add a ImageCloner

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "fimg"
-version = "0.4.3"
+version = "0.4.4"
 authors = ["bend-n <bend.n@outlook.com>"]
 license = "MIT"
 edition = "2021"

src/affine.rs

@@ -1,19 +1,58 @@
 //! Manages the affine image transformations.
-use crate::Image;
+use crate::{cloner::ImageCloner, Image};
 
 impl<const CHANNELS: usize> Image<Vec<u8>, CHANNELS> {
-    /// Flip a image horizontally.
+    /// Flip an image horizontally.
     pub fn flip_h(&mut self) {
         self.as_mut().flip_h();
     }
-    /// Flip a image vertically.
+    /// Flip an image vertically.
     pub fn flip_v(&mut self) {
         self.as_mut().flip_v();
     }
 }
+impl<const CHANNELS: usize> ImageCloner<'_, CHANNELS> {
+    /// Flip an image vertically.
+    /// ```
+    /// # use fimg::Image;
+    /// let a = Image::<_, 1>::build(2,2).buf(vec![21,42,90,01]);
+    /// assert_eq!(a.cloner().flip_v().take_buffer(), [90,01,21,42]);
+    /// ```
+    pub fn flip_v(&self) -> Image<Vec<u8>, CHANNELS> {
+        let mut out = self.alloc();
+        for y in 0..self.height() {
+            for x in 0..self.width() {
+                // SAFETY: looping over self, all ok (could be safe versions, bounds would be elided)
+                let p = unsafe { self.pixel(x, y) };
+                // SAFETY: looping over self.
+                unsafe { out.set_pixel(x, self.height() - y - 1, p) };
+            }
+        }
+        out
+    }
+
+    /// Flip an image horizontally
+    /// ```
+    /// # use fimg::Image;
+    /// let a = Image::<_,1>::build(2,2).buf(vec![90,01,21,42]);
+    /// assert_eq!(a.cloner().flip_h().take_buffer(), [01,90,42,21]);
+    /// ```
+    pub fn flip_h(&self) -> Image<Vec<u8>, CHANNELS> {
+        let mut out = self.alloc();
+        for y in 0..self.height() {
+            for x in 0..self.width() {
+                // SAFETY: looping over self, all ok
+                let p = unsafe { self.pixel(x, y) };
+                // SAFETY: looping over self, all ok
+                unsafe { out.set_pixel(self.width() - x - 1, y, p) };
+            }
+        }
+        out
+    }
+}
 
 impl<const CHANNELS: usize> Image<&mut [u8], CHANNELS> {
-    /// Flip a image vertically.
+    /// Flip an image vertically.
     pub fn flip_v(&mut self) {
         for y in 0..self.height() / 2 {
             for x in 0..self.width() {
@@ -30,7 +69,7 @@ impl<const CHANNELS: usize> Image<&mut [u8], CHANNELS> {
         }
     }
 
-    /// Flip a image horizontally.
+    /// Flip an image horizontally.
     pub fn flip_h(&mut self) {
         for y in 0..self.height() {
             for x in 0..self.width() / 2 {
@@ -49,12 +88,12 @@ impl<const CHANNELS: usize> Image<&mut [u8], CHANNELS> {
 }
 
 impl<const CHANNELS: usize> Image<Vec<u8>, CHANNELS> {
-    /// Rotate a image 180 degrees clockwise.
+    /// Rotate an image 180 degrees clockwise.
     pub fn rot_180(&mut self) {
         self.as_mut().rot_180();
     }
 
-    /// Rotate a image 90 degrees clockwise.
+    /// Rotate an image 90 degrees clockwise.
     /// # Safety
     ///
     /// UB if the image is not square
@@ -63,7 +102,7 @@ impl<const CHANNELS: usize> Image<Vec<u8>, CHANNELS> {
         unsafe { self.as_mut().rot_90() }
     }
 
-    /// Rotate a image 270 degrees clockwise, or 90 degrees anti clockwise.
+    /// Rotate an image 270 degrees clockwise, or 90 degrees anti clockwise.
     /// # Safety
     ///
     /// UB if the image is not square
@@ -73,42 +112,60 @@ impl<const CHANNELS: usize> Image<Vec<u8>, CHANNELS> {
     }
 }
 
