bevy/examples/2d/sprite_tile.rs
ickshonpe 4e02d3cdb9
Improved UiImage and Sprite scaling and slicing APIs (#16088)
# Objective

1. UI texture slicing chops and scales an image to fit the size of a
node and isn't meant to place any constraints on the size of the node
itself, but because the required components changes required `ImageSize`
and `ContentSize` for nodes with `UiImage`, texture sliced nodes are
laid out using an `ImageMeasure`.

2. In 0.14 users could spawn a `(UiImage, NodeBundle)` which would
display an image stretched to fill the UI node's bounds ignoring the
image's instrinsic size. Now that `UiImage` requires `ContentSize`,
there's no option to display an image without its size placing
constrains on the UI layout (unless you force the `Node` to a fixed
size, but that's not a solution).

3. It's desirable that the `Sprite` and `UiImage` share similar APIs.

Fixes #16109

## Solution

* Remove the `Component` impl from `ImageScaleMode`.
* Add a `Stretch` variant to `ImageScaleMode`.
* Add a field `scale_mode: ImageScaleMode` to `Sprite`.
* Add a field `mode: UiImageMode` to `UiImage`. 
* Add an enum `UiImageMode` similar to `ImageScaleMode` but with
additional UI specific variants.
* Remove the queries for `ImageScaleMode` from Sprite and UI extraction,
and refer to the new fields instead.
* Change `ui_layout_system` to update measure funcs on any change to
`ContentSize`s to enable manual clearing without removing the component.
* Don't add a measure unless `UiImageMode::Auto` is set in
`update_image_content_size_system`. Mutably deref the `Mut<ContentSize>`
if the `UiImage` is changed to force removal of any existing measure
func.

## Testing
Remove all the constraints from the ui_texture_slice example:

```rust
//! This example illustrates how to create buttons with their textures sliced
//! and kept in proportion instead of being stretched by the button dimensions

use bevy::{
    color::palettes::css::{GOLD, ORANGE},
    prelude::*,
    winit::WinitSettings,
};

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        // Only run the app when there is user input. This will significantly reduce CPU/GPU use.
        .insert_resource(WinitSettings::desktop_app())
        .add_systems(Startup, setup)
        .add_systems(Update, button_system)
        .run();
}

fn button_system(
    mut interaction_query: Query<
        (&Interaction, &Children, &mut UiImage),
        (Changed<Interaction>, With<Button>),
    >,
    mut text_query: Query<&mut Text>,
) {
    for (interaction, children, mut image) in &mut interaction_query {
        let mut text = text_query.get_mut(children[0]).unwrap();
        match *interaction {
            Interaction::Pressed => {
                **text = "Press".to_string();
                image.color = GOLD.into();
            }
            Interaction::Hovered => {
                **text = "Hover".to_string();
                image.color = ORANGE.into();
            }
            Interaction::None => {
                **text = "Button".to_string();
                image.color = Color::WHITE;
            }
        }
    }
}

fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
    let image = asset_server.load("textures/fantasy_ui_borders/panel-border-010.png");

    let slicer = TextureSlicer {
        border: BorderRect::square(22.0),
        center_scale_mode: SliceScaleMode::Stretch,
        sides_scale_mode: SliceScaleMode::Stretch,
        max_corner_scale: 1.0,
    };
    // ui camera
    commands.spawn(Camera2d);
    commands
        .spawn(Node {
            width: Val::Percent(100.0),
            height: Val::Percent(100.0),
            align_items: AlignItems::Center,
            justify_content: JustifyContent::Center,
            ..default()
        })
        .with_children(|parent| {
            for [w, h] in [[150.0, 150.0], [300.0, 150.0], [150.0, 300.0]] {
                parent
                    .spawn((
                        Button,
                        Node {
                            // width: Val::Px(w),
                            // height: Val::Px(h),
                            // horizontally center child text
                            justify_content: JustifyContent::Center,
                            // vertically center child text
                            align_items: AlignItems::Center,
                            margin: UiRect::all(Val::Px(20.0)),
                            ..default()
                        },
                        UiImage::new(image.clone()),
                        ImageScaleMode::Sliced(slicer.clone()),
                    ))
                    .with_children(|parent| {
                        // parent.spawn((
                        //     Text::new("Button"),
                        //     TextFont {
                        //         font: asset_server.load("fonts/FiraSans-Bold.ttf"),
                        //         font_size: 33.0,
                        //         ..default()
                        //     },
                        //     TextColor(Color::srgb(0.9, 0.9, 0.9)),
                        // ));
                    });
            }
        });
}
```

This should result in a blank window, since without any constraints the
texture slice image nodes should be zero-sized. But in main the image
nodes are given the size of the underlying unsliced source image
`textures/fantasy_ui_borders/panel-border-010.png`:

<img width="321" alt="slicing"
src="https://github.com/user-attachments/assets/cbd74c9c-14cd-4b4d-93c6-7c0152bb05ee">

For this PR need to change the lines:
```
                        UiImage::new(image.clone()),
                        ImageScaleMode::Sliced(slicer.clone()),
```
to
```
                        UiImage::new(image.clone()).with_mode(UiImageMode::Sliced(slicer.clone()),
```
and then nothing should be rendered, as desired.

---------

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-11-04 15:14:03 +00:00

48 lines
1.2 KiB
Rust

//! Displays a single [`Sprite`] tiled in a grid, with a scaling animation
use bevy::prelude::*;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, animate)
.run();
}
#[derive(Resource)]
struct AnimationState {
min: f32,
max: f32,
current: f32,
speed: f32,
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
commands.spawn(Camera2d);
commands.insert_resource(AnimationState {
min: 128.0,
max: 512.0,
current: 128.0,
speed: 50.0,
});
commands.spawn(Sprite {
image: asset_server.load("branding/icon.png"),
image_mode: SpriteImageMode::Tiled {
tile_x: true,
tile_y: true,
stretch_value: 0.5, // The image will tile every 128px
},
..default()
});
}
fn animate(mut sprites: Query<&mut Sprite>, mut state: ResMut<AnimationState>, time: Res<Time>) {
if state.current >= state.max || state.current <= state.min {
state.speed = -state.speed;
};
state.current += state.speed * time.delta_secs();
for mut sprite in &mut sprites {
sprite.custom_size = Some(Vec2::splat(state.current));
}
}