Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 53 insertions, 0 deletions

diff --git a/vendor/exr/examples/1b_convert_exr_to_png.rs b/vendor/exr/examples/1b_convert_exr_to_png.rs
new file mode 100644
index 0000000..c78716e
--- /dev/null
+++ b/vendor/exr/examples/1b_convert_exr_to_png.rs
@@ -0,0 +1,53 @@
+
+extern crate image as png;
+
+// exr imports
+extern crate exr;
+
+/// Converts one rgba exr with one layer to one png, or fail.
+fn main() {
+    use exr::prelude::*;
+    use exr::prelude as exrs;
+
+    // read from the exr file directly into a new `png::RgbaImage` image without intermediate buffers
+    let reader = exrs::read()
+        .no_deep_data()
+        .largest_resolution_level()
+        .rgba_channels(
+        |resolution, _channels: &RgbaChannels| -> png::RgbaImage {
+                png::ImageBuffer::new(
+                    resolution.width() as u32,
+                    resolution.height() as u32
+                )
+            },
+
+            // set each pixel in the png buffer from the exr file
+            |png_pixels, position, (r,g,b,a): (f32,f32,f32,f32)| { // TODO implicit argument types!
+                png_pixels.put_pixel(
+                    position.x() as u32, position.y() as u32,
+                    png::Rgba([tone_map(r), tone_map(g), tone_map(b), (a * 255.0) as u8])
+                );
+            }
+        )
+        .first_valid_layer()
+        .all_attributes();
+
+    // an image that contains a single layer containing an png rgba buffer
+    let image: Image<Layer<SpecificChannels<png::RgbaImage, RgbaChannels>>> = reader
+        .from_file("generated_rgba.exr")
+        .expect("run the `1_write_rgba` example to generate the required file");
+
+
+    /// compress any possible f32 into the range of [0,1].
+    /// and then convert it to an unsigned byte.
+    fn tone_map(linear: f32) -> u8 {
+        // TODO does the `image` crate expect gamma corrected data?
+        let clamped = (linear - 0.5).tanh() * 0.5 + 0.5;
+        (clamped * 255.0) as u8
+    }
+
+    // save the png buffer to a png file
+    let png_buffer = &image.layer_data.channel_data.pixels;
+    png_buffer.save("rgb.png").unwrap();
+    println!("created image rgb.png")
+}
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