[vtkusers] Offscreen rendering bug

[John Norris]

Two guesses off of the top of my head:

Less likely: VTK_USE_X is turned off (possible if you've compiled under 
OS X or cygwin).

More likely: your test program is not crashing because it successfully 
connects to an X server.  Unset DISPLAY and try again.

Thanks,
John

Francois Bertel wrote:
> So I cannot reproduce what you said.
> 
> I tried compiling VTK against Mesa with VTK_OPENGL_HAS_OSMESA  to OFF 
> and it crashes.
> 
> But if I set VTK_OPENGL_HAS_OSMESA to ON, it does not crash.
> 
> John Norris wrote:
>> Yes, that's right.  I was trying to explain that I was using only Mesa 
>> (including OSMesa) and not OpenGL + MangledMesa.  Sorry I didn't make 
>> that clearer.
>>
>> John
>>
>> Francois Bertel wrote:
>>> Hi John,
>>>
>>> By including OSMesa, do you really mean you set VTK_OPENGL_HAS_OSMESA 
>>> to ON?
>>>
>>> John Norris wrote:
>>>> Hi,
>>>>
>>>> I've compiled VTK (from CVS) using Mesa-7.0.3 (including OSMesa) on a
>>>> x86_64 linux system.  I've called
>>>> vtkGraphicsFactory::SetOffScreenOnlyMode(1)
>>>> before creating any of the rendering classes.  I've also called
>>>> OffScreenRenderingOn() from my render window before doing anything else
>>>> with it.  Still, VTK tries to contact the X server, causing a 
>>>> crash.  It
>>>> seems to be happening after line 496 in vtkOpenGLExtensionManager, in
>>>> the #ifdef VTK_USE_X block.  The call to
>>>> this->RenderWindow->GetGenericDisplayId() leads to a call to
>>>> XOpenDisplay(); XOpenDisplay() is explicitly called just a few lines
>>>> later, but my program doesn't get that far.
>>>>
>>>> Perhaps the return value of vtkGraphicsFactory::GetOffScreenOnlyMode()
>>>> or this->RenderWindow->GetOffScreenRendering() should be checked first.
>>>>
>>>> Thanks,
>>>> John
>>>
>>>
>>
> 
> 

-- 
John Norris
Scientific Visualization Developer
Center for Astrophysical Thermonuclear Flashes