+impl<const CHANNELS: usize> ImageCloner<'_, CHANNELS> {
+    /// Rotate an image 180 degrees clockwise.
+    ///
+    /// ```
+    /// # use fimg::Image;
+    /// let a = Image::<_,1>::build(2,2).buf(vec![00,01,02,10]);
+    /// assert_eq!(a.cloner().rot_180().take_buffer(), vec![10,02,01,00]);
+    /// ```
+    pub fn rot_180(&self) -> Image<Vec<u8>, CHANNELS> {
+        let s = (self.width() * self.height()) as usize;
+        let mut v: Vec<[u8; CHANNELS]> = Vec::with_capacity(s);
+        for (x, y) in self.chunked().rev().zip(&mut v.spare_capacity_mut()[..]) {
+            y.write(*x);
+        }
+        // SAFETY: we just wrote the right amount
+        unsafe { v.set_len(s) };
+        let (v, _, c) = v.into_raw_parts();
+        let s = s * CHANNELS;
+        // SAFETY: init with with_cap, set len to s, s is init amount, chunked returns nm, capacity handled, flatten vec
+        let v = unsafe { Vec::from_raw_parts(v.cast::<u8>(), s, c * CHANNELS) };
+        // SAFETY: s is w * h.
+        unsafe { Image::new(self.width, self.height, v) }
+    }
+
+    /// Rotate an image 90 degrees clockwise.
+    /// # Safety
+    ///
+    /// UB if the image is not square
+    pub unsafe fn rot_90(&self) -> Image<Vec<u8>, CHANNELS> {
+        let mut out = self.flip_v();
+        // SAFETY: sqar
+        unsafe { transpose(&mut out.as_mut()) };
+        out
+    }
+
+    /// Rotate an image 270 degrees clockwise, or 90 degrees anti clockwise.
+    /// # Safety
+    ///
+    /// UB if the image is not square
+    pub unsafe fn rot_270(&self) -> Image<Vec<u8>, CHANNELS> {
+        let mut out = self.flip_h();
+        // SAFETY: sqar
+        unsafe { transpose(&mut out.as_mut()) };
+        out
+    }
+}
+
 impl<const CHANNELS: usize> Image<&mut [u8], CHANNELS> {
-    /// Rotate a image 180 degrees clockwise.
+    /// Rotate an image 180 degrees clockwise.
     pub fn rot_180(&mut self) {
-        for y in 0..self.height() / 2 {
+        self.flatten_mut().reverse();
-            for x in 0..self.width() {
-                // SAFETY: x, y come from the loop, must be ok
-                let p = unsafe { self.pixel(x, y) };
-                let x2 = self.width() - x - 1;
-                let y2 = self.height() - y - 1;
-                // SAFETY: values are good
-                let p2 = unsafe { self.pixel(x2, y2) };
-                // SAFETY: swapping would be cool, alas.
-                unsafe { self.set_pixel(x, y, p2) };
-                // SAFETY: although maybe i can cast it to a `[[u8; CHANNELS]]` and swap that 🤔
-                unsafe { self.set_pixel(x2, y2, p) };
-            }
     }
 
-        if self.height() % 2 != 0 {
+    /// Rotate an image 90 degrees clockwise.
-            let middle = self.height() / 2;
-
-            for x in 0..self.width() / 2 {
-                let x2 = self.width() - x - 1;
-                #[allow(clippy::multiple_unsafe_ops_per_block)]
-                // SAFETY: its just doing the swappy
-                unsafe {
-                    let p = self.pixel(x, middle);
-                    let p2 = self.pixel(x2, middle);
-                    self.set_pixel(x, middle, p2);
-                    self.set_pixel(x2, middle, p);
-                }
-            }
-        }
-    }
-
-    /// Rotate a image 90 degrees clockwise.
     /// # Safety
     ///
     /// UB if the image is not square
@@ -121,7 +178,7 @@ impl<const CHANNELS: usize> Image<&mut [u8], CHANNELS> {
         unsafe { transpose(self) };
     }
 
