From 11a5346291d8813f946babfb779bd6af4b8c138f Mon Sep 17 00:00:00 2001
From: maku693 <me@maku693.net>
Date: Wed, 23 Feb 2022 17:32:34 +0900
Subject: [PATCH] Add support for cast using bytemuck crate

---
 Cargo.toml        |  1 +
 src/euler.rs      |  3 +++
 src/lib.rs        |  3 +++
 src/macros.rs     |  9 +++++++++
 src/matrix.rs     |  7 +++++++
 src/point.rs      |  7 +++++++
 src/quaternion.rs |  3 +++
 src/vector.rs     | 12 ++++++++++++
 8 files changed, 45 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index 82745c6..687a295 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,6 +29,7 @@ rand = { version = "0.8", features = ["small_rng"], optional = true }
 serde = { version = "1.0", features = ["serde_derive"], optional = true }
 # works only in rust toolchain up to 1.32, disabled indefinitely
 #simd = { version = "0.2", optional = true }
+bytemuck = { version = "1.0", optional = true }
 
 [dev-dependencies]
 serde_json = "1.0"
diff --git a/src/euler.rs b/src/euler.rs
index 264271a..2a11b60 100644
--- a/src/euler.rs
+++ b/src/euler.rs
@@ -224,3 +224,6 @@ impl<S: Clone, A: Angle + Into<S>> From<Euler<A>> for MintEuler<S> {
         MintEuler::from([v.x.into(), v.y.into(), v.z.into()])
     }
 }
+
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Euler);
diff --git a/src/lib.rs b/src/lib.rs
index b9642cb..44febaf 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -55,6 +55,9 @@
 #[macro_use]
 extern crate approx;
 
+#[cfg(feature = "bytemuck")]
+extern crate bytemuck;
+
 #[cfg(feature = "mint")]
 pub extern crate mint;
 
diff --git a/src/macros.rs b/src/macros.rs
index cd0cd1b..d044543 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -380,4 +380,13 @@ macro_rules! impl_mint_conversions {
     }
 }
 
+/// Generate implementation required to cast using `bytemuck`
+#[cfg(feature = "bytemuck")]
+macro_rules! impl_bytemuck_cast {
+    ($ArrayN:ident) => {
+        unsafe impl<S: bytemuck::Pod> bytemuck::Pod for $ArrayN<S> {}
+        unsafe impl<S: bytemuck::Zeroable> bytemuck::Zeroable for $ArrayN<S> {}
+    };
+}
+
 include!(concat!(env!("OUT_DIR"), "/swizzle_operator_macro.rs"));
diff --git a/src/matrix.rs b/src/matrix.rs
index ed96761..254d84e 100644
--- a/src/matrix.rs
+++ b/src/matrix.rs
@@ -1572,6 +1572,13 @@ mint_conversions!(Matrix3 { x, y, z }, ColumnMatrix3);
 #[cfg(feature = "mint")]
 mint_conversions!(Matrix4 { x, y, z, w }, ColumnMatrix4);
 
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Matrix2);
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Matrix3);
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Matrix4);
+
 impl<S: BaseNum> From<Matrix2<S>> for Matrix3<S> {
     /// Clone the elements of a 2-dimensional matrix into the top-left corner
     /// of a 3-dimensional identity matrix.
diff --git a/src/point.rs b/src/point.rs
index b65c334..77137dc 100644
--- a/src/point.rs
+++ b/src/point.rs
@@ -368,6 +368,13 @@ impl_mint_conversions!(Point2 { x, y }, Point2);
 #[cfg(feature = "mint")]
 impl_mint_conversions!(Point3 { x, y, z }, Point3);
 
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Point1);
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Point2);
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Point3);
+
 impl<S: fmt::Debug> fmt::Debug for Point1<S> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f, "Point1 ")?;
diff --git a/src/quaternion.rs b/src/quaternion.rs
index bf1c2cd..3f1f318 100644
--- a/src/quaternion.rs
+++ b/src/quaternion.rs
@@ -690,6 +690,9 @@ impl <S: Clone> mint::IntoMint for Quaternion<S> {
     type MintType = mint::Quaternion<S>;
 }
 
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Quaternion);
+
 #[cfg(test)]
 mod tests {
     use quaternion::*;
diff --git a/src/vector.rs b/src/vector.rs
index 92a59f9..a569687 100644
--- a/src/vector.rs
+++ b/src/vector.rs
@@ -597,6 +597,18 @@ impl<S: fmt::Debug> fmt::Debug for Vector4<S> {
     }
 }
 
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Vector1);
+
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Vector2);
+
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Vector3);
+
+#[cfg(feature = "bytemuck")]
+impl_bytemuck_cast!(Vector4);
+
 #[cfg(feature = "mint")]
 impl_mint_conversions!(Vector2 { x, y }, Vector2);
 #[cfg(feature = "mint")]