1553ee98ff
# Objective In #17905 we swapped to a named field on `ChildOf` to help resolve variable naming ambiguity of child vs parent (ex: `child_of.parent` clearly reads as "I am accessing the parent of the child_of relationship", whereas `child_of.0` is less clear). Unfortunately this has the side effect of making initialization less ideal. `ChildOf { parent }` reads just as well as `ChildOf(parent)`, but `ChildOf { parent: root }` doesn't read nearly as well as `ChildOf(root)`. ## Solution Move back to `ChildOf(pub Entity)` but add a `child_of.parent()` function and use it for all accesses. The downside here is that users are no longer "forced" to access the parent field with `parent` nomenclature, but I think this strikes the right balance. Take a look at the diff. I think the results provide strong evidence for this change. Initialization has the benefit of reading much better _and_ of taking up significantly less space, as many lines go from 3 to 1, and we're cutting out a bunch of syntax in some cases. Sadly I do think this should land in 0.16 as the cost of doing this _after_ the relationships migration is high.
526 lines
18 KiB
Rust
526 lines
18 KiB
Rust
//! Demonstrates how to combine baked and dynamic lighting.
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use bevy::{
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pbr::Lightmap,
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picking::{backend::HitData, pointer::PointerInteraction},
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prelude::*,
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scene::SceneInstanceReady,
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};
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use crate::widgets::{RadioButton, RadioButtonText, WidgetClickEvent, WidgetClickSender};
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#[path = "../helpers/widgets.rs"]
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mod widgets;
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/// How bright the lightmaps are.
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const LIGHTMAP_EXPOSURE: f32 = 600.0;
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/// How far above the ground the sphere's origin is when moved, in scene units.
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const SPHERE_OFFSET: f32 = 0.2;
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/// The settings that the user has currently chosen for the app.
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#[derive(Clone, Default, Resource)]
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struct AppStatus {
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/// The lighting mode that the user currently has set: baked, mixed, or
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/// real-time.
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lighting_mode: LightingMode,
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}
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/// The type of lighting to use in the scene.
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#[derive(Clone, Copy, PartialEq, Default)]
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enum LightingMode {
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/// All light is computed ahead of time; no lighting takes place at runtime.
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///
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/// In this mode, the sphere can't be moved, as the light shining on it was
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/// precomputed. On the plus side, the sphere has indirect lighting in this
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/// mode, as the red hue on the bottom of the sphere demonstrates.
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Baked,
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/// All light for the static objects is computed ahead of time, but the
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/// light for the dynamic sphere is computed at runtime.
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///
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/// In this mode, the sphere can be moved, and the light will be computed
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/// for it as you do so. The sphere loses indirect illumination; notice the
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/// lack of a red hue at the base of the sphere. However, the rest of the
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/// scene has indirect illumination. Note also that the sphere doesn't cast
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/// a shadow on the static objects in this mode, because shadows are part of
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/// the lighting computation.
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MixedDirect,
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/// Indirect light for the static objects is computed ahead of time, and
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/// direct light for all objects is computed at runtime.
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///
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/// In this mode, the sphere can be moved, and the light will be computed
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/// for it as you do so. The sphere loses indirect illumination; notice the
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/// lack of a red hue at the base of the sphere. However, the rest of the
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/// scene has indirect illumination. The sphere does cast a shadow on
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/// objects in this mode, because the direct light for all objects is being
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/// computed dynamically.
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#[default]
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MixedIndirect,
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/// Light is computed at runtime for all objects.
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///
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/// In this mode, no lightmaps are used at all. All objects are dynamically
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/// lit, which provides maximum flexibility. However, the downside is that
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/// global illumination is lost; note that the base of the sphere isn't red
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/// as it is in baked mode.
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RealTime,
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}
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/// An event that's fired whenever the user changes the lighting mode.
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///
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/// This is also fired when the scene loads for the first time.
