We had a ton of issues around `TexturesDelta` that weren't properly
applied because we early-out of some function:
* https://github.com/emilk/egui/pull/8313
* https://github.com/emilk/egui/pull/8250
* https://github.com/emilk/egui/pull/8279
This PR changes texture updates, so that we always store them after
taking them out of `FullOutput` and keep the delta around until it's
actually applied (by passing &mut refs and draining instead of
iterating). So even if we add a new early return somewhere, that can't
break texture updates.
It also optimizes `TexturesDelta::append` by dropping any previous
deltas if there's a new `whole` delta or a `free`.
It also adds a debug assert that any `TexturesDelta` is empty when
dropped, as an additional safeguard in case the bug sneaks back in.
---------
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
After upgrading to wgpu v30, it requires to drop the `BufferView` return
by `get_mapped_range` before unmap the buffer. Fix it in this pr, making
screenshot event crash no more
## Summary
This fixes macOS live-resize behavior for the `eframe`/`egui-wgpu` path
when using the low-latency wgpu surface configuration.
The problem I was seeing is that native window resize can look visibly
below the baseline expected from a desktop GUI: stale or stretched
frames (manifesting as wobble/jitter), or severe lag while dragging a
window edge.
The fix has three parts:
- use `CAMetalLayer.presentsWithTransaction` during live resize to avoid
stale/stretched frames
- temporarily use at least `desired_maximum_frame_latency = 2` while
live resize is active, so transaction presentation does not stall when
the app normally uses `SurfaceConfig::LOW_LATENCY`
- treat macOS `WindowEvent::Moved` as part of the live-resize event
stream, since resizing from the top or left edge changes the window
origin
This PR depends on the winit-side AppKit live-resize timing fix in
[rust-windowing/winit#4588](https://github.com/rust-windowing/winit/pull/4588)
A renderer-only frame-latency change is not enough by itself. The
temporary latency bump only solves the drawable starvation caused by
combining `presentsWithTransaction` with `SurfaceConfig::LOW_LATENCY`.
It does not change when winit emits resize/redraw events, whether
redraws are delivered during AppKit's live-resize event-tracking loop,
or whether the surface size is derived from the current backing rect.
That is why the winit fix is needed first: it makes the windowing layer
report the current AppKit backing size and request redraws from the
live-resize/display callbacks. egui-wgpu still needs this PR on top
because winit does not own the wgpu `Surface` or the underlying
`CAMetalLayer` presentation policy.
In other words: winit fixes when the windowing layer reports
resize/redraw work, while this PR fixes how egui-wgpu presents
Metal-backed wgpu frames during that resize.
## Why change the existing feature?
The existing `macos-window-resize-jitter-fix` feature addresses one
symptom by enabling transaction presentation during resize, but it is
not enough for the low-latency wgpu path.
In particular, `presentsWithTransaction` and
`SurfaceConfig::LOW_LATENCY` interact poorly during AppKit live resize.
The old code avoids that by [skipping transaction presentation when
latency is
`1`](71c4ff3c33/crates/egui-wgpu/src/winit.rs (L417)),
but that means low-latency users get the resize jitter/wobble back.
This PR keeps the low-latency path normally, but temporarily bumps frame
latency only while live resize is active. That gives the resize path
enough drawable slack without changing normal interaction latency.
I removed the `macos-window-resize-jitter-fix` feature because this
seems like the behavior the macOS wgpu path should have by default, not
a separate opt-in. If keeping the feature as a no-op compatibility alias
is preferred, I can adjust the PR.
## Validation
I created a small demo app that somewhat resembles the layout of my
actual app and highlights both horizontal and vertical resize jitter:
- a borderless macOS window
- a simple toolbar
- a scrolling side list
- `SurfaceConfig::LOW_LATENCY`
The toolbar and list make stale or stretched frames easy to see during
native resize. The jitter is visible even on the traffic light buttons.
Recordings:
### Before 1: no transaction presentation, low latency
Shows jitter/wobble and stale/stretched frames during live resize.
https://github.com/user-attachments/assets/2cf4467b-e14c-4f41-8021-0b8c23f41004
### Before 2: transaction presentation with low latency
Shows the other failure mode: live resize can become severely laggy when
transaction presentation is used while keeping
`SurfaceConfig::LOW_LATENCY`.
https://github.com/user-attachments/assets/2f866790-f472-4ede-a3c0-480e8f0f041a
### After: patched egui-wgpu + patched winit, low latency
No visible wobble/jitter and no severe live-resize lag.
https://github.com/user-attachments/assets/59e46e9f-7906-4b5c-a6c7-1d09eae644cd
---------
Co-authored-by: lucasmerlin <hi@lucasmerlin.me>
## Symptom
Fix this long-standing, occasional bug, that can cause text to look
compressed and "drunk":
<img width="552" height="226" alt="Screenshot 2026-06-22 at 13 12 56"
src="https://github.com/user-attachments/assets/9b1abad4-5ef6-4771-8168-f201afc341ab"
/>
## Root cause
`epaint::TextureAtlas::take_delta` is fire-and-forget: it resets the
dirty region as soon as it hands out a delta, assuming the delta will be
uploaded. Atlas growth always emits a **full** `ImageDelta` (`pos:
None`) which recreates the GPU texture at the new size — *as long as it
is applied*. But both native integrations applied `textures_delta`
inside skippable code paths:
- **wgpu** (`egui-wgpu/src/winit.rs`): textures were uploaded only
*after* surface-dependent early-returns (`render_state` /
`surfaces.get_mut(viewport_id)` missing). Texture uploads are
device-level and don't need a surface.
