/// <summary>
/// Gets a list of the auxiliary image ids.
/// </summary>
/// <returns>A list of the auxiliary image ids.</returns>
/// <exception cref="HeifException">A LibHeif error occurred.</exception>
/// <exception cref="ObjectDisposedException">The object has been disposed.</exception>
/// <remarks>
/// <para>The alpha and/or depth images are omitted from this list.</para>
/// <para>
/// LibHeif will include the alpha image (if present) when you call <see cref="Decode(HeifColorspace, HeifChroma, HeifDecodingOptions)"/>
/// with the <see cref="HeifChroma"/> parameter set to one of the <c>InterleavedRgba</c> values.
/// </para>
/// <para>
/// To read the depth images use <see cref="GetDepthImageIds"/> to get a list of the depth image item ids and
/// <see cref="GetDepthImage(HeifItemId)"/> to convert the item id to a <see cref="HeifImageHandle"/>.
/// </para>
/// </remarks>
/// <seealso cref="GetAuxiliaryImage(HeifItemId)"/>
/// <seealso cref="GetAuxiliaryType"/>
public IReadOnlyList <HeifItemId> GetAuxiliaryImageIds()
{
VerifyNotDisposed();
if (LibHeifVersion.Is1Point11OrLater)
{
const heif_auxiliary_image_filter filter = heif_auxiliary_image_filter.OmitAlpha | heif_auxiliary_image_filter.OmitDepth;
int count = LibHeifNative.heif_image_handle_get_number_of_auxiliary_images(this.imageHandle, filter);
if (count == 0)
{
return(Array.Empty <HeifItemId>());
}
var ids = new HeifItemId[count];
unsafe
{
fixed(HeifItemId *ptr = ids)
{
int filledCount = LibHeifNative.heif_image_handle_get_list_of_auxiliary_image_IDs(this.imageHandle,
filter,
ptr,
count);
if (filledCount != count)
{
ExceptionUtil.ThrowHeifException(Resources.CannotGetAllAuxillaryImages);
}
}
}
return(ids);
}
else
{
return(Array.Empty <HeifItemId>());
}
}
