[vtkusers] TEXTURE_BUFFER fails : pure OpenGL vs vtkgl ?

[Butterfly]

Hi, I have a very unpleasant bug and absolutely no idea what am I doing
wrong... I try to use  Buffer Texture
<https://www.opengl.org/wiki/Buffer_Texture>   - a functionality that is
available in OpenGL since 2006 (so, quite old and reliable). I need to do
exactly this because I want to generate data on the CUDA side, and there is
no other way (that I know of) except of using buffers. In the simplified
example below (without CUDA) I generate simple data and try to connect the
texture to the buffer.  * vtkgl::TexBufferEXT fails with
System.AccessViolationException...*

				GLuint bufferObject;
				GLuint _texname;
				glGenTextures(1, &_texname);
				vtkgl::ActiveTexture(vtkgl::TEXTURE0+_texname);
				glBindTexture(vtkgl::TEXTURE_BUFFER_EXT, _texname);   
		
				vtkgl::GenBuffers(1, &bufferObject);
				vtkgl::BindBuffer(vtkgl::TEXTURE_BUFFER_EXT, bufferObject);
			
				int nWidth = 8;
				int nHeight = 4;				
				vtkgl::BufferData(vtkgl::TEXTURE_BUFFER_EXT,
nWidth*nHeight*sizeof(float), NULL, vtkgl::DYNAMIC_DRAW);
				float *test = (float *)vtkgl::MapBuffer(vtkgl::TEXTURE_BUFFER_EXT,
vtkgl::READ_WRITE); 
				for(int i=0; i<nWidth*nHeight; i++)
					test[i] = 0.5;
				vtkgl::UnmapBuffer(vtkgl::TEXTURE_BUFFER_EXT); 
			
[fails here]		                
vtkgl::TexBufferEXT(vtkgl::TEXTURE_BUFFER_EXT, vtkgl::RGBA32F_ARB,
bufferObject);
				vtkgl::BindBuffer(vtkgl::TEXTURE_BUFFER_EXT, 0);


I tried to do the same in the "pure OpenGL" project, and it works great (the
code is below)!

				GLuint bufferObject;
                                GLuint _texname;
				glGenTextures(1, &_texname);
				glActiveTexture(GL_TEXTURE0+_texname);
				glBindTexture(GL_TEXTURE_BUFFER_EXT, _texname);   
		
				glGenBuffers(1, &bufferObject);
				glBindBuffer(GL_TEXTURE_BUFFER_EXT, bufferObject);
			
				int nWidth = 8;
				int nHeight = 4;				
				glBufferData(GL_TEXTURE_BUFFER_EXT, nWidth*nHeight*sizeof(float), NULL,
GL_DYNAMIC_DRAW);
				float *test = (float *)glMapBuffer(GL_TEXTURE_BUFFER_EXT,
GL_READ_WRITE); 
				for(int i=0; i<nWidth*nHeight; i++)
					test[i] = 0.5;
				glUnmapBuffer(GL_TEXTURE_BUFFER_EXT); 
			
				glTexBufferEXT(GL_TEXTURE_BUFFER_EXT, GL_RGBA32F_ARB, bufferObject);
				glBindBuffer(GL_TEXTURE_BUFFER_EXT, 0);

Any ideas? I double checked all enum values (like GL_RGBA32F_ARB and
GL_TEXTURE_BUFFER_EXT), they are the same in my both tests. I tried with
various buffer internal types (integer and float, R and RGBA). Nothing helps
:( The same error all the time! 
Many thanks in advance!!!



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