Merge pull request #159 from NiklasEi/add_image_sampler_to_readme_and…

…_example

Add image sampler to readme and example

CHANGELOG.md

@@ -1,6 +1,8 @@
 # Changelog
 
 - Make `loading_state::LoadingStateSet` public for explicit system ordering
+- Support configuring an image sampler through a derive attribute ([#156](https://github.com/NiklasEi/bevy_asset_loader/pull/156))
+  - See [the new example](bevy_asset_loader/examples/image_asset.rs)
 
 ## v0.17.0
 - update to Bevy 0.11

README.md

@@ -279,6 +279,26 @@ struct MyAssets {
 }
 ```
 
+### Images
+
+Asset collections support one of the most common operations for image asset: changing their sampler. You can configure either a linear or a nearest sampler like so:
+
+```rust
+use bevy::prelude::*;
+use bevy_asset_loader::asset_collection::AssetCollection;
+
+#[derive(AssetCollection, Resource)]
+struct ImageAssets {
+    #[asset(path = "images/pixel_tree.png")]
+    #[asset(image(sampler = linear))]
+    tree_linear: Handle<Image>,
+
+    #[asset(path = "images/pixel_tree.png")]
+    #[asset(image(sampler = nearest))]
+    tree_nearest: Handle<Image>,
+}
+```
+
 ### Standard materials
 
 You can directly load standard materials if you enable the feature `3d`. For a complete example please take a look at [standard_material.rs](bevy_asset_loader/examples/standard_material.rs).

bevy_asset_loader/examples/README.md

@@ -3,23 +3,23 @@
 These examples are simple Bevy Apps illustrating the capabilities of `bevy_asset_loader`. Run the examples
 with `cargo run --example <example>`.
 
-| Example                                                    | Description                                                              |
-|------------------------------------------------------------|--------------------------------------------------------------------------|
-| Example                                                    | Description                                                              |
-|------------------------------------------------------------|--------------------------------------------------------------------------|
-| [`atlas_from_grid.rs`](atlas_from_grid.rs)                 | Loading a texture atlas from a sprite sheet                              |
-| [`custom_dynamic_assets.rs`](custom_dynamic_assets.rs)     | Define and use your own dynamic assets                                   |
-| [`dynamic_asset.rs`](dynamic_asset.rs)                     | Load dynamic assets from a `.ron` file                                   |
-| [`failure_state.rs`](failure_state.rs)                     | Sets up a failure state                                                  |
-| [`full_collection.rs`](full_collection.rs)                 | A complete asset collection with all supported non-dynamic field types   |
-| [`full_dynamic_collection.rs`](full_dynamic_collection.rs) | A complete asset collection with all supported dynamic asset field types |
-| [`init_resource.rs`](init_resource.rs)                     | Inserting a `FromWorld` resource when all asset collections are loaded   |
-| [`manual_dynamic_asset.rs`](manual_dynamic_asset.rs)       | Load an image asset from a path resolved at run time                     |
-| [`no_loading_state.rs`](no_loading_state.rs)               | How to use asset collections without a loading state                     |
-| [`progress_tracking.rs`](progress_tracking.rs)             | How to set up progress tracking using `iyes_progress`                    |
-| [`standard_material.rs`](standard_material.rs)             | Loading a standard material from a png file                              |
-| [`two_collections.rs`](two_collections.rs)                 | Load multiple asset collections                                          |
-| [`image_asset.rs`](image_asset.rs)                         | How to set a different sampler for an image asset                        |
+| Example                                                      | Description                                                                |
+|--------------------------------------------------------------|----------------------------------------------------------------------------|
