Make bevy_ui not depend on bevy_render (#20502)

# Objective

- title

## Solution

- use the system set
- fix the InheritWeights system set naming convention while we're at it
- move transparent image handle uuid to bevy_image
- move ImagePlugin to bevy_image to initialize transparent image etc
- rename remaining plugin to TexturePlugin
- ok technically its a dev-dep still
- sorry this could be split up better

## Testing

Author: atlv24

crates/bevy_animation/src/lib.rs

@@ -1245,7 +1245,7 @@ impl Plugin for AnimationPlugin {
                     // `PostUpdate`. For now, we just disable ambiguity testing
                     // for this system.
                     animate_targets
-                        .before(bevy_mesh::InheritWeights)
+                        .before(bevy_mesh::InheritWeightSystems)
                         .ambiguous_with_all(),
                     trigger_untargeted_animation_events,
                     expire_completed_transitions,

crates/bevy_anti_aliasing/Cargo.toml

@@ -12,7 +12,7 @@ keywords = ["bevy"]
 trace = []
 webgl = []
 webgpu = []
-smaa_luts = ["bevy_render/ktx2", "bevy_image/ktx2", "bevy_image/zstd"]
+smaa_luts = ["bevy_image/ktx2", "bevy_image/zstd"]
 
 [dependencies]
 # bevy

crates/bevy_camera/src/lib.rs

@@ -6,6 +6,7 @@ pub mod primitives;
 mod projection;
 pub mod visibility;
 
+use bevy_ecs::schedule::SystemSet;
 pub use camera::*;
 pub use clear_color::*;
 pub use components::*;
@@ -37,3 +38,11 @@ pub mod prelude {
         PerspectiveProjection, Projection,
     };
 }
+
+/// Label for `camera_system<T>`, shared across all `T`.
+#[derive(SystemSet, Clone, Eq, PartialEq, Hash, Debug)]
+pub struct CameraUpdateSystems;
+
+/// Deprecated alias for [`CameraUpdateSystems`].
+#[deprecated(since = "0.17.0", note = "Renamed to `CameraUpdateSystems`.")]
+pub type CameraUpdateSystem = CameraUpdateSystems;

crates/bevy_camera/src/projection.rs

@@ -27,14 +27,6 @@ impl Plugin for CameraProjectionPlugin {
     }
 }
 
-/// Label for `camera_system<T>`, shared across all `T`.
-#[derive(SystemSet, Clone, Eq, PartialEq, Hash, Debug)]
-pub struct CameraUpdateSystems;
-
-/// Deprecated alias for [`CameraUpdateSystems`].
-#[deprecated(since = "0.17.0", note = "Renamed to `CameraUpdateSystems`.")]
-pub type CameraUpdateSystem = CameraUpdateSystems;
-
 /// Describes a type that can generate a projection matrix, allowing it to be added to a
 /// [`Camera`]'s [`Projection`] component.
 ///

crates/bevy_core_pipeline/Cargo.toml

@@ -16,7 +16,7 @@ keywords = ["bevy"]
 trace = []
 webgl = []
 webgpu = []
-tonemapping_luts = ["bevy_render/ktx2", "bevy_image/ktx2", "bevy_image/zstd"]
+tonemapping_luts = ["bevy_image/ktx2", "bevy_image/zstd"]
 
 [dependencies]
 # bevy

crates/bevy_image/src/image.rs

@@ -1,15 +1,18 @@
+use crate::ImageLoader;
+
 #[cfg(feature = "basis-universal")]
 use super::basis::*;
 #[cfg(feature = "dds")]
 use super::dds::*;
 #[cfg(feature = "ktx2")]
 use super::ktx2::*;
+use bevy_app::{App, Plugin};
 #[cfg(not(feature = "bevy_reflect"))]
 use bevy_reflect::TypePath;
 #[cfg(feature = "bevy_reflect")]
 use bevy_reflect::{std_traits::ReflectDefault, Reflect};
 
