[update] default backend to also be optional.

Author: vmarcella

crates/lambda-rs-platform/Cargo.toml

@@ -29,7 +29,7 @@ mockall = "=0.11.3"
 
 [features]
 default=["shaderc/build-from-source"]
-detect-platform=[]
+detect-platform=["dep:default_backend"]
 winit-windowing=[]
 gfx-with-opengl=["dep:gfx-backend-gl"]
 gfx-with-vulkan=["dep:gfx-backend-vulkan"]
@@ -41,14 +41,17 @@ gfx-with-dx12=["dep:gfx-backend-dx12"]
 crate-type = ["cdylib", "rlib"]
 incremental = true
 
-[target.'cfg(all(unix, not(target_os = "macos")))'.dependencies.gfx-backend-gl]
+[target.'cfg(all(unix, not(target_os = "macos")))'.dependencies.default_backend]
 package = "gfx-backend-gl"
 version = "=0.9.0"
+optional = true
 
-[target.'cfg(all(target_os = "macos"))'.dependencies.gfx-backend-metal]
+[target.'cfg(all(target_os = "macos"))'.dependencies.default_backend]
 package = "gfx-backend-metal"
 version = "=0.9.0"
+optional = true
 
-[target.'cfg(all(windows))'.dependencies.gfx-backend-dx12]
+[target.'cfg(all(windows))'.depedencies.default_backend]
 package = "gfx-backend-dx12"
 version = "=0.9.0"
+optional = true

crates/lambda-rs-platform/src/gfx/api.rs

@@ -12,13 +12,13 @@ if #[cfg(feature = "gfx-with-gl")] {
   pub use gfx_backend_dx11 as RenderingAPI;
 } else if #[cfg(feature = "gfx-with-dx12")] {
   pub use gfx_backend_dx12 as RenderingAPI;
-} else if #[cfg(all(feature = "detect-platform", windows))] {
-    pub use gfx_backend_dx12 as RenderingAPI;
+} else if #[cfg(all(feature = "detect-platform"))] {
+  pub use default_backend as RenderingAPI;
 } else if #[cfg(all(feature = "detect-platform", target_os = "macos"))] {
     pub use gfx_backend_metal as RenderingAPI;
 } else if #[cfg(all(feature = "detect-platform", unix, not(target_os = "macos")))] {
     pub use gfx_backend_gl as RenderingAPI;
 } else {
-    compile_error!("No supported GPU API found for the current platform.");
+    panic!("No supported GPU API found for the current platform.");
   }
 }

crates/lambda-rs/Cargo.toml

@@ -12,7 +12,7 @@ name = "lambda"
 path = "src/lib.rs"
 
 [dependencies]
-lambda-rs-platform = { path = "../lambda-rs-platform", version = "2023.1.26" }
+lambda-rs-platform = { path = "../lambda-rs-platform", version = "2023.1.26"}
 
 [dev-dependencies]
 cargo-audit = "0.16.0"