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#[derive(Clone, Copy, Default, Event)]
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struct LightingModeChanged;
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#[derive(Clone, Copy, Component, Debug)]
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struct HelpText;
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/// The name of every static object in the scene that has a lightmap, as well as
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/// the UV rect of its lightmap.
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///
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/// Storing this as an array and doing a linear search through it is rather
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/// inefficient, but we do it anyway for clarity's sake.
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static LIGHTMAPS: [(&str, Rect); 5] = [
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(
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"Plane",
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uv_rect_opengl(Vec2::splat(0.026), Vec2::splat(0.710)),
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),
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(
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"SheenChair_fabric",
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uv_rect_opengl(vec2(0.7864, 0.02377), vec2(0.1910, 0.1912)),
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),
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(
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"SheenChair_label",
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uv_rect_opengl(vec2(0.275, -0.016), vec2(0.858, 0.486)),
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),
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(
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"SheenChair_metal",
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uv_rect_opengl(vec2(0.998, 0.506), vec2(-0.029, -0.067)),
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),
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(
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"SheenChair_wood",
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uv_rect_opengl(vec2(0.787, 0.257), vec2(0.179, 0.177)),
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),
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];
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static SPHERE_UV_RECT: Rect = uv_rect_opengl(vec2(0.788, 0.484), Vec2::splat(0.062));
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/// The initial position of the sphere.
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///
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/// When the user sets the light mode to [`LightingMode::Baked`], we reset the
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/// position to this point.
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const INITIAL_SPHERE_POSITION: Vec3 = vec3(0.0, 0.5233223, 0.0);
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fn main() {
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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 Mixed Lighting 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_plugins(MeshPickingPlugin)
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.insert_resource(AmbientLight {
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color: ClearColor::default().0,
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brightness: 10000.0,
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affects_lightmapped_meshes: true,
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})
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.init_resource::<AppStatus>()
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.add_event::<WidgetClickEvent<LightingMode>>()
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.add_event::<LightingModeChanged>()
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.add_systems(Startup, setup)
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.add_systems(Update, update_lightmaps)
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.add_systems(Update, update_directional_light)
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.add_systems(Update, make_sphere_nonpickable)
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.add_systems(Update, update_radio_buttons)
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.add_systems(Update, handle_lighting_mode_change)
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.add_systems(Update, widgets::handle_ui_interactions::<LightingMode>)
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.add_systems(Update, reset_sphere_position)
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.add_systems(Update, move_sphere)
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.add_systems(Update, adjust_help_text)
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.run();
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}
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/// Creates the scene.
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fn setup(mut commands: Commands, asset_server: Res<AssetServer>, app_status: Res<AppStatus>) {
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spawn_camera(&mut commands);
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spawn_scene(&mut commands, &asset_server);
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spawn_buttons(&mut commands);
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spawn_help_text(&mut commands, &app_status);
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}
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/// Spawns the 3D camera.
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fn spawn_camera(commands: &mut Commands) {
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commands
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.spawn(Camera3d::default())
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.insert(Transform::from_xyz(-0.7, 0.7, 1.0).looking_at(vec3(0.0, 0.3, 0.0), Vec3::Y));
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}
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/// Spawns the scene.
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///
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/// The scene is loaded from a glTF file.
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fn spawn_scene(commands: &mut Commands, asset_server: &AssetServer) {
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commands
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.spawn(SceneRoot(
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asset_server.load(
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GltfAssetLabel::Scene(0)
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.from_asset("models/MixedLightingExample/MixedLightingExample.gltf"),
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),
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))
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.observe(
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|_: Trigger<SceneInstanceReady>,
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mut lighting_mode_change_event_writer: EventWriter<LightingModeChanged>| {
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// When the scene loads, send a `LightingModeChanged` event so
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// that we set up the lightmaps.
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lighting_mode_change_event_writer.write(LightingModeChanged);
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},
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);
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}
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/// Spawns the buttons that allow the user to change the lighting mode.