-use bevy_asset::{Asset, RenderAssetUsages};
+use bevy_asset::{uuid_handle, Asset, AssetApp, Assets, Handle, RenderAssetUsages};
 use bevy_color::{Color, ColorToComponents, Gray, LinearRgba, Srgba, Xyza};
 use bevy_ecs::resource::Resource;
 use bevy_math::{AspectRatio, UVec2, UVec3, Vec2};
@@ -35,6 +38,84 @@ impl BevyDefault for TextureFormat {
     }
 }
 
+/// A handle to a 1 x 1 transparent white image.
+///
+/// Like [`Handle<Image>::default`], this is a handle to a fallback image asset.
+/// While that handle points to an opaque white 1 x 1 image, this handle points to a transparent 1 x 1 white image.
+// Number randomly selected by fair WolframAlpha query. Totally arbitrary.
+pub const TRANSPARENT_IMAGE_HANDLE: Handle<Image> =
+    uuid_handle!("d18ad97e-a322-4981-9505-44c59a4b5e46");
+
+/// Adds the [`Image`] as an asset and makes sure that they are extracted and prepared for the GPU.
+pub struct ImagePlugin {
+    /// The default image sampler to use when [`ImageSampler`] is set to `Default`.
+    pub default_sampler: ImageSamplerDescriptor,
+}
+
+impl Default for ImagePlugin {
+    fn default() -> Self {
+        ImagePlugin::default_linear()
+    }
+}
+
+impl ImagePlugin {
+    /// Creates image settings with linear sampling by default.
+    pub fn default_linear() -> ImagePlugin {
+        ImagePlugin {
+            default_sampler: ImageSamplerDescriptor::linear(),
+        }
+    }
+
+    /// Creates image settings with nearest sampling by default.
+    pub fn default_nearest() -> ImagePlugin {
+        ImagePlugin {
+            default_sampler: ImageSamplerDescriptor::nearest(),
+        }
+    }
+}
+
+impl Plugin for ImagePlugin {
+    fn build(&self, app: &mut App) {
+        #[cfg(feature = "exr")]
+        app.init_asset_loader::<crate::ExrTextureLoader>();
+
+        #[cfg(feature = "hdr")]
+        app.init_asset_loader::<crate::HdrTextureLoader>();
+
+        app.init_asset::<Image>();
+        #[cfg(feature = "bevy_reflect")]
+        app.register_asset_reflect::<Image>();
+
+        let mut image_assets = app.world_mut().resource_mut::<Assets<Image>>();
+
+        image_assets
+            .insert(&Handle::default(), Image::default())
+            .unwrap();
+        image_assets
+            .insert(&TRANSPARENT_IMAGE_HANDLE, Image::transparent())
+            .unwrap();
+
+        #[cfg(feature = "compressed_image_saver")]
+        if let Some(processor) = app
+            .world()
+            .get_resource::<bevy_asset::processor::AssetProcessor>()
+        {
+            processor.register_processor::<bevy_asset::processor::LoadTransformAndSave<
+                ImageLoader,
+                bevy_asset::transformer::IdentityAssetTransformer<Image>,
+                crate::CompressedImageSaver,
+            >>(crate::CompressedImageSaver.into());
+            processor.set_default_processor::<bevy_asset::processor::LoadTransformAndSave<
+                ImageLoader,
+                bevy_asset::transformer::IdentityAssetTransformer<Image>,
+                crate::CompressedImageSaver,
+            >>("png");
+        }
+
+        app.preregister_asset_loader::<ImageLoader>(ImageLoader::SUPPORTED_FILE_EXTENSIONS);
+    }
+}
+
 pub const TEXTURE_ASSET_INDEX: u64 = 0;
 pub const SAMPLER_ASSET_INDEX: u64 = 1;
 

crates/bevy_image/src/lib.rs

@@ -6,7 +6,7 @@ pub mod prelude {
     pub use crate::{
         dynamic_texture_atlas_builder::DynamicTextureAtlasBuilder,
         texture_atlas::{TextureAtlas, TextureAtlasLayout, TextureAtlasSources},
-        BevyDefault as _, Image, ImageFormat, TextureAtlasBuilder, TextureError,
+        BevyDefault as _, Image, ImageFormat, ImagePlugin, TextureAtlasBuilder, TextureError,
     };
 }
 

crates/bevy_internal/Cargo.toml

@@ -29,24 +29,16 @@ detailed_trace = ["bevy_ecs/detailed_trace", "bevy_render?/detailed_trace"]
 sysinfo_plugin = ["bevy_diagnostic/sysinfo_plugin"]
 
