squoosh/codecs/rotate/rotate.rs

use std::slice::from_raw_parts_mut;

// This function is taken from Zachary Dremann
// https://github.com/GoogleChromeLabs/squoosh/pull/462
trait HardUnwrap<T> {
    fn unwrap_hard(self) -> T;
}

impl<T> HardUnwrap<T> for Option<T> {
    #[cfg(not(debug_assertions))]
    #[inline]
    fn unwrap_hard(self) -> T {
        match self {
            Some(t) => t,
            None => std::process::abort(),
        }
    }

    #[cfg(debug_assertions)]
    fn unwrap_hard(self) -> T {
        o.unwrap()
    }
}

#[no_mangle]
fn rotate(width: usize, height: usize, _rotate: usize) {
    let num_pixels = width * height;
    let in_b: &mut [u32];
    let out_b: &mut [u32];
    unsafe {
        in_b = from_raw_parts_mut::<u32>(8 as *mut u32, num_pixels);
        out_b = from_raw_parts_mut::<u32>((num_pixels * 4 + 8) as *mut u32, num_pixels);
    }

    let new_width = height;
    let _new_height = width;
    for y in 0..height {
        for x in 0..width {
            let new_x = (new_width - 1) - y;
            let new_y = x;
            *out_b.get_mut(new_y * new_width + new_x).unwrap_hard() =
                *in_b.get(y * width + x).unwrap_hard();
        }
    }
}