[vtkusers] Offscreen rendering bug

[Francois Bertel]

No. I'm using Linux gentoo x86 and I turned off the Xserver before testing and I tested that the DISPLAY environment variable is not set.

John Norris wrote:
> 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
>>>>
>>>>
>>>
>>
>>
> 


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