ObjectArx : where to start from ?

I am completely new to AutoCad and I was asked by my boss to explore
ObjectArx + C++ programming (he gave me a 15 days deadline) to see if
that was a viable way to draw some 2D graphics on the AutoCad window,
out of data stored in Excel format, possibly CSV. (Sorry if I didn't
use the proper terms, but I'm a AC newbie)

Of course I'm not new to C++, writing the math engine to process data
is not a problem. On the contrary I don't know how to draw graphics
primitive on a AutoCad window, so I began browsing some of the example
and help files shipped with AutoDesk MAp 3D (ObjectArxLabs.chm,
arxdev.chm and arxdoc.chm), coding the provided examples, but I soon
got lost.

I mean there's too much, too many details, while I just need to get an
overview of what ObjectArx is, and can do.

I don't need at all to master the AutoCad thing, I can't, I haven't
the time, and that's completely different from my programming
experience and attitude.

The final customer just asked to have these 2D graphics drawn on a
given window; what s/he will do then with that, it's not my own
business.

So can someone please help me and tell me where to look in the help
and examples files, to be on a fast(er) track, or where on the
InterNet can I find a FREE ObjectArx tutorial/primer which doesn't
require to master the whole AutoCad + ObjectArx thing, before being
able to understand how to do some basics ObjectArx programming ?

Thanks,

David

PS: I know that you can do some programming in AutoCad via VBA macros,
but that option has already been considered and rejected.

 

15 days, eh? To get a handle on two knowledge domains? A bit of a tight
timeline, isn't it?

Here are a couple of resources to check out:

Autodesk ObjectARX discussion forum:
news://discussion.autodesk.com/autodesk.autocad.objectarx

Autodesk Developer Center, ObjectARX SDK download:
http://usa.autodesk.com/adsk/servlet/item?siteID=123112&id=785550

If you don't have time to learn AutoCAD, and it's different from your
programming experience and attitude, then Object ARX programming
is NOT the route you need to take. You really need to know AutoCAD
before you go hacking into the guts of AutoCAD with ObjectARX.
Most ObjectARX developers worked with AutoCAD for years
before ever writing a single line of ObjectARX C++ code.

Out of curiosity, why was it rejected? It seems to me that using the VBA
approach
to read XLS or CSV data to create 2D graphics would be about the fastest,
easiest approach to the problem. But regardless of whether you choose VBA
macros,
or AutoLisp routines, or ObjectARX modules, you have to know how AutoCAD
works.

Just my $0.02...


-Rick

 

Hi David,

Some basic steps:

1. The drawing is represented by the AcDbDatabase class (there's a
acdbCurDwg macro to get the active database)
2. There's a lot of tables in there, you're interested in the
AcDbBlockTable
3. Find the modelspace record (use the ACDB_MODEL_SPACE macro)
4. Open it for write as an AcDbBlockTableRecord
5. Add any lines (AcDbLine), arcs (AcDbArc) or circles (AcDbCircle) to
the modelspace
6. close all opened objects

I'm getting close to releasing my own CAD software, due in January.
Using that would be easier for you:

1. Derive a command object from CommandStd
2. Create any Line, Arc or Circle and add it using the Add
memberfunction

Good luck,

Henrik Vallgren

www.stream-space.com
www.thecadproject.com