Auto-generated C++ and Python APIs for mupdf.

Status

As of 2020-5-11:

C++

• We generate C++ wrapper functions for most fz_ and pdf_ functions. These wrapper convert fz_ exceptions into C++ exceptions, and use auto-generated per-thread fz_context's.
• We generate C++ class wrappers for most fz_ and pdf_ structs.
• We auto-detect fz_*() and pdf_*() fns suitable for wrapping as constructors, methods or static methods.
• Some generated classes have auto-generated support for iteration.
• We add various custom methods/constructors.
• Wrapper class constructors and methods provide access to 1270 fz_*() and pdf_*() fns, out of a total of 1513 wrapped fz_*() and pdf_*() functions. Most of the omitted functions don't take struct args, e.g. fz_strlcpy().
• The C++ API is built by mupdf:scripts/mupdfwrap.py. It requires clang-6 or clang-7, and python-clang.

Python

• Python API is generated by running SWIG on the C++ API's header files.
• Python API is enough to allow implementation of mutool in Python - see mupdf:scripts/mutool.py and mupdf:scripts/mutool_draw.py.
• Building the Python API requires swig-3 or swig-4.

General

• We work on nuc1 and peeved and jules-laptop.
• We require:
  • python-clang (version 6 or 7)
  • python3-dev (version 3.6 or later)
  • swig (version 3 or 4)

Comments

• We use clang to extract doxygen-style comments, and propagate them into generated header files.
• If swig is version 4+, we tell it to propagate comments into the generated mupdf.py.

Here are Doxygen html representations of the mupdf C API and the generated mupdf C++ API:

• https://ghostscript.com/~julian/mupdf/include/html/index.html
• https://ghostscript.com/~julian/mupdf/platform/c++/include/html/index.html

And pydoc html representation of the generated mupdf.py API:

• https://ghostscript.com/~julian/mupdf/build/shared-release/mupdf.html

mutool.py

mudpdf:scripts/mutool*.py are an incomplete Python re-implementation of the mutool application.

Files

Auto-generated C++ headers and implementation files, plus test outputs (.html files have syntax-colouring):

• https://ghostscript.com/~julian/mupdf/platform/c++/
• https://ghostscript.com/~julian/mupdf/platform/python

Information about fz_*() and pdf_*() fns that are not in the class-based API:

• https://ghostscript.com/~julian/mupdf/platform/c++/fn_usage.txt

These were generated by the mupdfwrap.py programme, which also runs g++ and SWIG to generate a Python module that gives a Python API:

• https://git.ghostscript.com/?p=user/julian/mupdf.git;a=blob;f=scripts/mupdfwrap.py;hb=HEAD

The generated Python module is tested by the (rather hacky) test_mupdfcpp_swig() function in mupdfwrap.py. For convenience, this function and its output can be viewed in https://ghostscript.com/~julian/mupdf/platform/python.

Integration with mupdf git.

    mupdf/
        build/
            shared-release/
                libmupdf.so [generated file]
                libmupdfcpp.so [generated file, implements C++ API]
                mupdf.py [generated file, implements Python API]
                _mupdf.so [generated file, implements Python API internals]
            shared-debug/
                libmupdf.so
                libmupdfcpp.so [implements C++ API]
                mupdf.py [implements Python API]
                _mupdf.so [implements Python API internals]
        platform/
            c++/
                implementation/
                    *.cpp [generated files]
                include/
                    mupdf/
                        *.h [generated files]
            python/
                mupdfcpp_swig.cpp [generated by SWIG]
                mupdf_swig.i [generated by mupdfwraw.pynput to SWIG]
        scripts/
            mupdfwrap.py
            jlib.py
            mutool.py
            mutool_draw.py

See:

• https://git.ghostscript.com/?p=user/julian/mupdf.git;a=summary

To build:

    cd mupdf/
    ./scripts/mupdfwrap.py -b all -t

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-- Julian Smith - 2020-03-04

Comments