private void refillInflater(Inflater inflater)
{
while (chunkRemaining == 0)
{
closeChunk();
openChunk(IDAT);
}
int read = readChunk(buffer, 0, buffer.Length);
inflater.SetInput(buffer, 0, read);
}
private void readChunkUnzip(Inflater inflater, byte[] buffer, int offset, int length)
{
try
{
do
{
int read = inflater.Inflate(buffer, offset, length);
if (read <= 0)
{
if (inflater.Finished())
{
throw new EOFException();
}
if (inflater.NeedsInput())
{
refillInflater(inflater);
}
else
{
throw new IOException("Can't inflate " + length + " bytes");
}
}
else
{
offset += read;
length -= read;
}
} while (length > 0);
}
catch (DataFormatException ex)
{
throw (IOException)(new IOException("inflate error").InitCause(ex));
}
}
public void decode(ByteBuffer buffer, int stride, Format fmt)
{
int offset = buffer.Position();
int lineSize = ((width * bitdepth + 7) / 8) * bytesPerPixel;
byte[] curLine = new byte[lineSize + 1];
byte[] prevLine = new byte[lineSize + 1];
byte[] palLine = (bitdepth < 8) ? new byte[width + 1] : null;
Inflater inflater = new Inflater();
try
{
for (int y = 0; y < height; y++)
{
readChunkUnzip(inflater, curLine, 0, curLine.Length);
unfilter(curLine, prevLine);
buffer.Position(offset + y * stride);
switch (colorType)
{
case COLOR_TRUECOLOR:
switch (fmt)
{
case Format.ABGR:
copyRGBtoABGR(buffer, curLine);
break;
case Format.RGBA:
copyRGBtoRGBA(buffer, curLine);
break;
case Format.BGRA:
copyRGBtoBGRA(buffer, curLine);
break;
case Format.RGB:
copy(buffer, curLine);
break;
default:
throw new UnsupportedOperationException("Unsupported format for this image");
}
break;
case COLOR_TRUEALPHA:
switch (fmt)
{
case Format.ABGR:
copyRGBAtoABGR(buffer, curLine);
break;
case Format.RGBA:
copy(buffer, curLine);
break;
case Format.BGRA:
copyRGBAtoBGRA(buffer, curLine);
break;
case Format.RGB:
copyRGBAtoRGB(buffer, curLine);
break;
default:
throw new UnsupportedOperationException("Unsupported format for this image");
}
break;
case COLOR_GREYSCALE:
switch (fmt)
{
case Format.LUMINANCE:
case Format.ALPHA:
copy(buffer, curLine);
break;
default:
throw new UnsupportedOperationException("Unsupported format for this image");
}
break;
case COLOR_GREYALPHA:
switch (fmt)
{
case Format.LUMINANCE_ALPHA:
copy(buffer, curLine);
break;
default:
throw new UnsupportedOperationException("Unsupported format for this image");
}
break;
case COLOR_INDEXED:
switch (bitdepth)
{
case 8:
palLine = curLine;
break;
case 4:
expand4(curLine, palLine);
break;
case 2:
expand2(curLine, palLine);
break;
case 1:
expand1(curLine, palLine);
break;
default:
throw new UnsupportedOperationException("Unsupported bitdepth for this image");
}
switch (fmt)
{
case Format.ABGR:
copyPALtoABGR(buffer, palLine);
break;
case Format.RGBA:
copyPALtoRGBA(buffer, palLine);
break;
case Format.BGRA:
copyPALtoBGRA(buffer, palLine);
break;
default:
throw new UnsupportedOperationException("Unsupported format for this image");
}
break;
default:
throw new UnsupportedOperationException("Not yet implemented");
}
byte[] tmp = curLine;
curLine = prevLine;
prevLine = tmp;
}
}
finally
{
inflater.End();
}
}