How to know real text width, reading from a dxf file ?

I am developing software that reads from dxf files and processes the
results. I need to know the real height and width of text elements.

With height there is no problem since I can retrieve it. It appears
with code 40 in the dxf file.

The problem is width. I find no means to know the real text width. I
can read from the dxf file the "width / height ratio" ( code 41 ) ,
multiply this ratio by the the height and the number of characters, but
I have been disappointed to see that this is not exact. I have seen for
instance text elements with a "width / height ratio" of 1 with digits
which have a height much greater than width. I usually handle text
elements which display numbers, and their digits are usually drawn
taller than wider, even if they show a width/height ratio of 1 or
similar.

Any help would be appreciated, since I need to know what area these
elements cover.

Thanks

 

Hi Jose,
you can measure the length of any string using dxf codes 10 and 11
Good Luck.

 

Thanks for your post.

10 is reliable as the origin X coordinate.
11 should be the end X coordinate but is not reliable, sometimes it is
set to 0, even if obviously this not the case.

 

Hi Jose,
Code 72 must be non zero. Maybe you can play with that. Also check out
the 'textbox' function in lisp.Good luck with that, you'll have to
write a subroutine which does this. If you are still having a hard
time, I can send you an example routine which inserts a block with
attributes, and than draws a 3d face above each attribute (whatever the
length), to "wipe-out" whatever is under the text. You can e-mail me
directly, if you like. Bojar

 

Hi Jose,

Ok this helps, If I see 72 is non zero I can trust the 11 code, and
this is the case in most drawings, but the problem persists in those
cases in which code 72 is 0

I can't decide if 72 is informed or no, since I only process dxf files,
I can't decide what is in those files.

For the same reason I don't think lisp helps me. What I want to do is
to be able to process a dxf file, and get the information (such as real
text dimensions on the drawing) from this file, the user may not even
have autocad ( And I think autocad is necessary for executing your lisp
routine )

Thank you very much for your help