - dest_rect.min.x)
+ dest_rect.min.x;
let y = (position.y - src_rect.min.y) / (src_rect.max.y - src_rect.min.y)
* (dest_rect.max.y - dest_rect.min.y)
+ dest_rect.min.y;
Pos2::new(x, y)
}
pub fn draggable_scene_element(
ui: &mut Ui,
id: Id,
position: &mut Rect,
scene_rect: Rect,
container_rect: Rect,
) -> Response {
let is_being_dragged = ui.ctx().is_being_dragged(id);
if is_being_dragged {
let r = ui.put(*position, |ui: &mut Ui| ui.label("Draggable"));
if let Some(pointer_pos) = ui.ctx().pointer_interact_pos() {
let pointer_pos = map_to_rect(pointer_pos, container_rect, scene_rect);
let delta = pointer_pos.to_vec2() - position.center().to_vec2();
*position = position.translate(delta);
};
r
} else {
let r = ui.put(*position, |ui: &mut Ui| ui.label("Draggable"));
ui
.interact(position.clone(), id, Sense::drag())
.on_hover_cursor(CursorIcon::Grab);
r
}
}
struct MyApp {
scene_rect: Rect,
position: Rect,
}
impl MyApp {
fn new() -> Self {
Self {
scene_rect: Rect::ZERO,
position: Rect::from_min_size(Pos2::new(-50., -50.), Vec2::new(100., 100.)),
}
}
}
impl eframe::App for MyApp {
fn update(&mut self, ctx: &Context, _frame: &mut eframe::Frame) {
CentralPanel::default().show(ctx, |ui| {
let scene_rect = self.scene_rect.clone();
let container_rect = ui.min_rect();
Scene::default().show(ui, &mut self.scene_rect, |ui| {
ui.put(
Rect::from_min_size(Pos2::new(100., 200.), Vec2::new(100., 100.)),
|ui: &mut Ui| ui.label("static element"),
);
ui.put(self.position, |ui: &mut Ui| {
draggable_scene_element(
ui,
Id::from("demo"),
&mut self.position,
scene_rect,
container_rect,
)
});
});
});
}
}
```
# Summary
I need a way to map pointer coordinates to scene coordinates, in order
to support draggable elements in a scene. This patch makes that easier
by ensuring the scene_rect will always be the full size of the
outer_rect.
If you have a better way to accomplish what I'm after, I'm happy to
close this. Thanks!
The bug was in `Color32::from_rgba_unmultiplied` and by extension
affects:
* `Color32::from_rgba_unmultiplied`
* `hex_color!`
* `HexColor`
* `ColorImage::from_rgba_unmultiplied`
* All images with transparency (png, webp, …)
* `Color32::from_white_alpha`
The bug caused translucent colors to appear too bright.
## More
Color is hard.
When I started out egui I thought "linear space is objectively better,
for everything!" and then I've been slowly walking that back for various
reasons:
* sRGB textures not available everywhere
* gamma-space is more _perceptually_ even, so it makes sense to use for
anti-aliasing
* other applications do everything in gamma space, so that's what people
expect (this PR)
Similarly, pre-multiplied alpha _makes sense_ for blending colors. It
also enables additive colors, which is nice. But it does complicate
things. Especially when mixed with sRGB/gamma (As @karhu [points
out](https://github.com/emilk/egui/pull/5824#issuecomment-2738099254)).
## Related
* Closes https://github.com/emilk/egui/issues/5751
* Closes https://github.com/emilk/egui/issues/5771 ? (probably; hard to
tell without a repro)
* But not https://github.com/emilk/egui/issues/5810
## TODO
* [x] I broke the RGBA u8 color picker. Fix it
---------
Co-authored-by: Andreas Reich <andreas@rerun.io>
Continuation of #5713
**Silently breaking changes:**
- Menus now close on click by default, this is configurable via
`PopupCloseBehavior`
**Additional additions:**
- `Button::right_text`
- `StyleModifier`
This is a rewrite of the egui menus, with the following goals:
- submenu buttons should work everywhere, in a popup, context menu,
area, in some random Ui
- remove the menu state from Ui
- should work just like the previous menu
- ~proper support for keyboard navigation~
- It's better now but requires further work to be perfect
- support `PopupCloseBehavior`
* Closes#4607
* [x] I have followed the instructions in the PR template
