#630 transmute_vec_as_bytes potential fix (#662)

* chore(#630): reformatting transmute_vec_as_bytes to properly handle padding for usize and f32 types

* chore(630): added bytemuck to fyrox-core  and fyrox-impl . Updated transmute_vec_as_bytes to have the generic T implement pod trait

* chore(630): removing commented statement

* general cleanup

* removed podvector3 struct and enabled bytemuck on half dependency.

---------

Co-authored-by: Ouroboros <nathanael@Ouroboross-Mac-Studio.local>

Author: NathanaelG1

Diff for: fyrox-core/Cargo.toml

@@ -22,7 +22,7 @@ byteorder = "1.4.3"
 rand = "0.8.4"
 memoffset = "0.9.0"
 lazy_static = "1.4.0"
-nalgebra = "0.32.3"
+nalgebra = { version = "0.32.3", features = ["bytemuck"] }
 arrayvec = "0.7.2"
 futures = {version = "0.3.17", features = ["thread-pool"] }
 uuid = { version = "1", features = ["v4", "js"] }
@@ -35,6 +35,7 @@ once_cell = "1.17.1"
 notify = "6"
 serde = { version = "1", features = ["derive"] }
 bincode = "1.3.3"
+bytemuck = "1.16.1"
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 web-sys = { version = "0.3.53", features = ["Request", "Window", "Response", "AudioContext", "AudioBuffer", "AudioContextOptions", "AudioNode", "AudioBufferSourceNode", "AudioDestinationNode"] }

Diff for: fyrox-core/src/lib.rs

@@ -30,6 +30,7 @@ use std::{
     path::{Path, PathBuf},
 };
 
+use bytemuck::Pod;
 pub mod color;
 pub mod color_gradient;
 pub mod io;
@@ -66,7 +67,6 @@ pub use wasm_bindgen_futures;
 pub use web_sys;
 
 pub use type_traits::prelude::*;
-
 /// Defines as_(variant), as_mut_(variant) and is_(variant) methods.
 #[macro_export]
 macro_rules! define_is_as {
@@ -321,7 +321,7 @@ pub fn value_as_u8_slice<T: Sized>(v: &T) -> &'_ [u8] {
 }
 
 /// Takes a vector of trivially-copyable values and turns it into a vector of bytes.
-pub fn transmute_vec_as_bytes<T: Copy>(vec: Vec<T>) -> Vec<u8> {
+pub fn transmute_vec_as_bytes<T: Pod>(vec: Vec<T>) -> Vec<u8> {
     unsafe {
         let mut vec = std::mem::ManuallyDrop::new(vec);
         Vec::from_raw_parts(
@@ -449,15 +449,15 @@ where
 mod test {
     use std::path::Path;
 
-    use fxhash::FxHashMap;
-    use uuid::uuid;
-
     use crate::{
         append_extension, cmp_strings_case_insensitive, combine_uuids, hash_combine,
-        make_relative_path,
+        make_relative_path, transmute_vec_as_bytes,
         visitor::{Visit, Visitor},
         BiDirHashMap,
     };
+    use fxhash::FxHashMap;
+    use std::mem::size_of;
+    use uuid::uuid;
 
     #[test]
     fn test_combine_uuids() {
@@ -627,4 +627,20 @@ mod test {
         assert!(!cmp_strings_case_insensitive("FooBaz", "FOOBaR"));
         assert!(cmp_strings_case_insensitive("foobar", "foobar"));
     }
+
+    #[test]
+    fn test_transmute_vec_as_bytes_length_new_f32() {
+        let vec = vec![1.0f32, 2.0, 3.0];
+        let byte_vec = transmute_vec_as_bytes(vec.clone());
+        let expected_length = vec.len() * size_of::<f32>();
+        assert_eq!(byte_vec.len(), expected_length);
+    }
+
+    #[test]
+    fn test_transmute_vec_as_bytes_length_new_usize() {
+        let vec = vec![1usize, 2, 3];
+        let byte_vec = transmute_vec_as_bytes(vec.clone());
+        let expected_length = vec.len() * size_of::<usize>();
+        assert_eq!(byte_vec.len(), expected_length);
+    }
 }

Diff for: fyrox-impl/Cargo.toml

@@ -40,14 +40,14 @@ strum = "0.26.1"
 strum_macros = "0.26.1"
 clap = { version = "4", features = ["derive"] }
 winit = { version = "0.29.2", features = ["serde"] }
-half = "2.2.1"
+half = { version = "2.2.1", features = ["bytemuck"] }
 fast_image_resize = "4.0.0"
 base64 = "0.22.1"
 uvgen = "0.1.0"
 lightmap = "0.1.1"
 libloading = "0.8.1"
 gltf = { version = "1.4.0", optional = true, default-features = false, features = ["names", "utils"] }
-
+bytemuck = { version = "1.16.1", features = ["derive"]}
 # These dependencies isn't actually used by the engine, but it is needed to prevent cargo from rebuilding
 # the engine lib on different packages.
 hashbrown = { version = "0.14.3", features = ["raw"] }
@@ -67,4 +67,4 @@ raw-window-handle = "0.5.0"
 serde-wasm-bindgen = "0.6.3"
 
 [target.'cfg(target_os = "android")'.dependencies]
-winit = { version = "0.29.2", features = ["android-native-activity"] }
+winit = { version = "0.29.2", features = ["android-native-activity"] }

Diff for: fyrox-impl/src/scene/mesh/surface.rs

@@ -37,6 +37,7 @@ use crate::{
     },
     utils::raw_mesh::{RawMesh, RawMeshBuilder},
 };
+use bytemuck::{Pod, Zeroable};
 use fxhash::{FxHashMap, FxHasher};
 use half::f16;
 use lazy_static::lazy_static;
@@ -101,7 +102,7 @@ impl BlendShapesContainer {
         input_blend_shapes: &[InputBlendShapeData],
     ) -> Self {
         #[repr(C)]
-        #[derive(Default, Clone, Copy)]
+        #[derive(Default, Clone, Copy, Pod, Zeroable)]
         struct VertexData {
             position: Vector3<f16>,
             normal: Vector3<f16>,
@@ -167,7 +168,7 @@ impl BlendShapesContainer {
             }
         }
 
-        let bytes = crate::core::transmute_vec_as_bytes(vertex_data);
+        let bytes = crate::core::transmute_vec_as_bytes::<VertexData>(vertex_data);
 
         assert_eq!(
             bytes.len(),