internal virtual void ReadSegment(Jbig2SegmentReader.Jbig2Segment s)
{
int ptr = (int)ra.GetPosition();
if (s.dataLength == unchecked ((long)(0xffffffffl)))
{
// TODO figure this bit out, 7.2.7
return;
}
byte[] data = new byte[(int)s.dataLength];
ra.Read(data);
s.data = data;
if (s.type == PAGE_INFORMATION)
{
int last = (int)ra.GetPosition();
ra.Seek(ptr);
int page_bitmap_width = ra.ReadInt();
int page_bitmap_height = ra.ReadInt();
ra.Seek(last);
Jbig2SegmentReader.Jbig2Page p = pages.Get(s.page);
if (p == null)
{
throw new iText.IO.IOException("Referring to widht or height of a page we haven't seen yet: {0}").SetMessageParams
(s.page);
}
p.pageBitmapWidth = page_bitmap_width;
p.pageBitmapHeight = page_bitmap_height;
}
}
/// <exception cref="System.IO.IOException"/>
internal virtual Jbig2SegmentReader.Jbig2Segment ReadHeader()
{
int ptr = (int)ra.GetPosition();
// 7.2.1
int segment_number = ra.ReadInt();
Jbig2SegmentReader.Jbig2Segment s = new Jbig2SegmentReader.Jbig2Segment(segment_number);
// 7.2.3
int segment_header_flags = ra.Read();
bool deferred_non_retain = (segment_header_flags & 0x80) == 0x80;
s.deferredNonRetain = deferred_non_retain;
bool page_association_size = (segment_header_flags & 0x40) == 0x40;
int segment_type = segment_header_flags & 0x3f;
s.type = segment_type;
//7.2.4
int referred_to_byte0 = ra.Read();
int count_of_referred_to_segments = (referred_to_byte0 & 0xE0) >> 5;
int[] referred_to_segment_numbers = null;
bool[] segment_retention_flags = null;
if (count_of_referred_to_segments == 7)
{
// at least five bytes
ra.Seek(ra.GetPosition() - 1);
count_of_referred_to_segments = ra.ReadInt() & 0x1fffffff;
segment_retention_flags = new bool[count_of_referred_to_segments + 1];
int i = 0;
int referred_to_current_byte = 0;
do
{
int j = i % 8;
if (j == 0)
{
referred_to_current_byte = ra.Read();
}
segment_retention_flags[i] = (0x1 << j & referred_to_current_byte) >> j == 0x1;
i++;
}while (i <= count_of_referred_to_segments);
}
else
{
if (count_of_referred_to_segments <= 4)
{
// only one byte
segment_retention_flags = new bool[count_of_referred_to_segments + 1];
referred_to_byte0 &= 0x1f;
for (int i = 0; i <= count_of_referred_to_segments; i++)
{
segment_retention_flags[i] = (0x1 << i & referred_to_byte0) >> i == 0x1;
}
}
else
{
if (count_of_referred_to_segments == 5 || count_of_referred_to_segments == 6)
{
throw new iText.IO.IOException("count.of.referred.to.segments.had.bad.value.in.header.for.segment.1.starting.at.2"
).SetMessageParams(segment_number, ptr);
}
}
}
s.segmentRetentionFlags = segment_retention_flags;
s.countOfReferredToSegments = count_of_referred_to_segments;
// 7.2.5
referred_to_segment_numbers = new int[count_of_referred_to_segments + 1];
for (int i_1 = 1; i_1 <= count_of_referred_to_segments; i_1++)
{
if (segment_number <= 256)
{
referred_to_segment_numbers[i_1] = ra.Read();
}
else
{
if (segment_number <= 65536)
{
referred_to_segment_numbers[i_1] = ra.ReadUnsignedShort();
}
else
{
referred_to_segment_numbers[i_1] = (int)ra.ReadUnsignedInt();
}
}
}
// TODO wtf ack
s.referredToSegmentNumbers = referred_to_segment_numbers;
// 7.2.6
int segment_page_association;
int page_association_offset = (int)ra.GetPosition() - ptr;
if (page_association_size)
{
segment_page_association = ra.ReadInt();
}
else
{
segment_page_association = ra.Read();
}
if (segment_page_association < 0)
{
throw new iText.IO.IOException("page.1.invalid.for.segment.2.starting.at.3").SetMessageParams(segment_page_association
, segment_number, ptr);
}
s.page = segment_page_association;
// so we can change the page association at embedding time.
s.page_association_size = page_association_size;
s.page_association_offset = page_association_offset;
if (segment_page_association > 0 && !pages.ContainsKey(segment_page_association))
{
pages[segment_page_association] = new Jbig2SegmentReader.Jbig2Page(segment_page_association, this);
}
if (segment_page_association > 0)
{
pages.Get(segment_page_association).AddSegment(s);
}
else
{
globals.Add(s);
}
// 7.2.7
long segment_data_length = ra.ReadUnsignedInt();
// TODO the 0xffffffff value that might be here, and how to understand those afflicted segments
s.dataLength = segment_data_length;
int end_ptr = (int)ra.GetPosition();
ra.Seek(ptr);
byte[] header_data = new byte[end_ptr - ptr];
ra.Read(header_data);
s.headerData = header_data;
return(s);
}
