mirror of
https://github.com/bevyengine/bevy
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8b636f32cf
# Objective In the animation example, there is the code `.add_systems(Update, init_animations.before(animate_targets))`, where `animate_targets` is added to the `PostUpdate` in the `AnimationPlugin`. Therefore, the `.before(animate_targets)` here is ineffective and should be removed.
556 lines
17 KiB
Rust
556 lines
17 KiB
Rust
//! Demonstrates animation blending with animation graphs.
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//!
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//! The animation graph is shown on screen. You can change the weights of the
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//! playing animations by clicking and dragging left or right within the nodes.
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use bevy::{
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color::palettes::{
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basic::WHITE,
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css::{ANTIQUE_WHITE, DARK_GREEN},
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},
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prelude::*,
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ui::RelativeCursorPosition,
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};
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use argh::FromArgs;
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#[cfg(not(target_arch = "wasm32"))]
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use {
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bevy::{asset::io::file::FileAssetReader, tasks::IoTaskPool},
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ron::ser::PrettyConfig,
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std::{fs::File, path::Path},
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};
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/// Where to find the serialized animation graph.
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static ANIMATION_GRAPH_PATH: &str = "animation_graphs/Fox.animgraph.ron";
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/// The indices of the nodes containing animation clips in the graph.
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static CLIP_NODE_INDICES: [u32; 3] = [2, 3, 4];
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/// The help text in the upper left corner.
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static HELP_TEXT: &str = "Click and drag an animation clip node to change its weight";
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/// The node widgets in the UI.
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static NODE_TYPES: [NodeType; 5] = [
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NodeType::Clip(ClipNode::new("Idle", 0)),
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NodeType::Clip(ClipNode::new("Walk", 1)),
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NodeType::Blend("Root"),
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NodeType::Blend("Blend\n0.5"),
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NodeType::Clip(ClipNode::new("Run", 2)),
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];
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/// The positions of the node widgets in the UI.
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///
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/// These are in the same order as [`NODE_TYPES`] above.
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static NODE_RECTS: [NodeRect; 5] = [
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NodeRect::new(10.00, 10.00, 97.64, 48.41),
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NodeRect::new(10.00, 78.41, 97.64, 48.41),
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NodeRect::new(286.08, 78.41, 97.64, 48.41),
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NodeRect::new(148.04, 112.61, 97.64, 48.41), // was 44.20
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NodeRect::new(10.00, 146.82, 97.64, 48.41),
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];
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/// The positions of the horizontal lines in the UI.
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static HORIZONTAL_LINES: [Line; 6] = [
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Line::new(107.64, 34.21, 158.24),
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Line::new(107.64, 102.61, 20.20),
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Line::new(107.64, 171.02, 20.20),
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Line::new(127.84, 136.82, 20.20),
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Line::new(245.68, 136.82, 20.20),
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Line::new(265.88, 102.61, 20.20),
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];
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/// The positions of the vertical lines in the UI.
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static VERTICAL_LINES: [Line; 2] = [
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Line::new(127.83, 102.61, 68.40),
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Line::new(265.88, 34.21, 102.61),
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];
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/// Initializes the app.
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fn main() {
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#[cfg(not(target_arch = "wasm32"))]
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let args: Args = argh::from_env();
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#[cfg(target_arch = "wasm32")]
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let args = Args::from_args(&[], &[]).unwrap();
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App::new()
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.add_plugins(DefaultPlugins.set(WindowPlugin {
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primary_window: Some(Window {
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title: "Bevy Animation Graph Example".into(),
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..default()
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}),
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..default()
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}))
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.add_systems(Startup, (setup_assets, setup_scene, setup_ui))
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.add_systems(Update, init_animations)
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.add_systems(
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Update,
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(handle_weight_drag, update_ui, sync_weights).chain(),
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)
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.insert_resource(args)
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.insert_resource(AmbientLight {
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color: WHITE.into(),
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brightness: 100.0,
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})
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.run();
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}
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/// Demonstrates animation blending with animation graphs
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#[derive(FromArgs, Resource)]
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struct Args {
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/// disables loading of the animation graph asset from disk
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#[argh(switch)]
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no_load: bool,
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/// regenerates the asset file; implies `--no-load`
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#[argh(switch)]
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save: bool,
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}
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/// The [`AnimationGraph`] asset, which specifies how the animations are to
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/// be blended together.
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#[derive(Clone, Resource)]
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struct ExampleAnimationGraph(Handle<AnimationGraph>);
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/// The current weights of the three playing animations.
