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, {0}", ID);
}
///////////////////////////////////////////////////////////////////////////
private void LoadLayerAndMaskInfo(PsdBinaryReader reader)
{
Util.DebugMessage(reader.BaseStream, "Load, Begin, Layer and mask info");
var layersAndMaskLength = IsLargeDocument
? reader.ReadInt64()
: reader.ReadUInt32();
if (layersAndMaskLength <= 0)
{
return;
}
var startPosition = reader.BaseStream.Position;
var endPosition = startPosition + layersAndMaskLength;
LoadLayers(reader, true);
LoadGlobalLayerMask(reader);
//-----------------------------------------------------------------------
// Load Additional Layer Information
while (reader.BaseStream.Position < endPosition)
{
var info = LayerInfoFactory.Load(reader,
psdFile: this,
globalLayerInfo: true);
AdditionalInfo.Add(info);
if (info is RawLayerInfo)
{
var layerInfo = (RawLayerInfo)info;
switch (info.Key)
{
case "LMsk":
_globalLayerMaskData = layerInfo.Data;
break;
}
}
}
Util.DebugMessage(reader.BaseStream, "Load, End, Layer and mask info");
//-----------------------------------------------------------------------
// make sure we are not on a wrong offset, so set the stream position
// manually
reader.BaseStream.Position = startPosition + layersAndMaskLength;
}
///////////////////////////////////////////////////////////////////////////
/// <summary>
/// Load Layers Info section, including image data.
/// </summary>
/// <param name="reader">PSD reader.</param>
/// <param name="hasHeader">Whether the Layers Info section has a length header.</param>
internal void LoadLayers(PsdBinaryReader reader, bool hasHeader)
{
Util.DebugMessage(reader.BaseStream, "Load, Begin, Layers Info section");
long sectionLength = 0;
if (hasHeader)
{
sectionLength = IsLargeDocument
? reader.ReadInt64()
: reader.ReadUInt32();
if (sectionLength <= 0)
{
// The callback may take action when there are 0 layers, so it must
// be called even though the Layers Info section is empty.
LoadContext.OnLoadLayersHeader(this);
Util.DebugMessage(reader.BaseStream, "Load, End, Layers Info section");
return;
}
}
var startPosition = reader.BaseStream.Position;
var numLayers = reader.ReadInt16();
// If numLayers < 0, then number of layers is absolute value,
// and the first alpha channel contains the transparency data for
// the merged result.
if (numLayers < 0)
{
AbsoluteAlpha = true;
numLayers = Math.Abs(numLayers);
}
for (int i = 0; i < numLayers; i++)
{
var layer = new Layer(reader, this);
Layers.Add(layer);
}
// Header is complete just before loading pixel data
LoadContext.OnLoadLayersHeader(this);
//-----------------------------------------------------------------------
// Load image data for all channels.
foreach (var layer in Layers)
{
Util.DebugMessage(reader.BaseStream,
$"Load, Begin, Layer image, {layer.Name}");
foreach (var channel in layer.Channels)
{
channel.LoadPixelData(reader);
}
Util.DebugMessage(reader.BaseStream,
$"Load, End, Layer image, {layer.Name}");
}
// Length is set to 0 when called on higher bitdepth layers.
if (sectionLength > 0)
{
// Layers Info section is documented to be even-padded, but Photoshop
// actually pads to 4 bytes.
var endPosition = startPosition + sectionLength;
var positionOffset = reader.BaseStream.Position - endPosition;
Debug.Assert(positionOffset > -4,
"LoadLayers did not read the full length of the Layers Info section.");
Debug.Assert(positionOffset <= 0,
"LoadLayers read past the end of the Layers Info section.");
if (reader.BaseStream.Position < endPosition)
{
reader.BaseStream.Position = endPosition;
}
}
Util.DebugMessage(reader.BaseStream, "Load, End, Layers");
}
/// <summary>
/// Loads the next LayerInfo record.
/// </summary>
/// <param name="reader">The file reader</param>
/// <param name="psdFile">The PSD file.</param>
/// <param name="globalLayerInfo">True if the LayerInfo record is being
/// loaded from the end of the Layer and Mask Information section;
/// false if it is being loaded from the end of a Layer record.</param>
public static LayerInfo Load(PsdBinaryReader reader, PsdFile psdFile,
Boolean globalLayerInfo)
{
Util.DebugMessage(reader.BaseStream, "Load, Begin, LayerInfo");
// Some keys use a signature of 8B64, but the identity of these keys
// is undocumented. We will therefore accept either signature.
var signature = reader.ReadAsciiChars(4);
if ((signature != "8BIM") && (signature != "8B64"))
{
throw new PsdInvalidException(
$"{nameof(LayerInfo)} signature invalid, must be 8BIM or 8B64.");
}
var key = reader.ReadAsciiChars(4);
var hasLongLength = LayerInfoUtil.HasLongLength(key, psdFile.IsLargeDocument);
var length = hasLongLength
? reader.ReadInt64()
: reader.ReadInt32();
var startPosition = reader.BaseStream.Position;
LayerInfo result;
switch (key)
{
case "Layr":
case "Lr16":
case "Lr32":
result = new InfoLayers(reader, psdFile, key, length);
break;
case "lsct":
case "lsdk":
result = new LayerSectionInfo(reader, key, (Int32)length);
break;
case "luni":
result = new LayerUnicodeName(reader);
break;
default:
result = new RawLayerInfo(reader, signature, key, length);
break;
}
// May have additional padding applied.
var endPosition = startPosition + length;
if (reader.BaseStream.Position < endPosition)
{
reader.BaseStream.Position = endPosition;
}
// Documentation states that the length is even-padded. Actually:
// 1. Most keys have 4-padded lengths.
// 2. However, some keys (LMsk) have even-padded lengths.
// 3. Other keys (Txt2, Lr16, Lr32) have unpadded lengths.
//
// Photoshop writes data that is always 4-padded, even when the stated
// length is not a multiple of 4. The length mismatch seems to occur
// only on global layer info. We do not read extra padding in other
// cases because third-party programs are likely to follow the spec.
if (globalLayerInfo)
{
reader.ReadPadding(startPosition, 4);
}
Util.DebugMessage(reader.BaseStream, "Load, End, LayerInfo, {0}, {1}",
result.Signature, result.Key);
return(result);
}