the additional stored fields made the struct slower to copy and had an impact on the performance. this moves non-essential fields back to computed properties.
since the rectangle constructor is a hot path any calculations slow the library down considerably. for this reason we move calculations for the following properties into the property getter:
* width (cached)
* height (cached)
* rotation
* area
* centroid
where values are cached they set their backing field once calculated. this won't be thread safe if the same rectangle is accessed on multiple threads.
now that rectangle constructor uses the order [ llx, lly, urx, ury ] and does not apply correction for points constructor parameters must be passed in the correct order. this change fixes the hyperlink factory which was passing them in the wrong order.
in addition the pdfpath bounding box was using left, right, top and bottom to calculate the minimum bounding box. this produced incorrect values now individual path operator bounding boxes are rotated, since for a rotated rectangle top may be less than bottom.
the performance seems to have taken a hit due to these changes however.
if we are reading a cross reference offset which contains a number we assumed it was a stream object. if it's not we now brute-force the entire file looking for an 'xref' token. this should be combined with a search for cross-reference streams and should run when we read neither the numeric token or an 'xref' token but for now this fixes the observed issue.
also adds number of images to the page api to prevent consumers needing to enumerate.
in order to recreate the valid bytes for use in decryption it is necessary to know which encoding was used to read a string token. this is because utf16-be encoding has a byte-order marker which should be included in the resulting bytes.
our bounding rectangle values still seem to be wrong for rotated letters. this change adds some test cases for common transformation matrix operations on a rectangle, scale, translate and rotate.
by default nuget pack does not include project dependencies. this is suboptimal since it would require managing at least 5 nuget packages. this uses a workaround detailed here https://github.com/nuget/home/issues/3891 to copy the dependent dlls to the generated nuget package. this doesn't resolve the issue of how we publish the documentlayoutanalysis project, since it is the top of the dependency tree and we publish its parent, rather than it.
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.
to make the project more useful and expose more usable classes we're rearchitecting in the following way. code used to read fonts from external file formats like truetype, adobe font metrics (afm) and adobe type 1 fonts are moving to a new project which doesn't reference most of the pdf logic. the shared logic is moving to a new flat-structured project called core. this is a sort-of onion type architecture, with core being the... core, fonts being the next layer of the onion, pdfpig itself the next. this will then support additional libraries/projects as outer layers of the onion as well as releasing standalone version of the font library as pdfbox does with fontbox.
