internal static byte[] GetIndexedSMask(byte[] Img, int w, int h, byte[] tRNS, int BitsPerPixel)
{
int ScanLine = 1 + (w - 1) * BitsPerPixel / 8 + 1; //RowFilter+Bytes needed for a row.
byte[] RawImage = DecodeImage(Img, w, h, ScanLine);
byte[] SMask = BitsPerPixel == 8? RawImage: new byte[h * (w + 1)]; //no need for a new array if the image depth is 8.
int ScanPos = 0;
int SMaskPos = 1; //first byte is the row filter, already in 0.
byte MaxBit = (byte)(8 / BitsPerPixel);
byte[] Sh = new byte[8]; //Cached for speed.
byte[] Sr = new byte[8]; //Cached for speed.
for (int i = 0; i < BitsPerPixel; i++)
{
Sh[0] |= (byte)(1 << i);
}
for (int bit = 1; bit < MaxBit; bit++)
{
Sh[bit] = (byte)(Sh[bit - 1] << BitsPerPixel);
Sr[bit] = (byte)(Sr[bit - 1] + BitsPerPixel); //Sr[0]=0
}
for (int r = 0; r < h; r++)
{
int MaxSMaskPos = SMaskPos + w; //Some images might use only a part of the last byte.
for (int c = 1; c < ScanLine; c++)
{
byte b = RawImage[ScanPos + c];
for (int bit = MaxBit - 1; bit >= 0; bit--)
{
if (SMaskPos >= MaxSMaskPos)
{
break;
}
byte b0 = (byte)((b & Sh[bit]) >> Sr[bit]); byte x = b0 < tRNS.Length? (byte)tRNS[b0] : (byte)255;
SMask[SMaskPos] = x;
SMaskPos++;
}
}
ScanPos += ScanLine;
SMaskPos++; //Rowfilter
}
using (TCompressor Cmp = new TCompressor())
{
using (MemoryStream ms = new MemoryStream())
{
Cmp.Deflate(SMask, 0, ms);
return(ms.ToArray());
}
}
}
public static byte[] CompressData(byte[] Data)
{
using (TCompressor Cmp = new TCompressor())
{
using (MemoryStream ms = new MemoryStream())
{
Cmp.Deflate(Data, 0, ms);
return(ms.ToArray());
}
}
}
//Current implementation of TCompressor is not thread safe.
//private static TCompressor Cmp=null; //Wont be created until needed. //STATIC*
//[MethodImpl(MethodImplOptions.NoInlining)] //We don't want to check for ZLib until we are here.
internal static void ToXls(Byte[] ImgData, Stream OutStream, bool IsEMF)
{
#if (FRAMEWORK30 || !COMPACTFRAMEWORK)
int HeadOfs = 0;
if (!IsEMF && ImgData.Length > 4 && BitConverter.ToUInt32(ImgData, 0) == 0x9AC6CDD7)
{
HeadOfs += 22; //A wmf file might have a placeable header or not. If it does, it begins with the magic number 9AC6CDD7 and it must be stripped.
}
using (TCompressor Cmp = new TCompressor())
{
Cmp.Deflate(ImgData, HeadOfs, OutStream);
}
#else
throw new FlexCelException("Operation not supported in CF 2.0");
#endif
}