I thought about this - so we have two options here:
1. adding it to `SnapshotOptions`
2. adding it to every function which I do not like as this would be a
huge breaking change
## Summary
This pull request introduces a new feature to the `SnapshotOptions`
struct in the `egui_kittest` crate, allowing users to specify a
permissible percentage of pixel differences (`diff_percentage`) before a
snapshot comparison is considered a failure. This feature provides more
flexibility in handling minor visual discrepancies during snapshot
testing.
### Additions to `SnapshotOptions`:
* Added a new field `diff_percentage` of type `Option<f64>` to the
`SnapshotOptions` struct. This field allows users to define a tolerance
for pixel differences, with a default value of `None` (interpreted as 0%
tolerance).
* Updated the `Default` implementation of `SnapshotOptions` to
initialize `diff_percentage` to `None`.
### Integration into snapshot comparison logic:
* Updated the `try_image_snapshot_options` function to handle the new
`diff_percentage` field. If a `diff_percentage` is specified, the
function calculates the percentage of differing pixels and allows the
snapshot to pass if the difference is within the specified tolerance.
[[1]](diffhunk://#diff-6f481b5866b82a4fe126b7df2e6c9669040c79d1d200d76b87f376de5dec5065R204)
[[2]](diffhunk://#diff-6f481b5866b82a4fe126b7df2e6c9669040c79d1d200d76b87f376de5dec5065R294-R301)
* Closes <https://github.com/emilk/egui/issues/5683>
* [x] I have followed the instructions in the PR template
---------
Co-authored-by: lucasmerlin <hi@lucasmerlin.me>
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
I need to scroll in a snapshot test in my app, and kittest had no
utilities for this. Event::MouseWheel is error prone. This adds support
for some accesskit scroll actions, and uses this in kittest to add
helpers to scroll to a node / scroll the scroll area surrounding a node.
The accesskit code says down/up/left/right `Scrolls by approximately one
screen in a specific direction.`. Unfortunately it's difficult to get
the size of a "screen" (I guess that would be the size of the containing
scroll area)where I implemented the scrolling, so for now I've hardcoded
it to 100px. I think scrolling a fixed amount is still better than not
scrolling at all.
---------
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
This adds a custom Node struct with proper support for egui types
(`Key`, `Modifiers`, `egui::Event`, `Rect`) instead of needing to use
the kittest / accesskit types.
I also changed the `click` function to do a proper mouse move / mouse
down instead of the accesskit click. Also added `accesskit_click` to
trigger the accesskit event. This resulted in some changed snapshots,
since the elements are now hovered.
Also renamed `press_key` to `key_press` for consistency with
`key_down/key_up`.
Also removed the Deref to the AccessKit Node, to make it clearer when to
expect egui and when to expect accesskit types.
* Closes#5705
* [x] I have followed the instructions in the PR template
With kittest it was difficult to wait for images to be loaded before
taking a snapshot test.
This PR adds `Harness::with_wait_for_pending_images` (true by default)
which will cause `Harness::run` to sleep until all images are loaded (or
`HarnessBuilder::with_max_steps` is exceeded).
It also adds a new ImageLoader::has_pending and
BytesLoader::has_pending, which should be implemented if things are
loaded / decoded asynchronously.
It reverts https://github.com/emilk/egui/pull/6901 which was my previous
attempt to fix this (but this didn't work since only the tested crate is
compiled with cfg(test) and not it's dependencies)
* Closes <https://github.com/emilk/egui/issues/5690>
* [x] I have followed the instructions in the PR template
It still isn't ideal, since you have to remember to call key_up on a
separate frame.
---------
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
I got annoyed by all the slightly different variations of "collect
snapshot results and unwrap them at the end of test" I've written, so I
added a struct to make this nice and simple.
One controversial thing: It panics when dropped. I wanted to ensure
people cannot forget to unwrap the results at the end, and this was the
best thing I could come up with. I don't think this is possible via
clippy lint or something like that.
