bevy_vrm1 0.3.0

use bevy::app::{App, Plugin};
use bevy::asset::io::Reader;
use bevy::asset::{Asset, AssetLoader, Handle, LoadContext};
use bevy::gltf::{Gltf, GltfAssetLabel, GltfError, GltfLoader, GltfLoaderSettings};
use bevy::image::{CompressedImageFormats, Image};
use bevy::prelude::{AssetApp, Component, TypePath};
use bevy::render::renderer::RenderDevice;
use bevy::utils::default;

pub struct VrmLoaderPlugin;

impl Plugin for VrmLoaderPlugin {
    fn build(
        &self,
        app: &mut App,
    ) {
        app.preregister_asset_loader::<VrmLoader>(&["vrm"]);
    }

    fn finish(
        &self,
        app: &mut App,
    ) {
        let supported_compressed_formats = match app.world().get_resource::<RenderDevice>() {
            Some(render_device) => CompressedImageFormats::from_features(render_device.features()),
            None => CompressedImageFormats::NONE,
        };
        app.register_asset_loader(VrmLoader(GltfLoader {
            supported_compressed_formats,
            custom_vertex_attributes: Default::default(),
        }));
    }
}

/// A handle to load a VRM.
/// This component is removed after the VRM is loaded.
///
/// This handle is used to load a VRM, and after it is loaded, the following components are automatically inserted:
///
/// - [`Vrm`](crate::prelude::Vrm)
/// - [`VrmPath`](crate::prelude::VrmPath)
/// - [`BoneRestTransform`](crate::prelude::RestTransform)
/// - [`BoneRestGlobalTransform`](crate::prelude::RestGlobalTransform)
/// - [`SceneRoot`](bevy::scene::SceneRoot)
/// - Components hold the entity of each bone, refer to [here](crate::vrm::humanoid_bone) for more details.
///
/// ```no_run
/// use bevy::prelude::*;
/// use bevy_vrm1::prelude::*;
///
/// fn spawn_vrm(
///     mut commands: Commands,
///    asset_server: Res<AssetServer>,
/// ){
///     commands.spawn(VrmHandle(asset_server.load("<vrm>.vrm")));
/// }
/// ```
#[derive(Debug, Component)]
pub struct VrmHandle(pub Handle<VrmAsset>);

#[derive(Debug, Asset, TypePath)]
pub struct VrmAsset {
    pub(crate) gltf: Gltf,
    pub(crate) images: Vec<Handle<Image>>,
}

struct VrmLoader(GltfLoader);

impl AssetLoader for VrmLoader {
    type Asset = VrmAsset;
    type Settings = ();
    type Error = GltfError;
    async fn load(
        &self,
        reader: &mut dyn Reader,
        _: &Self::Settings,
        load_context: &mut LoadContext<'_>,
    ) -> Result<Self::Asset, Self::Error> {
        let settings = GltfLoaderSettings {
            include_source: true,
            ..default()
        };
        let gltf = self.0.load(reader, &settings, load_context).await?;
        Ok(VrmAsset {
            images: gltf
                .source
                .as_ref()
                .unwrap()
                .textures()
                .map(|tex| {
                    load_context.get_label_handle(GltfAssetLabel::Texture(tex.index()).to_string())
                })
                .collect(),
            gltf,
        })
    }

    fn extensions(&self) -> &[&str] {
        &["vrm"]
    }
}