[vtk-developers] Possible bug with vtkActor2D or with text actors.

[Prabhu Ramachandran]

hi,

After some painstaking debugging I think I found a bug in the
vtkActor2D/vtkTextActor.  I tested this with both a VTK 4.0 build
(built on 6th August) and an older vtk 3.2 build.  Here is a
description of the problem:

  (0) I have a collection of actors that I'd like to visualize.  Lets
  say for example a cone using a vtkActor and a vtkScalarBarActor.

  (1) I create a renderwindow and renderer and add these two actors to
  the renderer.  

  (2) I then do something with the rendered scene like say rotate the
  actors etc.  

  (3) Then I close this window, create a similar but new window and
  again repeat the process by going to step 1 by creating a new
  window.  Note that I use the same actors.

  (4) At this point the program crashes with a segfault.  I have
  tracked the problem to the vtkScalarBarActor.  The same thing also
  happens for the vtkCubeAxesActor.  I didnt compile the libraries
  with debugging symbols (yes, yes, very bad indeed!) but my backtrace
  gives me the following:

    Program received signal SIGSEGV, Segmentation fault.
    0x41b230c4 in __glXUseXFont () from /usr/lib/libGL.so.1
    (gdb) back
    #0  0x41b230c4 in __glXUseXFont () from /usr/lib/libGL.so.1
    #1  0x41b1f1db in glXUseXFont () from /usr/lib/libGL.so.1

I have a small Python example that demonstrates the problem with plain
VTK - i.e. no Tk/GTK/Wx stuff is necessary.  I have attached it with
this email.

I am also going to recompile VTK later so I will be able to get a
better backtrace but I thought someone might know why this happens and
if there is a fix.  Since the message is long I havent cross posted it
to vtkusers.

Any help will be most appreciated.

Thanks!

prabhu

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