Remove Shader weak_handles from bevy_render. (#19362)

# Objective

- Related to #19024

## Solution

- Use the new `load_shader_library` macro for the shader libraries and
`embedded_asset`/`load_embedded_asset` for the "shader binaries" in
bevy_render.

## Testing

- `animate_shader` example still works

P.S. I don't think this needs a migration guide. Technically users could
be using the `pub` weak handles, but there's no actual good use for
them, so omitting it seems fine. Alternatively, we could mix this in
with the migration guide notes for #19137.

crates/bevy_render/src/experimental/occlusion_culling/mod.rs

@@ -4,19 +4,13 @@
 //! Bevy.
 
 use bevy_app::{App, Plugin};
-use bevy_asset::{load_internal_asset, weak_handle, Handle};
 use bevy_ecs::{component::Component, entity::Entity, prelude::ReflectComponent};
 use bevy_reflect::{prelude::ReflectDefault, Reflect};
 
 use crate::{
-    extract_component::ExtractComponent,
-    render_resource::{Shader, TextureView},
+    extract_component::ExtractComponent, load_shader_library, render_resource::TextureView,
 };
 
-/// The handle to the `mesh_preprocess_types.wgsl` compute shader.
-pub const MESH_PREPROCESS_TYPES_SHADER_HANDLE: Handle<Shader> =
-    weak_handle!("7bf7bdb1-ec53-4417-987f-9ec36533287c");
-
 /// Enables GPU occlusion culling.
 ///
 /// See [`OcclusionCulling`] for a detailed description of occlusion culling in
@@ -25,12 +19,7 @@ pub struct OcclusionCullingPlugin;
 
 impl Plugin for OcclusionCullingPlugin {
     fn build(&self, app: &mut App) {
-        load_internal_asset!(
-            app,
-            MESH_PREPROCESS_TYPES_SHADER_HANDLE,
-            "mesh_preprocess_types.wgsl",
-            Shader::from_wgsl
-        );
+        load_shader_library!(app, "mesh_preprocess_types.wgsl");
     }
 }
 

crates/bevy_render/src/globals.rs

@@ -1,25 +1,21 @@
 use crate::{
     extract_resource::ExtractResource,
-    prelude::Shader,
+    load_shader_library,
     render_resource::{ShaderType, UniformBuffer},
     renderer::{RenderDevice, RenderQueue},
     Extract, ExtractSchedule, Render, RenderApp, RenderSystems,
 };
 use bevy_app::{App, Plugin};
-use bevy_asset::{load_internal_asset, weak_handle, Handle};
 use bevy_diagnostic::FrameCount;
 use bevy_ecs::prelude::*;
 use bevy_reflect::prelude::*;
 use bevy_time::Time;
 
-pub const GLOBALS_TYPE_HANDLE: Handle<Shader> =
-    weak_handle!("9e22a765-30ca-4070-9a4c-34ac08f1c0e7");
-
 pub struct GlobalsPlugin;
 
 impl Plugin for GlobalsPlugin {
     fn build(&self, app: &mut App) {
-        load_internal_asset!(app, GLOBALS_TYPE_HANDLE, "globals.wgsl", Shader::from_wgsl);
+        load_shader_library!(app, "globals.wgsl");
         app.register_type::<GlobalsUniform>();
 
         if let Some(render_app) = app.get_sub_app_mut(RenderApp) {

crates/bevy_render/src/view/mod.rs

@@ -1,7 +1,6 @@
 pub mod visibility;
 pub mod window;
 
-use bevy_asset::{load_internal_asset, weak_handle, Handle};
 use bevy_diagnostic::FrameCount;
 pub use visibility::*;
 pub use window::*;
@@ -13,7 +12,7 @@ use crate::{
     },
     experimental::occlusion_culling::OcclusionCulling,
     extract_component::ExtractComponentPlugin,
-    prelude::Shader,
+    load_shader_library,
     primitives::Frustum,
     render_asset::RenderAssets,
     render_phase::ViewRangefinder3d,
@@ -46,8 +45,6 @@ use wgpu::{
     TextureDescriptor, TextureDimension, TextureFormat, TextureUsages,
 };
 
