internal Channel(PsdBinaryReader reader, Layer layer)
{
Util.DebugMessage(reader.BaseStream, "Load, Begin, Channel");
ID = reader.ReadInt16();
Length = (layer.PsdFile.IsLargeDocument)
? reader.ReadInt64()
: reader.ReadInt32();
Layer = layer;
Util.DebugMessage(reader.BaseStream, $"Load, End, Channel, {ID}");
}
//////////////////////////////////////////////////////////////////
internal void LoadPixelData(PsdBinaryReader reader)
{
Util.DebugMessage(reader.BaseStream, "Load, Begin, Channel image");
if (Length == 0)
{
ImageCompression = ImageCompression.Raw;
ImageDataRaw = new byte[0];
return;
}
var endPosition = reader.BaseStream.Position + this.Length;
ImageCompression = (ImageCompression)reader.ReadInt16();
var longDataLength = this.Length - 2;
Util.CheckByteArrayLength(longDataLength);
var dataLength = (int)longDataLength;
switch (ImageCompression)
{
case ImageCompression.Raw:
ImageDataRaw = reader.ReadBytes(dataLength);
break;
case ImageCompression.Rle:
// RLE row lengths
RleRowLengths = new RleRowLengths(reader, Rect.Height,
Layer.PsdFile.IsLargeDocument);
var rleDataLength = (int)(endPosition - reader.BaseStream.Position);
Debug.Assert(rleDataLength == RleRowLengths.Total,
"RLE row lengths do not sum to length of channel image data.");
// The PSD specification states that rows are padded to even sizes.
// However, Photoshop doesn't actually do this. RLE rows can have
// odd lengths in the header, and there is no padding between rows.
ImageDataRaw = reader.ReadBytes(rleDataLength);
break;
case ImageCompression.Zip:
case ImageCompression.ZipPrediction:
ImageDataRaw = reader.ReadBytes(dataLength);
break;
}
Util.DebugMessage(reader.BaseStream, $"Load, End, Channel image, {ID}");
Debug.Assert(reader.BaseStream.Position == endPosition,
"Pixel data was not fully read in.");
}