glDrawRangeElements and _nv001100gl segfault

Hey guys, new comer here… please forgive me if i don’t post my stuff the way you’d like to see it .

Anyway, I’m working on a 3D engine and I’m responsible for the Linux and OpenGL portions. I’m implementing Vertex and Index Buffers at the moment and I’ve ran into a problem that has me stumped. Here’s what i do to setup the buffers:

Index Buffer

		GLExtensions::glGenBuffersARB(1, &m_buffer);
		
		// make active
		GLExtensions::glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, m_buffer);
	
		// allocate it
		GLenum bufferType = (isDynamic() ? GL_DYNAMIC_DRAW_ARB : GL_STATIC_DRAW_ARB);
		GLExtensions::glBufferDataARB(
			GL_ELEMENT_ARRAY_BUFFER_ARB,
			m_size,
			NULL,
			bufferType
		);
 

Vertex Buffer

		GLExtensions::glGenBuffersARB(1, &m_buffer);
		
		// make active
		GLExtensions::glBindBufferARB(GL_ARRAY_BUFFER_ARB, m_buffer);
		
		// allocate it
		GLenum bufferType = (isDynamic() ? GL_DYNAMIC_DRAW_ARB : GL_STATIC_DRAW_ARB);
		GLExtensions::glBufferDataARB(
			GL_ARRAY_BUFFER_ARB,
			m_size,
			NULL,
			bufferType
		);
		

Activation:

	if (pos>0) {
		int oset = m_pStreamSetDefinition->getElementOffset(index,IStreamDefinition::POSITION);
		glVertexPointer(
			3, 
			GL_FLOAT, 
			vertexSize,
			BUFFER_OFFSET(oset)
		);
		
		glEnableClientState(GL_VERTEX_ARRAY);
		
	} else {
		glDisableClientState(GL_VERTEX_ARRAY);
		
	}
	
	// normal?
	if (normal>0) {
		int oset = m_pStreamSetDefinition->getElementOffset(index,IStreamDefinition::NORMAL);
		glNormalPointer(
			GL_FLOAT, 
			vertexSize,
			BUFFER_OFFSET(oset)
		);
		
		glEnableClientState(GL_NORMAL_ARRAY);
		
	} else {
		glDisableClientState(GL_NORMAL_ARRAY);
		
	}
	
	// texcoords?
	if (texcoords>0) {
		int oset = m_pStreamSetDefinition->getElementOffset(index,IStreamDefinition::TEXTURE0);
		glTexCoordPointer(
			2, 
			GL_FLOAT, 
			vertexSize,
			BUFFER_OFFSET(oset)
		);
		
		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
		
	} else {
		glDisableClientState(GL_TEXTURE_COORD_ARRAY);
		
	}

Rendering:

	int indexCount = (triangleCount*3);
	
	GLExtensions::glDrawRangeElements(
		GL_TRIANGLES,
		firstIndex,
		firstIndex+indexCount,
		indexCount,
		GL_UNSIGNED_SHORT,
		NULL
	);

Ok, so I’m running Linux (kernel 2.6) latest stable Nvidia drivers. I have a 6800oc. The same engine code runs on windows with OpenGL… but an ATI card. When i run the direct rendering method (glBegin()…glEnd()) of OpenGL it works fine. I get an error in what looks like the nvidia driver, in a symbol named “_nv001100gl()”. What happens is that 4 iterations of the main loop render everything fine. On the 5th iteration i get a segfault in that symbol. I’ve verified that the values passed to glDrawRangeElements are accurate (they are the same every time, the desired result).

Thanks in advance for any help!

 int indexCount = (triangleCount*3);
	
	GLExtensions::glDrawRangeElements(
		GL_TRIANGLES,
		firstIndex,
		firstIndex+indexCount,
		indexCount,
		GL_UNSIGNED_SHORT,
		NULL
	); 

Looks a bit strange with the firstIndex+indexCount stuff. Is every vertex unique? (ie is a vertex not referenced more than once by an index?)

As an experiment, try using standard glDrawElements and see what happens.

I tried using glDrawElements and i get the same exact result. I’v also verified that the arguments passed to the glDrawElements and glDrawRangedElements functions are the same on every iteration… and the first 4 iterations function perfectly.

Not sure what else it could be.

I am sure you have already checked:

• ensure the index buffer references all valid vertices.
• ensure the number of indices is correct
• ensure the vertex buffer pointers are set up correctly.
• Try not using VBO and render directly from system memory.
• ensure you are not getting any GL errors.

As a test, try creating the VBO’s (index and vertex) to be twice as big as they need to be.

You may have to create a demo that reporoduces this.