-    /// Rotate a image 270 degrees clockwise, or 90 degrees anti clockwise.
+    /// Rotate an image 270 degrees clockwise, or 90 degrees anti clockwise.
     /// # Safety
     ///
     /// UB if the image is not square
@@ -156,8 +213,7 @@ unsafe fn transpose<const CHANNELS: usize>(img: &mut Image<&mut [u8], CHANNELS>)
 unsafe fn transpose_non_power_of_two<const CHANNELS: usize>(img: &mut Image<&mut [u8], CHANNELS>) {
     debug_assert_eq!(img.width(), img.height());
     let size = img.width() as usize;
-    // SAFETY: no half pixels
+    let b = img.flatten_mut();
-    let b = unsafe { img.buffer.as_chunks_unchecked_mut::<CHANNELS>() };
     for i in 0..size {
         for j in i..size {
             // SAFETY: caller ensures squarity

src/cloner.rs

@@ -0,0 +1,39 @@
+//! provides a [`ImageCloner`]
+//!
+//! ```
+//! # use fimg::Image;
+//! # let i = Image::<_, 1>::alloc(5, 5);
+//! unsafe { i.cloner().rot_270() };
+//! ```
+use crate::Image;
+
+/// A neat way to clone a image.
+///
+/// Consider it a way to clone->apply a image operation, but better.
+/// Please note that some methods may(although none at current) have different safety invariants from their in place counterparts.
+pub struct ImageCloner<'a, const C: usize>(Image<&'a [u8], C>);
+
+impl<'a, const C: usize> ImageCloner<'a, C> {
+    /// duplicate the inner image.
+    pub(crate) fn dup(&self) -> Image<Vec<u8>, C> {
+        self.0.to_owned()
+    }
+
+    /// Create a [`ImageCloner`] from a <code>[Image]<&\[[u8]\]></code>
+    pub const fn from(i: Image<&'a [u8], C>) -> Self {
+        Self(i)
+    }
+
+    /// Alloc a buffer the right size for use
+    pub(crate) fn alloc(&self) -> Image<Vec<u8>, C> {
+        Image::alloc(self.width(), self.height())
+    }
+}
+
+impl<'a, const C: usize> std::ops::Deref for ImageCloner<'a, C> {
+    type Target = Image<&'a [u8], C>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}

src/lib.rs

@@ -5,6 +5,7 @@
     slice_swap_unchecked,
     stmt_expr_attributes,
     generic_const_exprs,
+    vec_into_raw_parts,
     slice_as_chunks,
     unchecked_math,
     portable_simd,
@@ -28,9 +29,11 @@ use std::{num::NonZeroU32, slice::SliceIndex};
 
 mod affine;
 pub mod builder;
+pub mod cloner;
 mod drawing;
 mod overlay;
 pub mod scale;
+use cloner::ImageCloner;
 pub use overlay::{Overlay, OverlayAt};
 
 /// like assert!(), but causes undefined behaviour at runtime when the condition is not met.
@@ -81,7 +84,7 @@ unsafe fn really_unsafe_index(x: u32, y: u32, w: u32) -> usize {
 }
 
 /// A image with a variable number of channels, and a nonzero size.
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq)]
 pub struct Image<T, const CHANNELS: usize> {
     /// column order 2d slice/vec
     buffer: T,
@@ -91,6 +94,37 @@ pub struct Image<T, const CHANNELS: usize> {
     height: NonZeroU32,
 }
 
+impl<T: Clone, const CHANNELS: usize> Clone for Image<T, CHANNELS> {
+    /// Returns a duplicate of this image.
+    /// ```
+    /// # use fimg::Image;
+    /// # let i = Image::<Vec<_>, 1>::alloc(5,5);
+    /// let new_i = i.clone();
+    /// ```
+    /// If you find yourself in the pattern of
+    /// ```
+    /// # use fimg::Image;
+    /// # let i = Image::<Vec<_>, 1>::alloc(5,5);
+    /// let mut i = i.clone();
+    /// unsafe { i.rot_90() };
+    /// ```
+    /// STOP!
+    ///
+    /// Instead use
+    /// ```
+    /// # use fimg::Image;
+    /// # let i = Image::<Vec<_>, 1>::alloc(5,5);
+    /// let i = unsafe { i.cloner().rot_90() };
+    /// ```
+    fn clone(&self) -> Self {
+        Self {
+            buffer: self.buffer.clone(),
+            width: self.width,
+            height: self.height,
+        }
+    }
+}
+
 impl<T, const CHANNELS: usize> Image<T, CHANNELS> {
     #[inline]
     /// get the height as a [`u32`]
@@ -156,6 +190,8 @@ impl<const CHANNELS: usize, T: Clone> Image<&mut [T], CHANNELS> {
     }
 }
 
