Added method `ImageData<Vec<u32>>::from_buffer()`

src/image_data.rs

@@ -45,10 +45,16 @@ impl<T: AsRef<[u32]>> ImageData<T> {
     }
 
     #[inline(always)]
-    pub fn get_buffer(&self) -> &[u32] {
+    pub fn get_pixels(&self) -> &[u32] {
         self.pixels.as_ref()
     }
 
+    #[inline(always)]
+    pub fn get_buffer(&self) -> &[u8] {
+        let (_, buffer, _) = unsafe { self.pixels.as_ref().align_to::<u8>() };
+        buffer
+    }
+
     #[inline(always)]
     pub fn src_view(&self) -> SrcImageView {
         let pixels = self.pixels.as_ref();
@@ -77,4 +83,26 @@ impl ImageData<Vec<u32>> {
             pixel_type,
         }
     }
+
+    pub fn from_buffer(
+        width: NonZeroU32,
+        height: NonZeroU32,
+        buffer: &[u8],
+        pixel_type: PixelType,
+    ) -> Result<Self, ImageBufferError> {
+        let size = (width.get() * height.get()) as usize * 4;
+        if buffer.len() != size {
+            return Err(ImageBufferError::InvalidBufferSize);
+        }
+        let (head, pixels, _) = unsafe { buffer.align_to::<u32>() };
+        if !head.is_empty() {
+            return Err(ImageBufferError::InvalidBufferAlignment);
+        }
+        Ok(Self {
+            width,
+            height,
+            pixels: pixels.to_owned(),
+            pixel_type,
+        })
+    }
 }

src/image_view.rs

@@ -82,14 +82,14 @@ impl<'a> SrcImageView<'a> {
         buffer: &'a [u8],
         pixel_type: PixelType,
     ) -> Result<Self, ImageBufferError> {
+        let size = (width.get() * height.get()) as usize * 4;
+        if buffer.len() != size {
+            return Err(ImageBufferError::InvalidBufferSize);
+        }
         let (head, pixels, _) = unsafe { buffer.align_to::<u32>() };
         if !head.is_empty() {
             return Err(ImageBufferError::InvalidBufferAlignment);
         }
-        let size = (width.get() * height.get()) as usize;
-        if pixels.len() != size {
-            return Err(ImageBufferError::InvalidBufferSize);
-        }
 
         let rows = pixels.chunks(width.get() as usize).collect();
         Ok(Self::from_rows(width, height, rows, pixel_type).unwrap())

tests/alpha_tests.rs

@@ -1,5 +1,4 @@
 use fast_image_resize::{CpuExtensions, DstImageView, ImageData, MulDiv, PixelType, SrcImageView};
-use std::convert::TryInto;
 use std::num::NonZeroU32;
 
 const fn p(r: u8, g: u8, b: u8, a: u8) -> u32 {
@@ -46,11 +45,7 @@ fn multiply_alpha_test(cpu_extensions: CpuExtensions) {
         .multiply_alpha(&src_image_view, &mut dst_image_view)
         .unwrap();
 
-    let dst_pixels: Vec<u32> = dst_image
-        .get_buffer()
-        .chunks_exact(4)
-        .map(|c| u32::from_le_bytes(c.try_into().unwrap()))
-        .collect();
+    let dst_pixels: Vec<u32> = dst_image.get_pixels().to_vec();
     let dst_rows = dst_pixels.chunks_exact(width as usize);
     for (row, &valid_pixel) in dst_rows.zip(res_pixels.iter()) {
         for &pixel in row.iter() {
@@ -133,11 +128,7 @@ fn divide_alpha_test(cpu_extensions: CpuExtensions) {
         .divide_alpha(&src_image_view, &mut dst_image_view)
         .unwrap();
 
-    let dst_pixels: Vec<u32> = dst_image
-        .get_buffer()
-        .chunks_exact(4)
-        .map(|c| u32::from_le_bytes(c.try_into().unwrap()))
-        .collect();
+    let dst_pixels: Vec<u32> = dst_image.get_pixels().to_vec();
     let dst_rows = dst_pixels.chunks_exact(width as usize);
     for (row, &valid_pixel) in dst_rows.zip(res_pixels.iter()) {
         for &pixel in row.iter() {

tests/readme_examples.rs

@@ -25,7 +25,7 @@ fn resize_lanczos3(src_pixels: &[u8], width: NonZeroU32, height: NonZeroU32) ->
     dst_image.get_buffer().to_owned()
 }
 
-fn crop_and_resize_image(mut src_view: SrcImageView) -> ImageData<Vec<u8>> {
+fn crop_and_resize_image(mut src_view: SrcImageView) -> ImageData<Vec<u32>> {
     // Set crop-box for view of source image
     src_view
         .set_crop_box(CropBox {

tests/resize_tests.rs

@@ -15,16 +15,11 @@ fn get_source_image() -> ImageData<Vec<u32>> {
         .unwrap();
     let width = img.width();
     let height = img.height();
-    let rgb = img.to_rgba8();
-    let buf = rgb
-        .as_raw()
-        .chunks_exact(4)
-        .map(|p| u32::from_le_bytes([p[0], p[1], p[2], p[3]]))
-        .collect();
-    ImageData::new(
+    let rgba = img.to_rgba8();
+    ImageData::from_buffer(
         NonZeroU32::new(width).unwrap(),
         NonZeroU32::new(height).unwrap(),
-        buf,
+        rgba.as_raw(),
         PixelType::U8x4,
     )
     .unwrap()
@@ -37,16 +32,11 @@ fn get_small_source_image() -> ImageData<Vec<u32>> {
         .unwrap();
     let width = img.width();
     let height = img.height();
-    let rgb = img.to_rgba8();
-    let buf = rgb
-        .as_raw()
-        .chunks_exact(4)
-        .map(|p| u32::from_le_bytes([p[0], p[1], p[2], p[3]]))
-        .collect();
-    ImageData::new(
+    let rgba = img.to_rgba8();
+    ImageData::from_buffer(
         NonZeroU32::new(width).unwrap(),
         NonZeroU32::new(height).unwrap(),
-        buf,
+        rgba.as_raw(),
         PixelType::U8x4,
     )
     .unwrap()
@@ -115,7 +105,7 @@ fn resize_lanczos3(src_pixels: &[u32], width: NonZeroU32, height: NonZeroU32) ->
     let dst_height = NonZeroU32::new(768).unwrap();
     let mut dst_image = ImageData::new_owned(dst_width, dst_height, src_image.pixel_type());
     resizer.resize(&src_image.src_view(), &mut dst_image.dst_view());
-    dst_image.get_buffer().to_owned()
+    dst_image.get_pixels().to_owned()
 }
 
 #[test]