fn into_windows_icon()

in src/platform_impl/windows/icon.rs [23:50]

• 28 lines of code
• 3 McCabe index (conditional complexity)

    fn into_windows_icon(self) -> Result<WinIcon, BadIcon> {
        let mut rgba = self.rgba;
        let pixel_count = rgba.len() / PIXEL_SIZE;
        let mut and_mask = Vec::with_capacity(pixel_count);
        let pixels =
            unsafe { std::slice::from_raw_parts_mut(rgba.as_mut_ptr() as *mut Pixel, pixel_count) };
        for pixel in pixels {
            and_mask.push(pixel.a.wrapping_sub(std::u8::MAX)); // invert alpha channel
            pixel.to_bgra();
        }
        assert_eq!(and_mask.len(), pixel_count);
        let handle = unsafe {
            winuser::CreateIcon(
                ptr::null_mut(),
                self.width as c_int,
                self.height as c_int,
                1,
                (PIXEL_SIZE * 8) as BYTE,
                and_mask.as_ptr() as *const BYTE,
                rgba.as_ptr() as *const BYTE,
            ) as HICON
        };
        if !handle.is_null() {
            Ok(WinIcon::from_handle(handle))
        } else {
            Err(BadIcon::OsError(io::Error::last_os_error()))
        }
    }