-pub const VIEW_TYPE_HANDLE: Handle<Shader> = weak_handle!("7234423c-38bb-411c-acec-f67730f6db5b");
-
 /// The matrix that converts from the RGB to the LMS color space.
 ///
 /// To derive this, first we convert from RGB to [CIE 1931 XYZ]:
@@ -101,7 +98,7 @@ pub struct ViewPlugin;
 
 impl Plugin for ViewPlugin {
     fn build(&self, app: &mut App) {
-        load_internal_asset!(app, VIEW_TYPE_HANDLE, "view.wgsl", Shader::from_wgsl);
+        load_shader_library!(app, "view.wgsl");
 
         app.register_type::<InheritedVisibility>()
             .register_type::<ViewVisibility>()

crates/bevy_render/src/view/window/screenshot.rs

@@ -17,7 +17,7 @@ use crate::{
 };
 use alloc::{borrow::Cow, sync::Arc};
 use bevy_app::{First, Plugin, Update};
-use bevy_asset::{load_internal_asset, weak_handle, Handle};
+use bevy_asset::{embedded_asset, load_embedded_asset, Handle};
 use bevy_derive::{Deref, DerefMut};
 use bevy_ecs::{
     entity::EntityHashMap, event::event_update_system, prelude::*, system::SystemState,
@@ -392,9 +392,6 @@ fn prepare_screenshot_state(
 
 pub struct ScreenshotPlugin;
 
-const SCREENSHOT_SHADER_HANDLE: Handle<Shader> =
-    weak_handle!("c31753d6-326a-47cb-a359-65c97a471fda");
-
 impl Plugin for ScreenshotPlugin {
     fn build(&self, app: &mut bevy_app::App) {
         app.add_systems(
@@ -406,12 +403,7 @@ impl Plugin for ScreenshotPlugin {
         .register_type::<Screenshot>()
         .register_type::<ScreenshotCaptured>();
 
-        load_internal_asset!(
-            app,
-            SCREENSHOT_SHADER_HANDLE,
-            "screenshot.wgsl",
-            Shader::from_wgsl
-        );
+        embedded_asset!(app, "screenshot.wgsl");
     }
 
     fn finish(&self, app: &mut bevy_app::App) {
@@ -441,6 +433,7 @@ impl Plugin for ScreenshotPlugin {
 #[derive(Resource)]
 pub struct ScreenshotToScreenPipeline {
     pub bind_group_layout: BindGroupLayout,
+    pub shader: Handle<Shader>,
 }
 
 impl FromWorld for ScreenshotToScreenPipeline {
@@ -455,7 +448,12 @@ impl FromWorld for ScreenshotToScreenPipeline {
             ),
         );
 
-        Self { bind_group_layout }
+        let shader = load_embedded_asset!(render_world, "screenshot.wgsl");
+
+        Self {
+            bind_group_layout,
+            shader,
+        }
     }
 }
 
@@ -470,7 +468,7 @@ impl SpecializedRenderPipeline for ScreenshotToScreenPipeline {
                 buffers: vec![],
                 shader_defs: vec![],
                 entry_point: Cow::Borrowed("vs_main"),
-                shader: SCREENSHOT_SHADER_HANDLE,
+                shader: self.shader.clone(),
             },
             primitive: wgpu::PrimitiveState {
                 cull_mode: Some(wgpu::Face::Back),
@@ -479,7 +477,7 @@ impl SpecializedRenderPipeline for ScreenshotToScreenPipeline {
             depth_stencil: None,
             multisample: Default::default(),
             fragment: Some(FragmentState {
-                shader: SCREENSHOT_SHADER_HANDLE,
+                shader: self.shader.clone(),
                 entry_point: Cow::Borrowed("fs_main"),
                 shader_defs: vec![],
                 targets: vec![Some(wgpu::ColorTargetState {