fast-fail in as_bind_group (#12513)

# Objective prevent gpu buffer allocations when running `as_bind_group` for assets with texture dependencies that are not yet available. ## Solution reorder the binding creation so that fallible items are created first.
bevyengine · Mar 18, 2024 · 26f2d3f · 26f2d3f
1 parent 3549ae9
commit 26f2d3f
Showing 1 changed file with 6 additions and 3 deletions.
diff --git a/crates/bevy_render/macros/src/as_bind_group.rs b/crates/bevy_render/macros/src/as_bind_group.rs
@@ -272,7 +272,8 @@ pub fn derive_as_bind_group(ast: syn::DeriveInput) -> Result<TokenStream> {
 
                     let fallback_image = get_fallback_image(&render_path, dimension);
 
-                    binding_impls.push(quote! {
+                    // insert fallible texture-based entries at 0 so that if we fail here, we exit before allocating any buffers
+                    binding_impls.insert(0, quote! {
                         ( #binding_index,
                           #render_path::render_resource::OwnedBindingResource::TextureView({
                               let handle: Option<&#asset_path::Handle<#render_path::texture::Image>> = (&self.#field_name).into();
@@ -311,7 +312,8 @@ pub fn derive_as_bind_group(ast: syn::DeriveInput) -> Result<TokenStream> {
 
                     let fallback_image = get_fallback_image(&render_path, *dimension);
 
-                    binding_impls.push(quote! {
+                    // insert fallible texture-based entries at 0 so that if we fail here, we exit before allocating any buffers
+                    binding_impls.insert(0, quote! {
                         (
                             #binding_index,
                             #render_path::render_resource::OwnedBindingResource::TextureView({
@@ -353,7 +355,8 @@ pub fn derive_as_bind_group(ast: syn::DeriveInput) -> Result<TokenStream> {
 
                     let fallback_image = get_fallback_image(&render_path, *dimension);
 
-                    binding_impls.push(quote! {
+                    // insert fallible texture-based entries at 0 so that if we fail here, we exit before allocating any buffers
+                    binding_impls.insert(0, quote! {
                         (
                             #binding_index,
                             #render_path::render_resource::OwnedBindingResource::Sampler({