Raw-rs: Flip and rotate image based on camera orientation (#1954)

* add Orientation tag

* fix errors

* Apply the transformation to the image

* Fix BASE_PATH in raw-rs tests

* Create output folder if it doesn't exist

* Nit

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

libraries/raw-rs/src/postprocessing/mod.rs

@@ -1,2 +1,3 @@
 pub mod convert_to_rgb;
 pub mod gamma_correction;
+pub mod transform;

libraries/raw-rs/src/postprocessing/transform.rs

@@ -0,0 +1,67 @@
+use crate::Image;
+use crate::Transform;
+
+pub fn transform(mut image: Image<u16>) -> Image<u16> {
+	if image.transform.is_identity() {
+		return image;
+	}
+
+	let channels = image.channels as usize;
+	let mut data = vec![0; channels * image.width * image.height];
+
+	let (final_width, final_height) = if image.transform.will_swap_coordinates() {
+		(image.height, image.width)
+	} else {
+		(image.width, image.height)
+	};
+
+	let mut initial_index = inverse_transform_index(image.transform, 0, 0, image.width, image.height);
+	let column_step = inverse_transform_index(image.transform, 0, 1, image.width, image.height) as i64 - initial_index as i64;
+	let row_step = inverse_transform_index(image.transform, 1, 0, image.width, image.height) as i64 - inverse_transform_index(image.transform, 0, final_width, image.width, image.height) as i64;
+
+	for row in 0..final_height {
+		for col in 0..final_width {
+			let transformed_index = final_width * row + col;
+
+			let copy_from_range = channels * initial_index..channels * (initial_index + 1);
+			let copy_to_range = channels * transformed_index..channels * (transformed_index + 1);
+			data[copy_to_range].copy_from_slice(&image.data[copy_from_range]);
+
+			initial_index = (initial_index as i64 + column_step) as usize;
+		}
+		initial_index = (initial_index as i64 + row_step) as usize;
+	}
+
+	image.data = data;
+	image.width = final_width;
+	image.height = final_height;
+
+	image
+}
+
+pub fn inverse_transform_index(transform: Transform, mut row: usize, mut column: usize, width: usize, height: usize) -> usize {
+	let value = match transform {
+		Transform::Horizontal => 0,
+		Transform::MirrorHorizontal => 1,
+		Transform::Rotate180 => 3,
+		Transform::MirrorVertical => 2,
+		Transform::MirrorHorizontalRotate270 => 4,
+		Transform::Rotate90 => 6,
+		Transform::MirrorHorizontalRotate90 => 7,
+		Transform::Rotate270 => 5,
+	};
+
+	if value & 4 != 0 {
+		std::mem::swap(&mut row, &mut column)
+	}
+
+	if value & 2 != 0 {
+		row = height - 1 - row;
+	}
+
+	if value & 1 != 0 {
+		column = width - 1 - column;
+	}
+
+	width * row + column
+}