User:Xuwei/DevLog2019

Coummunity Bonding Period

• Set up the Development log
• Set up the development environment such as OS.
• Start to look at the different potential libraries code base.
• Discuss with mentors which external library to choose.

May 16th

• Start to check the checklist.
  • Agreement sent.
  • Dev log created.
  • My Profile created.

May 17th

• Had four of my wisdom teeth extracted. The progress for the following week may be slow due to teeth extraction.

May 19th

• Looking at Coin3D/Dime code base, a possible library for DXF import/export.
  • It has no external dependency.
  • It supports all past and should support the future version of DXF format.
  • It compiles on Windows, Linux, MacOS, etc.
  • But it only loads DXF files into Dime object hierarchies and saves Dime object hierarchies as files conforming to DXF format.
  • Seems only support 3D.

May 20th

• Looking at BRL-CAD DXF import/export code. Trying to understand how it works and see if it is suitable for OpenSCAD.
  • It converts DXF format to .g and .g to DXF which is a BRL-CAD format.
  • It seems that BRL-CAD does not support the entire format, only the part that is relative to solid-model.

May 21st

• Looking at dxflib which is used by QCAD and works fine, but it only supports 2D which is not ideal since OpenSCAD is already supporting 2D.
  • Maybe we can add the 3D part. But not sure how hard it is to add that.

May 22nd

• Searching for a library that supports both 3D and 2D DXF import/export.
  • Libraries above are for either 2D or 3D.
  • Found some libraries support both but they are written in python instead of C++.

May 23rd

• Continue on searching for the potential library.

May 24th

• Looking at and Compile libdxfrw code base which is used by LibreCAD.
• Will be out of town for the next two days.

Coding Period

May 27th

• Looking at both libdxfrw(libdxfrw.h, dxfreader.cpp) and OpenSCAD(dxfdata.cc, import.cc) relative code.
  • Comparing the differences between these two on how they handle DXF data.
  • Trying to form a connection between these two.
  • dxfdata.cc seems a bit complicated. Need some time to digest.
  • The way that libdxfrw reads DXF file is kind of mixing with DRW code.
  • libdxfrw encounters problems when dealing with elevated arcs(no response yet). [1]
• Looking at dxflib code base as well.
  • dxflib does not store any entities, only pass supported entities.
  • A useful link for understanding dxflib data structure.[2]