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#[derive(Component)]
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struct ExampleAnimationWeights {
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/// The weights of the three playing animations.
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weights: [f32; 3],
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}
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/// Initializes the scene.
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fn setup_assets(
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mut commands: Commands,
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mut asset_server: ResMut<AssetServer>,
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mut animation_graphs: ResMut<Assets<AnimationGraph>>,
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args: Res<Args>,
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) {
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// Create or load the assets.
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if args.no_load || args.save {
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setup_assets_programmatically(
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&mut commands,
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&mut asset_server,
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&mut animation_graphs,
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args.save,
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);
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} else {
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setup_assets_via_serialized_animation_graph(&mut commands, &mut asset_server);
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}
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}
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fn setup_ui(mut commands: Commands) {
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setup_help_text(&mut commands);
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setup_node_rects(&mut commands);
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setup_node_lines(&mut commands);
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}
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/// Creates the assets programmatically, including the animation graph.
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/// Optionally saves them to disk if `save` is present (corresponding to the
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/// `--save` option).
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fn setup_assets_programmatically(
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commands: &mut Commands,
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asset_server: &mut AssetServer,
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animation_graphs: &mut Assets<AnimationGraph>,
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_save: bool,
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) {
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// Create the nodes.
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let mut animation_graph = AnimationGraph::new();
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let blend_node = animation_graph.add_blend(0.5, animation_graph.root);
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animation_graph.add_clip(
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asset_server.load(GltfAssetLabel::Animation(0).from_asset("models/animated/Fox.glb")),
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1.0,
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animation_graph.root,
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);
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animation_graph.add_clip(
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asset_server.load(GltfAssetLabel::Animation(1).from_asset("models/animated/Fox.glb")),
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1.0,
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blend_node,
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);
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animation_graph.add_clip(
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asset_server.load(GltfAssetLabel::Animation(2).from_asset("models/animated/Fox.glb")),
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1.0,
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blend_node,
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);
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// If asked to save, do so.
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#[cfg(not(target_arch = "wasm32"))]
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if _save {
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let animation_graph = animation_graph.clone();
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IoTaskPool::get()
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.spawn(async move {
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let mut animation_graph_writer = File::create(Path::join(
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&FileAssetReader::get_base_path(),
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Path::join(Path::new("assets"), Path::new(ANIMATION_GRAPH_PATH)),
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))
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.expect("Failed to open the animation graph asset");
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ron::ser::to_writer_pretty(
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&mut animation_graph_writer,
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&animation_graph,
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PrettyConfig::default(),
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)
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.expect("Failed to serialize the animation graph");
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})
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.detach();
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}
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// Add the graph.
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let handle = animation_graphs.add(animation_graph);
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// Save the assets in a resource.
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commands.insert_resource(ExampleAnimationGraph(handle));
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}
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fn setup_assets_via_serialized_animation_graph(
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commands: &mut Commands,
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asset_server: &mut AssetServer,
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) {
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commands.insert_resource(ExampleAnimationGraph(
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asset_server.load(ANIMATION_GRAPH_PATH),
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));
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}
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/// Spawns the animated fox.
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fn setup_scene(
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mut commands: Commands,
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asset_server: Res<AssetServer>,
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mut meshes: ResMut<Assets<Mesh>>,
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mut materials: ResMut<Assets<StandardMaterial>>,
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) {
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commands.spawn((
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Camera3d::default(),
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Transform::from_xyz(-10.0, 5.0, 13.0).looking_at(Vec3::new(0., 1., 0.), Vec3::Y),
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));
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commands.spawn((
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PointLight {
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intensity: 10_000_000.0,
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shadows_enabled: true,
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..default()
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},
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Transform::from_xyz(-4.0, 8.0, 13.0),
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));
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commands.spawn((
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SceneRoot(
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asset_server.load(GltfAssetLabel::Scene(0).from_asset("models/animated/Fox.glb")),
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),
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Transform::from_scale(Vec3::splat(0.07)),
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));
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// Ground
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commands.spawn((
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Mesh3d(meshes.add(Circle::new(7.0))),
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MeshMaterial3d(materials.add(Color::srgb(0.3, 0.5, 0.3))),
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Transform::from_rotation(Quat::from_rotation_x(-std::f32::consts::FRAC_PI_2)),
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));
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}
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/// Places the help text at the top left of the window.
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fn setup_help_text(commands: &mut Commands) {
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commands.spawn((
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Text::new(HELP_TEXT),
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Node {
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position_type: PositionType::Absolute,
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top: Val::Px(12.0),
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left: Val::Px(12.0),
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..default()
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},
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));
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}
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/// Initializes the node UI widgets.