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fn spawn_buttons(commands: &mut Commands) {
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commands
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.spawn(widgets::main_ui_node())
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.with_children(|parent| {
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widgets::spawn_option_buttons(
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parent,
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"Lighting",
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&[
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(LightingMode::Baked, "Baked"),
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(LightingMode::MixedDirect, "Mixed (Direct)"),
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(LightingMode::MixedIndirect, "Mixed (Indirect)"),
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(LightingMode::RealTime, "Real-Time"),
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],
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);
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});
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}
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/// Spawns the help text at the top of the window.
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fn spawn_help_text(commands: &mut Commands, app_status: &AppStatus) {
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commands.spawn((
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create_help_text(app_status),
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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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HelpText,
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));
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}
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/// Adds lightmaps to and/or removes lightmaps from objects in the scene when
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/// the lighting mode changes.
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///
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/// This is also called right after the scene loads in order to set up the
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/// lightmaps.
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fn update_lightmaps(
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mut commands: Commands,
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asset_server: Res<AssetServer>,
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mut materials: ResMut<Assets<StandardMaterial>>,
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meshes: Query<(Entity, &Name, &MeshMaterial3d<StandardMaterial>), With<Mesh3d>>,
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mut lighting_mode_change_event_reader: EventReader<LightingModeChanged>,
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app_status: Res<AppStatus>,
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) {
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// Only run if the lighting mode changed. (Note that a change event is fired
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// when the scene first loads.)
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if lighting_mode_change_event_reader.read().next().is_none() {
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return;
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}
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// Select the lightmap to use, based on the lighting mode.
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let lightmap: Option<Handle<Image>> = match app_status.lighting_mode {
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LightingMode::Baked => {
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Some(asset_server.load("lightmaps/MixedLightingExample-Baked.zstd.ktx2"))
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}
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LightingMode::MixedDirect => {
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Some(asset_server.load("lightmaps/MixedLightingExample-MixedDirect.zstd.ktx2"))
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}
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LightingMode::MixedIndirect => {
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Some(asset_server.load("lightmaps/MixedLightingExample-MixedIndirect.zstd.ktx2"))
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}
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LightingMode::RealTime => None,
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};
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'outer: for (entity, name, material) in &meshes {
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// Add lightmaps to or remove lightmaps from the scenery objects in the
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// scene (all objects but the sphere).
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//
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// Note that doing a linear search through the `LIGHTMAPS` array is
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// inefficient, but we do it anyway in this example to improve clarity.
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for (lightmap_name, uv_rect) in LIGHTMAPS {
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if &**name != lightmap_name {
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continue;
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}
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// Lightmap exposure defaults to zero, so we need to set it.
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if let Some(ref mut material) = materials.get_mut(material) {
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material.lightmap_exposure = LIGHTMAP_EXPOSURE;
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}
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// Add or remove the lightmap.
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match lightmap {
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Some(ref lightmap) => {
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commands.entity(entity).insert(Lightmap {
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image: (*lightmap).clone(),
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uv_rect,
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bicubic_sampling: false,
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});
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}
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None => {
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commands.entity(entity).remove::<Lightmap>();
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}
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}
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continue 'outer;
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}
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// Add lightmaps to or remove lightmaps from the sphere.
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if &**name == "Sphere" {
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// Lightmap exposure defaults to zero, so we need to set it.
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if let Some(ref mut material) = materials.get_mut(material) {
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material.lightmap_exposure = LIGHTMAP_EXPOSURE;
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}
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// Add or remove the lightmap from the sphere. We only apply the
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// lightmap in fully-baked mode.
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match (&lightmap, app_status.lighting_mode) {
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(Some(lightmap), LightingMode::Baked) => {
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commands.entity(entity).insert(Lightmap {
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image: (*lightmap).clone(),
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uv_rect: SPHERE_UV_RECT,
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bicubic_sampling: false,
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});
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}
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_ => {
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commands.entity(entity).remove::<Lightmap>();
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}
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}
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}
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}
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}
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/// Converts a uv rectangle from the OpenGL coordinate system (origin in the
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/// lower left) to the Vulkan coordinate system (origin in the upper left) that
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/// Bevy uses.