* [x] I have followed the instructions in the PR template
## Defining what `Rounding` is
This PR defines what `Rounding` means: it is the corner radius of
underlying `RectShape` rectangle. If you use `StrokeKind::Inside`, this
means the rounding is of the outer part of the stroke. Conversely, if
you use `StrokeKind::Outside`, the stroke is outside the rounded
rectangle, so the stroke has an inner radius or `rounding`, and an outer
radius that is larger by `stroke.width`.
This definitions is the same as Figma uses.
## Improving general shape rendering
The rendering of filled shapes (rectangles, circles, paths, bezier) has
been rewritten. Instead of first painting the fill with the stroke on
top, we now paint them as one single mesh with shared vertices at the
border. This has several benefits:
* Less work (faster and with fewer vertices produced)
* No overdraw (nicer rendering of translucent shapes)
* Correct blending of stroke and fill
The logic for rendering thin strokes has also been improved, so that the
width of a stroke of `StrokeKind::Outside` never affects the filled area
(this used to be wrong for thin strokes).
## Improving of rectangle rendering
Rectangles also has specific improvements in how thin rectangles are
painted.
The handling of "Blur width" is also a lot better, and now works for
rectangles with strokes.
There also used to be bugs with specific combinations of corner radius
and stroke width, that are now fixed.
## But why?
With the new `egui::Scene` we end up with a lot of zoomed out shapes,
with sub-pixel strokes. These need to look good! One thing led to
another, and then I became obsessive 😅
## Tessellation Test
In order to investigate the rendering, I created a Tessellation Test in
the `egui_demo_lib`.
[Try it
here](https://egui-pr-preview.github.io/pr/5669-emilkimprove-tessellator)
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* ~Closes <https://github.com/emilk/egui/issues/THE_RELEVANT_ISSUE>~
(just a quick typo fix)
* [x] I have followed the instructions in the PR template
It used to be that `UPDATE_SNAPSHOTS=true cargo test --all-features`
would stop on the first crate with a failure, requiring you to run it
multiple times, which is annoying, and a waste of time.
Previously, `Harness::run` just called `Harness::step` 3 times. If that
wasn't enough, tests would often call run multiple times so all
animations would finish properly.
Also, I introduced `HarnessBuilder::with_step_dt` to customize with how
big of a dt each frame is called. I set the default to 1.0 / 6.0 (~6fps)
so we don't waste cpu in tests waiting on animations.
`HarnessBuilder::max_steps` allows us to control how many steps
`Harness::run` should run before panicing.
The default is 6, so we run for up to 1.0 logical seconds (six frames at
6 fps), which should be enough to finish most animations.
Turns out a lot of snapshots where rendered before fully shown and had a
light opacity, those are now fixed.
* [x] I have followed the instructions in the PR template
* Part of https://github.com/emilk/egui/issues/4019
`Frame` now includes the width of the stroke as part of its size. From
the new docs:
### `Frame` docs
The total (outer) size of a frame is `content_size + inner_margin +
2*stroke.width + outer_margin`.
Everything within the stroke is filled with the fill color (if any).
```text
+-----------------^-------------------------------------- -+
| | outer_margin |
| +------------v----^------------------------------+ |
| | | stroke width | |
| | +------------v---^---------------------+ | |
| | | | inner_margin | | |
| | | +-----------v----------------+ | | |
| | | | ^ | | | |
| | | | | | | | |
| | | |<------ content_size ------>| | | |
| | | | | | | | |
| | | | v | | | |
| | | +------- content_rect -------+ | | |
| | | | | |
| | +-------------fill_rect ---------------+ | |
| | | |
| +----------------- widget_rect ------------------+ |
| |
+---------------------- outer_rect ------------------------+
```
The four rectangles, from inside to outside, are:
* `content_rect`: the rectangle that is made available to the inner
[`Ui`] or widget.
* `fill_rect`: the rectangle that is filled with the fill color (inside
the stroke, if any).
* `widget_rect`: is the interactive part of the widget (what sense
clicks etc).
* `outer_rect`: what is allocated in the outer [`Ui`], and is what is
returned by [`Response::rect`].
