From 369dd33fd5644f5279f8e1d1c0c4aeeb3bf17c99 Mon Sep 17 00:00:00 2001
From: julianknodt <julianknodt@gmail.com>
Date: Wed, 19 Jul 2023 00:07:22 -0700
Subject: [PATCH] Switch to unsafe code instead of bytemuck

---
 src/codecs/hdr/decoder.rs | 18 ++++++++++++++++--
 src/color.rs              |  8 --------
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/codecs/hdr/decoder.rs b/src/codecs/hdr/decoder.rs
index ff01e8cf54..dcd2e9bf93 100644
--- a/src/codecs/hdr/decoder.rs
+++ b/src/codecs/hdr/decoder.rs
@@ -484,7 +484,14 @@ impl<R: BufRead> HdrDecoder<R> {
     pub fn read_image_ldr(self) -> ImageResult<Vec<Rgb<u8>>> {
         let sz = (self.width * self.height) as usize;
         let mut buf = vec![Rgb([0; 3]); sz];
-        self.read_image_ldr_buf(bytemuck::try_cast_slice_mut(buf.as_mut_slice()).unwrap())?;
+        // SAFETY:
+        // RGB is a loose wrapper around [T; 3], thus this
+        // cast is just flattening out the nesting.
+        let slice: &mut [u8] = unsafe {
+            let raw_ptr = buf.as_mut_ptr() as *mut u8;
+            std::slice::from_raw_parts_mut(raw_ptr, sz * 3)
+        };
+        self.read_image_ldr_buf(slice)?;
         Ok(buf)
     }
     fn read_image_ldr_buf(self, buf: &mut [u8]) -> ImageResult<()> {
@@ -497,7 +504,14 @@ impl<R: BufRead> HdrDecoder<R> {
     pub fn read_image_hdr(self) -> ImageResult<Vec<Rgb<f32>>> {
         let sz = (self.width * self.height) as usize;
         let mut buf = vec![Rgb([0.0f32; 3]); sz];
-        self.read_image_hdr_buf(bytemuck::try_cast_slice_mut(buf.as_mut_slice()).unwrap())?;
+        // SAFETY:
+        // RGB is a loose wrapper around [T; 3], thus this
+        // cast is just flattening out the nesting.
+        let slice: &mut [f32] = unsafe {
+            let raw_ptr = buf.as_mut_ptr() as *mut f32;
+            std::slice::from_raw_parts_mut(raw_ptr, sz * 3)
+        };
+        self.read_image_hdr_buf(slice)?;
         Ok(buf)
     }
 
diff --git a/src/color.rs b/src/color.rs
index 13814921b8..8426eb546e 100644
--- a/src/color.rs
+++ b/src/color.rs
@@ -349,14 +349,6 @@ impl<T> From<[T; $channels]> for $ident<T> {
         Self(c)
     }
 }
-
-unsafe impl<T> bytemuck::Zeroable for $ident<T> where T: bytemuck::Zeroable {
-  fn zeroed() -> Self {
-    Self(<[T; $channels] as bytemuck::Zeroable>::zeroed())
-  }
-}
-unsafe impl<T> bytemuck::Pod for $ident<T> where T: bytemuck::Pod {}
-
 )* // END Structure definitions
 
     }