bevy/examples/ui/ui_material.rs
ickshonpe 02985c3d56
ui_material example webgl2 fix (#17852)
# Objective

Fixes #17851

## Solution

Align the `slider` uniform to 16 bytes by making it a `vec4`.

## Testing

Run the example using:
```
cargo run -p build-wasm-example -- --api webgl2 ui_material
basic-http-server examples/wasm/
```
2025-02-13 20:52:26 +00:00

107 lines
3.6 KiB
Rust

//! Demonstrates the use of [`UiMaterials`](UiMaterial) and how to change material values
use bevy::{
color::palettes::css::DARK_BLUE, prelude::*, reflect::TypePath, render::render_resource::*,
};
/// This example uses a shader source file from the assets subdirectory
const SHADER_ASSET_PATH: &str = "shaders/custom_ui_material.wgsl";
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_plugins(UiMaterialPlugin::<CustomUiMaterial>::default())
.add_systems(Startup, setup)
.add_systems(Update, animate)
.run();
}
fn setup(
mut commands: Commands,
mut ui_materials: ResMut<Assets<CustomUiMaterial>>,
asset_server: Res<AssetServer>,
) {
// Camera so we can see UI
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| {
let banner_scale_factor = 0.5;
parent.spawn((
Node {
position_type: PositionType::Absolute,
width: Val::Px(905.0 * banner_scale_factor),
height: Val::Px(363.0 * banner_scale_factor),
border: UiRect::all(Val::Px(20.)),
..default()
},
MaterialNode(ui_materials.add(CustomUiMaterial {
color: LinearRgba::WHITE.to_f32_array().into(),
slider: Vec4::splat(0.5),
color_texture: asset_server.load("branding/banner.png"),
border_color: LinearRgba::WHITE.to_f32_array().into(),
})),
BorderRadius::all(Val::Px(20.)),
// UI material nodes can have outlines and shadows like any other UI node
Outline {
width: Val::Px(2.),
offset: Val::Px(100.),
color: DARK_BLUE.into(),
},
));
});
}
#[derive(AsBindGroup, Asset, TypePath, Debug, Clone)]
struct CustomUiMaterial {
/// Color multiplied with the image
#[uniform(0)]
color: Vec4,
/// Represents how much of the image is visible
/// Goes from 0 to 1
/// A `Vec4` is used here because Bevy with webgl2 requires that uniforms are 16-byte aligned but only the first component is read.
#[uniform(1)]
slider: Vec4,
/// Image used to represent the slider
#[texture(2)]
#[sampler(3)]
color_texture: Handle<Image>,
/// Color of the image's border
#[uniform(4)]
border_color: Vec4,
}
impl UiMaterial for CustomUiMaterial {
fn fragment_shader() -> ShaderRef {
SHADER_ASSET_PATH.into()
}
}
// Fills the slider slowly over 2 seconds and resets it
// Also updates the color of the image to a rainbow color
fn animate(
mut materials: ResMut<Assets<CustomUiMaterial>>,
q: Query<&MaterialNode<CustomUiMaterial>>,
time: Res<Time>,
) {
let duration = 2.0;
for handle in &q {
if let Some(material) = materials.get_mut(handle) {
// rainbow color effect
let new_color = Color::hsl((time.elapsed_secs() * 60.0) % 360.0, 1., 0.5);
let border_color = Color::hsl((time.elapsed_secs() * 60.0) % 360.0, 0.75, 0.75);
material.color = new_color.to_linear().to_vec4();
material.slider.x =
((time.elapsed_secs() % (duration * 2.0)) - duration).abs() / duration;
material.border_color = border_color.to_linear().to_vec4();
}
}
}