[Mesa-dev] VTK Offscreen Segfaults

Kevin H. Hobbs hobbsk at ohiou.edu
Wed Aug 11 07:47:49 PDT 2010

On 08/10/2010 04:44 PM, tom fogal wrote:
> "Kevin H. Hobbs" <hobbsk at ohiou.edu> writes:
>> VTK_USE_X:BOOL=ON is set the test segfaults.
> What does VTK_USE_X change/end up doing?

Most of the action seems to happen in Rendering/CMakeLists.txt where on
linux with VTK_USE_X=ON :

vtkXGPUInfoList.cxx is added to the list of sources.
vtkXRenderWindowInteractor.cxx is added to the list of sources.
cmake options for 3Dconnexion are exposed
vtkTestGLX.cmake is included
a try compile is made on CheckglXGetProcAddressARB.cxx
if OPENGL_gl_LIBRARY is also set
  vtkXOpenGLRenderWindow.cxx is added to the list of sources.
  and ${OPENGL_gl_LIBRARY} is added to the required libraries.
I'm leaving out stuff that seems to be for wrapping tcl and python.
a bunch of likely X11 directories are added to the search path.
cmake looks for X11 libraries

> It seems like the test should only be calling OSMesa functions.
> However, maybe the VTK_USE_X macro forces some "always do this X init"
> kind of stuff, even when an X context isn't needed?
> -tom

It's certainly possible. The test only does :

vtkRenderWindow *renWin = vtkRenderWindow::New();

And I've always found that I have to do :

// Graphics Factory
vtkGraphicsFactory * graphics_factory
  = vtkGraphicsFactory::New();
graphics_factory->SetOffScreenOnlyMode( 1);
graphics_factory->SetUseMesaClasses( 1 );

// Imaging Factory
vtkImagingFactory * imaging_factory
  = vtkImagingFactory::New();
imaging_factory->SetUseMesaClasses( 1 );

// Render Window
vtkRenderWindow * render_window = vtkRenderWindow::New();
render_window->SetOffScreenRendering( 1 );

in order to get an offscreen program to run without DISPLAY set.

VTK does have another "offscreen" mode pbuffers or something that still
requires a display but can't be overwritten with another window.

Maybe this is what's being used in the VTK test.

However even if I add the factory lines to VTK's test the segfault
happens the same way.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 253 bytes
Desc: OpenPGP digital signature
URL: <http://lists.freedesktop.org/archives/mesa-dev/attachments/20100811/f539d317/attachment.pgp>

More information about the mesa-dev mailing list