+impl<const CHANNELS: usize> Copy for Image<&[u8], CHANNELS> {}
+
 impl<const CHANNELS: usize> Image<&[u8], CHANNELS> {
     #[inline]
     #[must_use]
@@ -209,9 +245,20 @@ impl<T: std::ops::Deref<Target = [u8]>, const CHANNELS: usize> Image<T, CHANNELS
         index..unsafe { index.unchecked_add(CHANNELS) }
     }
 
+    /// Procure a [`ImageCloner`].
+    pub fn cloner(&self) -> ImageCloner<'_, CHANNELS> {
+        ImageCloner::from(self.as_ref())
+    }
+
+    /// Reference this image.
+    pub fn as_ref(&self) -> Image<&[u8], CHANNELS> {
+        // SAFETY: we got constructed okay, parameters must be valid
+        unsafe { Image::new(self.width, self.height, &*self.buffer) }
+    }
+
     #[inline]
     /// Returns a iterator over every pixel
-    pub fn chunked(&self) -> impl Iterator<Item = &[u8; CHANNELS]> {
+    pub fn chunked(&self) -> impl DoubleEndedIterator<Item = &[u8; CHANNELS]> {
         // SAFETY: 0 sized images illegal
         unsafe { assert_unchecked!(self.buffer.len() > CHANNELS) };
         // SAFETY: no half pixels!
@@ -266,6 +313,12 @@ impl<T: std::ops::DerefMut<Target = [u8]>, const CHANNELS: usize> Image<T, CHANN
         self.buffer.array_chunks_mut::<CHANNELS>()
     }
 
+    /// Create a mutref to this image
+    pub fn as_mut(&mut self) -> Image<&mut [u8], CHANNELS> {
+        // SAFETY: construction went okay
+        unsafe { Image::new(self.width, self.height, &mut self.buffer) }
+    }
+
     #[inline]
     /// Flatten the chunks of this image into a mutable slice of slices.
     pub fn flatten_mut(&mut self) -> &mut [[u8; CHANNELS]] {
@@ -288,12 +341,6 @@ impl<T: std::ops::DerefMut<Target = [u8]>, const CHANNELS: usize> Image<T, CHANN
 }
 
 impl<const CHANNELS: usize> Image<&mut [u8], CHANNELS> {
-    /// Downcast the mutable reference
-    pub fn as_ref(&self) -> Image<&[u8], CHANNELS> {
-        // SAFETY: we got constructed okay, parameters must be valid
-        unsafe { Image::new(self.width, self.height, self.buffer) }
-    }
-
     /// Copy this ref image
     pub fn copy(&mut self) -> Image<&mut [u8], CHANNELS> {
         #[allow(clippy::undocumented_unsafe_blocks)]
@@ -303,26 +350,6 @@ impl<const CHANNELS: usize> Image<&mut [u8], CHANNELS> {
     }
 }
 
-impl<const CHANNELS: usize> Image<Vec<u8>, CHANNELS> {
-    /// Create a reference to this owned image
-    pub fn as_ref(&self) -> Image<&[u8], CHANNELS> {
-        #[allow(clippy::undocumented_unsafe_blocks)]
-        unsafe {
-            Image::new(self.width, self.height, &self.buffer)
-        }
-    }
-}
-
-impl<const CHANNELS: usize> Image<Vec<u8>, CHANNELS> {
-    /// Create a mutable reference to this owned image
-    pub fn as_mut(&mut self) -> Image<&mut [u8], CHANNELS> {
-        #[allow(clippy::undocumented_unsafe_blocks)]
-        unsafe {
-            Image::new(self.width, self.height, &mut self.buffer)
-        }
-    }
-}
-
 impl<const CHANNELS: usize> Image<Vec<u8>, CHANNELS> {
     /// Allocates a new image
     ///

