284889c64b
An alternative to StateStages that uses SystemSets. Also includes pop and push operations since this was originally developed for my personal project which needed them.
84 lines
3.0 KiB
Rust
84 lines
3.0 KiB
Rust
use bevy::{asset::LoadState, prelude::*, sprite::TextureAtlasBuilder};
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/// In this example we generate a new texture atlas (sprite sheet) from a folder containing
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/// individual sprites
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fn main() {
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App::build()
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.init_resource::<RpgSpriteHandles>()
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.add_plugins(DefaultPlugins)
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.add_state(AppState::Setup)
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.add_system_set(SystemSet::on_enter(AppState::Setup).with_system(load_textures.system()))
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.add_system_set(SystemSet::on_update(AppState::Setup).with_system(check_textures.system()))
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.add_system_set(SystemSet::on_enter(AppState::Finished).with_system(setup.system()))
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.run();
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}
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#[derive(Clone, PartialEq, Eq)]
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enum AppState {
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Setup,
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Finished,
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}
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#[derive(Default)]
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struct RpgSpriteHandles {
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handles: Vec<HandleUntyped>,
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}
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fn load_textures(mut rpg_sprite_handles: ResMut<RpgSpriteHandles>, asset_server: Res<AssetServer>) {
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rpg_sprite_handles.handles = asset_server.load_folder("textures/rpg").unwrap();
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}
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fn check_textures(
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mut state: ResMut<State<AppState>>,
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rpg_sprite_handles: ResMut<RpgSpriteHandles>,
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asset_server: Res<AssetServer>,
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) {
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if let LoadState::Loaded =
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asset_server.get_group_load_state(rpg_sprite_handles.handles.iter().map(|handle| handle.id))
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{
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state.set_next(AppState::Finished).unwrap();
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}
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}
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fn setup(
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mut commands: Commands,
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rpg_sprite_handles: Res<RpgSpriteHandles>,
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asset_server: Res<AssetServer>,
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mut texture_atlases: ResMut<Assets<TextureAtlas>>,
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mut textures: ResMut<Assets<Texture>>,
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mut materials: ResMut<Assets<ColorMaterial>>,
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) {
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let mut texture_atlas_builder = TextureAtlasBuilder::default();
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for handle in rpg_sprite_handles.handles.iter() {
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let texture = textures.get(handle).unwrap();
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texture_atlas_builder.add_texture(handle.clone_weak().typed::<Texture>(), texture);
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}
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let texture_atlas = texture_atlas_builder.finish(&mut textures).unwrap();
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let texture_atlas_texture = texture_atlas.texture.clone();
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let vendor_handle = asset_server.get_handle("textures/rpg/chars/vendor/generic-rpg-vendor.png");
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let vendor_index = texture_atlas.get_texture_index(&vendor_handle).unwrap();
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let atlas_handle = texture_atlases.add(texture_atlas);
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// set up a scene to display our texture atlas
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commands
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.spawn(OrthographicCameraBundle::new_2d())
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// draw a sprite from the atlas
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.spawn(SpriteSheetBundle {
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transform: Transform {
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translation: Vec3::new(150.0, 0.0, 0.0),
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scale: Vec3::splat(4.0),
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..Default::default()
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},
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sprite: TextureAtlasSprite::new(vendor_index as u32),
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texture_atlas: atlas_handle,
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..Default::default()
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})
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// draw the atlas itself
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.spawn(SpriteBundle {
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material: materials.add(texture_atlas_texture.into()),
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transform: Transform::from_xyz(-300.0, 0.0, 0.0),
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..Default::default()
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});
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}
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