- **glow** (`eframe/src/native/glow_integration.rs`): textures were
uploaded only inside `if is_visible { … }` (and after a viewport-missing
early-return), while `integration.update` still ran and grew the atlas.
The root window even starts hidden on purpose (`with_visible(false)`, to
avoid a startup white flash), so the very first frames hit this.
When the delta was dropped, the GPU font texture stayed smaller than the
CPU-side atlas; every glyph UV (normalized by the CPU atlas size) then
sampled the wrong rows until the next full atlas recreation. wgpu/Metal
can't detect this — the read is in-bounds, just the wrong row.
## Fixes
- **wgpu**: apply `textures_delta.set` right after `render_state` is
obtained, **before** any surface-dependent early-return. `free` still
runs after submit (unchanged).
- **glow**: apply `textures_delta.set` (and `free`) regardless of
`is_visible`, making the GL context current when there's anything to
upload; only tessellation/paint/swap stay gated on visibility.
- **debug assert** in `egui-wgpu`'s `Renderer::update_texture`: a full
delta must (re)create the GPU texture at exactly the delta size —
catches any future CPU/GPU size desync at the source.
## wgpu ruled out
Confirmed the desync is **not** inside wgpu: Metal `create_texture` uses
the exact descriptor size, and `queue.write_texture` validates against
the texture's own live `desc` — a single texture can't have CPU/GPU
sizes disagree. The mismatch is born at the egui boundary (atlas size
for UVs vs. last-applied upload), which wgpu cannot see.
## Testing note
A headless regression test of `paint_and_update_textures` isn't
practical (it needs a real winit window; `render_state` is private with
no surface-less setter). I verified the failure *mechanism* separately
on macOS/Metal (texture lagging the atlas → silent wrong-row sampling,
no wgpu error), but that demo did not exercise the fixed code path, so
it's not included. The fixes rest on the reasoning above.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
### Related
* Closes#8134.
* Related to #5136.
Possibly fixes:
* #8123
* #5145
### What
We did not properly handle the variants of
[`CurrentSurfaceTexture`](https://docs.rs/wgpu/latest/wgpu/enum.CurrentSurfaceTexture.html)
and always returned `SkipFrame`.
Because of this `egui` could end up in a state where frames are always
skipped after observing `Outdated`, without the chance to recover
(unless an event arrives from the outside).
> [!NOTE]
> This is not Wayland-specific, but could happen on all platforms. It
just happens frequently for Wayland compositors that directly resize a
window after creation (such as tiling/scrolling compositors like
`hyprland` and `niri`).
This PR improves this by separating the code paths for `Outdated` and
`Lost`, to help recover from those events.
## Related
* https://github.com/emilk/egui/issues/8043
* Introduced in #8103
## What
I noticed resizing the native winit window was really choppy and bad on
macOS, and this was the readon
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"
/>
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
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* Closes <https://github.com/emilk/egui/issues/THE_RELEVANT_ISSUE>
* [x] I have followed the instructions in the PR template
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
* [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>
This PR enables users of `egui-wgpu` to render `epaint` primitives
without having to bring in the complete `egui` crate and all it's
dependencies.
---------
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
* [x] I have followed the instructions in the PR template
Splitting this out from the Parley work as requested. This removes
`FontImage` and makes the font atlas use a `ColorImage`. It converts
alpha to coverage at glyph-drawing time, not at delta-upload time.
This doesn't do much now, but will allow for color emoji rendering once
we start using Parley.
I've changed things around so that we pass in `text_alpha_to_coverage`
to the `Fonts` the same way we do with `pixels_per_point` and
`max_texture_side`, reusing the existing code to check if the setting
differs and recreating the font atlas if so. I'm not quite sure why this
wasn't done in the first place.
I've left `ImageData` as an enum for now, in case we want to add support
for more texture pixel formats in the future (which I personally think
would be worthwhile). If you'd like, I can just remove that enum
entirely.
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.
Hey! I am not sure if this is something that's been considered before
and decided against (I couldn't find any PR's or issues).
This change removes the internal profiling macros in library crates and
the `puffin` feature and replaces it with similar functions in the
[profiling](https://github.com/aclysma/profiling) crate. This crate
provides a layer of abstraction over various profiler instrumentation
crates and allows library users to pick their favorite (supported)
profiler.
An additional benefit for puffin users is that dependencies of egui are
included in the instrumentation output too (mainly wgpu which uses the
profiling crate), so more details might be available when profiling.
A breaking change is that instead of using the `puffin` feature on egui,
users that want to profile the crate with puffin instead have to enable
the `profile-with-puffin` feature on the profiling crate. Similarly they
could instead choose to use `profile-with-tracy` etc.
I tried to add a 'tracy' feature to egui_demo_app in order to showcase ,
however the /scripts/check.sh currently breaks on mutually exclusive
features (which this introduces), so I decided against including it for
the initial PR. I'm happy to iterate more on this if there is interest
in taking this PR though.
Screenshot showing the additional info for wgpu now available when using
puffin