src/overlay.rs

@@ -1,4 +1,6 @@
 //! Handles image overlay
+use crate::cloner::ImageCloner;
+
 use super::{assert_unchecked, really_unsafe_index, Image};
 use std::simd::SimdInt;
 use std::simd::SimdPartialOrd;
@@ -12,6 +14,16 @@ pub trait OverlayAt<W> {
     /// UB if x, y is out of bounds
     unsafe fn overlay_at(&mut self, with: &W, x: u32, y: u32) -> &mut Self;
 }
+
+/// [`OverlayAt`] but owned
+pub trait ClonerOverlayAt<const W: usize, const C: usize> {
+    /// Overlay with => self at coordinates x, y, without blending, and returning a new image.
+    /// # Safety
+    ///
+    /// UB if x, y is out of bounds
+    unsafe fn overlay_at(&self, with: &Image<&[u8], W>, x: u32, y: u32) -> Image<Vec<u8>, C>;
+}
+
 /// Trait for layering images ontop of each other.
 /// Think `magick a b -layers flatten a`
 pub trait Overlay<W> {
@@ -22,6 +34,15 @@ pub trait Overlay<W> {
     unsafe fn overlay(&mut self, with: &W) -> &mut Self;
 }
 
+/// [`Overlay`] but owned
+pub trait ClonerOverlay<const W: usize, const C: usize> {
+    /// Overlay with => self (does not blend)
+    /// # Safety
+    ///
+    /// UB if a.width != b.width || a.height != b.height
+    unsafe fn overlay(&self, with: &Image<&[u8], W>) -> Image<Vec<u8>, C>;
+}
+
 #[inline]
 /// SIMD accelerated rgba => rgb overlay.
 ///
@@ -88,6 +109,16 @@ impl Overlay<Image<&[u8], 4>> for Image<&mut [u8], 4> {
     }
 }
 
+impl ClonerOverlay<4, 4> for ImageCloner<'_, 4> {
+    #[inline]
+    unsafe fn overlay(&self, with: &Image<&[u8], 4>) -> Image<Vec<u8>, 4> {
+        let mut out = self.dup();
+        // SAFETY: same
+        unsafe { out.as_mut().overlay(with) };
+        out
+    }
+}
+
 impl OverlayAt<Image<&[u8], 4>> for Image<&mut [u8], 3> {
     #[inline]
     unsafe fn overlay_at(&mut self, with: &Image<&[u8], 4>, x: u32, y: u32) -> &mut Self {
@@ -113,6 +144,15 @@ impl OverlayAt<Image<&[u8], 4>> for Image<&mut [u8], 3> {
     }
 }
 
+impl ClonerOverlayAt<4, 3> for ImageCloner<'_, 3> {
+    unsafe fn overlay_at(&self, with: &Image<&[u8], 4>, x: u32, y: u32) -> Image<Vec<u8>, 3> {
+        let mut new = self.dup();
+        // SAFETY: same
+        unsafe { new.as_mut().overlay_at(with, x, y) };
+        new
+    }
+}
+
 impl OverlayAt<Image<&[u8], 3>> for Image<&mut [u8], 3> {
     /// Overlay a RGB image(with) => self at coordinates x, y.
     /// As this is a `RGBxRGB` operation, blending is unnecessary,
@@ -175,6 +215,16 @@ impl Overlay<Image<&[u8], 4>> for Image<&mut [u8], 3> {
     }
 }
 
+impl ClonerOverlay<4, 3> for ImageCloner<'_, 3> {
+    #[inline]
+    unsafe fn overlay(&self, with: &Image<&[u8], 4>) -> Image<Vec<u8>, 3> {
+        let mut out = self.dup();
+        // SAFETY: same
+        unsafe { out.as_mut().overlay(with) };
+        out
+    }
+}
+
 impl OverlayAt<Image<&[u8], 4>> for Image<&mut [u8], 4> {
     #[inline]
     /// Overlay with => self at coordinates x, y, without blending
@@ -210,3 +260,19 @@ impl OverlayAt<Image<&[u8], 4>> for Image<&mut [u8], 4> {
         self
     }
 }
+
+impl ClonerOverlayAt<4, 4> for ImageCloner<'_, 4> {
+    #[inline]
+    /// Overlay with => self at coordinates x, y, without blending, returning a new Image
+    ///
+    /// # Safety
+    /// - UB if x, y is out of bounds
+    /// - UB if x + with.width() > [`u32::MAX`]
+    /// - UB if y + with.height() > [`u32::MAX`]
+    unsafe fn overlay_at(&self, with: &Image<&[u8], 4>, x: u32, y: u32) -> Image<Vec<u8>, 4> {
+        let mut out = self.dup();
+        // SAFETY: same
+        unsafe { out.as_mut().overlay_at(with, x, y) };
+        out
+    }
+}