filter provider becomes single instance and no longer has constructor parameters.
tokenizers use list and stringbuilder pools to reduce allocations.
system font finder becomes static to preserve file cache across all documents.
since jpegs can be trivially embedded in pdf documents without changes to the data stream this is the first image format we will support. currently this is a naive approach which doesn't share an image resources between pages. ideally we will either de-duplicated images when added, return a re-usable key once an image is added, or both.
if the font descriptor uses the fromsubtype flag the actual type of the font can differ from that specified in the font dictionary. in this case a truetype font actually contains a type1c, compact font format, font. in this case we fall back to using the type1 parser.
also handles a closesubpath command appearing without any path construction operators.
the 3 font types mentioned are moved to the new fonts project, any referenced types are moved to the core project. most truetype classes are made public #8.
this starts to add logic for per-character mapping of unicode characters to byte values for truetype fonts in the pdf document builder. in order to support unicode characters outside the 0-255 range when creating new pdf documents without using composite fonts, we need to map values outside these range into this range. to do this we start at 1 and map each character we encounter to the next code, up to a maximum of 255. we provide a custom tounicode cmap in the font dictionary which maps these byte values, 0-255, back to unicode code points (short).
we also provide a custom firstchar, lastchar and widths array for the font mapping just the values we use.
since fonts no longer contain just the latin character set the font descriptor enum is set to have the symbolic flag set. this means values will be looked up in either the mac-roman (1, 0) or windows-symbol (3, 0) cmap tables (these cmap tables are distinct from cmap tables in the pdf file) inside the actual truetype font bytes. this means the currently generated font file is invalid, because while the widths array and tounicode cmap return the correct values the actual font itself returns whatever values where in those positions before the remapping occurred.
in order to fix this we will need to override the windows-symbol cmap contained in the underlying truetype font to match our mapping. this will be a lot of work and involve significant rewriting of the font file itself, in order to preserve checksum integrity.
support both xobject and inline images. adds unsupported filters so that exceptions are only thrown when accessing lazily evaluated image.bytes property rather than when opening the page.
treat all warnings as errors.
an inline image in a pdf content stream starts with the bi tag, then id declares the start of image data and ei the end. attempting to parse the bytes after the id tag as usual resulted in errors. this change adds special case handling for inline images.
- begin adding support for extended graphics state (the 'gs' operator) including setting the font #39.
- apply page level rotation to the glyph bounding box and width to get correct glyph sizes #41.
- wrap page rotation in a value type to ensure the value is restricted to right angle rotations and provide convenience members #42.
- fix bug where system font finder never worked for truetype fonts because it began reading the file from the wrong offset.
