From 1b6a04ca5504955c571d1c97504fb45ea0befee4 Mon Sep 17 00:00:00 2001
From: Valentin Popov <valentin@popov.link>
Date: Mon, 8 Jan 2024 01:21:28 +0400
Subject: Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>
---
 vendor/exr/examples/2_rgba_adjust_exposure.rs | 80 +++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 vendor/exr/examples/2_rgba_adjust_exposure.rs

(limited to 'vendor/exr/examples/2_rgba_adjust_exposure.rs')

diff --git a/vendor/exr/examples/2_rgba_adjust_exposure.rs b/vendor/exr/examples/2_rgba_adjust_exposure.rs
new file mode 100644
index 0000000..c4e6097
--- /dev/null
+++ b/vendor/exr/examples/2_rgba_adjust_exposure.rs
@@ -0,0 +1,80 @@
+
+// exr imports
+extern crate exr;
+
+/// Read an rgba image, increase the exposure, and then write it back.
+/// Uses multi-core compression where appropriate.
+///
+/// All non-rgba channels and all layers except the first rgba layers will not be present in the new file.
+fn main() {
+    use exr::prelude::*;
+
+    /// This is an example of a custom image type.
+    /// You use your own image struct here.
+    // This struct trades sub-optimal memory-efficiency for clarity,
+    // because this is an example, and does not have to be perfectly efficient.
+    #[derive(Debug, PartialEq)]
+    struct CustomPixels { lines: Vec<Vec<RgbaF32Pixel>> }
+    type RgbaF32Pixel = (f32, f32, f32, f32);
+
+    // read the image from a file
+    let mut image = read().no_deep_data()
+        .largest_resolution_level()
+        .rgba_channels(
+            // create our custom image based on the file info
+            |resolution, _channels| -> CustomPixels {
+                let default_rgba_pixel = (0.0, 0.0, 0.0, 0.0);
+                let default_line = vec![default_rgba_pixel; resolution.width()];
+                let lines = vec![default_line; resolution.height()];
+                CustomPixels { lines }
+            },
+
+            // request pixels with red, green, blue, and optionally and alpha values.
+            // transfer each pixel from the file to our image
+            |image, position, (r,g,b,a): RgbaF32Pixel| {
+
+                // insert the values into our custom image
+                image.lines[position.y()][position.x()] = (r,g,b,a);
+            }
+        )
+        .first_valid_layer()
+        .all_attributes()
+        .from_file("generated_rgba.exr")
+        .expect("run the `1_write_rgba` example to generate the required file");
+
+    let exposure_multiplier = 2.0;
+
+    {   // increase exposure of all pixels
+        for line in &mut image.layer_data.channel_data.pixels.lines {
+            for (r,g,b,_) in line {
+                // you should probably check the color space and white points
+                // for high quality color adjustments
+                *r *= exposure_multiplier;
+                *g *= exposure_multiplier;
+                *b *= exposure_multiplier;
+            }
+        }
+
+        // also update meta data after modifying the image
+        if let Some(exposure) = &mut image.layer_data.attributes.exposure {
+            println!("increased exposure from {}s to {}s", exposure, *exposure * exposure_multiplier);
+            *exposure *= exposure_multiplier;
+        }
+    }
+
+    // enable writing our custom pixel storage to a file
+    // FIXME this should be passed as a closure to the `write_with(|x| y)` call
+    impl GetPixel for CustomPixels {
+        type Pixel = RgbaF32Pixel;
+        fn get_pixel(&self, position: Vec2<usize>) -> Self::Pixel {
+            self.lines[position.y()][position.x()]
+        }
+    }
+
+    // write the image to a file
+    image
+        .write().to_file("rgba_exposure_adjusted.exr")
+        .unwrap();
+
+    println!("created file rgba_exposure_adjusted.exr");
+}
\ No newline at end of file
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