public ShpD2Frame(Stream s)
{
var flags = (FormatFlags)s.ReadUInt16();
s.Position += 1;
var width = s.ReadUInt16();
var height = s.ReadUInt8();
Size = new Size(width, height);
// Subtract header size
var dataLeft = s.ReadUInt16() - 10;
var dataSize = s.ReadUInt16();
byte[] table;
if ((flags & FormatFlags.PaletteTable) != 0)
{
var n = (flags & FormatFlags.VariableLengthTable) != 0 ? s.ReadUInt8() : (byte)16;
table = new byte[n];
for (var i = 0; i < n; i++)
{
table[i] = s.ReadUInt8();
}
dataLeft -= n;
}
else
{
table = new byte[256];
for (var i = 0; i < 256; i++)
{
table[i] = (byte)i;
}
table[1] = 0x7f;
table[2] = 0x7e;
table[3] = 0x7d;
table[4] = 0x7c;
}
Data = new byte[width * height];
// Decode image data
var compressed = s.ReadBytes(dataLeft);
if ((flags & FormatFlags.NotLCWCompressed) == 0)
{
var temp = new byte[dataSize];
LCWCompression.DecodeInto(compressed, temp);
compressed = temp;
}
RLEZerosCompression.DecodeInto(compressed, Data, 0);
// Lookup values in lookup table
for (var j = 0; j < Data.Length; j++)
{
Data[j] = table[Data[j]];
}
}
public ShpTSFrame(Stream s, Size frameSize)
{
var x = s.ReadUInt16();
var y = s.ReadUInt16();
var width = s.ReadUInt16();
var height = s.ReadUInt16();
// Pad the dimensions to an even number to avoid issues with half-integer offsets
var dataWidth = width;
var dataHeight = height;
if (dataWidth % 2 == 1)
{
dataWidth += 1;
}
if (dataHeight % 2 == 1)
{
dataHeight += 1;
}
Offset = new int2(x + (dataWidth - frameSize.Width) / 2, y + (dataHeight - frameSize.Height) / 2);
Size = new Size(dataWidth, dataHeight);
FrameSize = frameSize;
Format = s.ReadUInt8();
s.Position += 11;
FileOffset = s.ReadUInt32();
if (FileOffset == 0)
{
return;
}
// Parse the frame data as we go (but remember to jump back to the header before returning!)
var start = s.Position;
s.Position = FileOffset;
Data = new byte[dataWidth * dataHeight];
if (Format == 3)
{
// Format 3 provides RLE-zero compressed scanlines
for (var j = 0; j < height; j++)
{
var length = s.ReadUInt16() - 2;
RLEZerosCompression.DecodeInto(s.ReadBytes(length), Data, dataWidth * j);
}
}
else
{
// Format 2 provides uncompressed length-prefixed scanlines
// Formats 1 and 0 provide an uncompressed full-width row
var length = Format == 2 ? s.ReadUInt16() - 2 : width;
for (var j = 0; j < height; j++)
{
s.ReadBytes(Data, dataWidth * j, length);
}
}
s.Position = start;
}
