Re: [PATCH vkd3d 2/2] vkd3d: Handle plane slice for texture views.

[Henri Verbeet]

On Fri, 14 Jan 2022 at 05:57, Conor McCarthy  wrote:
> +static VkImageAspectFlags vk_image_aspect_flags_from_d3d12_plane_slice(const struct vkd3d_format *format,
> -
>    unsigned int plane_slice)
>
> +{
> - VkImageAspectFlags aspect_flags = format->vk_aspect_mask;
> - unsigned int i;
> -
> - /* For all formats we currently handle, the n-th aspect bit in Vulkan
> -
> * corresponds to the n-th plane in D3D12, so isolate the respective
> -
> * bit in the aspect flags. */
> - for (i = 0; i < plane_slice; i++)
> -
>    aspect_flags &= aspect_flags - 1;
> -

So above we're clearing the least significant bit set.
> - if (!aspect_flags)
> - {
> -
>    WARN("Invalid plane slice %u for format %#x.\n", plane_slice, format->vk_format);
> -
>    aspect_flags = format->vk_aspect_mask;
> - }
> -
> - return aspect_flags & -aspect_flags;

And then here we return the least significant bit set.
> +}
> -

That works, but I wouldn't say it's the most obvious code I've ever
seen; some comments wouldn't be inappropriate.