### Notes
This required rewriting a lot of the layout code for `egui::Window`,
which was a massive pain. But now the window margin and stroke width is
properly accounted for everywhere.
* Closes https://github.com/emilk/egui/issues/5423
New output is actionable
```
failures:
---- demo::demo_app_windows::tests::demos_should_match_snapshot stdout ----
thread 'demo::demo_app_windows::tests::demos_should_match_snapshot' panicked at crates/egui_demo_lib/src/demo/demo_app_windows.rs:433:9:
Errors: [
"'demos/Code Example' Image size did not match snapshot. Expected: (402, 574), Actual: (415, 574).
Run `UPDATE_SNAPSHOTS=1 cargo test` to update the snapshots.",
]
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
failures:
demo::demo_app_windows::tests::demos_should_match_snapshot
```
- fixes https://github.com/emilk/egui/issues/5359
For the test I added a `Harness::press_key` function. We should
eventually add these to kittest, probably via a trait one can implement
for the `Harness` but for now this should do.
The allows us to pass any state to the ui closure. While it is possible
to just store state in the closure itself, accessing that state after
the harness was created to e.g. read or modify it would require interior
mutability. With this change there are new `Harness::new_state`,
`Harness::run_state`, ... methods that allow passing state on each run.
This builds on top of #5301, which should be merged first
---------
Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
This adds a `Harness::new_ui`, which accepts a Ui closure and shows the
ui in a central panel. One big benefit is that this allows us to add a
fit_contents method that can run the ui closure with a sizing pass and
resize the "screen" based on the content size.
I also used this to add a snapshot test for the rendering_test at
different scales.
This adds `egui_kittest::try_image_snapshot_options` and
`egui_kittest::image_snapshot_options`, as well as
`Harness::wgpu_snapshot_options` and
`Harness::try_wgpu_snapshot_options`
* [X] I have followed the instructions in the PR template
This should hopefully make it easier for egui contributors and
egui_kittest users to understand the snapshot tests
* [X] I have followed the instructions in the PR template
- closes#3491
- closes#3926
This adds a testing library to egui based on
[kittest](https://github.com/rerun-io/kittest). Kittest is a new
[AccessKit](https://github.com/AccessKit/accesskit/)-based testing
library. The api is inspired by the js
[testing-library](https://testing-library.com/) where the idea is also
to query the dom based on accessibility attributes.
We made kittest with egui in mind but it should work with any rust gui
framework with AccessKit support.
It currently has support for:
- running the egui app, frame by frame
- building the AccessKit tree
- ergonomic queries via kittest
- via e.g. get_by_name, get_by_role
- simulating events based on the accesskit node id
- creating arbitrary events based on Harness::input_mut
- rendering screenshots via wgpu
- snapshot tests with these screenshots
A simple test looks like this:
```rust
fn main() {
let mut checked = false;
let app = |ctx: &Context| {
CentralPanel::default().show(ctx, |ui| {
ui.checkbox(&mut checked, "Check me!");
});
};
let mut harness = Harness::builder().with_size(egui::Vec2::new(200.0, 100.0)).build(app);
let checkbox = harness.get_by_name("Check me!");
assert_eq!(checkbox.toggled(), Some(Toggled::False));
checkbox.click();
harness.run();
let checkbox = harness.get_by_name("Check me!");
assert_eq!(checkbox.toggled(), Some(Toggled::True));
// You can even render the ui and do image snapshot tests
#[cfg(all(feature = "wgpu", feature = "snapshot"))]
egui_kittest::image_snapshot(&egui_kittest::wgpu::TestRenderer::new().render(&harness), "readme_example");
}
```
~Since getting wgpu to run in ci is a hassle, I'm taking another shot at
creating a software renderer for egui (ideally without a huge dependency
like skia)~ (this didn't work as well as I hoped and it turns out in CI
you can just run tests on a mac runner which comes with a real GPU)
Here is a example of a failed snapshot test in ci, it will say which
snapshot failed and upload an artifact with the before / after and diff
images:
https://github.com/emilk/egui/actions/runs/11183049487/job/31090724606?pr=5166