+| Example                                                      | Description                                                                |
+| ------------------------------------------------------------ | -------------------------------------------------------------------------- |
+| [`atlas_from_grid.rs`](atlas_from_grid.rs)                   | Loading a texture atlas from a sprite sheet                                |
+| [`custom_dynamic_assets.rs`](custom_dynamic_assets.rs)       | Define and use your own dynamic assets                                     |
+| [`dynamic_asset.rs`](dynamic_asset.rs)                       | Load dynamic assets from a `.ron` file                                     |
+| [`failure_state.rs`](failure_state.rs)                       | Sets up a failure state                                                    |
+| [`full_collection.rs`](full_collection.rs)                   | A complete asset collection with all supported non-dynamic field types     |
+| [`full_dynamic_collection.rs`](full_dynamic_collection.rs)   | A complete asset collection with all supported dynamic asset field types   |
+| [`init_resource.rs`](init_resource.rs)                       | Inserting a `FromWorld` resource when all asset collections are loaded     |
+| [`manual_dynamic_asset.rs`](manual_dynamic_asset.rs)         | Load an image asset from a path resolved at run time                       |
+| [`no_loading_state.rs`](no_loading_state.rs)                 | How to use asset collections without a loading state                       |
+| [`progress_tracking.rs`](progress_tracking.rs)               | How to set up progress tracking using `iyes_progress`                      |
+| [`standard_material.rs`](standard_material.rs)               | Loading a standard material from a png file                                |
+| [`two_collections.rs`](two_collections.rs)                   | Load multiple asset collections                                            |
+| [`image_asset.rs`](image_asset.rs)                           | How to set different samplers for image assets                             |
 
 ## Credits
 
@@ -30,3 +30,6 @@ by [Jay_You](https://freesound.org/people/Jay_You/sounds/460432/)
 
 Toon character sheets [CC0 1.0 Universal](https://creativecommons.org/publicdomain/zero/1.0/)
 by [Kenny](https://kenney.nl/assets/toon-characters-1)
+
+Pixelart tree [CC0 1.0 Universal](https://creativecommons.org/publicdomain/zero/1.0/)
+by [Kenny](https://www.kenney.nl/assets/tiny-town)

bevy_asset_loader/examples/full_collection.rs

@@ -1,6 +1,7 @@
 use bevy::app::AppExit;
 use bevy::asset::LoadState;
 use bevy::prelude::*;
+use bevy::render::texture::ImageSampler;
 use bevy::utils::HashMap;
 use bevy_asset_loader::prelude::*;
 use path_slash::PathExt;
@@ -34,6 +35,11 @@ struct MyAssets {
     // If no derive attributes are set, `from_world` will be used to set the value.
     from_world: ColorStandardMaterial<{ u8::MAX }, 0, 0, { u8::MAX }>,
 
+    // Image asset with sampler nearest (good for crisp pixel art)
+    #[asset(path = "images/pixel_tree.png")]
+    #[asset(image(sampler = nearest))]
+    image_tree_nearest: Handle<Image>,
+
     // Load collections of assets
 
     // A folder (not supported on the web)
@@ -70,6 +76,7 @@ fn expectations(
     asset_server: Res<AssetServer>,
     standard_materials: Res<Assets<StandardMaterial>>,
     texture_atlases: Res<Assets<TextureAtlas>>,
+    images: Res<Assets<Image>>,
     mut quit: EventWriter<AppExit>,
 ) {
     info!("Done loading the collection. Checking expectations...");
@@ -101,21 +108,30 @@ fn expectations(
         .get(&assets.from_world.handle)
         .expect("Standard material should be added to its assets resource.");
     assert_eq!(material.base_color, Color::RED);
-    assert_eq!(assets.folder_untyped.len(), 6);
+
+    let image = images
+        .get(&assets.image_tree_nearest)
+        .expect("Image should be added to its asset resource");
+    let ImageSampler::Descriptor(descriptor) = &image.sampler_descriptor else {
