LibreCAD › LibreCAD-dev

dwg format

_‹ Previous Topic Next Topic _›

Classic

List

Threaded

5 messages Options

zohir

dwg format

no new information about dwg format in librecad

R. van Twisk

Re: dwg format

Administrator

Zohir,

As you know, DWG is a proprietary format with a closed specification, it's hard to hack around in that format.

The Open Design alliance is just a name, nothing is open there and even if we get a license we

are not allowed to distribute any of the libraries and code as they are not compatible with GPL.

Additionally, we currently feel that libdwg isn't stable enough to read in all modern AutoCAD formats reliably

without crashing LibreCAD. May be later?

Ries

On Feb 25, 2013, at 10:17 AM, "zohir [via LibreCAD]" <[hidden email]> wrote:

no new information about dwg format in librecad

If you reply to this email, your message will be added to the discussion below:
http://forum.librecad.org/dwg-format-tp5707647.html

To start a new topic under LibreCAD, email [hidden email]
To unsubscribe from LibreCAD, click here.
NAML

Rallaz

Re: dwg format

In reply to this post by zohir

is quite possible that in version 2.1 LibreCAD can read versions 13, 14 and 2000 without crashing, but this is a big work and we are very few developers

R. van Twisk

Re: dwg format

Administrator

Rallas,

I think we could read up to version 2004 with LibDWG.

However, the last time I played with LibDWG the state of A-CAD version detection in LibDWG

was in such a bad shape that it would let LibreCAD crash.

Anything below I could read successfully, but frankly, why would we want to support DWG

while we can only read up to a format created 7 years ago?

On Feb 25, 2013, at 11:13 AM, "Rallaz [via LibreCAD]" <[hidden email]> wrote:

is quite possible that in version 2.1 LibreCAD can read versions 13, 14 and 2000 without crashing, but this is a big work and we are very few developers

If you reply to this email, your message will be added to the discussion below:
http://forum.librecad.org/dwg-format-tp5707647p5707649.html

To start a new topic under LibreCAD, email [hidden email]
To unsubscribe from LibreCAD, click here.
NAML

Rallaz

Re: dwg format

Hi Ries,

I think we should start with the easy and gradually then first 13, 14 & 2000 but keeping in mind to expand it with more modern versions. When the first versions work will be easily add more versions.

About libDWG (or libreDWG) I think not be as useful.

1. large memory consumption: First load the entire file in memory, parses it in memory and then passed the entities to the program (three times in memory)

2. Many crashes and no solution in the short / medium term, 2 year old example: http://savannah.gnu.org/bugs/?32264

3. license issues

4. code very difficult to maintain (and understand). In my opinion macros are abused.

A better solution is port jdwglib (supports from 13 to 2004) to c++, this GPLv2 library are used in gvsig.org and work without crashes. I have begun to experiment with it but I know java so I have begun adding support reading DWG in libdxfrw.
I have now stopped but can read linetypes, layers, points, lines, circles, arcs and ellipses since v2000 without crashes or excessive use of macros

Cheers,
Rallaz