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///
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/// For this particular example, the baking tool happened to use the OpenGL
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/// coordinate system, so it was more convenient to do the conversion at compile
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/// time than to pre-calculate and hard-code the values.
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const fn uv_rect_opengl(gl_min: Vec2, size: Vec2) -> Rect {
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let min = vec2(gl_min.x, 1.0 - gl_min.y - size.y);
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Rect {
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min,
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max: vec2(min.x + size.x, min.y + size.y),
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}
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}
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/// Ensures that clicking on the scene to move the sphere doesn't result in a
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/// hit on the sphere itself.
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fn make_sphere_nonpickable(
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mut commands: Commands,
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mut query: Query<(Entity, &Name), (With<Mesh3d>, Without<Pickable>)>,
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) {
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for (sphere, name) in &mut query {
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if &**name == "Sphere" {
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commands.entity(sphere).insert(Pickable::IGNORE);
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}
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}
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}
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/// Updates the directional light settings as necessary when the lighting mode
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/// changes.
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fn update_directional_light(
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mut lights: Query<&mut DirectionalLight>,
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mut lighting_mode_change_event_reader: EventReader<LightingModeChanged>,
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app_status: Res<AppStatus>,
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) {
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// Only run if the lighting mode changed. (Note that a change event is fired
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// when the scene first loads.)
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if lighting_mode_change_event_reader.read().next().is_none() {
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return;
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}
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// Real-time direct light is used on the scenery if we're using mixed
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// indirect or real-time mode.
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let scenery_is_lit_in_real_time = matches!(
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app_status.lighting_mode,
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LightingMode::MixedIndirect | LightingMode::RealTime
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);
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for mut light in &mut lights {
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light.affects_lightmapped_mesh_diffuse = scenery_is_lit_in_real_time;
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// Don't bother enabling shadows if they won't show up on the scenery.
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light.shadows_enabled = scenery_is_lit_in_real_time;
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}
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}
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/// Updates the state of the selection widgets at the bottom of the window when
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/// the lighting mode changes.
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fn update_radio_buttons(
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mut widgets: Query<
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(
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Entity,
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Option<&mut BackgroundColor>,
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Has<Text>,
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&WidgetClickSender<LightingMode>,
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),
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Or<(With<RadioButton>, With<RadioButtonText>)>,
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>,
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app_status: Res<AppStatus>,
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mut writer: TextUiWriter,
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) {
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for (entity, image, has_text, sender) in &mut widgets {
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let selected = **sender == app_status.lighting_mode;
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if let Some(mut bg_color) = image {
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widgets::update_ui_radio_button(&mut bg_color, selected);
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}
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if has_text {
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widgets::update_ui_radio_button_text(entity, &mut writer, selected);
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}
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}
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}
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/// Handles clicks on the widgets at the bottom of the screen and fires
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/// [`LightingModeChanged`] events.
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fn handle_lighting_mode_change(
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mut widget_click_event_reader: EventReader<WidgetClickEvent<LightingMode>>,
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mut lighting_mode_change_event_writer: EventWriter<LightingModeChanged>,
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mut app_status: ResMut<AppStatus>,
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) {
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for event in widget_click_event_reader.read() {
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app_status.lighting_mode = **event;
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lighting_mode_change_event_writer.write(LightingModeChanged);
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}
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}
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/// Moves the sphere to its original position when the user selects the baked
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/// lighting mode.
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///
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/// As the light from the sphere is precomputed and depends on the sphere's
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/// original position, the sphere must be placed there in order for the lighting
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/// to be correct.
