Vendor things

third-party/vendor/image/examples/concat/main.rs

@@ -0,0 +1,43 @@
+use image::{GenericImage, GenericImageView, ImageBuffer, Pixel, Primitive};
+
+/// Example showcasing a generic implementation of image concatenation.
+///
+/// The example images are coming from https://placeholder.com/
+///
+/// Run from the root of the repository with:
+/// cargo run --release --example concat
+fn main() {
+    h_concat(&[
+        image::open("examples/concat/200x300.png").unwrap(),
+        image::open("examples/concat/300x300.png").unwrap(),
+        image::open("examples/concat/400x300.png").unwrap(),
+    ])
+    .save("examples/concat/concatenated_900x300.png")
+    .unwrap();
+}
+
+/// Concatenate horizontally images with the same pixel type.
+fn h_concat<I, P, S>(images: &[I]) -> ImageBuffer<P, Vec<S>>
+where
+    I: GenericImageView<Pixel = P>,
+    P: Pixel<Subpixel = S> + 'static,
+    S: Primitive + 'static,
+{
+    // The final width is the sum of all images width.
+    let img_width_out: u32 = images.iter().map(|im| im.width()).sum();
+
+    // The final height is the maximum height from the input images.
+    let img_height_out: u32 = images.iter().map(|im| im.height()).max().unwrap_or(0);
+
+    // Initialize an image buffer with the appropriate size.
+    let mut imgbuf = image::ImageBuffer::new(img_width_out, img_height_out);
+    let mut accumulated_width = 0;
+
+    // Copy each input image at the correct location in the output image.
+    for img in images {
+        imgbuf.copy_from(img, accumulated_width, 0).unwrap();
+        accumulated_width += img.width();
+    }
+
+    imgbuf
+}