/// <summary>
/// Reads a PSD image resource from a stream and populates a <see cref="PSDImageResource"/> with the
/// information.
/// </summary>
/// <param name="resource">The PSD image resource object to populate.</param>
/// <param name="stream">The stream from which to read the PSD resource.</param>
public static void ReadResourceBlock(PSDImageResource resource, Stream stream)
{
string magic = stream.ReadUsAsciiString(4);
if (!string.Equals(magic, Magic, StringComparison.Ordinal))
{
throw new PSDFormatException($"unexpected image resource magic value (is \"{magic}\", expected \"{Magic}\")");
}
resource.ID = stream.ReadBigEndianInt16();
resource.Name = stream.ReadUsAsciiPascalStringPaddedToEven();
int dataSize = stream.ReadBigEndianInt32();
if (dataSize < 0)
{
throw new PSDFormatException($"image resource has data size {dataSize}, expected at least 0");
}
resource.Data = stream.ReadBytes(dataSize);
if (dataSize % 2 == 1)
{
// PSD files pad image resource data to even sizes; skip a byte
stream.ReadByteOrThrow();
}
}
/// <summary>
/// Reads the PSD image resources from a stream and populates a <see cref="PSDFile"/> with the information.
/// </summary>
/// <param name="psd">The PSD file object to populate.</param>
/// <param name="stream">The stream from which to read the PSD image resources.</param>
public static void ReadImageResources(PSDFile psd, Stream stream)
{
int imageResourceSectionLength = stream.ReadBigEndianInt32();
if (imageResourceSectionLength < 0)
{
throw new PSDFormatException(
$"image resource section length is {imageResourceSectionLength}, expected at least 0");
}
psd.ImageResources = new List <PSDImageResource>();
long endPosition = stream.Position + imageResourceSectionLength;
while (stream.Position < endPosition)
{
var resource = new PSDImageResource();
PSDImageResource.Reading.ReadResourceBlock(resource, stream);
psd.ImageResources.Add(resource);
}
}