Re: [matplotlib-devel] Re: Embedding TrueType fonts in PDF

[John H. <jdh...@ac...>]

>>>>> "Jouni" == Jouni K Seppanen <jk...@ik...> writes:

    Jouni> John Hunter <jdh...@ac...> writes:
    >> You shouldn't need to with the ft2font extension code, because
    >> it uses pycxx which has support for kwarg handling.  Eg in the
    >> _image.cpp src
    >> 
    >> Py::Object resize(const Py::Tuple& args, const Py::Dict&
    >> kwargs);
    Jouni>  [...]
    >> args.verify_length(2);
    >> 
    >> int norm = 1; if ( kwargs.hasKey("norm") ) norm = Py::Int(
    >> kwargs["norm"] );

    Jouni> This seems to mean that the function cannot be called using
    Jouni> the normal Python convention:

    >>>> img.resize(10,10,1)
    Jouni>   Traceback (most recent call last): File "<stdin>", line
    Jouni> 1, in ?  IndexError: Unexpected SeqBase<T> length.

The reason it raises is because I told it too :-)

  args.verify_length(2);

if you want normal python symantics, you could to something something
like (untested, freestyle code)

  int norm(0);
  if (args.length()==3)
      norm = Py::Int( args[2] );
  elif ( kwargs.hasKey("norm") ) 
    norm = Py::Int( kwargs["norm"] );

    Jouni> Instead you have to do img.resize(10,10,norm=1). This is
    Jouni> handled transparently by PyArg_ParseTupleAndKeywords: if
    Jouni> you set the format string to "ii|ii" and list the names of
    Jouni> all parameters as keywords, you automatically get the
    Jouni> normal Python convention where the last two args are
    Jouni> optional and all args are specifiable with their names.

    Jouni> But I guess this is not so important in extension code that
    Jouni> only gets called by matplotlib internals and not end users,
    Jouni> so I changed load_char to use the pycxx convention.

I do think it is useful in the pycxx extension code to stick where
possible to the cxx idioms -- for the most part the code is cleaner to
reads and helps with reference counting, etc....  You can check the
docs at 

  http://cxx.sourceforge.net/PyCXX.html

there may be a cleaner way to handle kwargs than what I suggested.

JDH