# Objective
Continue improving the user experience of our UI Node API in the
direction specified by [Bevy's Next Generation Scene / UI
System](https://github.com/bevyengine/bevy/discussions/14437)
## Solution
As specified in the document above, merge `Style` fields into `Node`,
and move "computed Node fields" into `ComputedNode` (I chose this name
over something like `ComputedNodeLayout` because it currently contains
more than just layout info. If we want to break this up / rename these
concepts, lets do that in a separate PR). `Style` has been removed.
This accomplishes a number of goals:
## Ergonomics wins
Specifying both `Node` and `Style` is now no longer required for
non-default styles
Before:
```rust
commands.spawn((
Node::default(),
Style {
width: Val::Px(100.),
..default()
},
));
```
After:
```rust
commands.spawn(Node {
width: Val::Px(100.),
..default()
});
```
## Conceptual clarity
`Style` was never a comprehensive "style sheet". It only defined "core"
style properties that all `Nodes` shared. Any "styled property" that
couldn't fit that mold had to be in a separate component. A "real" style
system would style properties _across_ components (`Node`, `Button`,
etc). We have plans to build a true style system (see the doc linked
above).
By moving the `Style` fields to `Node`, we fully embrace `Node` as the
driving concept and remove the "style system" confusion.
## Next Steps
* Consider identifying and splitting out "style properties that aren't
core to Node". This should not happen for Bevy 0.15.
---
## Migration Guide
Move any fields set on `Style` into `Node` and replace all `Style`
component usage with `Node`.
Before:
```rust
commands.spawn((
Node::default(),
Style {
width: Val::Px(100.),
..default()
},
));
```
After:
```rust
commands.spawn(Node {
width: Val::Px(100.),
..default()
});
```
For any usage of the "computed node properties" that used to live on
`Node`, use `ComputedNode` instead:
Before:
```rust
fn system(nodes: Query<&Node>) {
for node in &nodes {
let computed_size = node.size();
}
}
```
After:
```rust
fn system(computed_nodes: Query<&ComputedNode>) {
for computed_node in &computed_nodes {
let computed_size = computed_node.size();
}
}
```
# Objective
Cleanup naming and docs, add missing migration guide after #15591
All text root nodes now use `Text` (UI) / `Text2d`.
All text readers/writers use `Text<Type>Reader`/`Text<Type>Writer`
convention.
---
## Migration Guide
Doubles as #15591 migration guide.
Text bundles (`TextBundle` and `Text2dBundle`) were removed in favor of
`Text` and `Text2d`.
Shared configuration fields were replaced with `TextLayout`, `TextFont`
and `TextColor` components.
Just `TextBundle`'s additional field turned into `TextNodeFlags`
component,
while `Text2dBundle`'s additional fields turned into `TextBounds` and
`Anchor` components.
Text sections were removed in favor of hierarchy-based approach.
For root text entities with `Text` or `Text2d` components, child
entities with `TextSpan` will act as additional text sections.
To still access text spans by index, use the new `TextUiReader`,
`Text2dReader` and `TextUiWriter`, `Text2dWriter` system parameters.
# Objective
Currently text is recomputed unnecessarily on any changes to its color,
which is extremely expensive.
## Solution
Split up `TextStyle` into two separate components `TextFont` and
`TextColor`.
## Testing
I added this system to `many_buttons`:
```rust
fn set_text_colors_changed(mut colors: Query<&mut TextColor>) {
for mut text_color in colors.iter_mut() {
text_color.set_changed();
}
}
```
reports ~4fps on main, ~50fps with this PR.
## Migration Guide
`TextStyle` has been renamed to `TextFont` and its `color` field has
been moved to a separate component named `TextColor` which newtypes
`Color`.
**Ready for review. Examples migration progress: 100%.**
# Objective
- Implement https://github.com/bevyengine/bevy/discussions/15014
## Solution
This implements [cart's
proposal](https://github.com/bevyengine/bevy/discussions/15014#discussioncomment-10574459)
faithfully except for one change. I separated `TextSpan` from
`TextSpan2d` because `TextSpan` needs to require the `GhostNode`
component, which is a `bevy_ui` component only usable by UI.