 # Enables compressed KTX2 UASTC texture output on the asset processor
-compressed_image_saver = [
-  "bevy_image/compressed_image_saver",
-  "bevy_render/compressed_image_saver",
-]
-
-# Texture formats that have specific rendering support (HDR enabled by default)
-basis-universal = ["bevy_image/basis-universal", "bevy_render/basis-universal"]
-exr = ["bevy_image/exr", "bevy_render/exr"]
-hdr = ["bevy_image/hdr", "bevy_render/hdr"]
-ktx2 = ["bevy_image/ktx2", "bevy_render/ktx2"]
+compressed_image_saver = ["bevy_image/compressed_image_saver"]
 
 # For ktx2 supercompression
 zlib = ["bevy_image/zlib"]
 zstd = ["bevy_image/zstd"]
 zstd_rust = ["bevy_image/zstd_rust"]
 zstd_c = ["bevy_image/zstd_c"]
 
-# Image format support (PNG enabled by default)
+# Image format support (HDR and PNG enabled by default)
+basis-universal = ["bevy_image/basis-universal"]
 bmp = ["bevy_image/bmp"]
 ff = ["bevy_image/ff"]
 gif = ["bevy_image/gif"]
@@ -59,6 +51,9 @@ tga = ["bevy_image/tga"]
 tiff = ["bevy_image/tiff"]
 webp = ["bevy_image/webp"]
 dds = ["bevy_image/dds"]
+exr = ["bevy_image/exr"]
+hdr = ["bevy_image/hdr"]
+ktx2 = ["bevy_image/ktx2"]
 
 # Enable SPIR-V passthrough
 spirv_shader_passthrough = ["bevy_render/spirv_shader_passthrough"]
@@ -89,11 +84,14 @@ symphonia-wav = ["bevy_audio/symphonia-wav"]
 
 # Shader formats
 shader_format_glsl = [
-  "bevy_render/shader_format_glsl",
+  "bevy_shader/shader_format_glsl",
   "bevy_pbr?/shader_format_glsl",
 ]
-shader_format_spirv = ["bevy_render/shader_format_spirv"]
-shader_format_wesl = ["bevy_render/shader_format_wesl"]
+shader_format_spirv = [
+  "bevy_shader/shader_format_spirv",
+  "bevy_render?/shader_format_spirv",
+]
+shader_format_wesl = ["bevy_shader/shader_format_wesl"]
 
 serialize = [
   "bevy_a11y?/serialize",

crates/bevy_internal/src/default_plugins.rs

@@ -31,8 +31,8 @@ plugin_group! {
         bevy_render:::RenderPlugin,
         // NOTE: Load this after renderer initialization so that it knows about the supported
         // compressed texture formats.
-        #[cfg(feature = "bevy_render")]
-        bevy_render::texture:::ImagePlugin,
+        #[cfg(feature = "bevy_image")]
+        bevy_image:::ImagePlugin,
         #[cfg(feature = "bevy_render")]
         #[custom(cfg(all(not(target_arch = "wasm32"), feature = "multi_threaded")))]
         bevy_render::pipelined_rendering:::PipelinedRenderingPlugin,

crates/bevy_mesh/src/lib.rs

@@ -71,4 +71,4 @@ impl BaseMeshPipelineKey {
 
 /// `bevy_render::mesh::inherit_weights` runs in this `SystemSet`
 #[derive(Debug, Hash, PartialEq, Eq, Clone, SystemSet)]
-pub struct InheritWeights;
+pub struct InheritWeightSystems;