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fn setup_node_rects(commands: &mut Commands) {
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for (node_rect, node_type) in NODE_RECTS.iter().zip(NODE_TYPES.iter()) {
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let node_string = match *node_type {
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NodeType::Clip(ref clip) => clip.text,
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NodeType::Blend(text) => text,
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};
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let text = commands
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.spawn((
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Text::new(node_string),
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TextFont {
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font_size: 16.0,
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..default()
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},
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TextColor(ANTIQUE_WHITE.into()),
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TextLayout::new_with_justify(JustifyText::Center),
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))
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.id();
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let container = {
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let mut container = commands.spawn((
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Node {
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position_type: PositionType::Absolute,
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bottom: Val::Px(node_rect.bottom),
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left: Val::Px(node_rect.left),
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height: Val::Px(node_rect.height),
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width: Val::Px(node_rect.width),
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align_items: AlignItems::Center,
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justify_items: JustifyItems::Center,
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align_content: AlignContent::Center,
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justify_content: JustifyContent::Center,
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..default()
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},
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BorderColor(WHITE.into()),
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Outline::new(Val::Px(1.), Val::ZERO, Color::WHITE),
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));
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if let NodeType::Clip(ref clip) = node_type {
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container.insert((
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Interaction::None,
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RelativeCursorPosition::default(),
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(*clip).clone(),
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));
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}
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container.id()
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};
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// Create the background color.
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if let NodeType::Clip(_) = node_type {
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let background = commands
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.spawn((
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Node {
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position_type: PositionType::Absolute,
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top: Val::Px(0.),
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left: Val::Px(0.),
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height: Val::Px(node_rect.height),
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width: Val::Px(node_rect.width),
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..default()
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},
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BackgroundColor(DARK_GREEN.into()),
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))
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.id();
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commands.entity(container).add_child(background);
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}
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commands.entity(container).add_child(text);
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}
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}
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/// Creates boxes for the horizontal and vertical lines.
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///
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/// This is a bit hacky: it uses 1-pixel-wide and 1-pixel-high boxes to draw
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/// vertical and horizontal lines, respectively.
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fn setup_node_lines(commands: &mut Commands) {
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for line in &HORIZONTAL_LINES {
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commands.spawn((
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Node {
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position_type: PositionType::Absolute,
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bottom: Val::Px(line.bottom),
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left: Val::Px(line.left),
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height: Val::Px(0.0),
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width: Val::Px(line.length),
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border: UiRect::bottom(Val::Px(1.0)),
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..default()
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},
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BorderColor(WHITE.into()),
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));
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}
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for line in &VERTICAL_LINES {
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commands.spawn((
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Node {
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position_type: PositionType::Absolute,
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bottom: Val::Px(line.bottom),
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left: Val::Px(line.left),
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height: Val::Px(line.length),
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width: Val::Px(0.0),
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border: UiRect::left(Val::Px(1.0)),
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..default()
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},
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BorderColor(WHITE.into()),
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));
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}
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}
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/// Attaches the animation graph to the scene, and plays all three animations.
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fn init_animations(
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mut commands: Commands,
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mut query: Query<(Entity, &mut AnimationPlayer)>,
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animation_graph: Res<ExampleAnimationGraph>,
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mut done: Local<bool>,
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) {
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if *done {
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return;
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}
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for (entity, mut player) in query.iter_mut() {
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commands.entity(entity).insert((
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AnimationGraphHandle(animation_graph.0.clone()),
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ExampleAnimationWeights::default(),
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));
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for &node_index in &CLIP_NODE_INDICES {
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player.play(node_index.into()).repeat();
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}
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*done = true;
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}
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}
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/// Read cursor position relative to clip nodes, allowing the user to change weights
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/// when dragging the node UI widgets.
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fn handle_weight_drag(
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mut interaction_query: Query<(&Interaction, &RelativeCursorPosition, &ClipNode)>,
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mut animation_weights_query: Query<&mut ExampleAnimationWeights>,
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) {
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for (interaction, relative_cursor, clip_node) in &mut interaction_query {
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if !matches!(*interaction, Interaction::Pressed) {
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continue;
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}
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let Some(pos) = relative_cursor.normalized else {
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continue;
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};
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for mut animation_weights in animation_weights_query.iter_mut() {
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animation_weights.weights[clip_node.index] = pos.x.clamp(0., 1.);
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}
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}
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}
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// Updates the UI based on the weights that the user has chosen.
