public static ImageResource CreateImageResource(PsdBinaryReader reader)
{
Util.DebugMessage(reader.BaseStream, "Load, Begin, ImageResource");
var signature = reader.ReadAsciiChars(4);
var resourceIdInt = reader.ReadUInt16();
var name = reader.ReadPascalString(2);
var dataLength = (int)reader.ReadUInt32();
var dataPaddedLength = Util.RoundUp(dataLength, 2);
var endPosition = reader.BaseStream.Position + dataPaddedLength;
ImageResource resource = null;
var resourceId = (ResourceID)resourceIdInt;
switch (resourceId)
{
case ResourceID.ThumbnailRgb:
case ResourceID.ThumbnailBgr:
resource = new Thumbnail(reader, resourceId, name, dataLength);
break;
case ResourceID.AlphaChannelNames:
resource = new AlphaChannelNames(reader, name, dataLength);
break;
case ResourceID.UnicodeAlphaNames:
resource = new UnicodeAlphaNames(reader, name, dataLength);
break;
case ResourceID.VersionInfo:
resource = new VersionInfo(reader, name);
break;
default:
resource = new RawImageResource(reader, signature, resourceId, name, dataLength);
break;
}
Util.DebugMessage(reader.BaseStream,
$"Load, End, ImageResource, {resourceId}");
// Reposition the reader if we do not consume the full resource block.
// This takes care of the even-padding, and also preserves forward-
// compatibility in case a resource block is later extended with
// additional properties.
if (reader.BaseStream.Position < endPosition)
{
reader.BaseStream.Position = endPosition;
}
// However, overruns are definitely an error.
if (reader.BaseStream.Position > endPosition)
{
throw new PsdInvalidException("Corruption detected in resource.");
}
return(resource);
}
