Posted by dxli on Jan 24, 2014; 5:29pm
URL: https://forum.librecad.org/I-want-to-help-tp5709375p5709404.html

Hi Steve,

the bug is clearly there. Please apply the attached patch to clearly show the trouble:
v.patch

( you may apply the patch in the librecad source folder: patch -p1 < /path/to/v.patch )

After that, you can build and follow steps I added to the bug tracker to reproduce the bug. Debugging information is written to console/terminal.

Before file saving, polyline is draw with following info:
start
0
1
( 5  ,  5 )   r=  5
2
3
end
it says the second entity is an arc centered at (5,5) with radius 5.

After saving and reopening, the output changed to:

start
0
1
( 52.5  ,  52.5 )   r=  70.799
2
3
end

I think the trouble is due to polyline information, polyline has entities connected by startpoing/endpoint. In our example, the arc created by rounding doesn't follow this order.

Please have a look at methods: void RS_FilterDXFRW::addPolyline(const DRW_Polyline& data) ;

Clearly, we need to investigate how polyline data is saved/read, and used.

Steve Griffin wrote

I have browsed the bug tracker and I think I understand how the commits are numbered and how they are associated with a branch. A branch is a milestone identification. I saw where the last opened item gets placed on the top of the list of bugs. The latest bug has not received any responses yet. The next bug in the list has several responses and is fixed. I also understand that any new bug reports will be placed in milestone 2.1 where there are five bugs presently reported. I will now try to get an understanding of the files that are used to build LibreCad in Qt. I know to start with the main function file and go from there. Is there any way to get a short outline of the main function file? I want to see if I can at least find where the code is located that concerns the bug 449 milestone 2.0. I am very good with algorithms and math. I was a draftsman for 20 years. I coded using vba for AutoCad for most of that time as well as autolisp. I still have a lot of reading to do in the wiki but I believe I'll be able to help soon. Thanks, Steve.