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fn update_ui(
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mut text_query: Query<&mut Text>,
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mut background_query: Query<&mut Node, Without<Text>>,
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container_query: Query<(&Children, &ClipNode)>,
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animation_weights_query: Query<&ExampleAnimationWeights, Changed<ExampleAnimationWeights>>,
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) {
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for animation_weights in animation_weights_query.iter() {
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for (children, clip_node) in &container_query {
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// Draw the green background color to visually indicate the weight.
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let mut bg_iter = background_query.iter_many_mut(children);
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if let Some(mut node) = bg_iter.fetch_next() {
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// All nodes are the same width, so `NODE_RECTS[0]` is as good as any other.
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node.width =
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Val::Px(NODE_RECTS[0].width * animation_weights.weights[clip_node.index]);
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}
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// Update the node labels with the current weights.
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let mut text_iter = text_query.iter_many_mut(children);
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if let Some(mut text) = text_iter.fetch_next() {
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**text = format!(
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"{}\n{:.2}",
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clip_node.text, animation_weights.weights[clip_node.index]
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);
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}
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}
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}
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}
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/// Takes the weights that were set in the UI and assigns them to the actual
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/// playing animation.
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fn sync_weights(mut query: Query<(&mut AnimationPlayer, &ExampleAnimationWeights)>) {
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for (mut animation_player, animation_weights) in query.iter_mut() {
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for (&animation_node_index, &animation_weight) in CLIP_NODE_INDICES
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.iter()
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.zip(animation_weights.weights.iter())
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{
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// If the animation happens to be no longer active, restart it.
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if !animation_player.is_playing_animation(animation_node_index.into()) {
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animation_player.play(animation_node_index.into());
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}
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// Set the weight.
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if let Some(active_animation) =
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animation_player.animation_mut(animation_node_index.into())
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{
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active_animation.set_weight(animation_weight);
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}
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}
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}
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}
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/// An on-screen representation of a node.
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#[derive(Debug)]
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struct NodeRect {
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/// The number of pixels that this rectangle is from the left edge of the
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/// window.
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left: f32,
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/// The number of pixels that this rectangle is from the bottom edge of the
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/// window.
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bottom: f32,
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/// The width of this rectangle in pixels.
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width: f32,
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/// The height of this rectangle in pixels.
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height: f32,
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}
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/// Either a straight horizontal or a straight vertical line on screen.
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///
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/// The line starts at (`left`, `bottom`) and goes either right (if the line is
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/// horizontal) or down (if the line is vertical).
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struct Line {
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/// The number of pixels that the start of this line is from the left edge
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/// of the screen.
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left: f32,
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/// The number of pixels that the start of this line is from the bottom edge
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/// of the screen.
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bottom: f32,
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/// The length of the line.
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length: f32,
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}
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/// The type of each node in the UI: either a clip node or a blend node.
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enum NodeType {
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/// A clip node, which specifies an animation.
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Clip(ClipNode),
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/// A blend node with no animation and a string label.
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Blend(&'static str),
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}
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/// The label for the UI representation of a clip node.
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#[derive(Clone, Component)]
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struct ClipNode {
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/// The string label of the node.
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text: &'static str,
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/// Which of the three animations this UI widget represents.
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index: usize,
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}
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impl Default for ExampleAnimationWeights {
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fn default() -> Self {
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Self { weights: [1.0; 3] }
|
|
}
|
|
}
|
|
|
|
impl ClipNode {
|
|
/// Creates a new [`ClipNodeText`] from a label and the animation index.
|
|
const fn new(text: &'static str, index: usize) -> Self {
|
|
Self { text, index }
|
|
}
|
|
}
|
|
|
|
impl NodeRect {
|
|
/// Creates a new [`NodeRect`] from the lower-left corner and size.
|
|
///
|
|
/// Note that node rectangles are anchored in the *lower*-left corner. The
|
|
/// `bottom` parameter specifies vertical distance from the *bottom* of the
|
|
/// window.
|
|
const fn new(left: f32, bottom: f32, width: f32, height: f32) -> NodeRect {
|
|
NodeRect {
|
|
left,
|
|
bottom,
|
|
width,
|
|
height,
|
|
}
|
|
}
|
|
}
|
|
|
|
impl Line {
|
|
/// Creates a new [`Line`], either horizontal or vertical.
|
|
///
|
|
/// Note that the line's start point is anchored in the lower-*left* corner,
|
|
/// and that the `length` extends either to the right or downward.
|
|
const fn new(left: f32, bottom: f32, length: f32) -> Self {
|
|
Self {
|
|
left,
|
|
bottom,
|
|
length,
|
|
}
|
|
}
|
|
}
|