Expose data as separate module

Here we have all the copy engine implementations and the trait. For now
you are not expected to construct them by yourself directly, hence they
go into a submodule where the type is documented but not immediately
reachable.

Author: 197g

texel/src/image.rs

@@ -10,9 +10,10 @@
 //! advised, probably very common, and the only 'supported' use-case).
 mod atomic;
 mod cell;
-mod data;
 mod raw;
 
+pub mod data;
+
 use core::{fmt, ops};
 
 pub(crate) use self::raw::RawImage;
@@ -26,7 +27,7 @@ use crate::{BufferReuseError, Texel, TexelBuffer};
 pub use crate::stride::{StridedBufferMut, StridedBufferRef};
 pub use atomic::{AtomicImage, AtomicImageRef};
 pub use cell::{CellImage, CellImageRef};
-pub use data::{DataCells, DataMut, DataRef};
+pub use data::{AsCopySource, AsCopyTarget, DataCells, DataMut, DataRef};
 
 /// A container of allocated bytes, parameterized over the layout.
 ///

texel/src/image/atomic.rs

@@ -149,8 +149,8 @@ impl<L: Layout> AtomicImage<L> {
     /// Copy all bytes to a newly allocated image.
     ///
     /// Note this will allocate a buffer according to the capacity length of this reference, not
-    /// merely the layout. When this is not the intention, consider calling [`Self::split_layout`]
-    /// or [`Self::truncate_layout`] respectively.
+    /// merely the layout. When this is not the intention, consider first adjusting the buffer by
+    /// reference with [`Self::as_ref`].
     ///
     /// # Examples
     ///

texel/src/image/cell.rs

@@ -139,8 +139,8 @@ impl<L: Layout> CellImage<L> {
     /// Copy all bytes to a newly allocated image.
     ///
     /// Note this will allocate a buffer according to the capacity length of this reference, not
-    /// merely the layout. When this is not the intention, consider calling [`Self::split_layout`]
-    /// or [`Self::truncate_layout`] respectively.
+    /// merely the layout. When this is not the intention, consider first adjusting the buffer by
+    /// reference with [`Self::as_ref`].
     ///
     /// # Examples
     ///