From 3a37283c84f59e0af9dbca10c42251e85abe051c Mon Sep 17 00:00:00 2001
From: Lukas Lihotzki <lukas@lihotzki.de>
Date: Sun, 21 Jul 2024 19:46:58 +0200
Subject: [PATCH] Support multiple backends in blade-macros

---
 blade-graphics/Cargo.toml        |  2 ++
 blade-graphics/src/gles/mod.rs   |  3 +++
 blade-graphics/src/lib.rs        |  2 +-
 blade-graphics/src/vulkan/mod.rs |  3 +++
 blade-macros/src/lib.rs          | 26 +++++++++++++++++++++++---
 blade-macros/src/shader_data.rs  |  8 ++++----
 6 files changed, 36 insertions(+), 8 deletions(-)

diff --git a/blade-graphics/Cargo.toml b/blade-graphics/Cargo.toml
index 667261c6..1241c63c 100644
--- a/blade-graphics/Cargo.toml
+++ b/blade-graphics/Cargo.toml
@@ -12,6 +12,7 @@ repository = "https://github.com/kvark/blade"
 [features]
 default = ["gles"]
 gles = ["dep:glow", "dep:egl", "dep:libloading", "naga/glsl-out"]
+derive = ["dep:blade-macros"]
 
 [dependencies]
 bitflags = { workspace = true }
@@ -23,6 +24,7 @@ mint = { workspace = true }
 naga = { workspace = true }
 raw-window-handle = "0.6"
 glow = { version = "0.13", optional = true }
+blade-macros = { "path" = "../blade-macros", optional = true }
 
 [target.'cfg(any(target_os = "ios", target_os = "macos"))'.dependencies]
 block = "0.1"
diff --git a/blade-graphics/src/gles/mod.rs b/blade-graphics/src/gles/mod.rs
index a8912646..112848ed 100644
--- a/blade-graphics/src/gles/mod.rs
+++ b/blade-graphics/src/gles/mod.rs
@@ -576,3 +576,6 @@ mod derive;
 
 #[path = "../common/util.rs"]
 mod util;
+
+#[cfg(feature = "derive")]
+pub use blade_macros::ShaderDataGles as ShaderData;
diff --git a/blade-graphics/src/lib.rs b/blade-graphics/src/lib.rs
index 8707644a..8ff7a1fc 100644
--- a/blade-graphics/src/lib.rs
+++ b/blade-graphics/src/lib.rs
@@ -67,7 +67,7 @@ pub mod gles;
     ),
     path = "vulkan/mod.rs"
 )]
-mod hal;
+pub mod hal;
 mod shader;
 pub mod traits;
 pub mod util;
diff --git a/blade-graphics/src/vulkan/mod.rs b/blade-graphics/src/vulkan/mod.rs
index cbde515f..7db09d04 100644
--- a/blade-graphics/src/vulkan/mod.rs
+++ b/blade-graphics/src/vulkan/mod.rs
@@ -686,3 +686,6 @@ mod derive;
 
 #[path = "../common/util.rs"]
 mod util;
+
+#[cfg(feature = "derive")]
+pub use blade_macros::ShaderDataHal as ShaderData;
diff --git a/blade-macros/src/lib.rs b/blade-macros/src/lib.rs
index b59475ad..863ad892 100644
--- a/blade-macros/src/lib.rs
+++ b/blade-macros/src/lib.rs
@@ -4,6 +4,7 @@ mod shader_data;
 mod vertex;
 
 use proc_macro::TokenStream;
+use quote::quote;
 
 /// Derive the `ShaderData` trait for a struct
 ///
@@ -15,9 +16,28 @@ use proc_macro::TokenStream;
 ///   sm: blade_graphics::Sampler,
 /// }
 /// ```
-#[proc_macro_derive(ShaderData)]
-pub fn shader_data_derive(input: TokenStream) -> TokenStream {
-    let stream = match shader_data::generate(input) {
+#[proc_macro_derive(ShaderDataHal)]
+pub fn shader_data_hal_derive(input: TokenStream) -> TokenStream {
+    let stream = match shader_data::generate(input, quote! { blade_graphics::hal }) {
+        Ok(tokens) => tokens,
+        Err(err) => err.into_compile_error(),
+    };
+    stream.into()
+}
+
+/// Derive the `ShaderData` trait for a struct
+///
+/// ## Example
+///
+/// ```rust
+/// #[derive(blade_macros::ShaderData)]
+/// struct Test {
+///   sm: blade_graphics::Sampler,
+/// }
+/// ```
+#[proc_macro_derive(ShaderDataGles)]
+pub fn shader_data_gles_derive(input: TokenStream) -> TokenStream {
+    let stream = match shader_data::generate(input, quote! { blade_graphics::gles }) {
         Ok(tokens) => tokens,
         Err(err) => err.into_compile_error(),
     };
diff --git a/blade-macros/src/shader_data.rs b/blade-macros/src/shader_data.rs
index 13ffddcb..41350ff6 100644
--- a/blade-macros/src/shader_data.rs
+++ b/blade-macros/src/shader_data.rs
@@ -1,7 +1,7 @@
 use proc_macro::TokenStream;
 use quote::quote;
 
-pub fn generate(input_stream: TokenStream) -> syn::Result<proc_macro2::TokenStream> {
+pub fn generate(input_stream: TokenStream, namespace: proc_macro2::TokenStream) -> syn::Result<proc_macro2::TokenStream> {
     let item_struct = syn::parse::<syn::ItemStruct>(input_stream)?;
     let fields = match item_struct.fields {
         syn::Fields::Named(ref fields) => fields,
@@ -44,14 +44,14 @@ pub fn generate(input_stream: TokenStream) -> syn::Result<proc_macro2::TokenStre
 
     let struct_name = item_struct.ident;
     Ok(quote! {
-        impl<#(#generics),*> blade_graphics::ShaderData for #struct_name<#(#generics),*> {
+        impl<#(#generics,)*> #namespace::ShaderData for #struct_name<#(#generics),*> {
             fn layout() -> blade_graphics::ShaderDataLayout {
                 blade_graphics::ShaderDataLayout {
                     bindings: vec![#(#bindings),*],
                 }
             }
-            fn fill(&self, mut ctx: blade_graphics::PipelineContext) {
-                use blade_graphics::ShaderBindable as _;
+            fn fill(&self, mut ctx: #namespace::PipelineContext) {
+                use #namespace::ShaderBindable as _;
                 #(#assignments)*
             }
         }