Extra changes:
- Added `EntityCommands::commands_mut` that returns a mutable reference.
This is a blocker for extension methods that return something other than
`self`. Note that `sickle_ui`'s `UiBuilder::commands` returns a mutable
reference for this reason.
## Testing
- [x] Text examples all work.
---
## Showcase
TODO: showcase-worthy
## Migration Guide
TODO: very breaking
### Accessing text spans by index
Text sections are now text sections on different entities in a
hierarchy, Use the new `TextReader` and `TextWriter` system parameters
to access spans by index.
Before:
```rust
fn refresh_text(mut query: Query<&mut Text, With<TimeText>>, time: Res<Time>) {
let text = query.single_mut();
text.sections[1].value = format_time(time.elapsed());
}
```
After:
```rust
fn refresh_text(
query: Query<Entity, With<TimeText>>,
mut writer: UiTextWriter,
time: Res<Time>
) {
let entity = query.single();
*writer.text(entity, 1) = format_time(time.elapsed());
}
```
### Iterating text spans
Text spans are now entities in a hierarchy, so the new `UiTextReader`
and `UiTextWriter` system parameters provide ways to iterate that
hierarchy. The `UiTextReader::iter` method will give you a normal
iterator over spans, and `UiTextWriter::for_each` lets you visit each of
the spans.
---------
Co-authored-by: ickshonpe <david.curthoys@googlemail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
[*Percentage-closer soft shadows*] are a technique from 2004 that allow
shadows to become blurrier farther from the objects that cast them. It
works by introducing a *blocker search* step that runs before the normal
shadow map sampling. The blocker search step detects the difference
between the depth of the fragment being rasterized and the depth of the
nearby samples in the depth buffer. Larger depth differences result in a
larger penumbra and therefore a blurrier shadow.
To enable PCSS, fill in the `soft_shadow_size` value in
`DirectionalLight`, `PointLight`, or `SpotLight`, as appropriate. This
shadow size value represents the size of the light and should be tuned
as appropriate for your scene. Higher values result in a wider penumbra
(i.e. blurrier shadows).
When using PCSS, temporal shadow maps
(`ShadowFilteringMethod::Temporal`) are recommended. If you don't use
`ShadowFilteringMethod::Temporal` and instead use
`ShadowFilteringMethod::Gaussian`, Bevy will use the same technique as
`Temporal`, but the result won't vary over time. This produces a rather
noisy result. Doing better would likely require downsampling the shadow
map, which would be complex and slower (and would require PR #13003 to
land first).
In addition to PCSS, this commit makes the near Z plane for the shadow
map configurable on a per-light basis. Previously, it had been hardcoded
to 0.1 meters. This change was necessary to make the point light shadow
map in the example look reasonable, as otherwise the shadows appeared
far too aliased.
A new example, `pcss`, has been added. It demonstrates the
percentage-closer soft shadow technique with directional lights, point
lights, spot lights, non-temporal operation, and temporal operation. The
assets are my original work.
Both temporal and non-temporal shadows are rather noisy in the example,
and, as mentioned before, this is unavoidable without downsampling the
depth buffer, which we can't do yet. Note also that the shadows don't
look particularly great for point lights; the example simply isn't an
ideal scene for them. Nevertheless, I felt that the benefits of the
ability to do a side-by-side comparison of directional and point lights
outweighed the unsightliness of the point light shadows in that example,
so I kept the point light feature in.
Fixes#3631.
[*Percentage-closer soft shadows*]:
https://developer.download.nvidia.com/shaderlibrary/docs/shadow_PCSS.pdf
## Changelog
### Added
* Percentage-closer soft shadows (PCSS) are now supported, allowing
shadows to become blurrier as they stretch away from objects. To use
them, set the `soft_shadow_size` field in `DirectionalLight`,
`PointLight`, or `SpotLight`, as applicable.
* The near Z value for shadow maps is now customizable via the
`shadow_map_near_z` field in `DirectionalLight`, `PointLight`, and
`SpotLight`.
## Screenshots
PCSS off:
PCSS on:
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Torstein Grindvik <52322338+torsteingrindvik@users.noreply.github.com>
