Re: [Chromium-dev] Tilesort and 1.7 (Was CG Vertex Shader and Tilesort)

[Chris J. <cjo...@cs...>]

Alan Matsuoka wrote:

> > > >>Hi.  I have just installed Chromium 1.6 (due to segmentation faults with
> > > >>1.7) and am attempting to run an OpenGL application with a simple vertex
> > > >>shader across a mural.  My experience with Chromium is minimal, so
> > > >>please excuse my naiveness.
> > 
> > [...]
> > 
> > > Also, could you please tell us more about the segfault issues you are 
> > > having with 1.7?  What OS?  What applications?  What network? What 
> > > configuration? etc.
>  
> Try running glxinfo. Are you sure the right extensions are available on
> your cluster ?

Erm...  You're right.  The cluster machines don't support any
vertex_program extensions.  (I'm sorry to not have known this.)  This
makes sense -- I've been compiling on a machine that does support vertex
programs, but when the program is propagated by the mothership out to
the cluster, it's just rendering normally.  That is, without the vertex
shader.

So, let me see if I understand this.  The local machine, the application
node, is running my vertex shader application.  It is checking for the
supported extension (using cgGLIsProfileSupported), which *is* supported
locally, so the program continues.  Then, as OpenGL calls are issued,
the mothership picks them off and hands them out to the server nodes which don't support vertex programs.  No error occurs, but the vertex shader functionality is missing.  Should an error occur?  I'm not sure how Chromium handles this situation.

Thanks for the tipoff.  I've been wanting to blame it on hardware the
whole time.  Perhaps I should have looked a bit harder.

-- 
Chris Johnson
cjohnson AT cs.utk.edu