1 files changed, 48 insertions, 0 deletions
diff --git a/vendor/exr/examples/7_crop_alpha_rgba.rs b/vendor/exr/examples/7_crop_alpha_rgba.rs
new file mode 100644
index 0000000..18478d3
--- /dev/null
+++ b/vendor/exr/examples/7_crop_alpha_rgba.rs
@@ -0,0 +1,48 @@
+
+extern crate image as png;
+
+extern crate exr;
+
+
+/// Read an rgba image, or fail if none can be found.
+/// Then crop away transparent pixels,
+/// and write the cropped result to another file.
+/// This retains only the rgb pixels, and no other layers.
+pub fn main() {
+    use exr::prelude::*;
+    use exr::image::pixel_vec::*; // import predefined pixel storage
+
+    let path = "tests/images/valid/custom/oh crop.exr";
+
+    type DynamicRgbaPixel = (Sample, Sample, Sample, Sample); // `Sample` is an enum containing the original data type (f16,f32, or u32)
+
+    // load an rgba image
+    // this specific example discards all but the first valid rgb layers and converts all pixels to f32 values
+    // TODO optional alpha channel!
+    let image: PixelImage<PixelVec<DynamicRgbaPixel>, RgbaChannels> = read_first_rgba_layer_from_file(
+        path,
+        PixelVec::<DynamicRgbaPixel>::constructor,
+
+        // use this predefined rgba pixel container from the exr crate, requesting any type of pixels with 3 or 4 values
+        PixelVec::set_pixel
+    ).expect("this file exists in the exrs repository. download that?");
+
+    // construct a ~simple~ cropped image
+    let image: Image<Layer<CroppedChannels<SpecificChannels<PixelVec<DynamicRgbaPixel>, RgbaChannels>>>> = Image {
+        attributes: image.attributes,
+
+        // crop each layer
+        layer_data: {
+            println!("cropping layer {:#?}", image.layer_data);
+
+            // if has alpha, crop it where alpha is zero
+            image.layer_data
+                .crop_where(|(_r, _g, _b, alpha)| alpha.is_zero())
+                .or_crop_to_1x1_if_empty() // do not remove empty layers from image, because it could result in an image without content
+        },
+    };
+
+    image.write().to_file("cropped_rgba.exr").unwrap();
+    println!("cropped file to cropped_rgba.exr");
+}
+