[vtkusers] vtkgl::GenBuffers

[eugen]

Thanks for the quick reply,

I'm extending the vtkOpenGLVolumeTextureMapper3D class. So I've embedded  
the loadprocedure for ARB_pixel_buffer_object exactly like it is done for  
other extensions in that class (you've listed the same way in your mail.  
That's what I'm doing). After the extension is loaded successfully I still  
get:

"...0xC0000005: Access violation reading location 0x00000000..."

in the line calling vtkgl::GenBuffers(1, &texBuffer)



On Fri, 27 Apr 2007 09:54:55 +0200, John Biddiscombe <biddisco at cscs.ch>  
wrote:

> You need to make sure the extensions are loaded before using them, use  
> something like this...
>
>   //
>   // Test support for Framebuffers
>   //
>   int supports_GL_EXT_framebuffer_object  =  
> extensions->ExtensionSupported("GL_EXT_framebuffer_object");
>   int supports_GL_ARB_texture_float       =  
> extensions->ExtensionSupported("GL_ARB_texture_float");
>   int supports_GL_ARB_texture_rectangle   =  
> extensions->ExtensionSupported("GL_ARB_texture_rectangle");
>   int supports_GL_ARB_color_buffer_float  =  
> extensions->ExtensionSupported("GL_ARB_color_buffer_float");
>
> then...
>
>   //
>   // Set FrameBufferObject flags depending on test results
>   //
>   if (!supports_GL_EXT_framebuffer_object ||
>       !supports_GL_ARB_texture_float ||
>       !supports_GL_ARB_texture_rectangle ||
>       !supports_GL_ARB_color_buffer_float)
>   {
>     this->FrameBufferExtensionsOK = 0;
>   }
>   else {
>     this->FrameBufferExtensionsOK = 1;
>     extensions->LoadExtension("GL_EXT_framebuffer_object");
>     extensions->LoadExtension("GL_ARB_texture_float");
>     extensions->LoadExtension("GL_ARB_texture_rectangle");
>     extensions->LoadExtension("GL_ARB_color_buffer_float");
>     this->InitFrameBuffer();
>   }
>
>
>> Hi,
>> I cannot access vtkgl::GenBuffers(...) from VTK. This is an OpenGL  
>> Extension command from (ARB_pixel_buffer_object).
>> Access violation...
>>
>> Has anyone experiences with this?
>>
>> Thanks,
>> Eugen
>>
>> _______________________________________________
>> This is the private VTK discussion list.Please keep messages on-topic.  
>> Check the FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
>> Follow this link to subscribe/unsubscribe:
>> http://www.vtk.org/mailman/listinfo/vtkusers
>
>



-- 
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/