vertex_buffer_object

I can''t answer the question about the geometry not being display properly, since I haven''t had a chance to try out the extension (I''m working on a simple project that uses it now).

But for you question about glGenBuffersARB. It''s similar to glGenTextures. You don''t NEED to use it for buffer id''s but it''s best you do.

i miss the hungarian notation

i wonder where this obsession comes from. its like stopping cars just to tell them that youre missing their car being blue.

where exactly would the code above profit from it or be that much more readable to justify ugly long prefixes that are making it a pain to write AND read?

However hungarian or not ...here 2 screenshots:

VBO: http://utenti.lycos.it/frenz1979/vbo.jpg
Vertex Array: http://utenti.lycos.it/frenz1979/std.jpg

Did you looked at the examples in the end of the specs ?
Do you use genBuffer function ?

I think you need to have one memory chunk (contiguous memory) for the whole buffer, not one array/memory chunk per ARRAY like you do with vertex arrays.

You don't passe pointers to the gl*Pointer call but rather offset inside the buffer (contiguous memory chunk).

That's all I can say for now, I've not tested this extension yet, since only Catalyst 3.4 included it. (released a few days ago, and I've other priorities atm)

-EDIT-
You're using interleaved arrays right ?
That doesn't change my above comments, except you already have one contiguous memory chunk for the buffer
See GenBuffersARB in the doc it's similar to glGenTextures, and I think IT IS REQUIRED.

-* So many things to do, so little time to spend. *-


[edited by - Ingenu on May 20, 2003 1:13:00 PM]

[edited by - Ingenu on May 20, 2003 1:16:52 PM]

Yes I read the examples in the end of the specs..there''s no use of GenBuffersARB! :-(
I have one big Vertex buffer(contiguous memory chunk with all the scene vertex), and many other index buffer, one for each "Object" in my scene,I''ve done it with ATI VAO and now I''m trying to do with VBO.

If the use of gl*Pointer in VBO is that in standard vertex array the pointers are right...(..the scene is rendered correctly as you can see in the screeshot:-) )

Now it works!!!
Here''s the correct code :-)

...................

int Size;
Size = sizeof(_Vertex)*(Scene.NVertex);
glGenBuffersARB( 1 , &Scene.VBOBuffer );
glBindBufferARB( ARRAY_BUFFER_ARB, Scene.VBOBuffer );
glBufferDataARB( ARRAY_BUFFER_ARB, Size, &Scene.VBuffer[0], STATIC_DRAW_ARB );

glTexCoordPointer( 2, GL_FLOAT, sizeof(_Vertex), (char*)(0) );
glNormalPointer ( GL_FLOAT, sizeof(_Vertex), (char*)(SFLOAT*2) );
glVertexPointer ( 3, GL_FLOAT, sizeof(_Vertex), (char*)(SFLOAT*5) );
glColorPointer ( 4, GL_FLOAT, sizeof(_Vertex), (char*)(SFLOAT*8) );

// Indexes Buffer Allocation !!
for(int i=0 ; i< Scene.NObj ; i++)
{
Size = SINT*Scene.Obj.NVertex;
glGenBuffersARB( 1 , &Scene.Obj[i].IBuffer );
glBindBufferARB( ELEMENT_ARRAY_BUFFER_ARB, Scene.Obj[i].IBuffer );
glBufferDataARB( ELEMENT_ARRAY_BUFFER_ARB, Size, &Scene.Obj[i].Triangle[0].Edge[0], STATIC_DRAW_ARB );
}


...................
//Draw

glBindBufferARB( ELEMENT_ARRAY_BUFFER_ARB, O.IBuffer);
glBindBufferARB( ARRAY_BUFFER_ARB, Scene.VBOBuffer );
glDrawElements ( GL_TRIANGLES, O.NVertex, GL_UNSIGNED_INT, (char*)(0) );

thanks to all!!!