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fn reset_sphere_position(
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mut objects: Query<(&Name, &mut Transform)>,
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mut lighting_mode_change_event_reader: EventReader<LightingModeChanged>,
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app_status: Res<AppStatus>,
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) {
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// Only run if the lighting mode changed and if the lighting mode is
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// `LightingMode::Baked`. (Note that a change event is fired when the scene
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// first loads.)
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if lighting_mode_change_event_reader.read().next().is_none()
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|| app_status.lighting_mode != LightingMode::Baked
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{
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return;
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}
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for (name, mut transform) in &mut objects {
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if &**name == "Sphere" {
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transform.translation = INITIAL_SPHERE_POSITION;
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break;
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}
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}
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}
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/// Updates the position of the sphere when the user clicks on a spot in the
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/// scene.
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///
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/// Note that the position of the sphere is locked in baked lighting mode.
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fn move_sphere(
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mouse_button_input: Res<ButtonInput<MouseButton>>,
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pointers: Query<&PointerInteraction>,
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mut meshes: Query<(&Name, &ChildOf), With<Mesh3d>>,
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mut transforms: Query<&mut Transform>,
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app_status: Res<AppStatus>,
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) {
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// Only run when the left button is clicked and we're not in baked lighting
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// mode.
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if app_status.lighting_mode == LightingMode::Baked
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|| !mouse_button_input.pressed(MouseButton::Left)
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{
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return;
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}
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// Find the sphere.
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let Some(child_of) = meshes
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.iter_mut()
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.filter_map(|(name, child_of)| {
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if &**name == "Sphere" {
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Some(child_of)
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} else {
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None
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}
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})
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.next()
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else {
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return;
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};
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// Grab its transform.
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let Ok(mut transform) = transforms.get_mut(child_of.parent()) else {
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return;
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};
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// Set its transform to the appropriate position, as determined by the
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// picking subsystem.
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for interaction in pointers.iter() {
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if let Some(&(
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_,
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HitData {
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position: Some(position),
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..
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},
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)) = interaction.get_nearest_hit()
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{
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transform.translation = position + vec3(0.0, SPHERE_OFFSET, 0.0);
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}
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}
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}
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/// Changes the help text at the top of the screen when the lighting mode
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/// changes.
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fn adjust_help_text(
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mut commands: Commands,
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help_texts: Query<Entity, With<HelpText>>,
|
|
app_status: Res<AppStatus>,
|
|
mut lighting_mode_change_event_reader: EventReader<LightingModeChanged>,
|
|
) {
|
|
if lighting_mode_change_event_reader.read().next().is_none() {
|
|
return;
|
|
}
|
|
|
|
for help_text in &help_texts {
|
|
commands
|
|
.entity(help_text)
|
|
.insert(create_help_text(&app_status));
|
|
}
|
|
}
|
|
|
|
/// Returns appropriate text to display at the top of the screen.
|
|
fn create_help_text(app_status: &AppStatus) -> Text {
|
|
match app_status.lighting_mode {
|
|
LightingMode::Baked => Text::new(
|
|
"Scenery: Static, baked direct light, baked indirect light
|
|
Sphere: Static, baked direct light, baked indirect light",
|
|
),
|
|
LightingMode::MixedDirect => Text::new(
|
|
"Scenery: Static, baked direct light, baked indirect light
|
|
Sphere: Dynamic, real-time direct light, no indirect light
|
|
Click in the scene to move the sphere",
|
|
),
|
|
LightingMode::MixedIndirect => Text::new(
|
|
"Scenery: Static, real-time direct light, baked indirect light
|
|
Sphere: Dynamic, real-time direct light, no indirect light
|
|
Click in the scene to move the sphere",
|
|
),
|
|
LightingMode::RealTime => Text::new(
|
|
"Scenery: Dynamic, real-time direct light, no indirect light
|
|
Sphere: Dynamic, real-time direct light, no indirect light
|
|
Click in the scene to move the sphere",
|
|
),
|
|
}
|
|
}
|