Add new ImageLoaderSettings member for loading as stacked 2d array

Author: KirmesBude

crates/bevy_image/src/compressed_image_saver.rs

@@ -1,6 +1,7 @@
 use crate::{Image, ImageFormat, ImageFormatSetting, ImageLoader, ImageLoaderSettings};
 
 use bevy_asset::saver::{AssetSaver, SavedAsset};
+use core::num::NonZero;
 use futures_lite::AsyncWriteExt;
 use thiserror::Error;
 
@@ -64,11 +65,14 @@ impl AssetSaver for CompressedImageSaver {
         };
 
         writer.write_all(&compressed_basis_data).await?;
+
+        let layers = NonZero::new(image.texture_descriptor.size.depth_or_array_layers);
         Ok(ImageLoaderSettings {
             format: ImageFormatSetting::Format(ImageFormat::Basis),
             is_srgb,
             sampler: image.sampler.clone(),
             asset_usage: image.asset_usage,
+            layers,
         })
     }
 }

crates/bevy_image/src/image_loader.rs

@@ -1,3 +1,5 @@
+use core::num::NonZero;
+
 use crate::image::{Image, ImageFormat, ImageType, TextureError};
 use bevy_asset::{io::Reader, AssetLoader, LoadContext, RenderAssetUsages};
 use thiserror::Error;
@@ -111,6 +113,9 @@ pub struct ImageLoaderSettings {
     /// Where the asset will be used - see the docs on
     /// [`RenderAssetUsages`] for details.
     pub asset_usage: RenderAssetUsages,
+    /// If the image should be loaded as a stacked 2d array
+    /// image with the given number of layers
+    pub layers: Option<NonZero<u32>>,
 }
 
 impl Default for ImageLoaderSettings {
@@ -120,6 +125,7 @@ impl Default for ImageLoaderSettings {
             is_srgb: true,
             sampler: ImageSampler::Default,
             asset_usage: RenderAssetUsages::default(),
+            layers: Default::default(),
         }
     }
 }
@@ -168,7 +174,8 @@ impl AssetLoader for ImageLoader {
                 )?)
             }
         };
-        Ok(Image::from_buffer(
+
+        let mut image = Image::from_buffer(
             &bytes,
             image_type,
             self.supported_compressed_formats,
@@ -179,7 +186,13 @@ impl AssetLoader for ImageLoader {
         .map_err(|err| FileTextureError {
             error: err,
             path: format!("{}", load_context.path().display()),
-        })?)
+        })?;
+
+        if let Some(layers) = settings.layers {
+            image.reinterpret_stacked_2d_as_array(layers.into());
+        }
+
+        Ok(image)
     }
 
     fn extensions(&self) -> &[&str] {

examples/shader/array_texture.rs

@@ -1,9 +1,12 @@
 //! This example illustrates how to create a texture for use with a `texture_2d_array<f32>` shader
 //! uniform variable.
 
+use core::num::NonZero;
+
 use bevy::{
     prelude::*, reflect::TypePath, render::render_resource::AsBindGroup, shader::ShaderRef,
 };
+use bevy_image::ImageLoaderSettings;
 
 /// This example uses a shader source file from the assets subdirectory
 const SHADER_ASSET_PATH: &str = "shaders/array_texture.wgsl";
@@ -15,23 +18,15 @@ fn main() {
             MaterialPlugin::<ArrayTextureMaterial>::default(),
         ))
         .add_systems(Startup, setup)
-        .add_systems(Update, create_array_texture)
         .run();
 }
 
-#[derive(Resource)]
-struct LoadingTexture {
-    is_loaded: bool,
-    handle: Handle<Image>,
-}
-
-fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
-    // Start loading the texture.
-    commands.insert_resource(LoadingTexture {
-        is_loaded: false,
-        handle: asset_server.load("textures/array_texture.png"),
-    });
-
+fn setup(
+    mut commands: Commands,
+    asset_server: Res<AssetServer>,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<ArrayTextureMaterial>>,
+) {
     // light
     commands.spawn((
         DirectionalLight::default(),
@@ -43,34 +38,17 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
         Camera3d::default(),
         Transform::from_xyz(5.0, 5.0, 5.0).looking_at(Vec3::new(1.5, 0.0, 0.0), Vec3::Y),
     ));
-}
-
-fn create_array_texture(
-    mut commands: Commands,
-    asset_server: Res<AssetServer>,
-    mut loading_texture: ResMut<LoadingTexture>,
-    mut images: ResMut<Assets<Image>>,
-    mut meshes: ResMut<Assets<Mesh>>,
-    mut materials: ResMut<Assets<ArrayTextureMaterial>>,
-) {
-    if loading_texture.is_loaded
-        || !asset_server
-            .load_state(loading_texture.handle.id())
-            .is_loaded()
-    {
-        return;
-    }
-    loading_texture.is_loaded = true;
-    let image = images.get_mut(&loading_texture.handle).unwrap();
-
-    // Create a new array texture asset from the loaded texture.
-    let array_layers = 4;
-    image.reinterpret_stacked_2d_as_array(array_layers);
 
     // Spawn some cubes using the array texture
+    let array_layers = 4;
     let mesh_handle = meshes.add(Cuboid::default());
     let material_handle = materials.add(ArrayTextureMaterial {
-        array_texture: loading_texture.handle.clone(),
+        array_texture: asset_server.load_with_settings(
+            "textures/array_texture.png",
+            move |settings: &mut ImageLoaderSettings| {
+                settings.layers = NonZero::new(array_layers);
+            },
+        ),
     });
     for x in -5..=5 {
         commands.spawn((