+        panic!("Descriptor was not set to non default value nearest");
+    };
+    assert_eq!(descriptor, &ImageSampler::nearest_descriptor());
+
+    assert_eq!(assets.folder_untyped.len(), 7);
     for handle in assets.folder_untyped.iter() {
         assert_eq!(
             asset_server.get_load_state(handle.clone()),
             LoadState::Loaded
         );
     }
-    assert_eq!(assets.folder_typed.len(), 6);
+    assert_eq!(assets.folder_typed.len(), 7);
     for handle in assets.folder_typed.iter() {
         assert_eq!(
             asset_server.get_load_state(handle.clone()),
             LoadState::Loaded
         );
     }
-    assert_eq!(assets.mapped_folder_untyped.len(), 6);
+    assert_eq!(assets.mapped_folder_untyped.len(), 7);
     for (name, handle) in assets.mapped_folder_untyped.iter() {
         assert_eq!(
             asset_server.get_load_state(handle.clone()),
@@ -132,7 +148,7 @@ fn expectations(
             name
         );
     }
-    assert_eq!(assets.mapped_folder_typed.len(), 6);
+    assert_eq!(assets.mapped_folder_typed.len(), 7);
     for (name, handle) in assets.mapped_folder_typed.iter() {
         assert_eq!(
             asset_server.get_load_state(handle.clone()),

bevy_asset_loader/examples/image_asset.rs

@@ -17,11 +17,11 @@ fn main() {
 
 #[derive(AssetCollection, Resource)]
 struct ImageAssets {
-    #[asset(path = "images/tree_2.png")]
+    #[asset(path = "images/pixel_tree.png")]
     #[asset(image(sampler = linear))]
     tree_linear: Handle<Image>,
 
-    #[asset(path = "images/tree_2.png")]
+    #[asset(path = "images/pixel_tree.png")]
     #[asset(image(sampler = nearest))]
     tree_nearest: Handle<Image>,
 }

bevy_asset_loader_derive/src/assets.rs

@@ -122,20 +122,15 @@ impl AssetField {
             AssetField::Image(image) => {
                 let field_ident = image.field_ident.clone();
                 let asset_path = image.asset_path.clone();
-
                 let sampler = match image.sampler {
-                    SamplerType::Linear => "ImageSampler::linear()",
-                    SamplerType::Nearest => "ImageSampler::nearest()",
+                    SamplerType::Linear => quote!(ImageSampler::linear()),
+                    SamplerType::Nearest => quote!(ImageSampler::nearest()),
                 };
-
                 let descriptor = match image.sampler {
-                    SamplerType::Linear => "ImageSampler::linear_descriptor()",
-                    SamplerType::Nearest => "ImageSampler::nearest_descriptor()",
+                    SamplerType::Linear => quote!(ImageSampler::linear_descriptor()),
+                    SamplerType::Nearest => quote!(ImageSampler::nearest_descriptor()),
                 };
 
-                let sampler_token_stream = sampler.parse::<TokenStream>().unwrap();
-                let descriptor_token_stream = descriptor.parse::<TokenStream>().unwrap();
-
                 quote!(#token_stream #field_ident : {
                     use bevy::render::texture::ImageSampler;
                     let cell = world.cell();
@@ -146,17 +141,17 @@ impl AssetField {
                     let mut image = images.get_mut(&handle).expect("Only asset collection fields holding an `Image` handle can be annotated with `image`");
 
                     let is_different_sampler = if let ImageSampler::Descriptor(descriptor) = &image.sampler_descriptor {
-                        !descriptor.eq(&#descriptor_token_stream)
+                        !descriptor.eq(&#descriptor)
                     } else {
                         false
                     };
 
                     if is_different_sampler {
                         let mut cloned_image = image.clone();
-                        cloned_image.sampler_descriptor = #sampler_token_stream;
+                        cloned_image.sampler_descriptor = #sampler;
                         handle = images.add(cloned_image);
                     } else {
-                        image.sampler_descriptor = #sampler_token_stream;
+                        image.sampler_descriptor = #sampler;
                     }
 
                     handle