Remove Unsafe in macro.rs (#43)

* remove unsafe slice::from_raw_parts

this should be a way to remove the unsafe code in the Spirv Deref impl.
Not sure how it affects performance yet.
I will take a look at the bytecode and see if maybe the compiler is
smart enough to optimize that away.

* change renderers to accomodate new Deref

Let the deref return a `Vec<u32>` instead of a slice reference. This
should not hurt performance too much as this will be done a finite
amount of times att startup.

* replaced deref with normal impl

* fixed endianness, fixed offset + rustfmt

* bump version

* fixed clippy lints

* respect the target endianness

* use wgpu::read_spirv()

* remove an unneccessary allocation of a vec

* move borrow into macro

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "pixels"
 description = "A tiny library providing a GPU-powered pixel frame buffer."
-version = "0.0.2"
+version = "0.0.3"
 authors = ["Jay Oster <jay@kodewerx.org>"]
 edition = "2018"
 repository = "https://github.com/parasyte/pixels"

src/macros.rs

@@ -7,36 +7,11 @@
 //!
 //! This macro moves all of that complexity to build-time. At least for the SPIR-V part of the
 //! shader pipeline. (`gfx-hal` backends have their own SPIR-V-to-native compilers at runtime.)
-//!
-//! Cribbed with permission from Ralith
-//! See: https://github.com/MaikKlein/ash/pull/245
 
-/// Include correctly aligned and typed precompiled SPIR-V
-///
-/// Does not account for endianness mismatches between the SPIR-V file and the target. See
-/// [`wgpu::read_spirv`] for a more general solution.
 #[macro_export]
 macro_rules! include_spv {
     ($path:expr) => {
-        &$crate::Align4(*include_bytes!($path)) as &$crate::Spirv
+        &wgpu::read_spirv(std::io::Cursor::new(&include_bytes!($path)[..]))
+            .expect(&format!("Invalid SPIR-V shader in file: {}", $path))
     };
 }
-
-/// Type returned by `include_spv`, convertible to `&[u32]`
-///
-/// The definition of this type is unstable.
-pub type Spirv = Align4<[u8]>;
-
-impl std::ops::Deref for Spirv {
-    type Target = [u32];
-    fn deref(&self) -> &[u32] {
-        #[allow(clippy::cast_ptr_alignment)]
-        unsafe {
-            std::slice::from_raw_parts(self.0.as_ptr() as *const u32, self.0.len() / 4)
-        }
-    }
-}
-
-#[repr(align(4))]
-#[doc(hidden)]
-pub struct Align4<T: ?Sized>(pub T);